Select Page

M21-1, Part III, Subpart iv, Chapter 4, Section N – Neurological Conditions and Convulsive Disorders


In This Section

 This section contains the following topics:
Topic Name

1.  General Information on Neurological and Convulsive Disorders


This topic contains general information about neurological and convulsive disorders, including

Change Date

February 2, 2018

III.iv.4.N.1.a.  Considerations in SC for Neurological Disorders

See the table below for etiological considerations and manifestations involving specific neurological disorders.
When …
Then …
considering questions of incurrence or aggravation in service
bear in mind the etiology and clinical course of each separate disease.
considering conditions of infectious origin
consider both the circumstances of infection and the incubation period.
determining aggravation for conditions such as multiple sclerosis (MS), progressive muscular atrophy, and myasthenia gravis
be aware that increased symptomatology over a period of a few months may reflect natural progression of the disease.  Base determinations on the developed medical evidence of record.

III.iv.4.N.1.b.  Identifying Epilepsy

Seizures must be witnessed or verified by a physician to warrant service connection (SC) for epilepsy.  Verification may be by an electroencephalogram (EEG), which measures electrical activity in the brain.
A physician does not have to witness an actual seizure before a diagnosis of epilepsy can be accepted for evaluation purposes.  Verification by a physician based upon factors other than observing an actual seizure is sufficient.
References:  For more information on

III.iv.4.N.1.c.  Evaluating Progressive Spinal Muscular Atrophy

Progressive muscular atrophy, 38 CFR 4.124a, diagnostic code (DC) 8023, refers to progressive spinal muscular atrophy, which is a disease of the spinal cord.
Progressive muscular atrophy is subject to presumptive SC under 38 CFR 3.309(a)because it is an organic disease of the nervous system.

III.iv.4.N.1.d.  Other Organic Diseases of the Nervous System Under 38 CFR 3.309(a)

For purposes of establishing presumptive SC for a chronic disease under 38 CFR 3.307, the term other organic diseases of the nervous system in 38 CFR 3.309(a) includes any commonly recognized neurological disease (such as may be found in a valid contemporary medical treatise), which is not otherwise specifically enumerated under 38 CFR 3.309(a).  This includes, but is not limited to, the following conditions:
  • carpal tunnel syndrome
  • migraine headaches
  • sensorineural hearing loss
  • tinnitus
  • glaucoma
  • progressive spinal muscular atrophy
  • diseases of the cranial nervous system
  • cranial nerve conditions, and
  • peripheral nerve conditions, such as peripheral neuropathy.
Important:  If there is uncertainty as to whether or not a claimed disability may be considered as an organic disease of the nervous system for purposes of 38 CFR 3.309(a), send the case to Compensation Service’s Advisory Review Staff for guidance.
References:  For more information on

III.iv.4.N.1.e.   SC of Vertigo

Carefully consider the evidence of record when considering SC for vertigo.  Vertigo is generally considered a symptom of another disability such as traumatic brain injury (TBI), Meniere’s disease, vestibular neuritis/labyrinthitis, MS, stroke or tumor.
When the disability manifested by vertigo is adequately identified, SC should be established for that diagnosis rather than for “vertigo.”  However, SC can be established for “vertigo” in the absence of a known or established underlying etiology if there is
  • an event in service (such as a nonspecific diagnosis of vertigo in service)
  • vertigo present post service
  • a nexus establishing the vertigo post service is connected to the event in service, and
  • the condition is not associated with any other disease or injury.
References:  For more information on

2.  TBI


This topic contains information about TBI, including

Change Date
June 22, 2018

III.iv.4.N.2.a.  Definition: TBI

The term traumatic brain injury (TBI) means the physical, cognitive and/or behavioral/emotional residual disability resulting from an event of external force causing an injury to the brain.

III.iv.4.N.2.b.    TBI Events

The TBI event is a traumatically induced structural injury and/or physiological disruption of brain function resulting from an external force indicated by at least oneof the following clinical signs immediately following the event:
  • any period of loss of consciousness or decreased consciousness
  • any loss of memory for events immediately before or after the injury
  • any alteration in mental state at the time of the injury (confusion, disorientation, slowed thinking, etc.)
  • neurological deficits, whether or not transient, or
  • intracranial lesion.
  • The TBI event has two necessary components: the external force and theidentifiable acute manifestations of brain injury immediately following the external force.  Not all individuals exposed to an external force will have brain injury, and therefore, they will not meet the criteria for having a TBI event.
  • The acute manifestations may resolve without chronic disability, or a chronic disability may result.
  • Although unconsciousness or reduced consciousness is common in TBI events, these are not required.  Any one of the five signs will be sufficient.

III.iv.4.N.2.c.  External Force for the Purpose of TBI Events

External force means any of the following events:
  • a foreign body (such as a bullet or shell fragment) penetrating the brain
  • the head being struck by an object (such as a fist, a hatch, or flying debris)
  • the head striking an object (such as the ground or a windshield)
  • the brain undergoing an acceleration/deceleration movement without direct external trauma to the head
  • force generated from events such as a blast or explosion, or
  • other force yet to be defined.
Note:  TBI events may occur during combat or non-combat situations (such as a motor vehicle accident, fall, or personal assault).

III.iv.4.N.2.d.    TBI Residuals

The resultant disabling effects of a TBI event beyond those that follow immediately from the acute injury to the brain are known as TBI residuals or TBI sequelae.
The signs and symptoms of TBI residuals can be organized into the three main categories of physical, cognitive, and behavioral/emotional residuals for evaluation purposes.  Examples of TBI residuals in each of the three categories may include, but are not limited to, those listed below.
Apraxia (inability to execute purposeful, previously learned motor tasks, despite physical ability and willingness)
Dementias (pre-senile Alzheimer’s type, dementia pugilistica, post traumatic dementia)
Aphasia (difficulty communicating orally and/or in writing)
Attention and concentration deficits
Agitation and irritability
Paresis (muscle weakness or incomplete paralysis)
Memory, processing, and learning impairment
Plegia (paralysis or stroke)
Language deficiencies
Dysphagia (difficulty swallowing)
Planning difficulties
Disorders of balance and coordination
Judgment and control difficulties
Posttraumatic stress disorder
Diseases of hormone deficiency
Reasoning and abstract thinking limitations
Self-awareness limitations
Blurred vision
Seizure disorder
Sensory loss
Sleep disturbance
Note:  TBI residuals can resolve in a short period of time or can persist chronically or even permanently. Chronic TBI residuals may include some or all of the clinical signs that developed immediately during the TBI event. Others (such as seizures or spasticity) may have a delayed onset.

III.iv.4.N.2.e.  Determining the Issues in TBI Cases

A claim for SC for TBI may also be worded as a claim for “head injury,” or “concussion.”  A claim document mentioning any of the above must be sympathetically read and understood as a claim for all identifiable TBI residuals that can be attributed to one or more TBI events.
A claim for “combat injuries,” assault, automobile accident, fall, or other injurious events may also raise the issue of a TBI if there was an injury to the head.
As recognized by 38 CFR 4.124a, DC 8045, the external force of a claimed TBI event may result not only in brain injury but also in physical or psychological disorders distinct from brain injury residuals.  An explosion, for example, may cause burns, muscle injuries, orthopedic injuries including amputations, and posttraumatic stress disorder in addition to a brain injury.  A TBI claim mentioning a specific traumatic event must be sympathetically read as a claim for SC for alldisabling chronic residuals of the event.
Reference:  For more information on determining the issues, see M21-1, Part III, Subpart iv, 6.B.

