• see Psychiatry, PS24

4 As and one Dof AD

Anterograde amnesia

Aphasia

Apraxia

Agnosia

Disturbance in executive function

(Anterograde amnesia plus at least one

of the other features is required for AD

diagnosis)

Definition

• beyond criterion for NCD, the core features of AD include an insidious onset and gradual progression

of cognitive and behaviouralsymptoms

• typical presentation: amnestic

mild phase:impairment in memory and learning sometimes accompanied with deficits in

executive function

• moderate-severe phase: visuoconstructional/perceptual-motor ability and language may also be

impaired

• social cognition tends to be preserved until late in the course of the disease

• atypical nonamnestic presentation (one of the following):

1.language:aphasia, word-finding difficulty

2. visuospatial:object agnosia, prosopagnosia,simultanagnosia, alexia, limb apraxia

3. executive: reasoning, judgment, and problem-solving are affected

Pathophysiology

• genetic factors

minority (<1%) of AD cases are familial (autosomal dominant), associated with early onset AD

(<65 yr)

• 3 major genes, responsible for 5-10% of early onset AD cases,for autosomal dominant AD have

been identified:

amyloid precursor protein (chromosome 21),presenilin 1 (chromosome 14), presenilin 2

(chromosome 1)

the E4 polymorphism of APOE is a susceptibility genotype (e2 is protective)

note: APOE cannotserve as a diagnostic marker because it is only a risk factor and neither

necessary norsufficient for disease occurrence

• pathology (not necessarily specific for AD)

gross pathology

diffuse cortical atrophy, especially frontal, parietal,and temporal lobes(hippocampi)

microscopic pathology

senile p-amyloid plaques (extracellular deposits of amyloid in the grey'matter of the brain)

loss ofsynapses

neurofibrillary tangles(intracytoplasmic paired helical filaments with amyloid and

hyperphosphorylated tau protein)

loss of cholinergic neurons in the nucleus basalis of Meynert that project diffusely throughout

the cortex

biochemical pathology

50-90% reduction in action of choline acetyltransferase

Epidemiology

• 1/12 of population 65-75 yr

• up to 1/3 population >85 yr

• very rare <65 yr

• accounts for 60-90% of all dementias (depending on setting and diagnostic criteria)

Risk Factors

• age is the greatest risk factor

• genetic susceptibility polymorphism:APOE c4 increases risk and decreases age of onset

• other factors include:TBI, family history, Down syndrome,low education, and vascular risk factors

(e.g.smoking, HTN, hypercholesterolemia, DM)

Clinical Features

• cognitive impairment

• memory impairment for newly acquired information (early)

deficits in language, abstract reasoning, and executive function

• behavioural and psychiatric manifestations (80% of those with major NCD)

mild NCD:major depressive disorder and/or apathy

• major NCD: psychosis, irritability, agitation, combativeness, and wandering

• motor manifestations(late)

gait disturbance, dysphagia, incontinence, myoclonus, and seizures

Investigations

• perform investigations to rule out other potentially reversible causes of dementia

• EEC: usually normal in mild-moderate stages,slow waves in moderate-advanced stages.May observe

generalized slowing (nonspecific)

• MR1: preferential atrophy of the hippocampi and precuneus of the parietal lobe:dilatation of lateral

ventricles; widening of cortical sulci

Down syndrome predisposes to early

onset of AD fi.e. age of ~40) due to three

copiesof the amyloid gene (amyloid

precursor protein)

Vitanin E and Doaepebl far the Treatment of Mild

Cognitive Impsinnent

IEIM 2005:3522379-88

Purpose:In investigate the eScacy ofrtarnir Eor

dorepeal ia sievingthe progresses ofMl ia paSects

with rrri!d cognitive impairment

Methods:Patientsnrittr ttie asaesiic sstitype of

mild cognitive apartment were randomly assigned

toreceive vrtasnaE(2000IIIdaily),donepezi (10 ng

daily),or placet»!cr 3yr.

tesilts;DonepezL tart aot vitaminE.reducedtie

Hrettood of progression toIDdiringSefirst12

mo(P41.04).bot neither dooepeslcor- tiarasE

significantly redacedtheiikelhood of progression

to AD after 3 yr

Condisioo Athough donepezi:redcced tierate

of progressionaM) daring tieSrstCmo.dbadno

sigaiScait effect after 3 yr

See Landmart leirology TrialtaSefor more

Wotmaimoa Are CATIE-SD trial.liretrial

aaminedthe eflectsof timeaodtreatment oa

oeoropsyckoJogica!fsnctiocmgduring the CHaical

Aatrpsyctotic Inalsof die InterventionESecSienessAtzPermer’sDiseasestudy

r »

+

Activate Windows

GoToSettTrigstoactival

N25 Neurology Toronto Notes 2023

•SPECT: hypoperfusion in temporal and parietal lobes

•PET imaging using Pittsburgh compound B (P1B) as a tracer enables imaging of (1-amyloid plaque in

neuronal tissue

• FDG-PET can be used to identify regional patterns of cortical hypometabolism and can be helpful

to distinguish AD from other causes of dementia (e.g. FTD, DLB)

•LP: p-amyloid protein can be measured in CSP

•Note: common investigationsin a clinicalsetting include ruling out reversible causes with Woodwork,

CSP studies, and MR1 brain ± EEG.The remainder of the tests are lessfrequently done or done so in a

research setting

Treatment

•acetylcholinesterase inhibitors(donepezil,rivastigmine,galantamine) slow the decline in cognitive

function

•do not prolong life expectancy but reduce morbidity

•relative contraindications: bradycardia, heart block, arrhythmia,CHF, CAD, asthma,COPD, ulcers,or

risk factors for ulcers and/or G1 bleeding

•galantamine is contraindicated in patients with hepatic/renal impairment

•memantine is an NMDA-receptor antagonist that hassome benefitsin later stage AD (i.e. when MMSE

<17)

•behavioural symptom management

1. pharmacologic

low dose neurolepticsfor agitation (neuroleptics may worsen cognitive decline)

trazodone for sleep disturbance

antidepressants(SSRls)

2. non-pharmacologic

redirection

explore inciting factorsfor behaviour and modify behaviour of patient or caregiver

family support and daycare facilities

Prognosis

•mean duration ofsurvival after diagnosis is approximately 10 yr, reflecting the advanced age of the

majority of individuals rather than the course of the disease

•death commonly resultsfrom aspiration

Major or Mild Neurocognitive Dementia with Lewy Bodies

(formerly Dementia with Lewy Bodies)

Definition

• NCD characterized by progressive cognitive impairment(with early changesin complex attention,

executive, and visuospatial function) and recurrent complex visual hallucinations

