Chapter 20 - Neurological Impairment

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Contents

Introduction

This chapter provides criteria for assessing permanent impairment from entitled conditions of the central and peripheral nervous system (brain, cranial and peripheral nerves).

This chapter is divided into three sections. The first section provides criteria to assess impairment of cerebral function. The second section provides criteria to assess impairment of the cranial and peripheral nerves. The third section provides criteria to assess seizure disorders, narcolepsy and cataplexy, headache conditions and miscellaneous neurological conditions.

A rating is not given from this chapter for conditions listed below.

  • Impairment from spinal nerve root compression lesions/sciatica is rated within Chapter 17, Musculoskeletal Impairment.
  • Impairment from spinal cord injury or disease affecting the upper limbs only or the lower limbs only (but not both) is rated within Chapter 17, Musculoskeletal Impairment.
  • Impairment from spinal cord injury or disease affecting both the upper and lower limbs is rated within Chapter 19, Activities of Daily Living.
  • Impairment from polyneuropathy which affects the function of both the upper and lower limbs is rated within Chapter 19, Activities of Daily Living.
  • Impairment from brain injury or disease affecting the upper limbs only or the lower limbs only (but not both) is rated within Chapter 17, Musculoskeletal Impairment.
  • Impairment from neurological conditions that have multi-system or global body effects such as multiple sclerosis and amyotrophic lateral sclerosis (ALS) is rated within Chapter 19, Activities of Daily Living.
  • Impairment from sleep apnea is rated within Chapter 12, Cardiorespiratory Impairment.
  • Impairment from disequilibrium is rated within Chapter 9, Hearing Loss and Ear Impairment.
  • Impairment from psychiatric disorders is rated within Chapter 21, Psychiatric Impairment.
  • Impairment from brain injury or disease resulting only in both upper and lower limb effects is rated within Chapter 19, Activities of Daily Living.

Note: Brain injury or disease which results in multiple deficits (e.g. head injury or cerebral vascular accident resulting in cognitive, psychiatric and physical impairments) is rated on individual merits.

Impairment from malignant neurological conditions is rated within Chapter 18, Malignant Impairment. Follow the steps contained within the Malignant Impairment chapter.

Rating Tables and Charts

This chapter contains five "Loss of Function" tables and four "Other Impairment" tables which may be used to rate entitled neurological conditions. Two reference charts are also included within this chapter which describe the effects of a complete loss of function of a cranial or peripheral nerve at its origin.

The tables within this chapter are:

Rating Tables
Table Loss of Function Other Impairment
Table 20.1 Loss of Function - Cognition This table is used to rate impairment of cognition.
Table 20.2 Loss of Function - Speech and Expression This table is used to rate impairment of speech and/or expression.
Table 20.3 Loss of Function - Comprehension This table is used to rate impairment in comprehension.
Table 20.4 Loss of Function - Cranial Nerves This table is used to rate impairment in cranial nerve function.
Table 20.5 Loss of Function - Peripheral Nerves This table is used to rate impairment of peripheral nerve function.
Table 20.6 Other Impairment - Seizures This table is used to rate impairment from seizure disorders - major and minor.
Table 20.7 Other Impairment - Narcolepsy and Cataplexy This table is used to rate impairment from narcolepsy and cataplexy.
Table 20.8 Other Impairment - Headaches This table is used to rate impairment from headache conditions.
Table 20.9 Other Impairment - Miscellaneous Neurological This table is used to rate impairment from miscellaneous neurological conditions.
Chart 1 Chart of Cranial Nerve Function This reference chart describes the effect of a complete loss of function of a cranial nerve.
Chart 2 Chart of Peripheral Nerve Function This reference chart describes the effect of a complete loss of function of a peripheral nerve.

Section 1 - Determining Impairment Assessments of Cerebral Function

The tables that may be used to rate impairment from cerebral conditions are:

Section 1 - Determining Impairment Assessments of Cerebral Function
Table Loss of Function Other Impairment
Table 20.1 Loss of Function - Cognition This table is used to rate impairment of cognition.
Table 20.2 Loss of Function - Speech and Expression This table is used to rate impairment of speech and/or expression.
Table 20.3 Loss of Function - Comprehension This table is used to rate impairment in comprehension.

This section is used to rate impairment from conditions such as cerebral vascular accidents, dementia and other cognitive disorders (e.g. head injury).

Cognitive Function

Cognitive function deals with such aspects of knowledge as acquisition (learning), retention and recall (memory), and use (reasoning and problem solving). The Table 20.1 rating must relate only to cognitive deficits that were not present before the onset of the entitled condition.

Self reports of deteriorating mental function must be interpreted with caution. Dementia is often associated with a lack of insight or tendency to deny failing abilities. Self-reported complaints about poor memory may be more closely related to depressive symptoms than to true memory deficits. If there is doubt about the nature or extent of the deficit, formal neuropsychiatric testing may be required.

When rating neurological conditions which affect cognition, Table 20.1 – Loss of Function – Cognition is to be used. An impairment rating(s) may also be applicable from Table Table 20.2 – Loss of Function – Speech and Expression and/or Table Table 20.3 – Loss of Function – Comprehension. Impairment ratings are to be added when more than one table is used.

Note: Brain injury or disease which results in multiple deficits (e.g. head injury or cerebral vascular accident resulting in cognitive, psychiatric and physical impairments) is rated on individual merits.

Communication

Communication has two elements: expression and comprehension. "Expression" is the capacity to convey the content of one's mind to others. "Comprehension" means "understanding". It includes understanding of speech and gestures, recognition of sights and sounds, spatial and temporal orientation.