III.iv.4.N.2.f.     SC of TBI Residuals

When signs and symptoms are identified as TBI residuals and associated with an in-service TBI event, 38 CFR 3.303 allows for SC on a direct basis.
A medical opinion is necessary when the medical evidence of record does notshow a clear-cut etiology for a sign or symptom claimed as a delayed effect.

III.iv.4.N.2.g.   Evaluation of TBI Residuals

Evaluate service-connected (SC) TBI residuals under 38 CFR 4.124a, DC 8045.
In every case, one evaluation should be assigned using the highest level of impairment assigned to any facet contained in the table “Evaluation of Cognitive Impairment and Other Residuals of TBI not Otherwise Classified,” which has been incorporated into the Veterans Benefits Management System – Rating (VBMS-R).
Additional evaluations may be appropriate to assign as provided in M21-1, Part III, Subpart iv, 4.N.2.h and i.
Note:  A medical classification of severity of the TBI at the time of the acute traumafrom the TBI event has no bearing on evaluation for Department of Veterans Affairs (VA) compensation purposes.  It is not an evaluation factor and is not relevant to the application of the benefit of the doubt rule.  Do not imply or state that initial severity classification was given weight in assigning a disability evaluation.
References:  For more information on

III.iv.4.N.2.h.Multiple Evaluations and Pyramiding in TBI Cases

In addition to the evaluation for TBI manifestations under the table “Evaluation of Cognitive Impairment and Other Residuals of Residuals of TBI Not Otherwise Classified” in 38 CFR 4.124a, DC 8045 (and also incorporated into VBMS-R), manifestations of a comorbid mental, neurologic or other physical disorder can be separately evaluated under another DC if there is a distinct diagnosis – even if based on subjective symptoms – and no more than one evaluation is based on the same manifestation(s).
Follow the policy in the table below.
If …
Then …
manifestations are clearly separable
assign a separate evaluation using each applicable DC.
the manifestations of two or more conditions cannot be clearly separated
assign a single evaluation under whichever set of criteria allows the better assessment of the overall impaired functioning due to both conditions.
References:  For more information on

III.iv.4.N.2.i.  Evaluating TBI and Co-Morbid Symptoms/ Conditions

Use the table below when evaluating TBI and co-morbid symptoms and/or conditions.
If the Veteran has …
Then evaluate …
headaches according to the table below.
If the Veteran has …
Then …
subjective complaints of headaches
evaluate the subjective complaints as part of the TBI evaluation under 38 CFR 4.124a, DC 8045rather than under a separate DC.
Note:  Occasional subjective headaches are not a distinct comorbid diagnosis.
a distinct comorbid diagnosis of a headache disorder
Example:  Migraine headaches, post-concussive headaches, tension headaches
assign a separate evaluation under 38 CFR 4.124a, DC 8100 as long as the manifestations do not overlap with those used to assign the evaluation of TBI under 38 CFR 4.124a, DC 8045.
tinnitus based on one of the following methods, depending on which method results in a higher evaluation:
vertigo (whether referred to as “vertigo,” “constant vertigo,” “peripheral vestibular disorder,” “benign paroxysmal positional vertigo,” or any other similar wording)
vertigo in the subjective symptoms facet under 38 CFR 4.124a, DC 8045.
Note:  If vertigo was awarded a separate compensable evaluation prior to March 15, 2012, do not change or correct the evaluation.
Reference:  For more information on SC for vertigo, see M21-1, Part III, Subpart iv, 4.N.1.e.
cognitive and/or behavioral/emotional residuals
the symptoms according to the table below.
If …
Then …
the Veteran has subjective feelings of anxiety, depression, or other mental complaints
evaluate in the subjective symptoms facet under 38 CFR 4.124a, DC 8045.
Note:  Subjective mental complaints are not a distinct comorbid diagnosis.
  • the Veteran has a comorbid mental disorder and/or neurocognitive disorder, and
  • the examiner is able to delineate both
    • symptoms, and
    • occupational and social impairment
assign separate evaluations for
  • the Veteran has a comorbid mental disorder or neurocognitive disorder, and
  • the examiner isunable to delineate both
    • symptoms, and
    • occupational and social impairment
assign a single evaluation under the DC (either under 38 CFR 4.124a, DC 8045 or the appropriate 38 CFR 4.130 DC) that provides the higher evaluation based on overall impaired functioning due to both conditions.
Note:  This guidance applies to all cognitive and behavioral/emotional TBI residuals as defined in M21-1, Part III, Subpart iv, 4.N.2.d.  If separate and distinct physical symptoms due to TBI are present, evaluate them in the subjective or other applicable facet under 38 CFR 4.124a, DC 8045, as long as the physical symptoms are not the basis of an evaluation for another condition.

III.iv.4.N.2.j.  Example of Evaluating TBI With Co-Morbid Conditions

Situation:  VA examination shows the Veteran has numerous behavioral/emotional symptoms (depression that severely affects his work and his family relationships, frequent suicidal thoughts, confusion, apathy, and unpredictability) and meets the diagnostic criteria for both TBI and for major depression.  The examiner was unable to differentiate which symptoms are associated with TBI and which with major depression.  In addition, the TBI examination found multiple physical complaints related to TBI, including vertigo, sensitivity to light, blurred vision, and subjective headaches.  Evaluation under 38 CFR 4.130 criteria would result in the higher evaluation for the behavioral/emotional symptoms due to TBI and major depression.
Result:  Assign an evaluation for the behavioral/emotional residuals under 38 CFR 4.130, DC 9434.  Assign a separate evaluation under 38 CFR 4.124a, DC 8045 for the remaining physical symptoms and combine the evaluations under 38 CFR 4.25.

III.iv.4.N.2.k.  Opinion Evidence and Separate Evaluations of TBI and a Mental Disorder

Ensure that sufficiently clear and unequivocal medical opinion evidence exists in the claims folder whenever there is a question of whether TBI and a mental disorder are distinct and can be separately evaluated.  Veterans Benefits Administration (VBA) decision makers are not qualified to make such determinations.
The opinion may be provided by either an examiner assessing the TBI or an examiner assessing the mental disorder as long as the individual offering the opinion is properly qualified.
If a medical provider cannot make the required determination without resorting to mere speculation, then careful consideration must be given to whether that statement can be accepted under Jones v. Shinseki, 23 Vet.App. 382 (2010).

III.iv.4.N.2.l.  Additional TBI Signs or Symptoms Upon Reevaluation

When considering a claim for reevaluation of TBI, do not automatically concede that a new sign, symptom or diagnosis is a residual of TBI simply because it is listed in M21-1, Part III, Subpart iv, 4.N.2.d or in the evaluation criteria.
If there is not competent evidence that the sign, symptom or diagnosis is associated with the SC TBI, obtain medical clarification.

III.iv.4.N.2.m.   TBI and SMC

Brain injuries may be associated with loss of use of an extremity, sensory impairments, erectile dysfunction, need for regular aid and attendance (A&A) (including need for protection from hazards of the daily living environment due to cognitive impairment), and being factually housebound or statutorily housebound.
Carefully consider eligibility for special monthly compensation (SMC) when evaluating TBI residuals.
References:  For more information on

III.iv.4.N.2.n.  Temporary Total Evaluations and TBI

In cases of recently discharged Veterans, consider the applicability of a temporary 50-percent or 100-percent prestabilization evaluation under the provisions of 38 CFR 4.28.
Lengthy VA hospitalizations or surgeries with convalescence may also implicate consideration of eligibility for temporary total evaluation under 38 CFR 4.29 and 38 CFR 4.30.

