cerebellum

Question 1

vermis and floculondular lobe function

Answer 1

proximal limb, trunk coordination
gait, balance, VOR reflexes
coordination of eye movements in relation to posture

Question 2

intermediate hemisphere function

Answer 2

distal limb coordination

Question 3

lateral hemisphere function

Answer 3

motor planning for extremities

distal limb movement control

Question 4

Crossed cerebellar diaschisis (CCD)

Answer 4

depression of blood flow / metabolism affecting cerebellar hemisphere as a result of a contralateral focal, supratentorial lesion (infarct, radiation necrosis, following a tumor resection, etc.)

Question 5

CCD Pathophysiology

Answer 5

interruption of cortico-ponto-cerebellar connections due to the infarct which then causes deafferentation and transneuralmetabolic depression of the contralateral cerebellar hemisphere

Question 6

ataxia

Answer 6

ipsilateral to the cerebellar lesion
appendicular or axial
disorganized, poorly controlled or clumsy movement due to lesions in the cerebellum and its immediate connecting pathways
may be associtaed with involuntary movements

Question 7

pseudoataxia

Answer 7

Lack of proper sensory input -> need for visual system to help coordinate movements
Eyes closed -> worsening of ataxia
Positive Romberg test
May also present as pseudoathetosis
Problem with large sensory fibers / posterior colums

Question 8

asthenia

Answer 8

only apperent during movements, static resistance normal
easy fatigability and/or a lack of coordination or stability
inability to maintain steady force levels (astasia)

Question 9

dysdiadochokinesia

Answer 9

impaired coordination of different single-joint movement components when performing alternating multi-joint movements

Question 10

cerebellar tremor

Answer 10

Action / kinetic, postural
Intention 
Low frequency 
Present with rest, posture and action 
Typically worsens with ETOH
Tremor frequency may differ between limbs

Question 11

2 classifications of ataxias

Answer 11

degenerative/sporadic

hereditary/genetic (autosomal dominant)

Question 12

Friedreich’s ataxia

Answer 12

frequency: 1 in 40,000 
trinucleotide repeat disorder (GAA)
chromose 9 encoding frataxin
begins in childhood (5-15 years old); wheelchair-bound about 10 years after signs and symptoms appear
ataxia, dysarthria and sensory loss
hypertrophic cardiomyopathy
scoliosis, diabetes, hearing loss

Question 13

secondary ataxias

Answer 13

Toxic (ETOH, heavy metals, AEDs)
Autoimmune (Yo, Hu, Ri)
Vasculatr (stroke)
Structural (mass lesion, HC)
Vasculitis (Behcet)
Infectious (HIV, prions)
Demyelinating (MS)
Metabolic (thiamine – B1, B12
 or vit E deficiency)
Postanoxic

Question 14

common finding of SCAs

Answer 14

all have gradual onset of balance and gait difficulty, dysarthria and clumsiness of hands +/- visual symptoms

Question 15

SCA2 clinical

Answer 15

□ Onset 3rd-4th decade
□ Parkinsonism
□ Axonal sensory neuropathy
□ Dysarthria, tremor, hyporeflexia
□ Slowing of eye saccades
□ Survival- 25 years (median)

Question 16

SCA 3 clinical

Answer 16

Onset 3th – 4th decade
Highly variable clinical course 
Parkinsonism, Dystonia
Facial – lingual fasciculations
Axonal polyneuropathy, bulging eyes
4th ventricle enlargement
Survival – 20 years (median)

Question 17

SCA2 pathology key

Answer 17

cytoplasmic inclusions/aggregates

Question 18

SCA3 pathology key

Answer 18

internuclear inclusions