Ataxia

When does SCA usually onset?

3rd-5th decade but variable

What is the mean age at death for FA pts?

4th decade due to cardiac/respiratory effects

Classic presentation of sensory ataxia?

B12 deficiency, copper deficiency

What is affected in a sensory ataxia?

Dorsal column or large fiber sensory neuropathy (joint position/vibration)

Features of cerebellar ataxia

- ataxia of gait - dysdiadochokinesia - dysmetria - loss of rebound - intention tremor - eye mvmts - scanning dysarthria - hypotonia

what are the three types of ataxia?

- cerebellar - sensory - misc: vestibular, thalamic, frontal dysequilibrium ataxia

T/F: there is no assoc features of cerebellar ataxia

True

T/F: there is no effective treatment for friedreichs ataxia?

True

Symmetrical ataxia

acute (hrs-days), subacute (days-wks), chronic (mo-yrs)

Describe the alcoholic pt

acute ataxic gait - thiamine def (wernicke encephalopathy - confusion, eye movements) chronic ataxic gait - midline cerebellar atrophy, neuropathy in ft, dorsal column damage from B12 deficiency

Swelling can cause what other signs in the brain?

assoc w/motor/sensory loss, cranial nerve palsies from brainstem involvement

Spinocerebellar Ataxias (SCA)

autosomal dominant ataxia types 1-29, usually GRADUAL onset of cerebellar ataxia w/ features involving other systems CAG triplet repeats

Friedreich Ataxia

autosomal recessive ataxia presents younger age GAA triplet repeat... reduced Frataxin protein

SCA 6

benign, late onset

Symmetrical ataxia distribution

both side

Dysdiadochokinesia

breakup and irregularity that occur when limb is attempting to carry out rapid alternating movements (like flipping hand in palm)

other features of dandy walker?

corpus callosum dysgenesis, holoprosencephaly, malformation of heart, face, limbs, digits

subacute symmetrical ataxia

days-weeks intoxication (Hg, solvents, gas, glue), cytotoxic chemo drugs - cytarabine, alcoholic nutritional deficiences (B1 and B12 deficiency), EBV, CMV, Creutzfeldt jakobs disease

Focal subacute ataxia

days-wks Neoplastic: cerebellar glioma or met tumor (+on MR/CT) Demyelinating: MS, AIDS

Sensory ataxia

failure of relay or proprioceptive info to CNS

vestibulocerebellum

flocculonodular lobe & tiny part of vermis ataxic gait, truncal ataxia, vertigo, nausea, nystagmus & other eye mvmt abnormalities

What are other common characteristics of Friedreich Ataxia?

foot deformity, scoliosis, DM and cardiac hypertrophy MR results: cerebellar atrophy and thin spinal cord abnormal NCV/EMG

Acute symmetrical ataxia

hours-days intoxication (OH, Li, barbs), acute viral cerebellitis, post infective syndrome - usually viral

Focal acute ataxia

hr-days Vascular: cerebellar infarc, hemorrhage Infectious: cerebellar abcess (+mass on MR/CT)

Cerebellar Ataxia

intact sensory receptors & afferent pathways, just the integration of proprioception is faulty

What do lateral cerebellar lesions cause?

ipsilateral limb ataxia

What is ataxia?

lack of coordination resulting in breakdown of normal execution of voluntary movement

Neocerebellum (pontocerebellum)

lateral hemispheres ipsilateral dydiodochokinesia, dysmetria, intention tremor

Pediatric presentation of ataxia

may appear well, but wobbly when sitting. Typically a viral infection precedes these episodes commonly intoxication

Dysmetria

misjudging of distance, overshooting (hypermetria) and undershooting (hypometria) of target

What symptoms appear if you damage cerebellar inflow and outflow tracts?

mixture of features.... including rubral tremor, thalamic ataxia, frontal gait ataxia

Chronic symmetrical ataxia

mo-yrs Inherited ataxia, paraneoplastic, autoimmune, hypothyroidism, tabes dorsalis,

Focal chronic ataxia

mo-yrs stable gliosis 2nd to vascular lesion or demyelinating plaque Congenital lesion: chiari or dandy-walker malformation

Machado Joseph Disease (SCA-3)

most common SCA CAG repeat, ATXN3 gene... Ataxin 3 protein presenting sxs: opthalmoplegia, spasticity, parkinsonism, facial myokymia, neuropathy, cognitive decline

Dandy Walker malformation

non progressive cerebellar ataxia triad: - a-genesis of vermis - dilatation of 4th vent - enlarged post. fossa

Geriatric presentation of ataxia

normally tend to be age related (>65) if it occurs acutely, get a CT of head

What develops before the age of 30?

progressive limb and gait ataxia ambulation lost by 9-15 yrs after onset

How does dandy walker present in older children?

raised ICP and signs of cerebellar dysfunction - VP shunt for hydrocephalus

How does Dandy walker present in early infancy?

slower motor development and progressive enlargement of skull

Scanning Dysarthria

spoken words are broken up into separate syllables, often separated by a noticeable pause, and spoken w/varying voice

What might cause contralateral ataxia w/sensory loss?

thalamic infarcts

Vascular incidents

think acute, usually asymmetric, ischemia or hemorrhage in cerebellum or brainstem cerebellar pathways

Intention (terminal) tremor

tremor that presents when they reach out for an object and begin to tremor once extended

What do Midline cerebellar lesions cause?

truncal ataxia

Ataxia of gait

unsteadiness w/wide base, body swaying, and inability to walk on tandem (heel-to-toe)

Spinocerebellum

vermis and paravermian region gait ataxia or truncal ataxia

What makes the sensory ataxia worse?

worsening of coordination occurs when the eyes are closed.

focal ataxia distribution

just one side

Eye movements

nystagmus, dysmetric saccades

SCA 7

vision loss