• core diagnostic features(a diagnosis of probable DLB must have at least two core features,one is

essential for possible DLB)

fluctuating cognition with pronounced variationsin attention and alertness

recurrent visual hallucinationsthat are well formed and detailed

one or more spontaneous cardinal features of parkinsonism (bradykinesia, rest tremor,or

rigidity) with onset subsequent to development of cognitive decline

REM sleep behaviour disorder

• suggestive/supportive features

severe sensitivity to neuroleptic medications(rigidity, neuroleptic malignantsyndrome,

extrapyramidal symptoms)

repeated falls,syncope, or transient episodes of unexplained loss of consciousness

auditory or other non-visual hallucinations,systematic delusions, and depression

Etiology and Pathogenesis

• Lewy bodies (eosinophilic cytoplasmic inclusions) found in both cortical and subcortical structures

• mixed DLB and AD pathology is common

Diagnostic Features

• indicative

« low striatal dopamine transporter uptake on SPEC1or PET

• supportive

relative preservation of medial temporal structures on CT/MRI

generalized low uptake on SPECT/PET perfusion scan with reduced occipital atrophy

abnormal (low uptake) 123-l-metaiodobenzylguanidine (M1BG) myocardial scintigraphy

prominent slow wave activity on EEG with temporal lobe transientsharp waves

Epidemiology

• 0.1-5% of the general elderly population

• Lewy bodies are present in 20-35% of all dementia cases (more common in males)

n

c

+

Activate Windows

Go to Settings To activate Windows.

N26 Neurology Toronto Notes 2023

Treatment

• only symptomatic treatments available

• cognitive symptoms: acetylcholinesterase inhibitors(e.g. donepezil and rivastigmine)

• REM sleep behaviour disorder: melatonin, clonazepam (use with caution in patients with cognitive

impairment and gait disorders)

Prognosis

• average duration ofsurvival 5-7 yr

Major or Mild Frontotemporal Neurocognitive Dementia

(formerly Frontotemporal Dementia)

Definition

• group of disorders caused by progressive cell degeneration in the brain'

s frontal or temporal lobes

deficits in executive function (e.g. poor mental flexibility, abstract reasoning, response inhibition,

planning/organization, increased distractibility) with relative sparing of learning,memory, and

perceptual-motor function

• “probable” is distinguished from “possible" frontotemporal NCD by:

evidence of causative frontotemporal NCD genetic mutation,from either family history or genetic

testing

evidence of disproportionate frontal and/or anterior temporal atrophy on MR1 orCT

evidence of frontal and/or anterior temporal hypoperfusion or hypometabolism on PET or SPEC1’

Behavioural Variant FTD

• most common variant

• insidious onset: must show progressive deterioration of behaviour and/or cognition by observation or

history

• typically early symptom presentation (i.e. within the first 3yr)

• at least 3/5 of the following symptoms must be present and persistent/recurrent:

behavioural disinhibition (socially inappropriate behaviour, impulsive, careless)

apathy or inertia (decreased initiation or continuation of behaviour, requiring cues/prompts,less

likely to initiate or sustain conversations)

loss of sympathy or empathy (diminished response to others’ needs/feelings,social interest)

preservative,stereotyped, or compulsive/ritualistic behaviour

hyperoralitv and dietary changes (binge eating, increased consumption of alcohol/cigarettes or

inedible objects)

Language Variants (Primary Progressive Aphasia)

• prominent decline in language ability, in the form ofspeech production, word finding,object naming,

grammar, or word comprehension

• three subtypes

nonfluent/agrammatic variant PPA (NEAV-PPA) or progressive nonfluent aphasia (PNl-

'

A):

non-fluent,laboured articulation/speech, anomia, preserved single word comprehension,wordfinding deficit,impaired repetition

• semantic variant PPA (SV-PPA) orsemantic dementia (SD):fluent, normal rate, anomia,

impaired single word comprehension, intact repetition, use words of generalization (“thing") or

supraordinate categories (“animal” for “dog”)

logopenic progressive aphasia (LPA): naming difficulty and impaired repetition

FTD Movement Disorders

• corticobasal degeneration (CBD) (see Parkinson'

s Disease, N33)

• progressive supranuclear palsy ( PSP) (see Parkinson'

s Disease, N33)

Etiology and Pathogenesis

• unknown, however there islikely a genetic/familial component (40% have family history of early onset

NCD)

• genetic variants:MAPI gene (tau), PGRN gene (progranulin), VCP gene, TARDBP gene (TDP-43),

CHMP2D gene, C90RE72 gene (associated with ETD-ALS)

• unlike AD, ETD does notshow amyloid plaques or neurofibrillary tangles,instead it is characterized

by severe atrophy and specific neuronal inclusion bodies

• gross changes: atrophy in the frontal and anterior temporal lobes, cortical thinning, possible

ventricular enlargement

• histological changes:gliosis,swollen neurons, microvacuolation, inclusion bodies in neurons/glia (Tau

or TDP- 43)

Epidemiology

• 4th most common cause of dementia (5% of all dementia cases)

• common cause of early-onset NCD in individuals <65 yr

Prognosis

• median survival being6-11 yr after symptoms onset and 3-4 yr after diagnosis

• survival is shorter and decline isfaster than in typical AD

+

Activate Windows

Go to Settings to activate Windows.

N27 Neurology Toronto Notes 2023

Major or Mild Vascular Neurocognitive Dementia

Definition

• dia.gnosis of major or mild NCD with determination of CVD asthe dominant if not exclusive

pathology that accounts for the cognitive deficits

• vascular etiology suggested by one of the following:

» onset of cognitive deficits is temporally related to one or more cerebrovascular events

evidence for decline is prominent in complex attention (including processing speed) and frontalexecutive function

• neuroimaging evidence of CVD comprises one or more of the following:

one or more large vessel infarct or hemorrhage

a strategically placed single infarct or hemorrhage (e.g. angular gyrus, thalamus, basal forebrain)

two or more lacunar infarcts outside the brainstem

extensive and confluent white matter lesions

• for mild vascular NCD: history of a single stroke or extensive white matter disease is sufficient

• for major vascular NCD: history of two or more strokes, a strategically placed stroke, or a combination

of white matter disease, and one or more lacunae is generally necessary

• associated features supporting diagnosis: personality and mood changes, abulia, depression,

emotional lability, and psychomotor slowing

Etiology and Pathogenesis

• major risk factors are the same asthose for CVD (e.g. H I N, DM,smoking,

obesity, hig

levels, high homocysteine levels, other risk factors for atherosclerosis, atrial fibrillation, and

conditions increasing risk of cerebral emboli)

• major or mild vascular NCD with gradual onset and slow progression is generally due to small vessel

disease leading to lesions in white matter, basal ganglia, and/or thalamus

• cognitive deficits can be attributed to disruption of cortical

-subcortical circuits

h cholesterol

Epidemiology

• second most common cause of NCD

• prevalence estimates for vascular dcmentia/NCD range from 0.2-13% ( by age 70), 16% (ages 2:80) to