III.iv.4.N.2.o.  Training and Signature Requirements for TBI Decisions

All decisions that address TBI as an issue, including rating decisions, Statements of the Case (SOCs), and Supplemental Statements of the Case (SSOCs), mustonly be worked/reviewed by a Rating Veterans Service Representative (RVSR) or Decision Review Officer (DRO) who has completed the required TBI Training Performance Support System module.
Decisions for TBI require two signatures until a decision maker has demonstrated an accuracy rate of 90 percent or greater based on a review of at least 10 TBI cases.
References:  For more information on

III.iv.4.N.2.p.  Applicability of 38 CFR 3.114(a) in TBI Cases

The rating criteria for evaluating TBI were changed effective October 23, 2008.
Under Note (5) of 38 CFR 4.124a, DC 8045, a Veteran whose residuals of TBI are rated under a version of the diagnostic criteria in effect before October 23, 2008, may request review under the current regulation irrespective of whether his or her disability has worsened since the last review.  A request for review pursuant to this note will be treated as a claim for an increased rating for purposes of determining the effective date of an increased rating awarded as a result of such review, applying 38 CFR 3.114(a) as applicable.  However, in no case will the award be effective before October 23, 2008.
Reference:  For more information on liberalizing changes of law and VA issuances, see M21-1, Part III, Subpart iv, 5.C.7.

III.iv.4.N.2.q.   TBI Flash

Ensure that the Traumatic Brain Injury flash has been added in all cases involving claims for TBI by reviewing the VBMS profile screen.
The flash should be added when the claim is received.  It remains on the corporate record if TBI is granted and is removed if TBI is denied.
Reference:  For more information on claimant flashes, see

III.iv.4.N.2.r.  Anoxic Brain Injury

Anoxic brain injury is a condition resulting from a severe decrease in the oxygen supply to the brain that may be due to any of a number of possible etiologies, including trauma, strangulation, carbon monoxide poisoning, stroke, and many others.
As anoxic brain injury does not have its own unique DC in the rating schedule, it can be rated analogously, depending on the specific medical findings in a particular case.
Use the table below to determine the possible analogous rating.
If the residuals are similar to …
Then evaluate the symptoms analogous to …
brain hemorrhage
psychiatric disability
nerve damage
one or more DCs for specific nerves that are affected.
Important:  Follow the guidance in M21-1, Part III, Subpart iv, 4.N.2.h and i when considering the assignment of multiple evaluations for residuals.

3.  Secondary Conditions Associated with TBI


This topic contains information on secondary conditions associated with SC TBI, including

Change Date

May 9, 2016

III.iv.4.N.3.a.  Secondary SC under 38 CFR 3.310

38 CFR 3.310(d) was amended on December 17, 2013, to establish an association between TBI and certain illnesses.
In absence of clear evidence to the contrary, the following five diagnosable illnesses are held to be a secondary result of TBI:
  • Parkinsonism, including Parkinson’s disease, following moderate or severe TBI
  • unprovoked seizures, following moderate or severe TBI
  • dementias (presenile dementia of the Alzheimer’s type, frontotemporal dementia, and dementia with Lewy bodies), if the condition manifests within 15 years following moderate or severe TBI
  • depression, if the condition manifests within three years of moderate or severe TBI or within 12 months of mild TBI, or
  • diseases of hormone deficiency that result from hypothalamo-pituitary changes, if the condition manifests within 12 months of moderate or severe TBI.
Entitlement to secondary SC for these TBI-related conditions in 38 CFR 3.310(d)depends upon the initial severity of the TBI and the period of time between the injury and onset of the secondary illness.
Important:  There is no need to obtain a medical opinion to determine whether the above conditions are associated with TBI when there is a TBI of a qualifying degree of severity.
  • Determine the initial severity level of the TBI based on the TBI symptoms at the time of the original injury, or shortly thereafter, rather than the current level of functioning.
  • Regional offices (ROs) must continue to follow guidance in M21-1 Part III, Subpart iv, 4.N.2 when evaluating residuals of TBI.  However, ROs must follow guidance in this Topic when establishing secondary SC for claimants who have experienced a TBI in service and later develop one of the five diagnosable conditions listed in 38 CFR 3.310(d).
  • The determination of initial severity is adjudicative – although based on medical evidence.  That means the RVSR (or DRO) must decide the facts, such as initial severity, that correspond with the legal standard set forth in the regulation.
References:  For more information on

III.iv.4.N.3.b.  Evaluating the Initial Severity of TBI

For purposes of determining the initial severity of the TBI, consider the factors from the table in 38 CFR 3.310(d).  Review medical records and lay statements for evidence of
  • structural imaging of the brain, such as magnetic resonance imaging (MRIs) or positron emission tomography (PET) scans
  • loss of consciousness (LOC)
  • alteration of consciousness/mental state (AOC), including disorientation
  • post-traumatic amnesia (PTA), including any loss of memory, and
  • Glasgow Coma Scale (GCS), which provides a measurement of the degree of coma at or after 24 hours.
Reference:  For more information on verifying in-service blast injuries, see M21-1, Part III, Subpart iv, 4.N.3.e.

III.iv.4.N.3.c.  Using the TBI Initial Severity Table in 38 CFR 3.310

The TBI does not need to meet all the criteria listed under a certain severity level in order to classify the TBI under that severity level.
If the Veteran’s TBI meets the criteria in more than one severity level, evaluate the TBI at the highest level in which a criterion is met.
Because “normal structural imaging,” “abnormal structural imaging” and “AOC greater than 24 hours” may be found at more than one severity level, evaluate severity based on other criteria in the table.  If no other criteria are present, then determine the level of severity as follows:
  • If AOC is greater than 24 hours and no other criteria are present, determine the severity as moderate.
  • If structural imaging is noted as normal and no other criteria are present, determine the severity as mild.
  • If structural imaging is noted as abnormal and no other criteria are present, determine the severity as moderate.
If the level of severity cannot be determined based on the available evidence, then apply the provisions of 38 CFR 3.310 (a) and (b) and order a VA examination/medical opinion as necessary.

Evidence That May Be
Relevant to
the Initial
Severity Factors

Evidence that may be relevant in ascertaining the initial severity of TBI symptoms includes
  • lay statements provided by the Veteran
  • lay statements from witnesses to the injury
  • history provided by the Veteran in medical reports, to include VA exams, and
  • service treatment records (STRs) findings at any time after the TBI.
Note:  The evidence that establishes the initial severity of the TBI does not necessarily have to be contemporaneous to the injury as long as it relates to the condition of TBI at or shortly after the time of the injury.
Example:  A Korean War Veteran submits a claim for SC for Parkinsonism secondary to his SC TBI.  The Veteran’s discharge examination from 1954 mentions a history of TBI in service.  However, it does not contain information sufficient to determine the level of severity of the initial TBI injury.  The Veteran provides a statement that he experienced a loss of consciousness during the Battle of Chosin Reservoir.  A review of prior VA examination reports reveals a history provided by the Veteran that he was told by fellow soldiers that he fell unconscious for almost an hour after two grenades exploded near him.
Analysis:  Although service records do not reveal the specific level of TBI during service, the Veteran’s statement is credible, consistent with circumstances of his service, and therefore sufficient to determine that he experienced a moderate level of TBI during service.

