Percutaneous retrogasserian glycerol rhizolysis for treatment of chronic intractable cluster headaches: Long-term results

OBJECTIVE: To analyze the long-term effectiveness and safety of percutaneou s retrogasserian glycerol rhizolysis (PRGR) in the treatment of medically r efractive chronic cluster headache (CH). The current mainstay of surgical i ntervention for these patients is percutaneous radiofrequency retrogasseria n rhizotomy (PRFR). However, when performed for V1 distribution pathology, PRFR can lead to corneal anesthesia, which places the patient at risk for f uture visual loss. It also increases the risk of facial dysesthesia. METHODS: In a prospective, consecutive series, 18 patients with intractable CH were followed for a mean of 5.2 years (range, 40-78 mo) after they had undergone PRGR, performed using a standard technique. The significance of t his technique as an alternative to PRFR is that it should result in a lower rate of both corneal and facial anesthesia and provide an acceptable degre e of pain relief. RESULTS: Fifteen patients (83%) obtained immediate pain relief after one or two injections; the majority of them experienced relief after the first in jection. CH recurred in seven patients (39%) over the course of the study. Two of these patients received a second injection, and both met with equal success. Two other patients underwent PRFR. Excluding those who underwent P RFR, the overall daily headache frequency decreased from 3.5 +/- 0.3 attack s per day preoperatively to 0.6 +/- 0.2 attacks per day at last follow-up. The severity of these headaches, as assessed by verbal pain scales, also de creased from 10 preoperatively to 4.4 +/- 1.4 at follow-up. None of the pat ients, including those who required a second procedure, experienced corneal anesthesia or facial dysesthesia. CONCLUSION: This study provides the first long-term evaluation of PRGR for the treatment of medically refractive chronic CH and lends support to both the safety and long-term efficacy of this procedure. Further investigations are needed to compare directly the relative efficacy and safety of PRGR an d PRFR.