44.6% (ages S90)

• higher prevalence in African Americans

• prevalence higher in males than in females

Creutzfeldt-Jakob Disease

Definition

• rare degenerative,fatal brain disorder caused by prion proteins causing spongiform changes,

astrocytosis, and neuronal loss

rapidly progressive and common features include cognitive impairment, myoclonus, ataxia,

akinetic mutism, weakness, visual changes, etc

• most common forms are sporadic (85%), hereditary (5-10%), and acquired (<1%)

Investigations

• CSF analysis,MK1 brain (cortical (i.e. cortical ribbon sign) and/orsubcortical (i.e.hockey stick sign)

FLAIR changes), EEG (periodic complexes)

• definitive diagnosis is by brain biopsy

Treatment

• symptomatic management ofseizures and movement disorders, and neuropsychiatric symptoms but

there is no known cure for CJD

Prion proteins have a normal form and

an infectiousform, which resultsfrom

conversion of the protein from a-helix

(normal) to 0-pleated sheet (abnormal);

these abnormally folded proteins

aggregate leading to neuronal loss

Aphasia

Definition

• an acquired disturbance oflanguage characterized by errors in language production, writing,

comprehension,or reading

Neuroanatomy of Aphasia

• Brocas area (posterior inferior frontal lobe) is involved in language production (expressive)

• Wernicke’

s area (posteriorsuperior temporal lobe) isinvolved in comprehension of language

(receptive)

• angular gyrus is responsible for relaying written visual stimuli to Wernicke'

s area for reading

comprehension

• arcuate fasciculus association bundle connects Wernicke s and Brocas areas

>99% of right

-handed people have left

hemisphere language representation

70% of left-handed people have left

hemisphere language

15% have right hemisphere

representation, and 15% have bilateral

representation

representation.

n

L J

+

Types of Paraphasias

Semantic (e.g. “chair" for “table")

Phonemic (e.g.“dable" for “table")

Activate Windows

GotoSettingsto artivate^

Windows:

N28 Neurology Toronto Notes 2023

Assessment of Language

• assessment of context

• handedness (writing, drawing, toothbrush,scissors), education level, native language,learning

difficulties

• assessment of aphasia

• spontaneousspeech (fluency, paraphasias, repetition, naming, writing, neologism,

comprehension - auditory and reading)

Aphasia localizes the lesion to the

dominant cerebral hemisphere

APHASIA s

1

I f

RUENCY

# NON-FLUENT aUENT #

5

©

COMPREHENSION

Poor Good Poor Good

REPETITION

Poor Good Poor Good Poor Good Poor Good

NAMING

Poort r 1 rPoof POO', r

Broca's

PooS

- Motor TCA* Wernickes Sensory TCA* Conduction

3 rPoof Poor

t r , - -

|Po

°

r

Global Mixed TCA* Anomic

LESION LOCALIZATION

Posterior inferior frontal Sensory andmotor

lobe and poster or

superior temporal lobe

TCA-transcortiCal aphasa

^

Transcortical aphasias are typically associated wth cerebral anoxa le.g.post-Ml,CO poisonrg,nypotersior t

Posterior inferior Frontal lobe watersf

^

ed Posteror superior Temporopsrets

.-. 2

*

^ - r: L-rT.- .-rr-

'.C'i= PC*'

- Tr"t2'

=i

baseen MCA and ACA errporal obe

fienaories

transcorticalregions frontal lobe ocsosforleson

Figure 19. Aphasia classification

Apraxia

Definition

• inability to perform skilled voluntary motorsequences that cannot be accounted for by weakness,

ataxia,sensory loss, impaired comprehension, or inattention

Clinicopathological Correlations

Table 15. Apraxia

Description Tests Hemispheres

Blowing out amatch,combing Left

one'

s hair

Preparing and mailing an Right andleft

envelope

Copying a figure

Dressing

Ideomotor Inability to perform skilled

learned motor sequences

Ideational Inability to sequence actions

ConstructionalDressing*

Inability to draw or construct

Inability to dress

Right andleft

Right

’Refers specifically to the inability to carry out the learned movements involvedin construction,drawing,or dressing:not merely the inability to

construct, draw, or dress. Many skills aside from praxis are needed to carry out these tasks.

L J

+

Activate Windows

Go to Settings to activate Windows.

N29 Neurology Toronto Notes 2023

Agnosia

Definition

• inability to recognize the significance of sensory stimuli in the presence of intact sensation and

naming

Clinicopathological Correlations

Table 16. Agnosias

Description Lesion Parietal Lobe Lesions

• Lesions of the dominant parietal lobe

are characterized by Gerstmann's

syndrome: acalculia, agraphia, finger

agnosia, and left-right disorientation

• Lesions of the non-dominant parietal

lobe are characterized by neglect,

anosognosia. and asomatognosia

• Cortical sensory loss (graphesthesia.

astcreognosis. impaired 2 point

discrimination, and extinction) can be

seen with left or right parietal lesions

Bilateral temporo-occipital cortex

Bilateral interior ternporo occipital junction

Inability to name an object presented visually. Bilateral interior temporo-occipital junction

2° to disconnect between visual cortex and

language areas

Visual perception is intact as demonstrated by

visual matching

Apperceptive Visual Agnosia Bilateial temporo- occipital cortex

Associative Visual Agnosia

Inability to recognize lainlliar lacesin the Bilateral temporo-occipital areas or right

presence ol Intact visual perception and intact Interior temporo-occipital region

auditory recognition

Inability lo perceive colour

Inability lo identily objects by touch

Prosopagnosia

Coloui Agnosia

Impaired Slcrcognosis

Bilateral interior temporo-occipital lesions

Anterior parietal lobe in the hemisphere

opposite to iheallected hand

Dominant hemisphere parietal-occipital

lesions

finger Agnosia Inability to recognize, name, and point to

individual lingers

Mild Traumatic Brain Injury

Definition

• mild TBI = concussion

• trauma-induced transient alteration in mental status that may involve loss of consciousness

• hallmark symptoms: confusion and amnesia, which may occur within minutes

• loss of consciousness (if present) less than 30 min, initial CCS between 13-15, post-traumatic amnesia

<24 h

Epidemiology

• 75% of T Bis are estimated to be mild; the remainder are moderate or severe (see Neurosurgery. Brain

Injury,NS37 and Emergency Medicine, ER9)

• highest rates in children 0-4 yr, adolescents 15-19 yr, and elderly >65 yr

Clinical Features

• impairments following mild TBI

somatic: headache,sleep disturbance, nausea, vomiting, and blurred vision

cognitive dysfunction: attentional impairment, reduced processing speed, drowsiness, amnesia

emotion and behaviour:impulsivity, irritability, depression

• severe concussion: may precipitate seizure, bradycardia, hypotension,sluggish pupils

