Clinical Criteria for the Diagnosis of Essential Tremor

 

Features of essential tremor:

(1) The median age of onset is > 70 years.

(2) action (akinetic or postural) tremor: occurs during sustained extension of the arm or during voluntary motion

(3) distal tremor: greatest amplitude at the wrist and least at the shoulder

(4) The tremor in the hands is regularly oscillatory (rhythmic rather than irregular and jerky) and tends to range from 4-12 Hz.

(5) mildly asymmetric

(6) 30-50% are familial, showing an autosomal dominant pattern of inheritance

(7) In addition to the upper extremities, the tremor may affect the head, voice, trunk and legs

(8) Often disabling due to uncontrollable shaking of the hands.

 

Criteria for definite essential tremor - all of the following:

(1) postural tremor in one or both arms, of moderate amplitude

(2) tremor in one or both arms, of moderate amplitude, during 4 or more tasks, such as:

(2a) pouring water

(2b) using a spoon to drink water

(2c) drinking water

(2d) finger-to-nose maneuver

(2e) drawing a spiral

(3) tremor interferes with 1 one more activities of daily living

(4) medications (lithium, prednisone, levothyroxine, beta-adrenergic bronchodilators, valproate, selective serotonin reuptake inhibitors, others), caffeine, nicotine and alcohol are not the cause of the tremor

(5) other neurologic conditions are not the cause for the tremor

 

Criteria for probable essential tremor:

(1) The patient does not meet the criteria for definite essential tremor.

(2) one or both of the following is present:

(2A) tremor in one or both arms, of moderate amplitude, during 4 or more tasks, such as:

(2a1) pouring water

(2a2) using a spoon to drink water

(2a3) drinking water

(2a4) finger-to-nose maneuver

(2a4) drawing a spiral

(2B) head tremor is present

(3) medications (lithium, prednisone, levothyroxine, beta-adrenergic bronchodilators, valproate, selective serotonin reuptake inhibitors, others), caffeine, nicotine and alcohol are not the cause of the tremor

(4) other neurologic conditions are not the cause for the tremor

 

where:

• I am a little unsure of how to use head tremor for the diagnosis of probable essential tremor. Either head tremor is a substitute for the upper extremity tremor (none required), or it can be used when the upper extremity tremor involves fewer than 4 tasks. I will use the latter interpretation in the implementation.