Expression and comprehension are to be rated separately by applying Table 20.2 and Table 20.3 respectively. Impairment ratings from these tables are to be added when criteria from both are applicable. Impairment ratings from these tables are not to include communication deficits that were present before the onset of the entitled condition.

Table 20.2 and Table 20.3 are to be used to rate impairment from neurological or neuromuscular conditions as well as local lesions involving the mechanisms of speech production.

Communication restricted by vision loss, hearing loss, or loss of hand function is not to be rated within this chapter.

Loss of Function - Cognition

Table 20.1 is used to rate impairment from cerebral conditions that affect cognition. The table contains three columns (categories) which are rated independently. The ratings are compared and the highest selected.

If more than one condition is to be rated from Table 20.1, the conditions are bracketed for assessment purposes.

When entitled cognitive conditions result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Loss of Function - Speech and Expression

Table 20.2 is used to rate impairment of cerebral conditions that affect speech and/or the ability to write. The table contains three columns (categories) which are rated independently. The ratings are compared and the highest selected.

If more than one condition is to be rated from Table 20.2, the conditions are bracketed for assessment purposes.

When entitled speech and expression conditions result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Loss of Function - Comprehension

Table 20.3 is used to rate impairment of cerebral conditions that affect comprehension of oral and/or written language. Only one rating may be selected. If more than one rating is applicable, the ratings are compared and the highest selected.

If more than one condition is to be rated from Table 20.3, the conditions are bracketed for assessment purposes.

When entitled comprehension conditions result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Table 20.1 - Loss of Function - Cognition

Only one rating may be given from Table 20.1. Each column in Table 20.1 is rated independently. If more than one rating is applicable within a column, the highest rating is selected as the column rating. The ratings from each column are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.1, only one criterion must be met at a level of impairment for that rating to be selected.

Table 20.1 - Loss of Function - Cognition
Rating Cognitive Emotional &
Behavioural
Personal Care
Nil
  • Reasoning and memory are comparable with that of peers.
  • No difficulties with emotion and/or behaviour.
  • Fully capable of self-care.
Nine
  • Appropriate use is made of accumulated knowledge and reasonable judgement is shown in routine daily activities most of the time. Difficulties are apparent in new circumstances; or
  • Demonstrates impairment of memory: misplaces objects, and has increased difficulty in remembering names and appointments. Can learn, although at a slower rate than previously. Impairment has little impact on everyday activity because of compensation through reliance on written notes, schedules, check-lists and spouse.
  • May have mild symptoms of anxiety and/or depression with respect to cognitive difficulties; or
  • May have poor frustration tolerance.
Thirteen
  • Demonstrates difficulty with multi-tasking which may be apparent to co-workers and results in decreased level of work performance; or
  • Fully oriented except for difficulty with time relationships.
  • Resistive or apathetic to care provided.
  • May require prompting with grooming, dressing and toileting.
Twenty-Three
  • Has frequent difficulty in recalling details of recent experiences; fails to follow through with intentions or obligations; tends to get lost more easily in unfamiliar areas; or
  • Demonstrates impairment of problem-solving ability: suffers significant disadvantage in circumstances requiring complex decision-making or non-routine activities. Reduced capacity for abstract thinking (i.e. a rolling stone gathers no moss).
Thirty-Two
  • May show suspicious behaviour and/or occasional delusions; or
  • Wanders at least weekly. Social judgement may be impaired.
  • Requires assistance and/or supervision with most personal care activities.
Forty-Nine
  • Unable to function independently in new or complex situations; or
  • Severe memory deficit; has extreme difficulty in keeping track of finances, scheduling activities, social relationships, etc.; or
  • Disoriented to time and place but remains oriented to person.
  • Paranoia is present (i.e. spouse is poisoning food) and delusions are present most days; or
  • Difficulty in social behaviour shown by aggressive behaviour toward caregiver or others; or
  • Shows inappropriate sexual behaviour; or
  • Wanders constantly day and night.
  • Unable to live independently needing supervision to avoid harm (i.e. from fire caused by forgetting to put out cigarettes or to turn off appliances); or
  • Frequent incontinence (more than once weekly while awake).
Eighty-One
  • Unable to plan a course of action for the simplest activity; or
  • Unable to acquire or recall new information; or
  • Severe memory loss, only fragments remain; or
  • Unable to make judgements or solve problems; or
  • Complete disorientation and unaware of surroundings.
  • Delusions and hallucinations present almost constantly throughout the day; or
  • Difficulty in social behaviour shown by grossly inappropriate sexual or social behaviour; or
  • Violent toward caregiver or others; or
  • Intrusive wandering day and night.
  • Unable to care for self in any situation; or
  • No bowel or bladder control.

Table 20.2 - Loss of Function - Speech and Expression

Only one rating may be given from Table 20.2. Each column in Table 20.2 is rated independently. If more than one rating is applicable within a column, the highest rating is selected as the column rating. The ratings from each column are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.2, all criteria designated at that rating level must be met.