III.iv.4.N.3.e.  Registry for Verifying Blast Injuries

The U.S. Army Medical Research and Materiel Command Joint Trauma Analysis and Prevention of Injury in Combat (JTAPIC) has developed a registry of service members who were within 50 feet of a blast since mid-2010.
When existing Department of Defense records, to include STRs, are not sufficient to verify exposure to a blast injury that occurred since mid-2010, Compensation Service will contact JTAPIC to determine if there is a record of exposure.
Important:  E-mail Compensation Service at VAVBAWAS/CO/211 Policy Staff if exposure to an in-service blast injury from mid-2010 to the present cannot be verified.  Include the following information in the e-mail:
  • full name of Veteran
  • claim number and Social Security number
  • branch of service
  • brief description of the blast injury
  • location
  • date of blast/injury, and
  • unit.

III.iv.4.N.3.f.  Determination of Diagnosable Conditions as Secondary to TBI

Use the table below to determine secondary SC for conditions listed in 38 CFR 3.310(d).
If there is a diagnosis of…
And the initial severity of the TBI was …
Then …
Parkinsonism, including Parkinson’s disease
moderate or severe
award SC.
unprovoked seizures
moderate or severe
award SC.
dementia of the following types
  • presenile dementia of the Alzheimer type
  • frontotemporal dementia, and
  • dementia with Lewy bodies
moderate or severe
award SC if dementiamanifested within 15 years after the TBI.
moderate or severe
award SC if depressionmanifested within three years after the TBI.
award SC if depressionmanifested within one year after the TBI.
a disease of hormone deficiency that results from hypothalamo-pituitary changes (any condition in the endocrine system section of the rating schedule, 38 CFR 4.119, DCs 7900-7912, or any condition evaluated analogous to one of those conditions)
moderate or severe
award SC if the condition manifested within one year after the TBI.

III.iv.4.N.3.g.  Considerations When Establishing Secondary SC

When evaluating TBI-related secondary conditions, avoid pyramiding when considering the initial TBI evaluation and symptoms that are now associated with the five secondary conditions.  Also, consider Notes 1 and 2 under 38 CFR 4.124a, DC 8045, while ensuring that the claimant receives the highest overall evaluation under the provisions of 38 CFR 4.25 (Combined Ratings Table).
Depending on the most advantageous combined evaluation, it is permissible to reduce an existing TBI evaluation as long as the overall evaluation of both TBI and the separate secondary SC condition is not reduced.  Use the combinator tool in VBMS-R to determine the combined evaluation of TBI and the secondary SC condition.  Thoroughly explain the decision narrative in the rating decision.
Use the table below to consider symptoms which apply to both TBI and the secondary conditions.
If …
Then …
the symptoms associated with one of the five conditions were also used to provide the highest level of evaluation for any facet under 38 CFR 4.124a, DC 8045
  • consider removing evaluation of the facet, and
  • use the next highest-evaluated facet as the evaluation for the TBI residuals, as long asthe symptoms of that facet are not used to establish SC for one of the five diagnosable conditions.
the same symptoms apply to both disabilities
  • evaluate the evidence and determine whether the symptoms can be entirely associated with one disability versus the other disability, and
  • do not request an additional medical examination for this determination.  If it is unclear, assume that the manifestations are not separable.
the same symptoms apply to both disabilities, and the symptoms are clearly associated with one disability versus the other disability
select the most advantageous option from the following:
  • Remove symptoms from the TBI facet
  • evaluate the TBI under the next highest-evaluated facet that does not contain those symptoms
  • award secondary SC for the diagnosable condition, and
  • evaluate the secondary condition using those symptoms.
  • Keep the symptoms under the TBI facet, and
  • do not award secondary SC for the diagnosable condition, but
  • ensure the diagnosable condition is included with the description of the SC TBI disability in the rating decision.
  • Keep the symptoms under the TBI facet
  • award secondary SC for the diagnosable condition, and
  • evaluate based on the distinct symptoms.
Reference:  For more information on evaluating TBI residuals, see M21-1, Part III, Subpart iv, 4.N.2.g.

III.iv.4.N.3.h.Action When Evidence Shows a 38 CFR 3.310(d) Condition

Use the table below to determine how to proceed when evidence shows one of the five diagnosable conditions in 38 CFR 3.310(d).
If …
Then …
one of the five diagnosable conditions in 38 CFR 3.310(d) is identified in the evidence of record while processing a claim unrelated to SC TBI
a claim for that secondary conditionmust be invited.
evidence shows one of the five diagnosable conditions while evaluating a claim related to SC TBI
develop under normal claim processing procedures and make a determination on the secondary condition under the provisions of 38 CFR 3.310(d).

III.iv.4.N.3.i.  Determining Effective Dates for Secondary Conditions

The rule authorizing VA to establish the five secondary TBI-related conditions in 38 CFR 3.310 is effective, January 16, 2014.
This rule will be applied to all cases pending before VA on or after, January 16, 2014, and does constitute a liberalizing VA regulation under 38 U.S.C. 5110(g) and38 CFR 3.114.  Apply these principles when determining effective dates and retroactive benefits.
Reference:  For more information on 38 CFR 3.114(a), see M21-1, Part III, Subpart iv, 5.C.7.

4.  Peripheral Nerves


This topic contains information on evaluating peripheral nerves, including

Change Date

November 16, 2017

III.iv.4.N.4.a.Regulations for Evaluating Peripheral Nerves

38 CFR 4.124a, DC 8510-8730 provides evaluation levels for complete paralysis and incomplete paralysis, neuritis or neuralgia of peripheral nerves.
At the beginning of the DCs for the peripheral nerves, the regulation also states that “incomplete paralysis” anticipates substantially less impaired function than described for complete paralysis of the nerve.  When impairment is wholly sensory, the evaluation should be that specified for the mild, or at most, the moderate degree of incomplete paralysis for the nerve.
The regulations listed below also provide guidance on evaluating peripheral nerves.
38 CFR 4.120 provides that when rating peripheral nerve injuries and residuals consider the relative impairment of motor function, trophic changes, and/or sensory disturbances.  Attention should be given to the site and character of the injury.
38 CFR 4.123 provides several principles relating to peripheral nerves.
  • Neuritis, characterized by loss of reflexes, muscle atrophy, sensory disturbances, and constant pain, is to be rated on the scale provided for injury of the nerve involved under the DCs and evaluations provided in 38 CFR 4.124a.
  • The maximum evaluation for neuritis is the evaluation provided for severeincomplete paralysis of the affected nerve.
  • The maximum evaluation that may be assigned for neuritis not characterized by the organic changes referred to in the regulation:
    • is generally the evaluation level specified for moderateincomplete paralysis of the nerve, but
    • is the evaluation level specified for moderately severeimpairment when the affected nerve is the sciatic nerve.
38 CFR 4.124 provides that the maximum evaluation for neuralgia, characterized usually by a dull and intermittent pain in the distribution of a nerve, should be the evaluation provided for moderate incomplete paralysis of the nerve under theapplicable DC.

