Figure 2.

Archimedes spiral tests and EMG recordings of ET patients described in this study. (A–C) Archimedes spirals. Archimedes spirals were drawn on a digitizing tablet. L represents the non-dominant left hand, and R represents the dominant right hand. Left- and right-hand spirals of patients 1(A), 2 (B) and 4 (C) are shown. (D and E) Surface EMG (SEMG) recordings. SEMG recordings of Patient 1 at the postural position at rest and with the arms outstretched are illustrated. The upper register of each figure corresponds to the biceps and the lower to the triceps. SEMGs show a tremor with the synchronous pattern at rest (D) and an alternating pattern with the arms outstretched (E).