Figure 5.

Dystonic tremor. (A) Oscillations occur in all sections of the spirals, denoting a multidirectional axis. The amplitude and frequency also vary, giving a jerky appearance. (B) There is evidence of forceful pen pressure consistent with dystonic posturing in the spiral drawings and handwriting samples. We have observed that many patients with dystonia have a tendency to draw more than three turns of the spiral. The left-handed spiral demonstrates a multidirectional tremor axis. Straight lines drawn at a steady rate, particularly the vertical one, show that the frequency is variable. On horizontal line and spiral drawings, the tremor amplitude is asymmetric, being larger on the right. (C) The spiral and line drawings demonstrate a multidirectional tremor axis with a jerky pattern caused by variable amplitude and frequency—all features consistent with dystonic tremor. In this case, the handwriting is normal with very little tremor intrusion.