Clinical

Question 1

What is the main function of the cerebellum?

Answer 1

Coordination of the motor systems to all precision motor movements and accurate timing of precision motor movements.

Question 2

Where are the cerebellar afferents and efferent fibres from?

Answer 2

Afferent
spinal cord (spinocerbellar fibres)
Inferior olivary complex - olivocerebellar fibres
Vestibular system - vestibulocerebellar fibres
Pontocerebellar fibres from the cerebrum via the pontine

Efferents to:
Lateral vestibular nuclei, red nucleus and reticular formation

Question 3

What is ataxia?

Answer 3

Uncoordinated movements

Question 4

What are the symptoms of cerebellar disease?

Answer 4

Ataxia - speech/swallowing difficulties, limb clumsiness (falls common), torso (difficulty sitting), gait (wide stance)
Dysarthria (slurred speech), dysphagia (difficulty swallowing).

May also have visual symptoms (oscillopsia/diplopia), vertigo (sensation of movement), nausea and vomiting.

Question 5

What is dysarthria?

Answer 5

Slurred speech

Question 6

What is dysphagia?

Answer 6

Difficulty swallowing.

Question 7

What are the signs of cerebellar disease?

Answer 7

Abnormal eye movements: nystagmus, square wave jerks.
Dysarthria - laboured/slurred, staccato (broken sounds), rapid tongue movements slowed.
Limb ataxia - intention tremor, past pointing (dysmetria), impaired rapid alternating movements

Truncal and gait ataxia - may be the only sign, broard based gait, sways, irregular steps in time/distance.

Question 8

What is dysmetria?

Answer 8

Over or undershoot for objects when pointing or grasping.

Question 9

What happens to tone, reflexes and sensation in cerebellar disease.

Answer 9

There is no muscle weakness
Tone - normal to decreased
Reflexes - normal
Sensation - normal

Question 10

What are some of the causes of cerebellar disease?

Answer 10

Toxins - alcohol
Congenital abnormalities
Strokes
Inflammation/demyelination
Tumours
Infections
Degenerative disorders

Question 11

What are some reflexes and their nerves/spinal levels?

Answer 11

Jaw reflex - trigeminal nerve
Biceps - C5
Brachioradialis -C6
Triceps C7
Fingers - C8
Knee - L3/L4
Ankle -S1

Question 12

What is tone?

Answer 12

The resistance of muscles to passive lengthening. It requires muscle elasticity and neural input.

Question 13

What happens to muscles in peripheral motor neuron lesions?

Answer 13

Tone - decreased
Muscle wasting
Reflexes - decreased/absent 
Muscle fasciculations
Flexor plantar response
Normal rapid alternating movements.
Power is reduced

This involves diseases of snesnory axons, cell bodor of motor neuron or axon of motor neuron.

Question 14

What happens to muscles in upper motor neuron lesions?

Answer 14

Reflexes - increased (spasticity)
Tone - increased
Plantor - extensor
Power - reduced
Rapid alternating movements - reduced

Seen in strokes, brain tumours, spinal cord lesions

Question 15

What happens to muscles with a spinal cord lesion at C5?

Answer 15

Bicep and supinator jerks - reflexes decreased, tone at elbow is decreased.
For lower myotomes the reflexes are increased (tricep - C7, fingers C8, knee L3, and ankle S1)
Tone in the lower limbs is increased.

Question 16

What are the motor symptoms of parkinson’s disease?

Answer 16

Rest tremor - pill rolling tremor - tremor is lost with posture
Bradykinesia - slow movement, emotionless face, impaired rapid alternating movements, reduced or absent arm swinging, shortened stride length, freezing, decrement (starts fast but movements slow until stopped an has to start over)
Rigidity - cog wheel
Postural instability and gait abnormalities - difficulty standing from a chair, rolling over, stooped/flexed position, tendency to take several steps to turn, falls

Question 17

What are the non-motor symptoms of parkinsons disease?

Answer 17

Depression, anxiety, dementia, anosmia (loss of smell), constipation, pain, sleep disturbances, change in mood, ANS dysfnction

Question 18

What is the Braak staging system for parkinson’s disease?

Answer 18

Stage 1: vagus nerve and olfactory nerve
Constipation and sense of smell reduced
Stage 2: Reticular formation - REM sleep disturbance
Stage 3: substantia nigra - physical symptoms
Stage 4: Temporal cortex - memory problems
Stage 5: Neocortex and prefrontal cortex - dementia

Question 19

What are the pathogenesis of parkinson’s disease

Answer 19

degredation of the dopamine neurons in the pars compacta f the substantia nigra.
Accumulation of Lewy bodies in those damaged neurons containing alpha synuclean

There is a genetic component alpha synuclean gene
Toxins can cause it rapidly - MPTP parkinsonism
Infection

Question 20

How is OD diagnosed?

Answer 20

Two cardinal signs - resting tremor, bradykineia, rigidity, postural anormalities
Progressive course
Response to levodopa
No other cause

Question 21

What are the treatments for parkinson’s disease?

Answer 21

Levodopa + dopa decarboxylase inhibitor (carbidopa)
Anticholinesterases
Monoamine oxidase B inhibitor

Apomorphine: Liquid absorbed from subcutaneous fat avoiding first pass metabolism
Duodopa: Liquid levodopa absorbed from the duodenum to get around short half life

Stereotactic thalamotomy (for tremor)
Stereotactic pallidotomy (improve all features of Parkinson’s disease, including dyskinesias)
Transplantation of dopamine-producing tissue (e.g. fetal tissue)
 Deep brain stimulation (inhibits overactive neurons without the need for a destructive procedure)