• associated conditions:brain contusion, diffuse axonal injury, C-spine injury

Investigations

• neurological exam to identify focal neurologic deficits

• neurocognitive assessment

* simple orientation questions are inadequate to detect cognitive changes

initial assessment ofseverity is determined by GCS

mild:13-15, moderate:9-12,severe: 3-8

* sideline evaluation:Standardized Assessment of Concussion, Westmead Post-Traumatic Amnesia

Scale,Sport Concussion Assessment fool

• neuroimaging

x-ray skull: not indicated for routine evaluation of mild TBI

CT head asindicated by Canadian CT Head Rules

MR1 not indicated in initial evaluation; consider if continued or worsening symptoms despite

normal CT

Extent of retrograde amnesia correlates

with severity of injury

Rjgained from most distant to recent

memories

r T

L J

+

Activate Windows

Go to Settings to activate Wi

X30 Neurology Toronto Notes 2023

Treatment

•observation for the first 24 h after mild TBI because of risk of intracranial complications

•emergency department for assessment if any loss of consciousness or persistent symptoms

•hospitalization with normal CT if GCS <15,seizures,or bleeding diathesis; or abnormal CTscan

•early rehabilitation to maximize outcomes

OT, FT, SLP, vestibular therapy, driving,therapeutic recreation

•pharmacological management of headaches, pain,depression

•CBT, relaxation therapy

•follow Return to Play guidelines(www.thinkfirst.ca)

Prognosis

•most recover from mild TBI with minimal treatment, but some experience long-term consequences

•patients with a previous concussion are at increased risk ofsubsequent concussions and cumulative

brain injury

•repeat TBI can lead to life threatening cerebral edema (controversially known assecond impact

syndrome) or permanent impairment

•sequelae include:

• post-concussion syndrome: dizziness, headache, neuropsychiatric symptoms, cognitive

impairment (usually resolves within weeks to months)

post-traumatic headaches: begin within 7d ofinjury

• post-traumatic epilepsy: approximately 2% risk post-mild TBI;prophylactic anticonvulsants are

noteffective

post-traumatic vertigo

Neuro-Oncology

Paraneoplastic Syndromes

• see Endocrinology, K56

Tumours of the Nervous System s • see Neurosurgery, NS11

Movement Disorders

Function of the Basal Ganglia

• the cerebral cortex initiates movement via excitatory (glutamatergic) projections to the striatum,

where they then activate two pathways: direct and indirect

direct: cortex activates the thalamus, allowing movement

indirect cortex inhibits the thalamus, preventing movement

+

Activate Windows

Go to Settingsto activate Jt ndows.

r1

L J

+

Activate Windows

Go to Settings to activate Windows.

X32 Neurology Toronto Notes 2023

Overview of Movement Disorders

Table 17. Movement Disorder Definitions

Subjective genera ned restlessness relieved by voluntary stereotypic movements|e.g.squirming)

Transient loss ofmuscle tone (negative myoclonus)

Slow writhing movements,especially distally

Large-amplitude,involuntary,flinging movements tiiatare most commonly unilateral (hemiballism)

Slow,small amplitude movements

Brief,unpredictable,irregular movements,flowing from one body part to another:can appear purposeful mmilder

forms

Inability to smoothlyperform rapidly alternatingmovements

Any involuntary movement,but the term is often used to describe tirestereotypical movements that come with longterm neurolepticuse (tardive dyskinesia) or levodopa use (ievodopa induced dyskinesia)

Co-contraction of agonist and antagonist muscles causing sustained twisting movements which can be tonic (dystonic

postures) or phasic (dystonic movements)

Episodes of haltedmotor action,especially during repetitive actions (e.g. walking)

Brief muscle group contraction that is either focal,segmental,or generated

Spontaneous,fine,fascicular contraction of muscle

Predictable,repetitive,involuntary movements that do not appear tohave any purpose|commonly associated with

intellectual disability or autism)

Accelerationof movements e.g.acceleratedwalking Ifestrnation)

Stereotyped,nonrhythmic,and brief repetitive actions due to inner urge

Can be phonic (vocal) or motor and can be suppressed

Rhythmic and involuntary antagonistic muscle contractions

Akathisia

Asterixis

Athetosis

Ballism

Bradykinesia

Chorea

In some cases,dystonias may occur

only during voluntary movements and

sometimes only during specific activities,

such as writing,chewing,or speaking

(task-specific dystonia)

Oysdiadochokinesia

Dyskinesia

Dystonia

Hemiballismus is most often due to a

vascular lesion Freezing

Myoclonus

Myokymia

Stereotypies

Myoclonus can be stimulus-sensitive

(induced by sudden noise,movement,

light,visual threat or pinprick)

Tadiykinesia

Tics

Tremor

In a young patient (<45 yr) must do

TSH (thyroid disease),ceruloplasmin

(Wilson’s disease),and CT/MRI

(cerebellar disease) as indicated by type

of tremor

Movement Disorders

1.Tremor

Table 18. Approach to Tremors

Resting Tremor Action-Postural Tremor Action-Intention Tremor

Most of the time,essential tremor does

not need treatment UE>jaw»lE>head

3 6 Hr pillrollmg

Rest while concentrating

“TRAP"

UE>head>lE>tongue

6-12 Hjfme tremor

UE>voice>li

‘

5 HT coarse tremor

Sustained posture (outstretched Finger tonose

arms)

± Autosomal dominant FHx

Physiologic,essential tremor. Cerebellar disorders.Wilson'

s

hyperthyroidism,hyperglycemia, disease. MS.anticonvulsants,

heavy metal poisoning,CO

poisoning,drug toxicity,sedative/

alcohol withdrawal

Affected Body Part

Characteristics

Worse with Associated Sx

Cerebellar findings

Alcohol

• Dampens essential tremor

. Potentiates intention tremor during

abstinence (delirium tremens)

• Does not improve resting tremor

of PD

DDi PD.Parkinsonism.Wilson's

disease,mercury poisoning,

severe essential tremor alcohol,sedatives

Levodopacarbidopa (Smemet :

). Propranolol,primidone, Treat underlying cause

topiraraate.and other

anticonvulsants,surgery

(thalamotomy.DBS)

Treatment

DBS

Most common cause of chorea is drug

therapy for PD (levodopa induced

dyskinesias)

2. Chorea

• HD, HD-like syndromes, neuroacanthocytosis,SLE, APLA syndrome, Wilson’s disease,CYD,tardive

dyskinesia,senile chorea,Sydenham’s chorea, pregnancy chorea (chorea gravidarum),levodopa

induced dyskinesia

3. Dystonia

• primary dystonia: familial,sporadic (torticollis, blepharospasm, writer’s cramp)

