Trigeminal cisternal injection of glycerol for treatment of chronic intractable cluster headaches.

: Medical treatment of chronic cluster headaches (cluster headaches that occur frequently without remission) can be very difficult. In many patients, the pain remains severe despite all medication trials. For these patients, previous reports recommend radiofrequency trigeminal rhizotomy, which risks corneal anesthesia and subsequent corneal decompensation. As a safer, yet effective, treatment, retro-Gasserian injections of glycerol were given to eight patients having intractable chronic cluster headaches. Needle penetration into the trigeminal cistern, glycerol amount (0.55 ml), and length of patient elevation after the procedure (80-90 degrees upright for 10 h) were modified for maximal exposure of the V1 division. Three patients required one additional injection, and one patient required two additional injections. Verbal pain scales (means +/- 1 standard error of the mean) were: 9.1 +/- 0.30 (preoperative), 2.6 +/- 1.10 (1 mo postoperative), and 2.1 +/- 0.64 (1 yr postoperative). Daily headache frequency decreased from 6.0 +/- 2.0 (preoperative) to 0.2 +/- 0.09 (i.e., one headache every 5 days) (1 yr postoperative). Three of the eight patients had no headaches after 1 year. There were no instances of corneal or facial anesthesia. One year postoperatively, five patients required no medication, and three remained on low doses of medication for headache treatment. In contrast to previous limited reports of glycerol injections for cluster headaches, results with these patients having chronic cluster headaches support the use of glycerol injections as a viable treatment alternative, with significant pain relief and corneal safety.