Twelve clinical pearls to help distinguish essential tremor from other tremors.

The features of the tremor in essential tremor are often not fully appreciated, and essential tremor is frequently mis-diagnosed. Close inspection indicates that the tremor is characterized by a specific and definable pattern of features. Recognizing these features will aid in the diagnosis. The features are as follows: (1) kinetic tremor is greater than postural tremor, for postural tremor, (2) wrist tremor is greater than metacarpal joint tremor and wrist flexion-extension tremor is greater than wrist rotation tremor, (3) tremor is regularly recurrent and without directionality, (4) arm tremor is generally mildly asymmetric, (5) postural tremors (right, left) are out of phase, (6) on spiral drawing, a single tremor orientation axis is often identifiable, (7) intention tremor (finger-nose-finger) occurs in 50% of cases, (8) rest tremor (in the arms but not the legs) can occur as a late feature, (9) arm tremor precedes head tremor, and head tremor occurs mainly in women, (10) head tremor, unless severe, resolves while supine, (11) patients are often unaware of head tremor, (12) tremor is progressive.