CLINICO-TREMORGRAPHIC FEATURES OF NEUROLEPTIC-INDUCED TREMOR

Instrumental tremorgrams have been used to improve the diagnostic accu racy of various movement disorders, including tardive akathisia. The a im of the present work was to evaluate their place in the diagnosis of neuroleptic-induced tremor and to determine whether they can help to differentiate this disorder from other neuroleptic-induced movement di sorders and from other types of tremor. Fourteen psychiatric patients treated with various neuroleptic medications were diagnosed as having neuroleptic-induced tremor on the basis of clinical criteria. They und erwent accelerometric recordings following diagnosis. All patients dem onstrated upper-limb tremor; four also had involvement of the lower li mbs, jaw or tongue. Most demonstrated both resting and postural tremor , the latter being the more prominent. The tremor was mainly rhythmic, regular and sinusoidal. It did not significantly interfere with activ ities of daily living in the majority of patients, but four did exhibi t some degree of impairment. Repeated accelerometric recordings showed constant and regular waveforms and frequencies (between 4 and 7 Hz) i n each patient. We conclude that the presence of repeated constant wav eforms and frequencies on accelerometric tracings may serve as confirm ation of the diagnosis of neuroleptic-induced tremor. In light of the findings of this and other studies, we suggest that tremorgrams may be helpful in differentiating neuroleptic-induced tremor from other neur oleptic-induced movement disorders (e.g., tardive dyskinesia and tardi ve akathisia) and from psychogenic tremor. Although these techniques m ay also assist in the differentiation of neuroleptic-induced tremor fr om some tremor disorders (e.g., asterixis or ataxic tremor), their ove rall potential to distinguish it from other types of organic tremor is more limited. Int Clin Psychopharmacol 13:115-120 (C) 1998 Lippincott -Raven Publishers.