Essential tremor: functional disability vs. subjective impairment.

78 patients with essential tremor (ET) were investigated to uncover correlation and discrepancies between functional (motor) disabilities and subjective impairment. Various self-rating scales (Zung, v. Zerssen etc.) were used for the assessment of the latter: 2/5 of the patients rated themselves as severely impaired; 1/3 was depressive. Patients who showed nearly the same functional (motor) disability felt very differently subjectively impaired. Semiquantitative clinical scores of action tremor correlated best with the subjective impairment in activities of daily living. Objective measurements of motor disability were performed with the "Motorische Leistungsserie nach Schoppe" (motor performance test) and showed good correlation to the subjective impairment in simple tasks of every day life, such as drinking from a glass, eating soup, and writing. Asking for the subjective impairment in these tasks allows to estimate the objective disability correctly. This may be of value in long-term studies of essential tremor.