Types of Involuntary Movements:
Tremor – rhythmical movements
- Resting Tremor – e.g. Parkinson’s disease: 4-8 Hz
- facilitated by mental arithmetic or moving contralateral limb
- Postural Tremor – e.g. Physiological – i.e. “Essential Tremor”
- facilitated by sympathetic activation: fear, cold, exhaustion
- Intention Tremor – cerebellar disease
- intensified by voluntary movement
Twitches – irregular, rapid movements
- Chorea (corpus striatum)
- non-repetitive, abrupt, involuntary, distal jerky movements
- commonly unilateral
- [dopaminergic] > [cholinergic]
- lack of sustained hand grip (“milkmaids grip”)
- ask patient to hold out hand: finger/thumb hyperextension and wrist flexion (due to hypotonia)
- examine eyes
- exophthalmos (thyrotoxicosis)
- Keiser-Fleischer rings (Wilson’s Disease)
- conjunctival injection (polycythaemia)
- “poke out tongue” → frequent retraction (serpentine movements)
- skin rashes (SLE, vasculitis)
- signs of renal failure in young (Sydenham’s chorea)
- higher centres dementia (Huntington’s chorea)
- reflexes: abdominal brisk; deep tendon reduced (hypotonia)
- Hemiballismus (contralateral subthalamus) — unilateral wild rotatory movements of proximal joints ± during sleep (may injure their arm)
- Myoclonus
- Tics – can be suppressed e.g. blinking
Twisting – irregular, slow movements
- Athetosis (putamen) – slow, sinuous writhing, distal movements at rest
- (Pseudo-athetosis: athetoid movements in fingers in patients with severe proprioceptive loss, especially when they shut their eyes)
