Distinguishing psychogenic and essential tremor

Area of Science:

• Neurology
• Movement Disorders
• Clinical Diagnosis

Background:

• Essential tremor (ET) and psychogenic tremor (PT) are distinct neurological conditions.
• Differentiating ET from PT is crucial for accurate diagnosis and treatment.
• Key clinical features like distractibility, suggestibility, and entrainment are noted in PT but require systematic examination for diagnostic utility.

Purpose of the Study:

• To systematically examine the sensitivity and specificity of clinical findings in differentiating psychogenic tremor (PT) from essential tremor (ET).
• To identify reliable clinical features that can reliably distinguish between PT and ET.

Main Methods:

• Collected patient data on tremor onset, spontaneous remissions, family history, and employment history.
• A blinded rater evaluated video segments using a standardized protocol, focusing on distractibility, suggestibility, and entrainment.
• Analyzed data from 45 subjects (33 ET, 12 PT) using statistical comparisons.

Main Results:

• Psychogenic tremor (PT) subjects were more likely to report sudden onset, spontaneous remissions, and shorter tremor duration.
• Family history of tremor was more prevalent in the essential tremor (ET) group.
• Distractibility during tasks (finger tapping, serial 7s) and suggestibility (tuning fork) were more common in PT. Entrainment did not differ between groups.

Conclusions:

• A history of sudden onset and spontaneous remissions, coupled with examination findings of distractibility and suggestibility, are strong predictors of psychogenic tremor (PT).
• These clinical features aid in differentiating PT from essential tremor (ET).