Assessing Neurological Disability

Corina Azores-Macalintal, M.D., F.P.N.A

Questions

 When is the patient neurologically disabled?

 What kind of neurological disabilities does neurological diseases brings?

Disability

 Definition:  Inability to engage in any substantial gainful activity by reason of any medically determined physical or mental impairment(s) which can be expected to result to death or which has lasted or can be expected to last for a continuous period of time.

When is the patient neurologically disabled?

 Mental/ cognitive  Visual / auditory  Motor  Sensory  Balance and Coordination  Gait

Mental Disability

 Language dysfunction (Aphasia)  Executive dysfunction  Memory dysfunction

Aphasia

 Acquired impairment of comprehension and production of verbal language caused by brain damage.

 Alexia and agraphia often co-exist with aphasia

Aphasia

 Four areas of language functioning  Auditory comprehension  Repetition  Fluency of verbal expression  Confrontation naming

 Non-fluent      Broca’s Transcortical motor Global Mixed Transcortical Fluent  Wernicke’s    Transcortical sensory Conduction Anomic

Aphasia

 Auditory comprehension     Asyntactic Can be asyntactic Severe impairment and Retain prosody     Like global Milder than global Asyntactic intact

 Non-fluent     Broca’s Transcortical motor Global Mixed Transcortical  Fluent  Wernicke’s    Transcortical sensory Conduction Anomic

Aphasia

 Verbal expression     Agrammatism, aprosodia, apraxia of speech, poor repetition Poor initiation, elaboration, intact repetition,echolalia Limited to automatisms, stereotypies, poor repetition Limited spontaneous, intact repetition, echolalia  Nonmeaningful logorrhea, anosognosia   Intact repetition, echolalia Conduit d’approche, poor repetition  Pauses for word retrieval, intact repetition

 Non-fluent      Broca’s Transcortical motor Global Mixed Transcortical Fluent  Wernicke’s  Transcortical sensory   Conduction Anomic

Aphasia

 Typical word retrieval errors     Semantic, verbs worse than nouns No response, perseverations Stereotypies, semantic Stereotypies, semantic     Neogolisms, semantic, phonemics Semantic, phonemic, circumlocutions Phonemics, semantic Circumlocutions, no response, semantic, nouns worse than verbs

 Non-fluent      Broca’s Transcortical motor Global Mixed Transcortical Fluent  Wernicke’s  Transcortical sensory   Conduction Anomic

Aphasia

 Left Hemisphere lesion locations     Inf. Frontal, operculum Dosolateral frontal, or thalamus Large pre-rolandic + post rolandic Watershed/ extrasylvian cortex   Superior temporal Temoral-parietal or degenerative   Parietal, insula Inferior temporal or thalamus or degenerative

Executive Dysfunction

 Impairments in initiation, intention, planning, sequencing, inhibition, flexibility, monitoring and various complex aspects of attention

Memory Dysfunction

 MCI  Dementia

Dementia

 Memory impairment (learning and recall)  One or more:  Aphasia  Apraxia  Agnosia  Dysexecutive function (planning, organizing, sequencing, abstracting) *** deficits of sufficient severity to affect social or occupational functioning

Limb Apraxia

 Impaired ability to perform skilled, purposeful limb movements as a result of neurologic dysfunction ***excluding weakness, akinesia, abnormalities of tone or posture and movement disorders

 Type  Limb-kinetic  Ideomotor

Limb Apraxia

 Clinical features   Impaired ability to make finem precise, independent finger movements Gesture production errors  Ideational  conceptual  Impaired sequencing of tool use  Content errors in tool use, errors in tool selection

 Type  Limb-kinetic  Ideomotor  Ideational  conceptual

Limb Apraxia

 Assessment tasks  Rotate coin between thumb and fingers  Gesture to command, gesture imitation  Serial acts (e.g. fold letter place in envelope, seal, stamp)  Tool-object matching (hammer and nail)