III.iv.4.N.4.b.      38 CFR 4.124a Guidance on Evaluating Completely Sensory Peripheral Nerve Impairment

In cases where a peripheral nerve disability is only manifested by sensory impairment, 38 CFR 4.124a directs decision makers to assign the evaluation corresponding with the mild or at most the moderate degree of impairment.
To make a choice between mild and moderate, consider the evidence of record and the following guidelines:
  • The mild level of evaluation would be more reasonably assigned when sensory symptoms are
    • recurrent but not continuous
    • assigned a lower medical grade reflecting less impairment
    • and/or affecting a smaller area in the nerve distribution.
  • Reserve the moderate level of evaluation for the most significant and disabling cases of sensory-only involvement. These are cases where the sensory symptoms are
    • continuous
    • assigned a higher medical grade reflecting greater impairment,and/or
    • affecting a larger area in the nerve distribution.
Important:  This provision does not mean that if there is any impairment that is non-sensory (or involves a non-sensory component) such as a reflex abnormality, weakness or muscle atrophy, the disability must be evaluated as greater than moderate.  Significant and widespread sensory impairment may potentially indicate the same or even more disability than a case involving a minimally reduced or increased reflex or minimally reduced strength.
References:  For more information on
  • evaluating wholly sensory manifestations of peripheral nerves, see Miller v. Shulkin, 28 Vet.App. 376 (2017)
  • considering the complete findings when evaluating incomplete paralysis, see M21-1, Part III, Subpart iv, 4.N.4.d
  • the importance of fully descriptive examinations and limitations from the disabling condition, see 38 CFR 4.1, and
  • the importance of coordinating the evaluation with impairment of function based on sufficiently characteristic findings, see 38 CFR 4.21.

III.iv.4.N.4.c.  Assigning Level of Incomplete Paralysis, Neuritis or Neuralgia

The table below provides general guidelines for each level of incomplete paralysis of the upper and lower peripheral nerves.
Degree of Incomplete Paralysis
  • As this is the lowest level of evaluation for each nerve this is the default assigned based on the symptoms, however slight, as long as they were sufficient to support a diagnosis of the peripheral nerve impairment for SC purposes.
  • In general look for a disability limited to sensory deficits that are lower graded, less persistent, or affecting a small area.
  • A very minimal reflex or motor abnormality potentially could also be consistent with mild incomplete paralysis.
  • Moderate is the maximum evaluation reserved for the most significant cases of sensory-only impairment (38 CFR 4.124a).
    • Symptoms will likely be described by the claimants and medically graded as significantly disabling.
    • In such cases a larger area in the nerve distribution may be affected by sensory symptoms.
  • Other sign/symptom combinations that may fall into the moderate category include
    • combinations of significant sensory changes and reflex or motor changes of a lower degree, or
    • motor and/or reflex impairment such as weakness or diminished or hyperactive reflexes (with or without sensory impairment) graded as medically moderate.
  • Moderate is also the maximum evaluation that can be assigned for
    • neuritis not characterized by organic changes referred to in38 CFR 4.123, or
    • neuralgia characterized usually by a dull and intermittent pain in the distribution of a nerve (38 CFR 4.124).
Moderately Severe
  • The moderately severe evaluation level is only applicable for involvement of the sciatic nerve.
  • This is the maximum rating for sciatic nerve neuritis not characterized by the organic changes specified in 38 CFR 4.123.
  • Motor and/or reflex impairment (for example, weakness or diminished or hyperactive reflexes) at a grade reflecting a high level of limitation or disability is expected.
  • Atrophy may be present. However, for marked muscular atrophy see the criteria for a severe evaluation under 38 CFR 4.124a, DC 8520.
  • In general, expect motor and/or reflex impairment (for example, atrophy, weakness, or diminished or hyperactive reflexes) at a grade reflecting a very high level of limitation or disability.
  • Trophic changes may be seen in severe longstanding neuropathy cases.
  • For the sciatic nerve (38 CFR 4.124a, DC 8520) marked muscular atrophy is expected.
  • Even though severe incomplete paralysis cases should show findings substantially less than representative findings for complete impairment of the nerve, the disability picture for severe incomplete paralysis may contain signs/symptoms resembling some of those expected in cases of complete paralysis of the nerve.
  • Neuritis characterized by loss of reflexes, muscle atrophy, sensory disturbances, and constant pain should be rated as high as severe incomplete paralysis of the nerve (38 CFR 4.123).
  • Always consider the specific criteria in the 38 CFR 4.124a DC at issue as well as the general guidance on neuritis and neuralgia under 38 CFR 4.123 and 38 CFR 4.124.
  • This guidance also applies to radiculopathy, which is evaluated under a peripheral nerve code.
  • Separate evaluations may not be assigned when evaluating an upper extremity peripheral nerve disability. See note under 38 CFR 4.124a, DC 8719.
Reference:  For more information on evaluating peripheral nerves, see thePeripheral Nerve Evaluation Matrix.

III.iv.4.N.4.d.  Considering the Complete Findings When Evaluating Incomplete Paralysis

Evaluation Builder entries must be based upon the complete findings of the Disability Benefits Questionnaire (DBQ) and/or evidentiary record including
  • the nerve(s) involved
  • whether the impairment involves
    • reduced or elevated sensation to various tests, or abnormal sensations
    • reduced or hyperactive reflexes
    • muscle weakness
    • muscle atrophy, and/or
    • trophic changes
  • the amount of area in the nerve distribution affected by symptoms
  • the frequency of symptoms, and
  • the grade of any impairments that are identified.
Do not base the entries solely upon the examiner’s assessment of the level of incomplete paralysis.
The examiner’s clinical assessment of the extent of incomplete paralysis, as indicated on the DBQ, may be inconsistent with or appear to contradict the objective findings that are documented in other sections of the DBQ or other evidence of record.
Important:  The rating activity, not the examining medical professional, determines whether the overall evidentiary record shows the severity of the condition meets the criteria for a classification of mild, moderate, moderately severe, or severe.
Example 1:  An examiner assesses the peripheral nerve disability as “mild incomplete paralysis.”  However, the DBQ shows muscle weakness, atrophy, and diminished reflexes, which are clearly demonstrative of more than mild incomplete paralysis.  In this case, the complete evidentiary record shows the condition is more than mild under guidance contained in 38 CFR 4.124 and therefore warrants a higher evaluation.
Example 2:  An examiner renders an assessment of “severe incomplete paralysis” when the objective test results are wholly sensory.  Therefore the condition warrants an evaluation no higher than moderate incomplete paralysis under 38 CFR 4.124a.
References:  For more information on

III.iv.4.N.4.e.Nerve Branches of the Lower Extremities for Which Separate Evaluations May Be Assigned

The table below lists the five nerve branches of the lower extremities for which separate evaluations may be assigned.  See M21-1, Part III, Subpart iv, 4.N.4.f for rating guidance on assigning separate evaluations for nerve conditions of the lower extremities.
To assist in evaluating these nerves, the table below also includes any associated nerves in each branch, corresponding DCs under 38 CFR 4.124a, and the general functions covered by each nerve branch.
Lower Extremity Nerve Branches
  • sciatic nerve (DCs 8520, 8620, and 8720)
  • external popliteal nerve (common peroneal) (DCs 8521, 8621, and 8721)
  • musculocutaneous nerve (superficial peroneal) (DCs 8522, 8622, and 8722)
  • anterior tibial nerve (deep peroneal) (DCs 8523, 8623, 8723)
  • internal popliteal nerve (tibial) (DCs 8524, 8624, and 8724), and
  • posterior tibial nerve (DCs 8525, 8625, and 8725).
Foot and leg sensory and motor function of the
  • buttock
  • leg
  • knee
  • muscles below knee
  • lower leg
  • fibula
  • foot, muscles of foot, sole of foot, plantar flexion, and
  • toes.
  • anterior crural nerve (femoral) (DCs 8526, 8626, and 8726)
  • internal saphenous nerve (DCs 8527, 8627, and 8727)
Thigh and leg sensory and motor function of the
  • quadriceps muscle, front of thigh
  • medial calf, and
  • medial malleolus.
Obturator (DCs 8528, 8628, and 8728)
Motor and sensory function of the
  • hip and muscles of the hip, and
  • medial thigh.
External cutaneous nerve of thigh(DCs 8529, 8629, and 8729)
Sensory function of the lateral thigh.
Illio-inguinal nerve (DCs 8530, 8630, and 8730)
Motor and sensory function of the
  • lower abdominal wall
  • thigh
  • scrotum, and
  • labia majora.

