Object: Gamma Knife radiosurgery (GKRS) is the least invasive treatment option for medically refractory, intractable trigeminal neuralgia (TN) and is especially valuable for treating elderly, infirm patients or those on anticoagulation therapy. The authors reviewed pain outcomes and complications in TN patients who required 3 radiosurgical procedures for recurrent or persistent pain.
Methods: A retrospective review of all patients who underwent 3 GKRS procedures for TN at 4 participating centers of the North American Gamma Knife Consortium from 1995 to 2012 was performed. The Barrow Neurological Institute (BNI) pain score was used to evaluate pain outcomes.
Results: Seventeen patients were identified; 7 were male and 10 were female. The mean age at the time of last GKRS was 79.6 years (range 51.2-95.6 years). The TN was Type I in 16 patients and Type II in 1 patient. No patient suffered from multiple sclerosis. Eight patients (47.1%) reported initial complete pain relief (BNI Score I) following their third GKRS and 8 others (47.1%) experienced at least partial relief (BNI Scores II-IIIb). The average time to initial response was 2.9 months following the third GKRS. Although 3 patients (17.6%) developed new facial sensory dysfunction following primary GKRS and 2 patients (11.8%) experienced new or worsening sensory disturbance following the second GKRS, no patient sustained additional sensory disturbances after the third procedure. At a mean follow-up of 22.9 months following the third GKRS, 6 patients (35.3%) reported continued Score I complete pain relief, while 7 others (41.2%) reported pain improvement (BNI Scores II-IIIb). Four patients (23.5%) suffered recurrent TN following the third procedure at a mean interval of 19.1 months.
Conclusions: A third GKRS resulted in pain reduction with a low risk of additional complications in most patients with medically refractory and recurrent, intractable TN. In patients unsuitable for other microsurgical or percutaneous strategies, especially those receiving long-term oral anticoagulation or antiplatelet agents, GKRS repeated for a third time was a satisfactory, low risk option.
Keywords: BNI = Barrow Neurological Institute; GKRS = Gamma Knife radiosurgery; Gamma Knife; MVD = microvascular decompression; NAGKC = North American Gamma Knife Consortium; PRGR = percutaneous retrogasserian glycerol rhizotomy; TN = trigeminal neuralgia; functional neurosurgery; microvascular decompression; refractory; stereotactic radiosurgery; trigeminal neuralgia.