Table 20.2 - Loss of Function - Speech and Expression
Rating Criteria
Speech Conversation Ability to Write
Nil
  • Normal speech.
  • Normal conversational ability.
  • No writing difficulties.
Four
  • Speech is of sufficient intensity and vocal quality for most everyday needs, e.g.:
    • normal speech, but unable to shout; or
    • needs to repeat self at times; or
    • is unable to produce some phonetic units; or
    • speech is sustained over a 10-minute period, but with difficulty that includes hesitancy and word retrieval problems; or
    • is permanently hoarse.
  • Has difficulty initiating conversation, is hesitant and suffers mild word retrieval difficulties.
Nine
  • Speech is of sufficient intensity and vocal quality for many of the needs of everyday speech, e.g.:
    • is adequate with low background noise, but is heard with some difficulty in vehicles or public places; or
    • has many inaccuracies, but is easily understood by strangers; or
    • is slow or discontinuous, conveying the distinct impression of difficulty.
  • Converses in simple sentences on familiar topics and has difficulty in explaining long or complex ideas.
Eighteen
  • Speech is of sufficient intensity and vocal quality for some of the needs of everyday speech, e.g.:
    • is adequate under quiet conditions, but is heard with great difficulty against any background noise; voice fades rapidly; or
    • is understood by family and friends, but is difficult for strangers; or
    • needs frequent repetition; or
    • speech is sustained for short period only: fatigues rapidly.
  • Is unable to initiate conversation. But, with considerable effort, is able to respond in short simple sentences or phrases.

Has moderate dysgraphia*. Unable to write more than short sentences which include frequent spelling errors, e.g.: has difficulty filling in bank forms.

Twenty-Six
  • Speech is of sufficient intensity and vocal quality for only a few of the needs of everyday speech, e.g.:
    • is reduced to a whisper at best; inaudible over the telephone; or
    • can produce only a few phonetic units approximating some words, but these are not intelligible if the context is unknown; or
    • can produce only short phrases or single words: speech flow is not maintained, or is too slow to be useful.
  • Is limited to single words or familiar social or stereotyped phrases requiring considerable listener inference.
  • Has severe dysgraphia*. Able to write only some recognizable words, e.g. items for a shopping list, or names of family.
Thirty-Four
  • Has no speech production, but is able to use non-verbal means of expression.
  • Is unable to participate in conversation.
  • Has agraphia. No functional writing ability, although is able to copy or write much practised sequences, such as own name.

* Dysgraphia is the inability to write properly due to an expression problem from an acquired neurological condition.

Table 20.3 - Loss of Function - Comprehension

Only one rating may be given from Table 20.3. If more than one rating is applicable, the ratings are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.3, only one criterion designated at that rating level must be met.

Table 20.3 - Loss of Function - Comprehension
Rating Criteria
Nil
  • Normal comprehension.
Four
  • Understands movies, radio programs or group discussions with some difficulty. Comprehension is good in most circumstances and situations but understanding is difficult in large groups or when tired and upset. Has difficulty dealing with rapid changes of topic.
Nine
  • Understands speech face to face but confusion or fatigue occurs rapidly in a group. Is unable to cope with rapid change in topic or with complex topics (e.g. is able to grasp the meaning of simple story lines, simple TV serials, but cannot grasp the meaning of more complex ideas, for example, "a stitch in time saves nine"); or
  • Mild alexia* (e.g. is able to grasp the meaning of basic newspaper and magazine articles, but has difficulty understanding details such as a story line in a book).
Twenty-One
  • Understands simple sentences only. Can understand and follow simple conversation when some points are repeated; or
  • Moderate alexia*. Reading comprehension is limited to sentences and short paragraphs (e.g. can follow two to three line instructions and cope with shopping and other short lists, but nothing more complex).
Thirty-Four
  • Understands only single words. Shows some understanding of slowly spoken simple sentences from context and gesture, although frequent repetition is needed; or
  • Severe alexia* (e.g. is able to read single words, to match words to pictures and to read labels and signs, but is unable to read instructions).
Seventy
  • Unable to read single words, labels or signs.
Eighty-One
  • Unable to understand simple instructions, even simple yes/no questions, even with gestures.

* Alexia is a form of receptive aphasia in which there is inability to understand written language.

Steps to Determine Cognition / Speech and Expression / Comprehension Assessment

  • Step 1: Determine a rating from each column in Table 20.1 (Loss of Function-Cognition) (if applicable). Compare and select the highest column rating as the Table 20.1 rating.
  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3:Determine a rating from each column in Table 20.2 (Loss of Function-Speech and Expression) (if applicable). Compare and select the highest column rating as the Table 20.2 rating.
  • Step 4: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 3.
  • Step 5: Determine a rating from Table 20.3 (Loss of Function - Comprehension) (if applicable)..
  • Step 6: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 5.
  • Step 7: Add the ratings from Step 2, Step 4 and Step 6.
  • Step 8: Determine the Quality of Life rating.
  • Step 9: Add the ratings at Step 7 and Step 8.
  • Step 10: If partial entitlement exists, apply to the rating at Step 9.

This is the Disability Assessment.

Section 2 - Determining Impairment Assessments of Cranial and Peripheral Nerve Conditions

The tables that may be used to rate impairment from cranial and peripheral nerve conditions are:

Section 2 - Determining Impairment Assessments of Cranial and Peripheral Nerve Conditions
Table Loss of Function Other Impairment
Table 20.4 Loss of Function - Cranial Nerves This table is used to rate impairment of cranial nerve function.
Table 20.5 Loss of Function - Peripheral Nerves This table is used to rate impairment of peripheral nerve function.
Chart 1 Chart of Cranial Nerve Function This reference chart describes the effect of a complete loss of function of a cranial nerve.
Chart 2 Chart of Peripheral Nerve Function This reference chart describes the effect of a complete loss of function of a peripheral nerve.

