Gamma knife thalamotomy for multiple sclerosis tremor.
BACKGROUND
Some patients with MS suffer from disabling tremor. Improvement with medical treatment is modest, at best. Stereotactic surgery targeting the vim nucleus of the thalamus has been successful in alleviating MS tremor. Gamma knife radiosurgery represents a minimally invasive alternative to radiofrequency lesioning and DBS that can provide improvement in patients suffering from essential and parkinsonian tremor. We reviewed our experience with GK thalamotomy in the management of six consecutive patients suffering from disabling MS tremor.


METHODS
The median age at the time of radiosurgery was 46 years (range, 31 to 57 years). Intention tremor had been present for a median of three years (range 8 months to 12 years). One 4-mm isocenter was used to deliver a median maximum dose of 140 Gy (range, 130-150 Gy) to the vim nucleus of the thalamus opposite the side of the most disabling tremor. Clinical outcome was assessed using the Fahn-Tolosa-Marin scale.


RESULTS
The median follow-up was 27.5 months (range, 5-46 months). All patients experienced improvement in tremor after a median latency period of 2.5 months. More improvement was noted in tremor amplitude than in writing and drawing ability. In four patients, the tremor reduction led to functional improvement. One patient suffered from transient contralateral hemiparesis, which resolved after brief corticosteroid administration. No other complication was seen.


CONCLUSIONS
Gamma knife radiosurgical thalamotomy is effective as a minimally invasive alternative to stereotactic surgery for the palliative treatment of disabling MS tremor.
Mathieu
David
D
Department of Neurological Surgery, University of Pittsburgh, Center for Image-Guided Neurosurgery, Pittsburgh, PA 15213, USA.
Kondziolka
Douglas
D
Niranjan
Ajay
A
Flickinger
John
J
Lunsford
L Dade
LD
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006236:Handwriting; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications*; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D011597:Psychomotor Performance / Q000502:physiology; D016634:Radiosurgery / Q000009:adverse effects; D013787:Thalamic Nuclei / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D014202:Tremor / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*