To the Enditor.
—In his article Heilman1 describes irregular, asynchronous movements of the trunk and proximal legs that occur only when a person stands and that may eventually progress to loss of extensor tone with the patient falling. In two of three patients, these movements were significantly reduced by clonazepam. Dr Heilman is to be thanked for bringing this condition and its treatment to our attention, but I wonder if tremor is an appropriate designation. Because of their irregular and asynchronous nature, these movements may be myoclonic. Movements appropriately termed tremor are rhythmic, a definition that excludes myoclonus as well as most types of cerebellar ataxia and dysmetria. Clonazepam is also known to be useful in the therapy of several types of myoclonus.Unfortunately, no objective measurements of these movements were published and the reader is therefore uncertain about the nature of the movements. One hopes the day will
Robert R. Young. Movement Disorders and Objective Measurements. Arch Neurol. 1985;42(10):932. doi:10.1001/archneur.1985.04060090010002