Can subthalamic nucleus stimulation reveal parkinsonian rest tremor?; [La stimulation du noyau subthalamique peut-elle révéler un tremblement de repos parkinsonien ?]

Introduction. Rest tremor, one of the main symptoms in Parkinsons disease (PD), is dramatically improved following subthalamic nucleus stimulation (STN). Results are often better than after L-dopa treatment. The occurrence of rest tremor after neurosurgery in patients without preoperative tremor is uncommon. Aim. The aim of this work was to investigate the role of subthalamic nucleus stimulation in the appearance of parkinsonian rest tremor. Patientsresults. Thirty PD patients (14%) out of 215 undergoing STN deep brain stimulation had an akinetorigid form of the disease, without preoperative tremor 11 years after onset of the disease. Six of them experienced the appearance of tremor six months after bilateral STN stimulation when the stimulator was switched off in the Off medication state. This de novo parkinsonian tremor was improved by L-dopa treatment and disappeared when the stimulator was turned on. Conclusion. This finding suggests that infraclinical parkinsonian tremor is probably present in all PD patients. © 2008 Elsevier Masson SAS.