Loss of Function - Cranial Nerves

The twelve pairs of cranial nerves emerge from the base of the brain to control sensory, motor and autonomic functions. Some of the nerves have a mixture of sensory, motor and/or autonomic fibres, while others are purely sensory or motor.

Table 20.4 - Loss of Function - Cranial Nerves rates impairment of cranial nerve conditions. Instructions are provided within this table when a rating for a cranial nerve condition is required from another table within this chapter or from another chapter.

When entitled conditions of the cranial nerves result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Loss of Function - Peripheral Nerves

Peripheral nerves convey nerve impulses to and from the central nervous system (brain and spinal cord) to control sensory, motor and autonomic functions. A Member/Veteran/Client may have a disturbance of any one of or all of these functions. The disturbance may be partial or complete, unilateral or bilateral, of one nerve or of multiple nerves. A deficit in nerve conduction may result in a functional impairment.

Table 20.5 - Loss of Function - Peripheral Nerves rates impairment of specific peripheral nerves. The first column (category) is used to rate complete loss of nerve function at its origin. This includes paralysis and associated loss of sensation. The second column (category) is used when there is only a complete loss of sensation. A rating cannot be taken from both columns for the same peripheral nerve condition.

For peripheral nerve conditions not included in Table 20.5 (e.g. incomplete loss of function of a peripheral nerve or loss of sensation in a "glove" or "stocking" distribution) a rating may be applicable from Table 17.1 - Loss of Function - Upper Limb or Table 17.9 - Loss of Function - Lower Limb.

In cases where the same limb is affected by both a complete loss of a nerve's function at its origin and a condition which is rated from Table 17.1 - Loss of Function - Upper Limb or Table 17.9 - Loss of Function - Lower Limb, the conditions are bracketed for assessment purposes. The Table 20.5 rating is compared to the Table 17.1 or the Table 17.9 rating and the highest selected. For example, an entitled complete transection of the left ulnar nerve and an entitled complex regional pain syndrome of the left hand both require a rating. A rating for the complete transection of the left ulnar nerve is taken from Table 20.5 and a rating is taken from Table 17.1 for the complex regional pain syndrome of the left hand. The ratings are compared and the highest selected. The conditions are bracketed for assessment purposes.

In cases where the same limb is affected by two or more complete losses of nerve function, a rating is selected for each nerve. The individual ratings are added and the conditions bracketed for assessment purposes.

For peripheral nerve conditions that cannot be rated in Table 20.5, Table 17.1 or Table 17.9, a rating will be determined based on individual merits.

Note: Only one rating for each upper limb or for the lower limbs as a functional unit may be obtained from Table 17.1 and 17.9 respectively, regardless of the number of entitled musculoskeletal or neurological conditions rated within these tables.

If more than one musculoskeletal or neurological condition is rated from these tables, the conditions are bracketed for assessment purposes.

In cases of peripheral motor, sensory or mixed polyneuropathy which affects the function of both the upper and lower limbs, a rating is not obtained from this chapter or from Chapter 17, Musculoskeletal Impairment. The impairment is rated from Chapter 19, Activities of Daily Living.

If a Member/Veteran/Client has impairment of autonomic function associated with a peripheral neuropathy (e.g. voiding dysfunction) or has a permanent complication from peripheral neuropathy (e.g. Charcot's joint), a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

When entitled conditions of the peripheral nerves result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Table 20.4 - Loss of Function - Cranial Nerves

More than one rating may be applicable for each entitled unilateral or bilateral cranial nerve condition from Table 20.4. If more than one rating is applicable for an entitled condition, the ratings are added.

Note: Where applicable, Table 20.4 indicates the appropriate chapter or table to be used for rating cranial nerve conditions.

If partial losses exist, the ratings are to be reduced proportionately.

Table 20.4 - Loss of Function - Cranial Nerves
Cranial Nerve Function Apply Complete Unilateral Loss Rating Complete Bilateral Loss Rating
I (olfactory)

Smell

NIL

4

II (optic)

Vision

Chapter 8
III, IV, VI (oculomotor, trochlear, abducens)

Eye Movement

Chapter 8
V (trigeminal)

Opthalmic Division (sensory)

4

9

Maxillary Division (sensory)

4

9

Mandibular Division (sensory)

4

9

Chewing

Chapter 14

Speech

Table 20.2
VII (facial)

Taste

NIL

4

Facial Expression

9

18

Chewing

Chapter 14

Speech

Table 20.2
VIII (vestibulocochlear)

Hearing

Chapter 9

Balance

Chapter 9
IX, X, XI, XII (glossopharyngeal, vagus, spinal accessory, hypoglossal)

Swallowing

Table 20.9

Speech

Table 20.2
XI (spinal accessory)

Shoulder elevation/head rotation

4

9

Refer to Chart 1 for a description of the effects of a complete loss of function of a cranial nerve.

Steps to Determine Cranial Nerve Assessment

  • Step 1: Determine the rating from Table 20.4 (Loss of Function-Cranial Nerves).
  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3: Determine the Quality of Life rating.
  • Step 4: Add the ratings at Step 2 and Step 3.
  • Step 5: If partial entitlement exists, apply to the rating at Step 4.

This is the Disability Assessment.

Table 20.5 - Loss of Function - Peripheral Nerves

Only one rating may be given for each entitled unilateral peripheral nerve condition from Table 20.5.

In cases where the same limb is affected by two or more complete losses of nerve function, a rating is selected for each nerve. The individual ratings are added and the conditions bracketed for assessment purposes.

Note: A rating cannot be taken from both columns for the same peripheral nerve condition.