• dystonia-plussyndromes: dopa-responsive dystonia, myoclonus-dystonia

• secondary dystonia: stroke,CNS tumour, demyelination,drugs/toxins (L-dopa, neuroleptics,

anticonvulsants, Mn,CO, cyanide, methanol)

• heredodegenerative dystonias: Parkinsonian disorders, Wilson’

s disease, HD

4. Myoclonus

• physiologic myoclonus: hiccups, nocturnal myoclonus

• essential myoclonus: myoclonus-dystonia with minimal or no occurrence of dystonia

• epileptic myoclonus

• symptomatic myoclonus

Palatal tremor can result from lesion to

the Dentato-Rubro-Olrvary tract

+

Activate Windows

YjU IU Settingsto activate W

N33 Neurology Toronto Notes 2023

• degenerative disorders:Wilson’

s disease, HD,corticobasal degeneration

• infectious disorders:C|D, viral encephalitis, AIDS-dementia complex

• metabolic disorders: drug intoxication/withdrawal, hypoglycemia, hyponatremia, hyperglycemic

hyperosmolarsyndrome, hepatic encephalopathy, uremia, hypoxia

• focal brain damage: head injury,stroke, mass

Parkinson’s Disease

Etiology

t sporadic: combination of oxidative stressto dopaminergic neurons, environmental toxins (e.g.

pesticides), accelerated aging, genetics

• familial ( I0%): autosomal dominant a-synudein or LRRK2 mutations, autosomal recessive parkin,

RINK I ,or Dl-l mutation (juvenile onset)

• M P I P (neurotoxin)

Epidemiology

• prevalence of 0.3% in industrialized countries, but rises with increased age

• second most common neurodegenerative disorder, after AD

• mean age of onset is 60 yr

Associated Factors

• risk:family history, male, head injury, rural living, exposure to certain neurotoxins

• protective: coffee drinking,smoking, estrogen replacement in post-menopausal women

Pathophysiology

• loss of dopaminergic neurons in pars compacta ofsubstantia nigra -> decreased dopamine in striatum

-» 1. disinhibition of the indirect pathway, and 2. decreased activation of the direct pathway -»

increased inhibition of cortical motor areas

• a-synudeinopathy:a-synudein accumulates in Lewy bodies and causes neurotoxicity in substantia

nigra

Key Parkinsonian Features

TRAP

Tremor (resting)

Rigidity

Akincsia /bradykinesia

Postural instability

2015 MDS Clinical Diagnostic Criteria

for PD

• “Clinically Established PD" requires:

• Cardinal Parkinsonism

Manifestations:Bradykinesia with

either resting tremor or rigidity

• 2 or more supportive criteria (clear

and dramatic beneficial response to

dopaminergic therapy,levodopainduced dyskinesia,rest tremor of

a limb,and/or olfactory loss/cardiac

sympathetic denervation on MIB6

scintigraphy)

• No absolute exclusion criteria and no

red flags (see full diagnostic criteria -

Mov Disord 2015;30:1591-601)

Clinical Features

• diagnosis is based on clinical features:

1. Negative motor features

bradykinesia:slow,small amplitude movements,fatigue from rapid alternating movements,

difficulty initiating movement

2. Positive motor features

resting tremor:typically 4-6 Hz “pill-rolling” tremor, especially in hands

rigidity:lead-pipe rigidity with cogwheeling due to superimposed tremor

3. Asymmetric onset of tremor,rigidity, bradykinesia

4. Progressive course

related findings: hypomimia (reduced facial expression), hypophonia, aprosody (monotonous

speech),dysarthria, micrographia,shuffling gait with decreased arm swing

freezing of gait:occurs with walking triggered by initiating stride or barriers/reaching

destinations,lasting seconds

postural instability: a late finding that presents as falls

cognition: bradyphrenia (slow to think/respond), dementia (late finding)

behavioural:decreased spontaneousspeech,depression,sleep disturbances, anxiety

autonomic: constipation, urinary dysfunction (nocturia, urgency, frequency),sexual

dysfunction, orthostatic hypotension, clinostatic hypertension

sleep: REM sleep behaviour disorder, insomnia, hypersomnolence

Consider an Alternative Diagnosis if

Atypical Parkinsonism

. Poor response to levodopa

. Abrupt onset of symptoms

• Rapid progression

. Early falls

• Early autonomic dysfunction

. Symmetric symptoms at onset

. Early age of onset («50 yr)

• Early cognitive impairment

• FHx of psychiatric disorders and/or

dementia

• Recent diagnosis of psychiatric

disease

• History of encephalitis

• Unusual toxin exposure

• Extensive travel history

Treatment

• pharmacologic

• mainstay of treatment:levodopa/carbidopa (Sinemet*) or levodopa/benserazide (Prolopa*)

levodopa is a dopamine precursor. Both carbidopa and benserazide decrease levodopa peripheral

metabolism, decreasing levodopa side effects and increasing its half-life

levodopa-related fluctuation: delayed onset of response (affected by mealtime), end-of-dose

deterioration (“wearing-off"), random oscillations of on-off symptoms

major adverse effect of levodopa:dyskinesia

treatment of early PD:levodopa, dopamine agonists, amantadine, MAOI

• adjuncts: dopamine agonists, MAOI, anticholinergics (especially if prominent tremors), catecholO-methyltransferase inhibitors

• surgical

thalamotomy

pallidotomy

• DBS (thalamic, pallidal,subthalamic)

• psychiatric

SSRlsfirst line

r i

1

_ J

+

« TCAs(beware fall risk,cognitive impairment, and worsening symptoms of PD)

Activate Windows

-Go to Settingstoaetivate-Windewsr

N34 Neurology Toronto Notes 2023

Other Parkinsonian Disorders

Dopamine Agonist therapy in Early Parkinson'

s

Disease

Cochrane OBSyst Her 2009;2:CDM55(4

Study:Meta -analysisof trialsoidopanne agonsts

-

tart) N

Desalts:Twenty-nine trialswertinctaded <n ^5247|.

Dopamine agonistswere foand to halt decreased

motorside effects (dyskinesia (OD 0.51).dystoeia (01

0.(4).motor fluctuations|0R 0.25).hut proirded

poorersymptom control compared to lesodopa.Also,

other side effects were increased (constipation (OD

1.59). hallucinations (OR 1.(9).dullness(OR 1.45)).

Conclusion: Oopammeagonists hare fewer motor

side effectsthan leiodopa,hut provide worse

sym ptom control and increased rate of otherside

effects.

