Long-term measurement of tremor: early diagnostic possibilities

Summary

Long-term recording is able to detect small amounts of low intensity tremor, which due to its intermittent manifestation may be missed during the routine clinical examination. Examples are given from patients with an established diagnosis of Parkinson’s disease in whom tremor could be observed only under special conditions, such as mental or emotional stress, or was just reported by the patient but could not be observed by the examiner. For reevaluation, data sample epochs classified by the automatic analysis as exhibiting tremor can be stored and visually inspected. Problems may arise with the diagnostic classification of tremor based on its frequency, since a considerable variation in frequency is observed in long-term recordings from parkinsonian patients. This may partially originate from the otherwise very advantageous fact that subjects are not restricted to a fixed position of the arms but are recorded under every day conditions.