Table 20.5 - Loss of Function - Peripheral Nerves
Peripheral Nerve Rating - Complete Unilateral Loss of Function (Motor and Sensation) Rating - Complete Unilateral Loss of Function (Sensation Only)

Greater Auricular

N/A

1

Brachial Plexus: Upper Trunk (C5 and C6)

34

N/A

Brachial Plexus: Middle Trunk (C7)

34

N/A

Brachial Plexus: Lower Trunk (C8, T1)

34

N/A

Full Brachial Plexus (C5, C6, C7, C8, and T1)

65

N/A

Radial

43

2

Median

34

13

Ulnar

26

4

Musculocutaneous Nerve of the Arm

13

2

Axillary

18

2

Long Thoracic

4

N/A

Sciatic

51

9

Femoral

18

4

Obturator

4

NIL

Common Peroneal

18

4

Superficial Peroneal

9

3

Deep Peroneal

13

NIL

Tibial

18

4

Posterior Femoral Cutaneous

N/A

4

Lateral Cutaneous Nerve of the Thigh

N/A

4

Ilioinguinal

NIL

4

Refer to Chart 2 for a description of the effects of a complete loss of function of a peripheral nerve.

For peripheral nerve conditions that cannot be rated in Table 20.5, Table 17.1 or Table 17.9, a rating will be determined based on individual merits.

Steps to Determine Peripheral Nerve Assessment

  • Step 1: Determine the rating from Table 20.5 (Loss of Function - Peripheral Nerve).

Note: A rating cannot be taken from both columns of Table 20.5 for the same peripheral nerve condition.
If the same limb is affected by two or more complete losses of peripheral nerve function, a rating is selected for each nerve. The individual ratings are added and the conditions bracketed.

  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3: Determine the Quality of Life rating.
  • Step 4: Add ratings at Step 2 and Step 3.
  • Step 5: If partial entitlement exists, apply to rating at Step 4.

This is the Disability Assessment.

Note: If entitled bilateral peripheral nerve conditions require assessment, the steps must be repeated.

Chart 1 - Chart of Cranial Nerve Function

Chart 1 describes what functions are affected as a result of a complete loss of a cranial nerve's function at its origin, unless otherwise specified.

Chart 1 may be used as reference for rating loss of function of cranial nerves.

Chart 1 - Chart of Cranial Nerve Function
Cranial Nerve Functions Affected
I Olfactory
  • Motor
    • Nil
  • Sensory
    • Loss of sense of smell
II Optic
  • Motor
    • Nil
  • Sensory
    • Loss of vision
III Oculomotor
  • Motor
    • Eye movement - paralysis of internal rectus, superior rectus, inferior rectus, inferior oblique
  • Sensory
    • Nil
  • Clinical Presentation
    • Divergent strabismus, diplopia, ptosis of lid
    • Dilated pupil, loss of light and accommodation reflex
    • Eyeball deviated outward and slightly downward
IV Trochlear
  • Motor
    • Paralysis of superior oblique
  • Sensory
    • Nil
  • Clinical Presentation
    • Slight convergent strabismus
    • Cannot look down and out
    • May hold head tilted
    • Difficulty descending stairs
V Trigeminal
  • Motor (via mandibular branch)
    • Paralysis of muscles of mastication
    • Paralysis of tensor tympani may result in impaired hearing
  • Sensory
    • Face, sinuses, oral cavity, tongue, part of the ear and the eye
    • Corneal anesthesia may present early
    • 1st Division (opthalmic)
      • Sensory to forehead, upper eyelid, conjunctiva and side of the nose
    • 2nd Division (maxillary)
      • Sensory to posterior side of the nose, lower eyelid, cheek, upper lip and lateral side of the orbital opening including upper teeth and hard palate
    • 3rd Division (mandibular)
      • Sensory to lower lip and face, temporal regions and part of auricle
      • Muscles of mastication
      • Tensor tympani of the middle ear
  • Clinical Presentation
    • Jaw deviates to affected side
    • Impaired hearing
    • Loss of corneal reflex
VI Abducens
  • Motor
    • Paralysis of external or lateral rectus
  • Sensory
    • Nil
  • Clinical Presentation
    • Convergent strabismus and diplopia
    • Eyeball deviated inward
VII Facial
  • Motor (Bell's Palsy)
    • Paralysis of superficial muscles of the face and scalp
    • Disturbance in secretion of lacrimal and parotid glands
  • Sensory
    • Loss of taste from anterior 2/3 of tongue
  • Clinical Presentation
    • Facial asymmetry with smiling
    • Sagging of muscles of face and eyelid
    • Mouth droops
    • Unable to close eye or wrinkle forehead
    • Decreased salivation
VIII Vestibulocochlear
(Acoustic) (Auditory)
  • Motor
    • Nil
  • Sensory
    • Cochlear portion: deafness
    • Vestibular portion: disorders of equilibrium
  • Clinical Presentation
    • Cochlear portion: deafness, tinnitus
    • Vestibular portion: vertigo, nystagmus
IX Glossopharyngeal
  • Motor
    • Dysphagia
  • Sensory
    • Loss over posterior pharynx
  • Clinical Presentation
    • Loss of gag reflex
    • Orthostatic dizziness
X Vagus
  • Motor
    • Hoarseness, dysphagia
  • Sensory
    • Pain or paresthesia of larynx, pharynx
  • Clinical Presentation
    • Salivary gland dysfunction
    • Autonomic dysfunction of cardiopulmonary and gastrointestinal systems
XI Spinal Accessory
  • Motor
    • Absence of cervical rotation
    • Absence of shoulder elevation
  • Sensory
    • Nil
  • Clinical Presentation
    • Cannot rotate head to healthy side or shrug affected shoulder
    • May have some dysphagia systems
XII Hypoglossal
  • Motor
    • Paralysis of tongue
  • Sensory
    • Nil
  • Clinical Presentation
    • Tongue deviates to affected side with protrusion

Chart 2 - Chart of Peripheral Nerve Function

Chart 2 describes what functions are affected as a result of complete loss of a peripheral nerve's function at its origin, unless otherwise specified.

