Parkinson’s Disease

Definition: Degenerative disease affecting the basal ganglia causing increasing bradykinesia and rigidity with associated tremor and instability.

Causes: Idiopathic. Cause remains unknown but there are possible familial links. Dopaminergic neurons in substantia nigra are depleted and Lewy bodies are present, and other atrophic changes. Decreased dopamine production reduces inhibition of cells which become more active and inhibit the cortex resulting in bradykinesia.

Examination: Parkinson’s syndrome presents with the classic triad of rigidity, resting tremor and bradykinesia. Patient’s speech and motor skills are affected. Prior to developing severe bradykinesia patient may complain of vague symptoms of tiredness, mental slowness, depression, aching muscles and micrographia (small handwriting). Posture is typically rigid and stopped. Tremor is described as cogwheel and is apparent at rest in upper extremeties. Gait displays hesitance to initiate walking, then short shuffling gait which speed up (festination). Leg movement is described as ‘leadpipe’. Normal arm swing is reduced and balance is poor when turning. Face lacks normal spontaneous facial expression, skin is often greasy and there is tongue tremor. Tremor can present unilaterally at first in upper limbs and typically persists with movement.