III.iv.4.N.4.f.  Assigning Separate Evaluations for Lower Extremity Peripheral Nerves

Unlike the upper extremities, separate evaluations of the lower extremities may be assigned for symptoms that are separate and distinct, do not overlap, and are attributed to different lower extremity nerves.  This means that separate evaluations are warranted when symptoms arise from any of the five nerve branches listed in the table in M21-1, Part III, Subpart iv, 4.N.4.e.
If symptoms arise from within the same nerve branch of any of the five individual nerve branches in the lower extremity, assigning separate evaluations for those symptoms are not warranted as this would constitute pyramiding.
Example 1:  Separate Evaluations Warranted
A Veteran has severe incomplete paralysis of the common peroneal nerve and mild incomplete paralysis of the femoral nerve.  Assign separate evaluations of 30 percent under 38 CFR 4.124a, DC 8521 and 10 percent under 38 CFR 4.124a, DC 8526.
Analysis:  The common peroneal nerve is part of the sciatic branch and the femoral nerve is part of the femoral branch.  The functions for these branches are separate and distinct and therefore warrant separate evaluations.
Example 2:  Separate Evaluations Not Warranted
A Veteran has severe incomplete paralysis of the common peroneal nerve under38 CFR 4.124a, DC 8521 and moderate incomplete paralysis of the tibial nerve under 38 CFR 4.124a, DC 8524.  In this case, a single 30-percent evaluation is assigned under 38 CFR 4.124a, DC 8521.
Analysis:  Both of these nerves are part of the same sciatic branch, and therefore the functions associated with these nerves are not separate and distinct.  The 30-percent evaluation shall be assigned under 38 CFR 4.124a, DC 8521 since it represents the predominant disability.
References:  For more information about

III.iv.4.N.4.g.  Determining Individual Nerves Affected in the Upper and Lower Extremities When Evaluating Disabilities

When evaluating peripheral nerve disabilities of the upper and lower extremities, the rating activity must conduct a thorough review of the medical evidence of record to determine the individual nerve(s) affected.
VA examiners are required, to the extent possible, to select the individual nerves affected when completing DBQs.  However, the examiner may not necessarily conduct a review of all previous clinical records or perform comprehensive tests to pinpoint the exact nerve and/or symptoms attributable to that nerve.
  • It is the responsibility of the rating activity, in accordance with 38 CFR 4.2, to interpret the DBQ along with the whole recorded history, and accurately identify and assess the current level of peripheral nerve disability.  This includes identifying the appropriate nerve from a review of the evidence so that the appropriate evaluation can be assigned.
  • Include the following language in all Peripheral Nerves DBQ requests:
Examiner:  Please identify the specific nerve(s) affected.  If you are unable to identify the specific nerve(s), please provide a rationale in the Remarks section.  Thank you.
Follow the guidance in the table below when reviewing medical evidence pertaining to peripheral nerve disabilities of the upper and lower extremities.
If the DBQ or equivalent indicates …
And …
Then evaluate …
the specific nerve affected
there is no conflicting information
the specific nerve under the appropriate DC.
there is conflicting information on what nerve is affected, but the nerves identified are within the same nerve branch
the nerve that is most beneficial to the Veteran as long as the DC supports the symptoms.
the identified nerves are in different nerve branches; however, the symptoms identified in the medical evidence are not clearly associated with an individual nerve
all symptoms shown in the medical evidence for the individual nerve(s) in the associated nerve branches.
the examiner is unable to specify the affected nerve(s)
there is no other evidence adequately documenting the affected nerve
Exception:  Where the disability at issue is lower extremity radiculopathy associated with SC thoracolumbar disability, follow the guidance inM21-1, Part III, Subpart iv, 4.A.3.a and evaluate using 38 CFR 4.124a, DC 8520 (the sciatic nerve).
Note:  The nerve branches and general functions of the nerve branches of the lower extremities are described in the table found in M21-1, Part III, Subpart iv, 4.N.4.e.

III.iv.4.N.4.h.   EMG and Other Tests for Peripheral Nerve Conditions

Electromyography (EMG) results are required for evaluations of peripheral nerve disabilities unless there is a previous EMG test of record or the record contains sufficient clinical evidence to determine the extent of paralysis in the peripheral nerve.
As noted in the Peripheral Nerves DBQ, EMG studies are usually rarely required to diagnose specific peripheral nerve conditions in the appropriate clinical setting and, if EMG studies are in the medical record and reflect the Veteran’s current condition, repeat studies are not indicated.
Important:  Ultimately, it is the role of the rating activity to determine if the examination was sufficient to confirm the question and extent of peripheral nerve involvement.
Note:  Other clinical findings that may be sufficient to document a peripheral nerve disability include
  • sensation to light touch testing
  • deep tendon reflex testing
  • certain signs for the median nerve
  • trophic changes
  • gait testing
  • muscle strength testing, and
  • the presence of muscle atrophy.

III.iv.4.N.4.i.   Applying the Amputation Rule to Peripheral Nerve Disabilities

In determining whether the amputation rule under 38 CFR 4.68 applies to peripheral nerve evaluations, decision makers must consider the etiology of the peripheral nerve disability.
If the peripheral nerve disability is associated with a musculoskeletal injury or amputation, follow the guidance in &M21-1, Part III, Subpart iv, 4.B.7.j regarding the application of the amputation rule.
When peripheral nerve disabilities are not associated with a musculoskeletal injury, such as diabetic neuropathy, the amputation rule does not apply.
Reference:  For more information on evaluating peripheral nerve injuries associated with a muscle injury, see 38 CFR 4.55.

5.  MS


This topic contains information about MS, including

Change Date

June 15, 2015

III.iv.4.N.5.a.   Definition: MS

Multiple sclerosis (MS) is a slowly progressive central nervous system disease, and is characterized by
  • disseminated patches of demyelination in the brain and spinal cord which cause multiple and varied neurologic symptoms and signs, and
  • the occurrence of remissions and exacerbations in the symptoms.

III.iv.4.N.5.b.  Evaluating a Residual MS Disability 30 Percent or More

In cases of MS
  • evaluate each affected system or body part separately
  • show the DC for MS only once by listing it with the most severely affected function
  • code involvement of other manifestations thereafter under the DC assignable for the condition on which the evaluation is based, and
  • show the remaining conditions as secondary to MS.
  • This is a change from the previous requirement to evaluate MS as a single disability when the combined degree was less than 100 percent.
  • If the combined evaluation for all disabilities due to MS is 20 percent or less, assign a 30-percent evaluation under 38 CFR 4.124a, DC 8018.
Important:  Readjudicate cases previously evaluated as a single disability as they are encountered under the procedure outlined above.

