Repeat Gamma Knife radiosurgery relieves pain in majority of patients with trigeminal neuralgia, long-term data indicate
Tuesday, December 16 2008 | Comments
Repeat Gamma Knife radiosurgery (GKRS) relieves pain in more than two-thirds of patients with trigeminal neuralgia, according to long-term follow-up data, although additional studies are needed to determine an optimized treatment protocol.
Researchers evaluated 93 patients with trigeminal neuralgia who underwent stereotactic radiosurgery at the Medical University of Graz
in Austria between 1994 and 2006. Of these patients, 22 had pain recurrence or inadequate pain relief and underwent a second GKRS procedure an average of 18.8 months (range, 6-63 months) after the initial procedure. The mean prescription dose was 75.2 Gy for the first treatment and 74.3 Gy for the second treatment.
The researchers used the Barrow Neurological Institute
(BNI) Pain Intensity Scale to measure pain relief and the BNI Facial Numbness Scale to measure facial numbness.
At a mean follow-up of 5.4 years after the second GKRS treatment, pain relief was noted in 16 of the 22 patients (72.7%). The other 6 patients experienced recurrent pain at a mean of 9.3 months (range, 1-24 months); 2 of the 6 patients underwent a third and fourth GKRS treatment.
One patient was subsequently lost to follow-up. As a result, 21 of the patients were included in the BNI pain scale analysis, which showed that 16 (76.2%) were pain-free or had only occasional pain without medication (BNI grade of I or II). All 21 of the patients reported that their pain had improved after the procedure.
Fourteen of 19 patients (74.3%) reported experiencing new or increased facial numbness after GKRS. Only 1 patient classified the numbness as "somewhat" bothersome, however, and none reported having "very" bothersome numbness.
The researchers said the higher delivered dose was most likely the reason for the greater incidence of facial numbness. Nonetheless, they deemed repeat GKRS to be safe.
"Further investigations require multicenter participation with adapted treatment protocols and standardized outcome measurements," they concluded. (Gellner V, et al. J Neurol Neurosurg Psychiatry