Assessment Tools

Mini Mental State Examination (MMSE)

 Orientation  Registration  Attention and Calculation  Recall  Language

Neuropsychological Testing

 Comprehensive examinations may be used to establish the existence and extent of compromise of brain function

Neuropsychological Testing

      Cerebral dominance basic sensation and perception motor speed and coordination, attention and concentration, visual-motor function memory across verbal and visual modalities      Receptive and expressive speech Higher-order linguistic operations Problem-solving Abstraction ability General intelligence

Neuropsychological Testing

 Should include evaluating pathological features as:  Emotional lability  Abnormality of mood  Impaired impulse control  Passivity and apathy  Inappropriate social behavior

Criteria for Organic Mental Disorder

A. Loss of specific cognitive abilities and medically documented persistence of at least one of the FF:        Disorientation to time and place, or Memory impairment (short-term, intermediate, or long term), or Perceptual or thinking disturbances (e.g. hallucinations, delusions, or Change in personality, or Disturbance in mood, or Emotional lability (e.g. explosive temper outbursts, sudden crying…) and impairment of impulse control Loss of measured intellectual ability of at least 15 I.Q points from premorbid levels or severely impaired range on neuropsychological testing

And B. Resulting in at least two of the following  Marked restriction of activities of daily living; or  Marked difficulties in maintaining social functioning; or  Marked difficulties in maintaining concentration, persistence, or pace; or  Repeated episodes of decompensation, each of extended duration

Or C. Medically documented history of chronic organic mental disorder of at least 2 years and one of the following:  Repeated episodes of decompensation, each of extended duration  A residual disease process that has resulted in such marginal adjustment that even a minimal increase in mental demands or change in the environment would be predicted to cause the individual to decompensate

 Current history of 1 or more years’ inability to function outside a highly supportive living arrangement, with an indication of continued need for such an arrangement

 Presentations:  Visual loss/blurring  Visual field defects (anopsia)

Visual

 Assessment  Field testing  Fundoscopy  Visual acuity test (Snellen)  VEP

 Presentation:  Deafness  Tinnitus  Dizziness

auditory

 Assessment  Weber, Rinne’s  Audiogram  BAER

 Motor, sensory, balance, coordination and gait disabilities = disorganization of motor function

Disorganization of Motor function

 In the form of paresis or paralysis, tremor or other involuntary movements, ataxia, sensory disturbances which may occur singly or in various combinations

Disorganization of Motor function

 Assessment of impairment depends on the degree of interference with locomotion and/or interference with the use of fingers, hands and arms.

Assessment

 Motor Strength  Sensory  Light touch, pressure, heat / cold, proprioception *** abnormal sensation as dysaesthesia, allodynia, hyperaesthesia

Assessment

 Balance, coordination and gait  Finger to nose test / heal to shin test  Tandem walking

Category of Neurological Impairments

Convulsive Seizure

 Degree of impairment  Determined according to type, frequency, duration and sequelae  At least 1 detailed description of a typical seizure  Presence of associated signs/ symptoms  Documentation with at least 1 EEG

Convulsive seizure

 Only if impairment persists despite treatment  Blood levels of anticonvulsant medications  Compliance to anticonvulsant medication  Idiosyncrasy in absorption or metabolism  Use of alcohol or drug interactions

Convulsive Seizure

 Category of impairments:  Major motor seizures: (grand mal or psychomotor)  Occuring > 1 / month, in spite of at least 3 months of prescribed treatment with:  Daytime episodes  Nocturnal episodes with residuals ( significantly interfering with activity during the day)

Convulsive Seizure

 Minor motor seizures: (petit mal, psychomotor or focal)  > 1x / week in spite of at least 3 months of prescribed treatment  With alteration of consciousness and transient postictal manifestations of conventional behavior or significant interference with activity during the day

Vascular Accidents

(> 3 most post=vascular accident)  Sensory or motor aphasia resulting in ineffective speech or communication; or  Significant or persistent disorganization of motor function in two extremities, resulting in sustained disturbances of gross and dexterous movements, or gait and station.