III.iv.4.N.5.c.  Example of Evaluating Residual MS Disability 30 Percent or More

This exhibit contains an example of evaluating a residual MS disability 30 percent or more.
Coded Conclusion:
40% from 12-10-81
Multiple sclerosis with bladder dysfunction
10% from 12-10-81
Weakness of right lower extremity secondary to multiple sclerosis
10% from 12-10-81
Weakness of left lower extremity secondary to multiple sclerosis
0% from 12-10-81
Impotency without penile deformity, secondary to multiple sclerosis
50% from 12-10-81
43. Bilateral Factor of 1.9% added for diagnostic codes 8521 and 8521
Entitled to special monthly compensation under 38 U.S.C. 1114, subsection (k) and 38 CFR 3.350(a) on account of loss of use of a creative organ from 12-10-81.
Note:  SMC coding is 01-01-00-00-1.

III.iv.4.N.5.d.Presumptive SC for MS

Presumptive SC may be established for MS if the disease becomes manifest within seven years from the date of separation.
Reference:  For more information on requirements for establishment of presumptive SC, see 38 CFR 3.307(a) and 38 CFR 3.309.

6.  ALS


This topic contains information about ALS, including

Change Date

July 8, 2016

III.iv.4.N.6.a.  Definition: ALS

Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig’s disease, is a neuromuscular disease that causes degeneration of nerve cells in the brain and spinal cord, resulting in muscle weakness, muscle atrophy, and spontaneous muscle activity.

III.iv.4.N.6.b.  Establishing Presumptive SC for ALS

Effective September 23, 2008, 38 CFR 3.318 established a presumption of SC for ALS manifested at any time after discharge or release from active military, naval, or air service.
Exceptions:  SC will not be established if
  • there is affirmative evidence that ALS was
    • not incurred or aggravated by military, naval, or air service, or
    • was due to the Veteran’s own willful misconduct; or
  • if the Veteran did not have active, continuous service of 90 days or more.
In Bowers v. Shinseki, 748 F.3d. 1351 (Fed. Cir., 2014), the Federal Circuit held that the presumption of SC for ALS only applies to individuals having attained Veteran status by virtue of having performed active military, naval, or air service.  National Guard service that did not meet the requirements of active military, naval, or air service did not qualify for the presumption.  Active duty for training of 90 days did not qualify unless the individual was disabled (or died) as a result of a disease or an injury incurred or aggravated in the line of duty.
Note:  Primary lateral sclerosis (PLS) is not considered to be a qualifying disease under 38 CFR 3.318.  Because PLS and ALS are diseases of the nervous system and both affect motor neurons, treating physicians may not be able to identify whether the Veteran has PLS or ALS in the initial stages.  If the diagnosis is uncertain after reviewing the medical evidence, request a medical opinion with examiner review of all pertinent evidence in the claims folder.
This was considered a liberalizing regulation.  Therefore consider the application of38 CFR 3.114(a) when granting presumptive SC for ALS under the provisions of 38 CFR 3.318.
Reference:  For more information on liberalizing changes of law and VA issuances, see M21-1, Part III, Subpart iv, 5.C.7.

III.iv.4.N.6.c.  Assigning a 100 Percent Minimum Evaluation for ALS

ALS is evaluated under 38 CFR 4.124a, DC 8017.
Effective January 19, 2012, the diagnostic criteria for ALS was amended in 38 CFR 4.124a to provide a 100-percent evaluation for any Veteran with SC ALS.  A diagnosis of ALS alone is sufficient to support an evaluation of 100 percent.  A total disability evaluation is the minimum evaluation to be assigned for ALS because of the possibility of SMC and automatic entitlement to ancillary benefits.
Note:  This rule will be applied to all cases pending before VA on or after, January 19, 2012, and does constitute a liberalizing VA regulation under 38 U.S.C. 5110(g)and 38 CFR 3.114 for the purpose of determinations of effective dates and retroactive benefits.

III.iv.4.N.6.d.  Evaluation Guidelines for ALS

Determine the proper evaluation for all complications of ALS prior to coding a single 100-percent evaluation under 38 CFR 4.124a, DC 8017.  Refer to the table below for guidance.
If …
Then …
there is no complication warranting a single 100-percent evaluation
  • assign a 100-percent evaluation under 38 CFR 4.124a, DC 8017, and
  • include all compensable complications in the description of the diagnosis.
Example:  ALS with loss of use of the left foot and partial ninth cranial nerve paralysis.
a single 100-percent evaluation is warranted for a complication of ALS
  • assign a 100-percent evaluation for that complication.
    • Use a hyphenated DC.
    • Example:  8017-5110, loss of use of both feet.
  • Separately evaluate additional complications.
  • Do not assign a separate evaluation under 38 CFR 4.124a, DC 8017 alone; this would be pyramiding under38 CFR 4.14.
Note:  A 100-percent evaluation for a complication of ALS satisfies the policy that all ALS awards will be assigned at least a 100-percent evaluation.

III.iv.4.N.6.e.   ALS and Ancillary Benefits

Consider eligibility for SMC and/or other ancillary benefits in all ALS cases.
  • Ensure the codesheet reflects all complications that can be separately evaluated.
  • Entitlement to SMC at the statutory housebound rate may be warranted when
    • ALS and complications are assigned one 100-percent evaluation under 38 CFR 4.124a, DC 8017 and the combined evaluation of other SC conditions totals 60 percent or higher, or
    • an ALS complication is evaluated as 100-percent disabling and the combined evaluation of other SC conditions, including additional separately evaluated complications of ALS, total 60 percent or higher.
  • Entitlement to SMC, such as SMC K for loss of use of a foot, may still be warranted when one total disability evaluation is assigned for ALS and all complications under 38 CFR 4.124a, DC 8017.
  • Effective December 3, 2013, 38 C.F.R. 3.809d provides that SC ALS is a qualifying condition for the purpose of entitlement to specially adapted housing.
  • Effective February 25, 2015, 38 CFR 3.808 provides that SC ALS is a qualifying condition for entitlement to a certificate of eligibility for automobile or other conveyance and adaptive equipment.  The amendment applies to all applications pending before VA on, or received after, February 25, 2015.
References:  For more information on

7.  Migraine Headaches


This topic contains information on migraine headaches, including

Change Date

June 15, 2015

III.iv.4.N.7.a.  Evaluation Criteria for Migraine Headaches

Migraine headaches are evaluated under the criteria of 38 CFR 4.124a, DC 8100.  Evaluations depend primarily on the frequency of attacks and the degree to which symptoms are prostrating.  The extent to which the headaches cause work impairment is also a factor and is considered for the 50-percent evaluation.

III.iv.4.N.7.b.   DC 8100 Terminology:  Prostrating and Completely Prostrating

Prostrating, as used in 38 CFR 4.124a, DC 8100, means “causing extreme exhaustion, powerlessness, debilitation or incapacitation with substantial inability to engage in ordinary activities.”
Completely prostrating as used in 38 CFR 4.124a, DC 8100, means extreme exhaustion or powerlessness with essentially total inability to engage in ordinary activities.