• NCD with Lewy bodies:see Behavioural Neurology, N2I

• progressive supranuclear palsy:tauopathy with limited vertical gaze (downgaze more specific that

can be overcome by the oculocephalic reflex), early falls, wide-based unsteady gait, axial rigidity,

akinesia,dysarthia, and dysphagia

• corticobasalsyndrome: tauopathy with varied presentations but classically presenting with

unilateral parkinsonism, dystonia/myoclonus, and apraxia ± “alien limbs” phenomenon; ±

progressive non-fluent aphasia

• multiple system atrophy:synucleinopathy presenting as either cerebellar predominant (MSA-C,

previously olivopontocerebellar atrophy) or parkinsonism predominant (MSA-P, previously

nigrostriatal degeneration ); both are associated with early autonomic dysfunction (urinary

incontinence or orthostatic hypotension, previously Shy-Drager syndrome)

• vascular parkinsonism: multi-infarct presentation with gait instability and lower body

parkinsonism;step-wise decline over time;less likely associated with tremor

Huntington’s Disease

Etiology and Pathogenesis

• genetics: autosomal dominant CAG repeats (with anticipation) in HIT on chromosome 4, which leads

to accumulation of defective protein in neurons

• pathology:global cerebral atrophy, especially affecting the striatum, leading to increased activity of

the direct pathway, and decreased activity of the indirect pathway

Epidemiology

• North American prevalence 4-8 in 100000

• mean age of onset 35-44 yr, but varies with degree of anticipation from 5-70 yr

Clinical Features

• typical progression: insidious onset with clumsiness,fidgetiness, and irritability, progressing over 15

yr to major NCD, psychosis, and chorea

• major NCD: progressive memory impairment and loss of intellectual capacity

• chorea: begins as movement of eyebrows and forehead,shrugging of shoulders, and parakinesia

(pseudo-purposeful movement to mask involuntary limb jerking)

• progresses to dance-like or ballism, and in late stage is replaced by dystonia and rigidity

mood changes: irritability, depression, anhedonia, impulsivity, bouts of violence

• luvenile-onset HD (Westphal variant) characterized by Parkinsonism, dystonia, rigidity,seizures

Investigations

• MK1

• enlarged ventricles, atrophy of cerebral cortex, and caudate nucleus

• genetic testing

• cytosine-adenine-guanine (CAG) trinucleotide repeats within the HITgene located on

chromosome 4pl6.3

• CAG repeat sizes that result in: meiotic instability (27-35 repeats), reduced disease penetrance

(36-39 repeats), and full disease penetrance (S40 repeats)

Treatment

• no disease-modifying treatment

• psychiatric symptoms: antidepressants and antipsychotics

• chorea:tetrabenazine, amantadine, and neuroleptics

• dystonia: botulinum toxin (for focal dystonia)

Wilson’s Disease

• see Gastroenterology,G37

Dystonia

Epidemiology

• 3rd most common movement disorder after PD and essential tremor n

L J

Clinical Features

• sustained or intermittent twitching movements caused by co-contraction of agonist and antagonist

muscles

• symptoms exacerbated by fatigue,stress,and emotions;relieved by sleep orspecific tactile/

proprioceptive stimuli ( “geste antagoniste,” e.g. place hand on face for cervical dystonia)

• more likely to be progressive and generalized if younger onset or leg dystonia

+

Activate Windows

Goto-Settings^

o-activateWtndowsr

N35 Neurology Toronto Xotes 2023

Treatment

• local medical:botulinum toxin

• systemic medical: anticholinergics(trihexyphenidyl,benztropine), muscle relaxants(baclofen),

benzodiazepines,dopamine depletors (tetrabenazine), dopamine for dopa-responsive dystonia

• surgical:DBS,pallidotomy, orsurgical denervation of affected muscle

Tic Disorders

Definition

• a tic is a sudden,rapid, recurrent, nonrhythmic,stereotyped motor movement or vocalization

• common criteria

• tics may wax and wane in frequency but have persisted for an extended period of time

onset is <18 yr

disturbance is not attributable to the physiological effects of a substance or another medical

condition

Clinical Classification

• Tourette’s Syndrome: multiple motor and I vocal tics that have persisted for >1 yr since onset

• persistent (chronic) motor or vocal tic disorder:single or multiple motor or vocal tics (but not both

motor and vocal) that have persisted for >1 yr since onset

• provisional tic disorder:single or multiple motor and/or vocal tics present for < I yr since first tic

onset

• otherspecified or unspecified tic disorder:symptoms characteristic of a tic disorder but do not meet

full criteria

• secondary tic disorders: encephalitis,C|D, Sydenham'

s chorea, head trauma, drugs(stimulants,

levodopa),intellectual disability syndromes

• ncurodegcncrativc diseases: neuroacanthocytosis, HD (see Huntington's Disease, N34 )

Tic Types

• simple tics:short duration (msec)

• complex tics:longer (sec), more purposeful and often include a combination of simple tics

• motor tics

• simple: blinking, head jerking,shoulder shrugging, extension of the extremities

dystonic:bruxism (grinding teeth), abdominal tension, sustained mouth opening

complex: copropraxia (obscene gestures), echopraxia (imitate gestures), throwing, touching

• vocal tics

simple:blowing, coughing, grunting, throat clearing

complex: coprolalia (shout obscenities), echolalia (repeat others'

phrases), palilalia (repeat own

phrases)

Treatment

• mild tics: education, counselling,supportive care,Comprehensive Behavioural Intervention for T ics

• debilitating tics:a-2 adrenergic agonists (guanfacine, donidine), antipsychotics (e.g. haloperidol,

pimozide), botulinum toxin, topiramate

Tourette’s Syndrome (Gilles de la Tourette

Syndrome)

DSM-V Definition

1. presence of both multiple motor and one or more vocal tics atsome point during the illness, although

not necessarily concurrently

2. tics may wax and wane in frequency but have persisted >1 yr since first tic onset (with no tic-free

periods >3 mo)

3.onset is <18 yr

4.not due to effect of a substance or another medical condition

Epidemiology

• estimated prevalence among adolescents 3-8 in 1000 school-age children, M:F=2-4:1

Signs and Symptoms

• tics:wide variety that wax and wane in type and severity (see Tic Disorders-Tic Types)

can be associated with the presence of premonitory feelings orsensations that are relieved by

carrying out the tic

can be voluntarily suppressed for some time

can be worsened by anxiety, excitement, and exhaustion; improved by calm, focused activities

• psychiatric:compulsive behaviour (associated with OCD and ADHD), hyperactive behaviour, “rages,

"

sleep-wake disturbances, or learning disabilities

Treatment

• mild tics:(see Tic Disorders-Treatment)

• debilitating tics: DBS,(see Tic Disorders-Treatment)

n

L J

+

Activate Windows

T3crto5ettingsAo-aettvateWindowsT

NJ6 Neurology Toronto Notes 2023

Prognosis

• typically begins between ages 4-6

• peak severity occurs between ages 10-12,with a decline in severity during adolescence (50% are ticfree by age 18)