 Depends on the degree of interference with locomotion and/or interference with the use of fingers, hands and arms

Brain Tumors

 Definitive diagnosis  Histologically malignant tumor – pathological diagnosis alone will be the decisive criterion for severity and expected duration  Other tumors – severity and duration of the impairment will be determined on the basis of symptoms, signs and pertinent laboratory findings  Persistence of the tumor

Brain tumors

 The site of primary, recurrent and metastatic lesion must be specified- in malignant neoplastic diseases  Operative procedure or hospitalization with findings of surgery and results of pathologist’s gross and microscopic examination of tissues

Brain Tumors

 Maligant gliomas( astrocytomas grades III IV, glioblastoma multiforme) medulloblastoma, epenymoblastoma, primary sarcoma) or  Astrosarcoma (grades I-II), meningioma, pituitary tumors, oligodendroglioma, epndymoma, clivus chordoma and benign tumors

Brain Tumors

 Assessment based on:  Secondary Epilepsy, major or minor  > 3 months of  Sensory or motor aphasia  Significant or persistent disorganization of motor function  Secondary mental disorders

Parkinsonian syndrome

 Significant rigidity, bradykinesia or tremor in two extremities which singly or in combination, result in sustained disturbance of gross and dexterous movements, or gait and station

Cerebral Palsy

 IQ of 70 or less; or  Abnormal behavior patterns, as destructive or emotional instability  Significant interference in communication due to speech, hearing or visual defect; or  Disorganization of motor functions

Spinal cord or nerve root lesions

 Disorganization of motor function

Other Episodic conditions

 Multiple sclerosis/ myasthenia gravis  Frequency and duration of exacerbation  Length of remissions  Permanent residuals

Multiple Sclerosis

I. Disorganization of motor function  Significant and persistent disorganization of motor function in two extremities, resulting in sustained disturbance of gross and dexterous movements, or gait and station

Multiple Sclerosis

II. Visual impairments  Impairment of central visual acuity  Contraction of peripheral visual fields in the better eye  Loss of visual efficiency

Multiple Sclerosis

III. Mental impairments  History and PE or laboratory tests demonstrate the presence of a specific organic factor judged to be etiologically related to the abnormal mental state and loss of previously acquired functional abilities

Multiple Sclerosis

IV. Significant reproducible fatigue of motor function with substantial muscle weakness on repetitive activity, demonstrated of PE with CNS correlation - use of assessment scale - evoke response tests during exercise

Myasthenia Gravis

 Significant difficulty with speaking, swallowing or breathing while on prescribed therapy; or  Significant motor weakness of muscles of extremities on repetitive activity against resistance while on prescribed therapy

Amyotrophic lateral sclerosis

 Significant bulbar signs  Disorganization of motor function

Anterior Poliomyelitis

 Persistent difficulty with swallowing or breathing  Unintelligible speech  Disorganization of motor function

Muscular Dystrophy

 Disorganization of motor function

Tabes Dorsalis

 Tabetic crisis occuring more frequently than once monthly; or  Unsteady, broad based or ataxic gait causing significant restriction of mobility substantiated by appropriate posterior column signs

Subacute combined cord Degeneration

 Disorganization of motor function, not significantly improved by prescribed treatment

Degenerative disease

(Huntington’s chorea, Friedreich’s ataxia, and Spino cerebellar degeneration, Alzhiemer’s dementia…)  Disorganization of motor function  Chronic brain syndrome

Traumatic Brain Injury

 May result in neurological and mental impairments with a wide variety of posttraumatic s/sx  May need to defer adjudication of the claim at least 6 months post-injury

Traumatic Brain Injury

 Evaluated according to:  Secondary seizure  Secondary motor or sensory aphasia  Significant or persistent disorganization of motor function  Cognitive dysfunction