Chart 2 may be used as a reference for rating loss of function of peripheral nerves.

Chart 2 - Chart of Peripheral Nerve Function
Peripheral Nerve Functions Affected

Brachial plexus:
Upper Trunk
(C5 and C6)

(Erb Duchene palsy or waiter's tip)

  • Motor
    • Shoulder - loss of abduction, internal rotation, external rotation
    • Elbow - loss of flexion
  • Sensory
    • Incomplete loss over lateral aspect of arm and forearm
  • Clinical Presentation
    • Limb hangs limply at side, rotated medially.

Brachial Plexus:
Middle Trunk
(C7)

  • Motor
    • Rarely seen alone
    • Paralysis of the triceps
    • Elbow - loss of extension
    • Wrist - weak extension
    • Hands - weak extension
  • Sensory
    • Loss over radial aspect of forearm and hand

Brachial Plexus:
Lower Trunk
(C8 and T1)

(Klumpke's palsy)

  • Motor
    • Paralysis in all small muscles of hand
    • May cause Horner's syndrome (T1).
  • Sensory
    • Radial side of forearm, hand and ulnar two fingers
  • Clinical Presentation
    • "Claw" hand
    • Hyperextension MIP joints and flexion IP joint

Radial
(C6, C7, C8 and T1)

(musculospiral)

  • Motor
    • At axilla - paralysis
      • Elbow - loss of extension
      • Wrist - loss of extension
      • Fingers - loss of extension
      • Unable to grip firmly
    • At elbow
      • Elbow extension maintained
      • Loss of extension of wrist and fingers
  • Sensory
    • Posterior aspect arm and forearm
    • Lateral area dorsum of hand
  • Clinical Presentation
    • Thumb turned into palm

Median
(C6, C7, C8 and T1)

  • At Elbow
    • Motor
      • Wrist - weak flexion
      • Thumb - loss of flexion
      • Index and middle fingers - loss of flexion
    • Sensory
      • Loss over radial (lateral) aspect of palm
      • Loss over palmar aspect of the radial 3 1/2 fingers
      • Total loss over tips of index and middle fingers
    • Clinical Presentation
      • Hand looks flattened or "apelike".
      • Atrophy of lateral forearm and thenar eminence
      • Thumb at side of palm
  • At Wrist
    • Motor
      • Thumb - cannot be opposed.
      • Fingers - decreased ability to abduct
    • Sensory
      • As at elbow
    • Clinical Presentation
      • Thenar atrophy

Ulnar
(C8, T1)

  • Above Elbow
    • Motor
      • Wrist - flexion weak with hand deviating to radial (lateral) side
      • Fingers - loss of flexion PIP joints;
        loss of adduction;
        loss of abduction
      • Thumb - loss of adduction
    • Sensory
      • Loss over ulnar (medial) portion of hand and ring finger; entire little finger
    • Clinical Presentation
      • "Claw" hand or "main en griffe"
      • Ring and little finger hyperextended at MTP and flexed at PIP joints
      • Atrophy medial aspect of forearm and hypothenar eminence
  • Below Elbow
    • Motor
      • Wrist - flexion maintained
      • Finger and thumbs as above

Musculocutaneous nerve of the arm
(C5 and C6)

  • At Elbow
    • Motor
      • Weakness in flexion and supination
    • Sensory
      • Loss over lateral side of forearm

Axillary

(circumflex)

  • Motor
    • Shoulder - weakness of flexion, extension and initiation of abduction
    • Difficulty raising to horizontal position
  • Sensory
    • Loss of sensation over lower half of deltoid muscle
  • Clinical Presentation
    • Wasting over the shoulder

Long thoracic
(C5, C6, C7)

  • Motor
    • Shoulder - weakness in elevation beyond horizontal plane. Cannot raise arm above head.
  • Sensory
    • Nil
  • Clinical Presentation
    • Winged scapula

Sciatic
(L4, L5, S1, S2, S3)

  • Motor
    • At knee
      • Loss or weakness of flexion
    • At ankle, foot and toes
      • Complete paralysis
  • Sensory
    • Pain often present
    • Loss over posterior and lateral aspects of leg and foot
  • Clinical Presentation
    • Foot drop
    • Walks with steppage gait: lifts foot high
    • Unable to stand on heel or toes

Femoral
(L2, L3, L4)

(anterior crural)

  • Motor
    • Hip - loss of flexion
    • Knee - loss of flexion
  • Sensory
    • May be pain
    • Loss over medial side of thigh, leg and foot
  • Clinical Presentation
    • May steady thigh with hand when walking

Obturator
(L2, L3, L4)

  • Motor
    • Hip - weakness of external rotation and adduction
  • Sensory
    • Usually insignificant
    • Minimal loss over medial side of thigh

Common Peroneal
(L4, L5, S1, S2)

(external popliteal)
(lateral popliteal)

  • Motor
    • Ankle and toes - loss of dorsiflexion
  • Sensory
    • Loss over lateral aspect of leg, foot and toes
  • Clinical Presentation
    • Foot drop and steppage gait
    • Foot plantar flexed and inverted (equinovarus)