• tic symptoms, however, can manifestsimilarly in all age groups and across the lifespan

Cerebellar Disorders

Clinico-Anatomic Correlations

• vermis:trunk/gait ataxia

• cerebellarlobe (i.e.lateral):rebound phenomenon,scanning dysarthria, dysdiadochokinesia,

dvsmetria, nystagmus

Symptoms and Signs of Cerebellar Dysfunction

• nystagmus: observe during EOM testing (most common is gaze-evoked nystagmus)

• dysarthria (ataxic): abnormal modulation ofspeech velocity and volume (elicit scanning/telegraphic/

slurred speech on spontaneousspeech)

• hypermetric saccades

• dvsmetria:under/overshooting the target during voluntary movement of limb or eye

• dysdiadochokinesia:impairment of rapid alternating movements(e.g. pronation-supination task)

• rebound phenomenon:overcorrection after displacement of a limb

• intention tremor,

typically orthogonal to intended movement, and increases as target is approached

• hypotonia:decreased resistance to passive muscular extension (occursshortly after injury to lateral

cerebellum)

• pendular patellar reflex:knee reflex causes pendular motion of leg (occurs after injury to cerebellar

hemispheres), pendular reflexes at triceps

• truncal ataxia:on sitting, titubation (rhythmic rocking of trunk and head )

• ataxic gait: broad-based and lurchinggait,difficulty with tandem gait

Wernicke-Korsakoff Syndrome

• acute (Wernicke’s encephalopathy) and chronic (KorsakofFs psychosis) disorders caused by thiamine

(vitamin Bl) deficiency,see Psychiatry.PS29

• etiology:alcohol use disorder, gastrointestinal disorders especially malabsorption,surgeries(e.g.

gastric bypass), acquired immune deficiency syndrome, hemodialysis, malignancies

• note that alcohol can also cause a cerebellar ataxia separate from thiamine deficiency; this ataxia can

be due to cerebellar atrophy or alcohol polyneuropathy

Cerebellar Ataxias

Congenital Ataxias

• early onset non-progressive ataxias associated with varioussyndromes as well as developmental

abnormalities (e.g.Arnold-Chiari malformation,Dandy-Walker cysts)

Hereditary Ataxias

• autosomal recessive:Friedrich’s ataxia,ataxia with oculomotor apraxia, ataxia telangiectasia, ataxia

with vitamin E deficiency

Friedrich’s ataxia: prevalence 2 in 100000;typical onset between 8-15 yr

signs:gait and limb ataxia, weakness, areflexia, extensor plantar reflex, impaired

proprioception and vibration,dysarthria

death in 10-20 yr from cardiomyopathy or kyphoscoliotic pulmonary restriction

• autosomal dominant: most commonly spinocerebellar ataxias(SCAs);30+ types, most commonly due

to CAG repeats

• signs:ataxia and dysarthria, chorea, polyneuropathy, pyramidal and/or extrapyramidal features,

dementia

Acquired Ataxias

• neurodegeneration: multiple system atrophy,SCAs

• systemic:alcohol, celiac sprue, hypothyroidism,Wilsons, thiamine deficiency, vitamin E deficiency

• toxins:CO,heavy metals,lithium, anticonvulsants,solvents

• vascular infarct, bleed, basilar migraine

• autoimmune:MS, Miller-Fischer (GBS)

• primary and secondary neoplasm

n

L J

+

Activate Windows

AL GRAWANY Go to Settings to activate Windows.

X37 Neurology Toronto Notes 2023

Vertigo s

Face/throat

iCramobulbul

:

• see Otolaryngology.0112 5

I

Arm

iCervicall Motor Neuron Disease :

Trunk

(Thoracic)

Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease)

Definition

• progressive neurodegenerative disease that causes UMN and LMN symptoms and is ultimately fatal

Etiology

• idiopathic (most common),genetic (5-10% familial, most commonly C9orf72 mutation, other

mutations include:SOD1,TARDBP)

Pathology

• disorder of anterior horn cells of the spinal cord, cranial nerve nuclei, and corticospinal tract

Epidemiology

• Sin 100000; incidence increases with age

Clinical Features

• limb motor symptoms:segmental and asymmetrical UMN and LMN symptoms

• bulbar findings:dysarthria (flaccid or spastic or mixed),dysphagia, tongue atrophy and fasciculations,

facial weakness and atrophy

• pseudobulbar affect, FI D (up to 10%)

• sparing of sensation, ocular muscles, bowels, bladder,sphincters

Investigations

• EMG: active and chronic denervation and reinnervation,fasciculations

• NCS:to rule out peripheral neuropathy (e.g. multifocal motor neuropathy with conduction block)

• Cl'

/MRl:to rule outspinal cord disease/compression

Treatment

• riluzole (modestly slows disease progression)

• symptomatic relief

spasticity/cramping: baclofen, tizanidine (Zanaflex*), regular exercise, and physical therapy

• sialorrhea:TCA (e.g. amitriptyline),sublingual atropine drops, parotid and/orsubmandibular

Botox* (rare)

• pseudobulbar affect:dextromethorphan and quinidine, TCA,SSR1

• edaravone is FDA and Health Canada approved; reducesfunctional decline by 33% in early stage ALS

• non-pharmacologic:high caloric diet, ventilatory support (especially BiPAP),early nutritionalsupport

(e.g.percutaneous endoscopic gastrostomy tube),rehabilitation (PI'

, OT,SLP),and psychosocial

support

Prognosis

• median survival is 3 yr; death is typically due to respiratory failure

iLumbosacrall L

_

Figure 22. Regions affected by ALS

Adapted from:https://www.mda.orgdisease’

amyotrophic-lateral.sclerosis/srgn$

-antSsyrrptoms and labels:ALS and Other Motor

Neuron Diseases (2017) lecture by Dr. Aaron

Irenberg

Safety and Efficacy of Edaravone in Bell Defiled

Patients withAmyotrophic Lateral Sderosis:A

fendomised. Double-Blind. Placebo-Controlled

Trial

lancet Heurol 2017;16:505-12

Purpose In assessthe safety and eScacy of

edararone in patients with earlystage AIS

Methods: 13? early-stage ALS setrests ceefrg

stnogeni incloston criteria wera raodoofy ass g-ed to

recenre 60 mg IV edararone or IV sabre:acridfor 6

cydes(4 weeks/cycle with 2 weeks on.2 weeks off)

for a ‘.ota! treatment duration of 24 weeks

Pnaa-y Outcome: OifferencE in tie lersed ALS

frrbonal Rat.ig Scale (ALSftS-RI score tom

base me to 24weeks

Besnlts: TheALSFRS- R score caasgewas-5.01|Se

0.64|and -7.S010.66) in the eda»arone grousard

placebo,respectively. The betweec-grocp ieaslsguares mean difference was 2.49 (S6 0.76. 9SV 0

039-3.98: P‘0.0013), liasfavourrgelareiane.