III.iv.4.N.7.c.  The Role of Medical Evidence in Establishing the Fact of Prostration

Although prostration is substantially defined by how the disabled individual subjectively feels and functions when having migraine headache symptoms, medical evidence is required to establish that the reported symptoms are due to the SC migraine headaches.
The following is an example of a medical statement that would ordinarily establish the fact of prostration if the medical report and the history provided by the claimant are both credible.
The patient reports symptoms of severe head pain, blurred vision, nausea and vomiting, and being unable to tolerate light or noise, worsened by most activities including reading, writing, and engaging in conversations or physical activities.  When experiencing these symptoms, the patient only sleeps or rests.  The symptoms reported by the patient are consistent with the diagnosis of migraine headaches and the reported limitations are consistent with those seen in patients suffering from migraine headaches of similar clinical severity. 
Note:  Medical reports may not use the word “prostration.”  However this is an adjudicative determination based on the extent to which the facts meet the definition of the term.

III.iv.4.N.7.d.  Lay Evidence of Prostration from Migraine Headaches

A claimant’s own testimony regarding his or her symptoms and limitations when having those symptoms can establish prostration as long as the testimony is credible and symptoms are otherwise competently attributed to migraine headaches through medical evidence.
Example:  A claimant provides testimony that he/she 1) experiences severe headaches and vomiting when exposed to light; 2) does not engage in any activities when this occurs; and 3) must rest or sleep during these episodes.  If there is medical evidence that the claimant’s description of symptoms is in fact symptoms of migraine headaches, a determination that the headaches cause prostration can be made.
Reference:  For more information on competency of lay testimony, see

III.iv.4.N.7.e.  DC 8100 Terminology: Severe Economic Inadaptability

Severe economic inadaptability denotes a degree of substantial work impairment.  It does not mean the individual is incapable of any substantially gainful employment.  Evidence of work impairment includes, but is not necessarily limited to, the use of sick leave or unpaid absence.
Note:  In cases where migraine headaches meet the criterion of severe economic inadaptability and, additionally, the evidence shows that the claimant is incapable of substantially gainful employment due to the headaches, referral for consideration of an extraschedular award of a total evaluation based on individual unemployability is appropriate.
Reference:  For more information on severe economic inadaptability, see Pierce v. Principi, 18 Vet.App 440 (2004).

III.iv.4.N.7.f.  DC 8100 Terminology: Less Frequent and Very Frequent

38 CFR 4.124a, DC 8100 does not define the terms less frequent for the 0- percent criterion or very frequent for the 50-percent criterion.  However, the overall rating criteria structure for migraine headaches provides a basis for guidance.
As noted in 38 CFR 4.124a, DC 8100, the 10-percent evaluation specifies average frequency (“averaging one in 2 months over the last several months”), which is half of what is required for a 30-percent evaluation (“on average once a month over the last several months”).
For definitions of the terms less frequent and very frequent, refer to the tablebelow.
Evaluation Level
less frequent
0 percent
Duration of characteristic prostrating attacks, on average, are more than two months apart over the last several months.
very frequent
50 percent
Duration of characteristic prostrating attacks, on average, are less than one month apart over the last several months.

III.iv.4.N.7.g.  Frequency Determinations:  Types of Proof

Frequency of migraine headache attacks or episodes is a factual determination.  Analyze all evidence in the record bearing on the question.
Probative evidence may include
  • medical progress notes
  • competent and credible lay evidence on how often the claimant experiences symptoms (as long as those symptoms have been competently identified as symptoms of migraine headaches)
  • contemporaneous notes (a headache journal)
  • prescription refills, and
  • witness statements.
Note:  The absence of treatment reports is not necessarily probative on the question of headache frequency as a claimant may not seek treatment for headaches during every episode.
Reference:  For more information on evaluating evidence, including competency and credibility, see M21-1, Part III, Subpart iv, 5.A.

III.iv.4.N.7.h.  Headache Journals

Headache journals, which routinely and relatively contemporaneously record headache episodes, may be accepted as credible lay testimony regarding
  • headache frequency
  • prostration, and
  • occupational impairment (e.g., sick leave due to headaches).
Note:  Headaches recorded on non-work days may be used to prove frequency and prostration.  However, they will not generally be relevant to work availability, and performance or limitations, which are considerations in determining severe economic inadaptability.

 8.  Parkinson’s Disease


Change Date

 September 29, 2016

III.iv.4.N.8.a.  Definition: Parkinson’s Disease

Parkinson’s disease is a chronic, slowly progressive central nervous system disorder characterized by muscular rigidity, a tremor of resting muscles, slow and decreased voluntary movements and positional instability.  An outdated term for Parkinson’s disease is paralysis agitans.
Early signs and symptoms of the condition may include:
  • infrequent blinking
  • lack of facial expression
  • decreased movement, and
  • impaired postural reflexes.
The condition is characterized by muscle tremors at rest which diminish during movement and are absent during sleep.  The tremors are enhanced by emotional tension or fatigue and the hands are most affected. Muscle rigidity may be present without tremors.  As the muscle rigidity progresses, movement becomes slow (bradykinesia), decreased or diminished (hypokinesia), and difficult to initiate (akinesia).  Other signs and symptoms may include:
  • muscular aches and fatigue
  • mask-like expression with open mouth
  • drooling
  • stooped posture
  • gait characterized by involuntary, short, accelerating steps
  • difficulty in walking
  • loss of postural reflexes (tendency to fall forward or backward with respective shift in center of gravity)
  • speech manifestations – specifically low speech volume with stuttering or slurred speech, or uniformity of tone and high pitch, and
  • dysphagia.

III.iv.4.N.8.b.  SC for Parkinson’s Disease

Parkinson’s disease can be directly incurred in service but in most cases it will be SC on a presumptive or secondary basis.
  • Paralysis agitans is listed as a chronic disease in 38 CFR 3.309(a) and as such Parkinson’s disease is presumed to have had its inception in service if manifested to a compensable degree within one year of discharge under38 CFR 3.307(a)(3).
  • Parkinson’s disease is listed as a disease associated with exposure to certain herbicide agents in 38 CFR 3.309(e) and therefore is presumed to be related to herbicide exposure in the Republic of Vietnam when manifested to a compensable degree at any time after service as provided in 38 CFR 3.307(a)(6).
  • Finally, under 38 CFR 3.310(d), Parkinson’s disease is treated as secondary to TBI when the TBI was moderate or severe.
References:  For more information on

III.iv.4.N.8.c.  Evaluating Parkinson’s Disease

Evaluate Parkinson’s disease using the diagnostic criteria for paralysis agitans under 38 CFR. 4.124a, DC 8004.
Use the same rating guidance as for MS as provided in M21-1, Part III, Subpart iv, 4.N.5.b.

III.iv.4.N.8.d. SMC and Parkinson’s Disease

Give careful consideration to SMC in cases of Parkinson’s disease, particularly losses of use and A&A.
References:  For more information on
Historical_M21-1III_iv_4_SecN_1-24-18.docx May 15, 2019 150 KB
6-22-18_Key-Changes_M21-1III_iv_4_SecN.docx May 15, 2019 96 KB
Historical_M21-1III_iv_4_SecN_2-2-18.docx May 15, 2019 121 KB
1-24-18_Key-Changes_M21-1III_iv_4_SecN.docx May 15, 2019 111 KB
Did this article answer your question?

Leave a Reply

Pin It on Pinterest

Share This