Transcranial magnetic stimulation of the cerebellum in essential tremor: a controlled study.
BACKGROUND
Growing evidence implicates an overactivity of the cerebellum in the pathophysiology of essential tremor. In a small series of patients, we explored the acute effects and therapeutic possibilities of low-frequency repetitive transcranial magnetic stimulation (rTMS) of the cerebellum in patients with essential tremor in a double-blind, crossover, placebo-controlled design.


METHODS
Ten patients with essential tremor underwent an active and a sham rTMS session, at a 1-week interval. The rTMS was performed with a focal double 70-mm butterfly coil (maximum peak field of 2.2 T) applied 2 cm below the inion. Each session consisted of 30 trains of 10-second duration separated by 30-second pauses, at 100% of the maximum output intensity and at 1-Hz frequency. Major evaluation outcomes were the score on the Tremor Clinical Rating Scale and accelerometric recordings obtained before (-5 minutes), immediately after (+5 minutes), and 1 hour after (+60 minutes) each rTMS session. Both clinical and accelerometric measurements were obtained by a blinded neurologist.


RESULTS
On the +5-minute assessment, active rTMS produced a notable tremor improvement compared with sham rTMS, as evidenced by a significant reduction in scores on the clinical rating scale and accelerometric values. At +60 minutes, no clinical or accelerometric benefit was evidenced. No adverse effects of rTMS were observed.


CONCLUSIONS
This exploratory study of the potential therapeutic properties of rTMS on essential tremor showed an acute antitremor effect. Further investigation in search of a more lasting benefit is warranted.
Gironell
Alexandre
A
Servei de Neurologia, Hospital de Sant Pau, Av Sant Antoni Ma Claret 167, 08025 Barcelona, Catalonia, Spain. agironell@cataloniamail.com
Kulisevsky
Jaime
J
Lorenzo
José
J
Barbanoj
Manel
M
Pascual-Sedano
Berta
B
Otermin
Pilar
P
D000368:Aged; D002531:Cerebellum / Q000503:physiopathology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D012720:Severity of Illness Index; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation; D014202:Tremor / Q000503:physiopathology* / Q000628:therapy*