Dopa-responsive postural tremor in Parkinson's disease

In the present study postural tremor of the hands was assessed in 20 patien ts with idiopathic Parkinson's disease. In 16 cases postural tremor was bil ateral. Clinical rating and spectral analysis of accelerometry and electrom yography were performed with and without loading of the limb. All assessmen ts were done before and after administration of levodopa. Accelerometry dis closed different types of postural tremor. In 27 hands a postural tremor os cillating in the frequency-band of rest-tremor was found (Type I). In 9 han ds postural tremor occurred without corresponding rest tremor or with a dif ferent peak frequency (Type II). Type II tremor was further differentiated according to the presence (4 hands) or absence (5 hands) of peripheral comp onents. Tremors with peripheral components showed slowing of peak frequency with weight load and partly lack of EMC synchronisation. All types of post ural tremor responded well to levodopa challenge.