Table 5.14.

Types of hand tremor and distinguishing features

	Exaggerated physiologic	Essential tremor	Parkinsonian tremor
Occurrence	Posture, movement	Posture, movement	Resting limb
Frequency	6–12 Hz	5–9 Hz	4–6 Hz
Other findings		Head or voice tremor	Chin tremor, bradykinesia, cogwheel rigidity
Causes	Drugs: prednisone, lithium, valproic acid, SSRIs, TCAs, beta adrenergic drugs, caffeine and other stimulants	Familial (genetic)	Dopamine-depleting drugs, including antipsychotics and antiemetics
	Anxiety		Parkinson’s disease
	Hyperthyroidism
	Alcohol or sedative withdrawal