Airese even's were similara bo3g-wps

Condnsion: In early-sfage ALS pateris idertiied

c ppst-ooc analysis of a previous pbase 3 study,

edaravone significantly reduced fee decree tf

MSRS-tscores

The

m

only interventions shown to extend

survival in ALS are riluzole and use

of BiPAP.Edavarone in early ALS can

decrease functional decline

Other Motor Neuron Diseases

• degenerative

• progressive muscular atrophy (progressive bulbar palsy):only LMN symptoms with

asymmetric weakness,later onset than ALS,5-10% of patients in ALS centres (considered the

isolated LMN version of ALS)

• primary lateral sclerosis (progressive pseudobulbar palsy): UMN symptoms, later onset, not

fatal, variable disability, 5-10% of patients in ALS centres (considered the isolated UMN version

of ALS)

Red Flags Inconsistent with ALS

Sensory Sx. predominant pain,bowel

Of bladder incontinence ocular muscle

weakness

• genetic

spinal muscular atrophy: paediatric or adult-onset disease with symmetric LMN symptoms

(genetic disorder)

spino-bulbar muscular atrophy (Kennedy disease):speech and swallowing difficulty and limb

weakness (X-linked genetic)

Denervation on EMG

Fibrillations,positive sharp waves,

complex repetitive discharges

r“i

c j

• infectious

• post-polio syndrome

• West Nile infection: residual asymmetric muscle weakness, atrophy

Reinnervation on EMG

Increased amplitude and duration of

motor units +

Activate Windows

Go to Settings to activate Windows.

X38 Xcurologv Toronto Xotes 2023

Peripheral Neuropathies

Diagnostic Approach to Peripheral Neuropathies

1.differentiate:motor vs.sensory vs.autonomic vs. mixed

2. pattern of deficit:symmetry,focal vs. diffuse; upper vs. lower limb; cranial nerve involvement

3.temporal pattern:acute vs.chronic;relapsing/remitting vs. constant vs. progressive

4. history: PMHx, detailed I Hx, exposures (e.g.insects, toxins,sexual, travel),systemic symptoms

5.detailed peripheral neuro exam:LMX findings,differentiate between root and peripheral nerves,

cranial nerves,respiratory status

Diabetic Neuropathies

• Peripheral neuropathy:pain or loss

of sensation in a stocking-glove

distribution (hands and feet affected

before arms and legs)

• Autonomic anhidrosis,orthostatic

hypotension,impotence,

gastroparesis. bowel, and bladder

dysfunction

. Mononeuropathy multiplex:nerve

infarct or compression

• Cranial neuropathy:CN III (pupil

sparing) > IV > VI

• Lumbosacral plexopathy fee.diabetic

amyotrophy)

DDx of Demyelinating Neuropathy

GBS.OOP. paraproteinemia, diphtheria,

amiodarone.Charcot-Marie-Tooth

(including hereditary neuropathy with

liability to pressure palsy),storage

diseases, pressure palsy predisposition,

paraneoplastic

polyradiculopathy

Icauda equina

syndrome)

radiculopathy plexopathy

(brachial)

mononeuropathy

(peroneal)

mononeuropathy

multiplex polyneuropathy ICE)

Figure 23.Pattern of distribution forperipheral neuropathies

Classification

• radiculopathy:dermatomalsensory deficit and myotomal weakness in distribution ofsingle nerve

root (e.g.C7)

• often due to disc herniation or root compression causing radicular pain

» little tactile anesthesia, as dermatomes overlap

• polvradiculopathy:multiple dermatome sensory deficits and myotomal weakness

• due to multiple nerve root lesions(e.g.cauda equina syndrome due to lumbosacral rootslesion)

• plexopathy: deficit matching distribution of a nerve plexus

• due to lesion distal to nerve roots but proximal to origin of individual peripheral nerves

brachial plexopathy

upper (C5-C7):LMX Sx of shoulder and upper arm muscles (Hrb'

s palsy)

lower (C8-TI):LMX Sx and sensory Sx of forearm and hand (Klumpke’s palsy)

DDx: trauma, idiopathic neuritis, tumour infiltration, radiation, thoracic outlet syndrome

(e.g.cervical rib)

lumbosacral plexopathy ( rare,especially unilateral)

DDx:idiopathic neuritis,infarction (e.g. DM), compression

• mononeuropathy:single nerve deficit

• carpal tunnelsyndrome (most common): compression of median nerve at wrist

symptoms:wrist pain, paresthesia first 3 and Vi digits, ± radiation to elbow, worse at night

signs:Tinel’

ssign, Phalen’

stest,thenar muscle wasting,sensor)'deficit

EMG/NCS:slowing at wrist (both motor and sensory)

etiology:entrapment, pregnancy,DM,gammopathy, rheumatoid arthritis,thyroid disease

Bell’s palsy (most common cranial neuropathy):see Otolaryngology,OT23

• entrapment/compression: ulnar (compression at elbow'), median (at pronator teres),radial (at

spiral groove of humerus),obturator (from childbirth), peroneal (due to crossing legs orsurgical

positioning),posterior tibial (tarsal canal)

• mononeuropathy multiplex:subacute involvement of multiple individual peripheral nerves in

asymmetric,non-length-dependent manner;often painful

• must rule out vasculitis or collagen vascular disease; consider MMN (multifocal motor

neuropathy) or MADSAM (multifocal acquired demyelinating sensory and motor neuropathy),

multiple compressive neuropathies

• polyneuropathy: chronic progressive involvement of multiple peripheral nerves in symmetrical,

distal-predominant pattern

• length-dependent, i.e.longest fibres affected first (stocking-glove distribution)

sensorimotor,with progression of dysesthesia earlier and weaknesslater

etiology: DM (most common), renal disease,substances, toxins, genetic, SLE, HIV,leprosy,

alcohol,Bi:deficiency

Tinet’

sSign

Tap lightly overthe median nerve at the

wrist the patientssymptoms of carpal

tunnel will be elicited in a positive test

Phalen’

s Test

Hold both wristsin forced flexion (with

the dorsalsurfaces of the hands pressed

against each other) for 30-60s:test is

positive if symptoms of carpal tunnel

are elicited

Axonal neuropathies have decreased

amplitude on NCS:demyelinating

neuropathies have decreased

conduction velocity on NCS

Ototoxic drugs(e.g.aminoglycosides)

should not be given to diabetics

Sensory neuropathy of the feet prevents

them from adequately compensating for

loss of vestibular function n

L J

+