Single-institution retrospective series of gamma knife radiosurgery in the treatment of multiple sclerosis-related trigeminal neuralgia: factors that predict efficacy.
BACKGROUND
Gamma knife radiosurgery (GKRS) has been reported as a treatment option for multiple sclerosis (MS)-related trigeminal neuralgia.


OBJECTIVE
To report the outcomes of a single-institution retrospective series of MS-related trigeminal neuralgia.


METHODS
Between 2002 and 2010, 35 patients with MS-related trigeminal neuralgia were treated with GKRS. The median maximum dose was 90 Gy. Data were analyzed to determine the response to GKRS and factors that may predict for efficacy.


RESULTS
Of the 35 patients, 88% experienced a Barrow Neurological Institute (BNI) pain score of I-III at 3 months after GKRS. Kaplan-Meier estimates of 1-, 2- and 5-year freedom from BNI IV-V pain relapse were 57, 57 and 52%, respectively. Numbness was experienced by 39% of patients after GKRS, though no patients reported bothersome numbness. Several differences were noted between how the MS-related variant responded to GKRS and what has previously been reported for idiopathic trigeminal neuralgia. These include the observations that development of post-GKRS numbness did not predict for treatment response (p = 0.62) and that dorsal root entry zone dose did not predict for freedom from pain relapse (odds ratio 1.01, p = 0.1). Active smoking predicted for freedom from pain relapse (odds ratio 67.4, p = 0.04).


CONCLUSIONS
GKRS is a viable noninvasive treatment option for MS-related trigeminal neuralgia.
Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio, USA.
Michael
M
Weller
Kopriva
K
Marshall
James F
JF
Lovato
J Daniel
JD
Bourland
Allan F
AF
deGuzman
Michael T
MT
Munley
Edward G
EG
Shaw
Stephen B
SB
Tatter
Michael D
MD
Chan
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications*; D015999:Multivariate Analysis; D009657:North Carolina; D016634:Radiosurgery; D012189:Retrospective Studies; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000209:etiology* / Q000601:surgery*