title: Abnormal involuntary movements induced by subthalamic nucleus stimulation in parkinsonian patients.
abstract: Chronic electrical subthalamic nucleus (STN) stimulation is under investigation for alleviating parkinsonian symptoms. STN alterations may carry the risk of provoking abnormal involuntary movements (AIMs). We took advantage of the reversibility of the stimulation technique to assess the possibility of inducing AIMs, using different electrical variables with or without concomitant levodopa intake. Above a given threshold voltage, stimulation could induce contralateral distal mobile AIMs or hemiballism in the off-drug condition in two patients. AIMs occurred after a latency that varied from a few minutes up to several hours after switching on the stimulator. Hemiballism immediately disappeared upon switching off the stimulator. In these patients, levodopa had never provoked that type of AIMs before surgery. Levodopa-induced AIMs were not modified by electrical stimulation, but off-phase dystonia disappeared in one patient. Stimulation of the STN induced AIMs that resembled both those observed following spontaneous lesions of the STN and levodopa-induced diphasic AIMs in parkinsonian patients. As electrical stimulation provoked AIMs and antiparkinsonian benefit occurred with different electrical variables and different timing, the mechanisms responsible for these two effects could be distinct.
authors.affiliation: Department of Clinical and Biological Neurosciences, Joseph Fourier University of Grenoble, France.
authors.forename: P
authors.initials: P
authors.lastname: Limousin
authors.forename: P
authors.initials: P
authors.lastname: Pollak
authors.forename: D
authors.initials: D
authors.lastname: Hoffmann
authors.forename: A
authors.initials: A
authors.lastname: Benazzouz
authors.forename: J E
authors.initials: JE
authors.lastname: Perret
authors.forename: A L
authors.initials: AL
authors.lastname: Benabid
mesh_terms: D000978:Antiparkinson Agents / Q000008:administration & dosage / Q000009:adverse effects; D001971:Bromocriptine / Q000008:administration & dosage / Q000009:adverse effects; D003131:Combined Modality Therapy; D004292:Dominance, Cerebral / Q000187:drug effects / Q000502:physiology; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D009048:Motor Skills / Q000187:drug effects / Q000502:physiology*; D009460:Neurologic Examination / Q000187:drug effects; D010300:Parkinson Disease / Q000503:physiopathology*; D013787:Thalamic Nuclei / Q000187:drug effects / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D001971:Bromocriptine; D007980:Levodopa