Parkinson's Disease and Parkinsonism

Question 1

What is the parkinsonism syndrome?

Answer 1

Rigidity, akinesia/bradykinesia, resting tremor

Question 2

What is dystonia?

Answer 2

Prolonged muscle spasms and abnormal postures.

Question 3

Sections through the brainstem show what changes in Parkinson’s disease?

Answer 3

Show loss of the normally dark pigment in the substantia nigra and locus coeruleus.

Pigment loss correlates with dopaminergic cell loss.

Question 4

What is a neurohistological hallmark of PD?

Answer 4

Lewy bodies.

Question 5

What is the most important risk factor for Parkinson’s disease?

Answer 5

Age > 60 yrs.

Pesticide exposure and family history are possible other risk factors.

Question 6

Describe bradykinesia as seen in PD and how you could assess it?

Answer 6

Slowness of movement with progressive loss of amplitude or speed during attempted rapid alternating movements of body segments.

• ask patient to open and close hand, or foot tap.
• hypomimia (decreased facial expressions and blinking)
• Hypophonia
• Micrographia (progressive smaller handwriting)

Question 7

Describe the rest tremor seen in Parkinson’s disease?

Answer 7

Rhythmic oscillatory involuntary movement of affected body part at rest
– Vanishes with acLve movement
– Typically reappears ader few sec when arms held outstreched (‘reemerging tremor’)
– Tremor frequency in low to midrange (36 Hz) with variable amplitude
– Most disLnguishing resLng tremor is “Pillrolling”type or
– Finger flexionextension or abducLonadducLon
– Tremor can also affect lower limbs, jaw, and tongue
– Head tremor is not typical for PD
– In clinical pracLce, tremor is best observed while paLent is focused on a parLcular mental task (counLng backwards from 100)

Question 8

Describe rigidity as seen in Parkinson’s disease.

Answer 8

Increased muscle tone felt during examinaLon by passive movement
– Resistance is felt throughout full range of movement
– No increase with higher mobilizing speed
– This disLnguishes rigidity from spasLcity owing to UMN lesions
– Rigidity + resLng tremor = “cog wheel” rigidity (especially felt at wrist)
– PosiLve Froment’s maneuver (rigidity increases in examined body segment by voluntary movement of other body parts)

Question 9

What are some of the non-motor features of parkinson’s disease?

Answer 9

• Hyposmia
• REM sleep disorder
• Constipation
• Depression

Others e.g. dementia and hallucinations occur later.

Question 10

Some possible investigations of PD include:

Dopamine functional imaging (PET with fluora dopa)

What sort of challenge can be indicative?

Answer 10

A positive levo dopa challenge.

Question 11

What is the clinical vignette of multi system atrophy?

Answer 11

Common cause of degeneraLve Parkinsonism
– Age of onset in late 6th or 7th decades
– Core triad of dysautonomia, cerebellar features, and Parkinsonism
– Jerky postural tremor, pyramidal signs (generalized hyperreflexia and extensor plantar responses)
– SubopLmal and shortlived levodopa response in 1/3 of paLents – Other suggesLve features: severe dysarthria or dysphonia, marked antecollis, inspiratory sighing, orofacial dystonia – MRI may show cerebellar and ponLne atrophy (“hot cross bun” sign, or hyperintense rim surrounding the putamen in T2weighted sequences