Superficial Peroneal
(L5, S1)

(musculocutaneous nerve of the leg)

  • Motor
    • Foot - weakness or loss of eversion
  • Sensory
    • Dorsal and lateral surface of leg

Deep Peroneal

(anterior tibial)

  • Motor
    • Ankle and toes - loss of dorsiflexion
  • Sensory
    • Loss over 1st webspace of the foot

Tibial
(L4, L5, S1, S2, S3)

(posterior tibial internal popliteal)

  • Motor
    • Foot - loss of plantar flexion, adduction and inversion
  • Sensory
    • Causalgia common
    • Loss over sole of the foot
  • Clinical Presentation
    • Toes separated
    • Ankle dorsiflexed

Posterior Femoral Cutaneous
(S1, S2, S3)

(small sciatic nerve)

  • Sensory
    • Loss over perineum and posterior surface of the thigh and leg

Lateral Cutaneous nerve of the thigh
(L2, L3)

  • Sensory (meralgia paresthetica)
    • Loss over the lower lateral quadrant of the buttock
    • Loss over the lateral aspect of the thigh and knee

Ilioinguinal
(L1)

  • Sensory
    • Loss over perineum and upper medial thigh

Section 3 - Determining Impairment Assessments of Seizure Disorders, Narcolepsy and Cataplexy, Headache Conditions and Miscellaneous Neurological Conditions

The tables used to rate impairment from seizure disorders, narcolepsy and cataplexy, headache conditions and miscellaneous neurological conditions are:

Section 3 - Determining Impairment Assessments of Seizure Disorders, Narcolepsy and Cataplexy, Headache Conditions and Miscellaneous Neurological Conditions
Table Loss of Function Other Impairment
Table 20.6 Other Impairment - Seizures This table is used to rate impairment from seizure disorders - major and minor.
Table 20.7 Other Impairment - Narcolepsy and Cataplexy This table is used to rate impairment from narcolepsy and cataplexy.
Table 20.8 Other Impairment - Headaches This table is used to rate impairment from headache conditions.
Table 20.9 Other Impairment - Miscellaneous Neurological This table is used to rate impairment from miscellaneous neurological conditions.

Other Impairment - Seizures

Table 20.6 is used to rate impairment from seizure disorders. Only one rating may be selected. If more than one rating is applicable, the ratings are compared and the highest selected.

If more than one type of seizure disorder is to be rated from Table 20.6, the conditions are bracketed for assessment purposes.

When entitled seizure disorders result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Other Impairment - Narcolepsy and Cataplexy

Table 20.7 is used to rate impairment from narcolepsy and cataplexy. Only one rating may be selected. If more than one rating is applicable, the ratings are compared and the highest selected.

When entitled narcolepsy and cataplexy disorders result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Other Impairment - Headaches

Table 20.8 is used to rate impairment from headache conditions. Only one rating may be selected. If more than one rating is applicable, the ratings are compared and the highest selected.

If more than one type of headache is to be rated from Table 20.8, the conditions are bracketed for assessment purposes.

When rating migraine headaches, common auras such as scotomas and flashing lights are considered to be included in the Table 20.8 rating. Migraine headaches associated with transient neurological deficits including but not limited to hemiplegia, dysarthria and ocular muscle weakness are rated on individual merits.

When entitled headache conditions result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Other Impairment - Miscellaneous Neurological Conditions

Table 20.9 is used to rate impairment from miscellaneous neurological conditions. One rating may be selected for each entitled condition. If more than one rating is applicable for an entitled condition, the ratings are compared and the highest selected.

When entitled miscellaneous neurological conditions result in permanent impairment of other organ systems, a consequential entitlement decision is required. If awarded, the resulting impairment of that organ system(s) will be rated using the applicable body system specific table(s).

If non-entitled conditions or conditions rated within another chapter/table of the Table of Disabilities are contributing to the overall impairment, then the Partially Contributing Table (PCT) must be applied to arrive at the rating which is due to the entitled condition(s) rated within this table.

Table 20.6 - Loss of Function - Seizures

Only one rating may be given from Table 20.6. If more than one rating is applicable, the ratings are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.6, follow the "ands" and "ors".

Table 20.6 - Loss of Function - Seizures
Rating Criteria
Nil
  • Remote history of seizures with none in the previous 5-year period; and
  • No anti-convulsive medication required; and
  • No protective equipment required; and
  • No requirement for supervision.
Four
  • Remote history of seizures with none in the previous 5-year period; and
  • Regular anti-convulsive medication required.
Nine
  • An average of less than one major* seizure per year in the previous 5-year period; or
  • An average of less than one minor** seizure per week in the previous 12-month period; and
  • Regular anti-convulsive medication required.
Eighteen
  • One major* seizure in the previous 12-month period; or
  • One minor** seizure per week in the previous 12-month period; and
  • Regular anti-convulsive medication required.
Thirty-five
  • More than one major* seizure in the previous 12-month period but averages less than one major* seizure per month; or
  • Two to five minor** seizures per week in the previous 12-month period; or
  • Requires supervision for certain activities (eg. swimming); and
  • Regular anti-convulsive medication required.
Fifty
  • Averages one major* seizure per month in the previous 12-month period; or
  • Five to ten minor** seizures per week in the previous 12-month period; or
  • Requires protective equipment for safety reasons most of the time (eg. helmet); and
  • Regular anti-convulsive medication required.
Eighty-five
  • Averages more than one major* seizure per month in the previous 12-month period; or
  • More than 10 minor** seizures per week in the previous 12-month period; or
  • Requires constant supervision; and
  • Regular anti-convulsive medication required.

