Sample of handwriting
- Micrographia is somewhat insensitive, but is specific for distinguishing PD from other causes of tremor.
- Macrographia is more typical of dystonic tremor and HD.
- Dystonic posturing may become obvious with writing.
Spiral drawing
The Archimedes spiral drawing captures the frequency, amplitude and direction of tremor. Encourage the patient to draw spontaneously (ideally not copy the doctor’s version), without resting the arm on the paper in an effort to steady the hand.
Since it requires a continuous pen movement without brief breaks as seen when writing words, the spiral emphasises the abnormal movements of dystonia, hypokinesia and tremor4. (Similarly, when testing for micrographia, it is necessary for the patient to write continuously in order to bring out the sequence effect of progressive decrease in amplitude of the letters).
The patient can be asked to draw continuous loops (or cursive “Ls”) across a page, trying not to break when drawing the loops. The patient could also be asked to draw a line connecting dots.
Examples of abnormalities for specific conditions may be found in the following sections under Types of Tremor:
Typical characteristics of tremor types seen in writing and drawing tasks1.