* A major seizure is characterized by generalized tonic-clonic convulsion with unconsciousness.

** A minor seizure is characterized by a brief interruption in consciousness or conscious control associated with staring, rhythmic eye blinking, or head nodding, or sudden jerking movements of the limbs and/or head, or sudden loss of postural control.

Steps to Determine Seizure Assessment

  • Step 1: Determine the rating from Table 20.6 (Other Impairment - Seizures).
  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3: Determine the Quality of Life rating.
  • Step 4: Add the ratings at Step 2 and Step 3.
  • Step 5: If partial entitlement exists, apply to the rating at Step 4.

This is the Disability Assessment.

Table 20.7 - Other Impairment - Narcolepsy and Cataplexy

Only one rating may be given from Table 20.7. If more than one rating is applicable, the ratings are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.7, follow the "ands" and "ors".

Table 20.7 - Other Impairment - Narcolepsy and Cataplexy
Rating Criteria
Four
  • Narcoleptic attacks requiring no medication or intermittent use of medications; or
  • Cataplectic attacks requiring no medication or intermittent use of medications.
Nine
  • Narcoleptic attacks requiring continuous use of medications; or
  • Cataplectic attacks requiring continuous use of medications.
Thirteen
  • Narcoleptic attacks requiring continuous use of medications; and
  • Cataplectic attacks requiring continuous use of medications.
Eighteen
  • Narcoleptic attacks and/or cataplectic attacks requiring continuous use of medications; and
  • Narcoleptic and/or cataplectic attacks which impact on the safety of self or others, despite continuous medications.

Steps to Determine Narcolepsy/Cataplexy Assessment

  • Step 1: Determine the rating from Table 20.7 (Other Impairment - Narcolepsy and Cataplexy).
  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3: Determine the Quality of Life rating.
  • Step 4: Add the ratings at Step 2 and Step 3.
  • Step 5: If partial entitlement exists, apply to the rating at Step 4.

This is the Disability Assessment.

Table 20.8 - Loss of Function - Headaches

Only one rating may be given from Table 20.8. If more than one rating is applicable, the ratings are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.8, follow the "ands" and "ors".

Table 20.8 - Loss of Function - Headaches
Rating Criteria
Two
  • Headache experienced less than 30 days per year. Bed rest not required or may be occasionally required
Four
  • Headache experienced less than 30 days per year. Bed rest is required during most episodes; or
  • Headache experienced 30 - 100 days per year. Bed rest not required or may be occasionally required.
Nine
  • Headache is experienced 30 - 100 days per year or headache is experienced on a weekly basis and bed rest is required during most episodes; or
  • Headache experienced on more than 100 days per year or lasts for at least two consecutive days on a weekly basis or headache is constant and unremitting. Bed rest not required or may be occasionally required
Thirteen
  • Headache experienced on more than 100 days per year or lasts for at least two consecutive days on a weekly basis or headache is constant and unremitting. Bed rest is required during most episodes.

Migraine headaches associated with transient neurological deficits including but not limited to hemiplegia, dysarthria and ocular muscle weakness is rated on individual merits.

Steps to Determine Headache Assessment

  • Step 1: Determine the rating from Table 20.8 (Other Impairment - Headaches).
  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3: Determine the Quality of Life rating.
  • Step 4: Add the ratings at Step 2 and Step 3.
  • Step 5: If partial entitlement exists, apply to the rating at Step 4.

This is the Disability Assessment.

Table 20.9 - Other Impairment - Miscellaneous Neurological

Only one rating may be given for each entitled condition from Table 20.9. If more than one rating is applicable for an entitled condition, the ratings are compared and the highest selected.

Each bullet (•) represents one criterion. In order for a rating to be established for Table 20.9, only one criterion must be met at a level of impairment for that rating to be selected.

Table 20.9 - Other Impairment - Miscellaneous Neurological

Rating Tables
Rating Criteria
Four
  • Documented cerebrovascular disease e.g. history of recurrent transient ischemic attacks; or
  • Cerebral aneurysms not surgically repaired; or
  • Facial tics (i.e. hemifacial spasm); or
  • Intermittent trigeminal neuralgia* (tic douloureux); or
  • Dysphagia from a neurological condition requiring avoidance of certain foods.
Nine
  • Trigeminal neuralgia* (tic douloureux) on most days.
Thirteen
  • Dysphagia with choking on liquids or semi-solid foods on a frequent basis.
Thirty-four
  • Dysphagia with nasal regurgitation or aspiration on a frequent basis.
Seventy-one
  • Dysphagia with inability to handle oral secretions without choking, requiring assistance and suctioning.

* Trigeminal neuralgia with intractable pain (severe, persistent, ongoing pain that is unresponsive to the usual treatment modalities) is rated on individual merits.

Steps to Determine Miscellaneous Neurological Assessment

  • Step 1: Determine the rating from Table 20.9 (Other Impairment - Miscellaneous Neurological).
  • Step 2: Does the Partially Contributing Table apply? If yes, then apply to rating at Step 1.
  • Step 3: Determine the Quality of Life rating.
  • Step 4: Add the ratings at Step 2 and Step 3.
  • Step 5: If partial entitlement exists, apply to the rating at Step 4.

This is the Disability Assessment.

Note: If more than one entitled condition requires rating from Table 20.9, the steps must be repeated.

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