Retrosigmoid approach for glycerin rhizotomy in the treatment of trigeminal neuralgia without overt arterial compression: updated case series

Internal neurolysis versus intraoperative glycerin rhizotomy for trigeminal neuralgia

OBJECTIVE

Internal neurolysis (IN) and intraoperative glycerin rhizotomy (ioGR) are emerging surgical options for patients with trigeminal neuralgia without neurovascular contact. The objective of this study was to compare the neurological outcomes of patients who underwent IN with those of patients who underwent ioGR.

METHODS

The authors retrospectively reviewed all patients who underwent IN or ioGR for trigeminal neuralgia at our institution. Patient demographic characteristics and immediate postoperative outcomes, as well as long-term neurological outcomes, were compared.

RESULTS

Of 1044 patients who underwent open surgical treatment for trigeminal neuralgia, 56 patients underwent IN and 91 underwent ioGR. Of these 147 patients, 37 had no evidence of intraoperative neurovascular conflict. All patients who underwent IN and 96.7% of patients who underwent ioGR had immediate postoperative pain relief. At last follow-up, patients who underwent IN had lower Barrow Neurological Institute (BNI) pain intensity scores (p = 0.05), better BNI facial numbness scores (p < 0.01), and a greater degree of pain improvement (p = 0.05) compared with those who underwent ioGR. Patients who underwent IN also had significantly lower rates of symptomatic pain recurrence (p < 0.01) at last follow-up over an average of 9.5 months.

CONCLUSIONS

IN appears to provide patients with a greater degree of pain relief, lower rates of facial numbness, and lower rates of pain recurrence compared with ioGR. Future prospective studies will better characterize long-term pain recurrence and outcomes.

Trigeminal Neuralgia: Current Approaches and Emerging Interventions

Trigeminal neuralgia (TN) has been described in the literature as one of the most debilitating presentations of orofacial pain. This review summarizes over 150 years of collective clinical experience in the medical and surgical treatment of TN. Fundamentally, TN remains a clinical diagnosis that must be distinguished from other types of trigeminal neuropathic pain and/or facial pain associated with other neuralgias or headache syndromes. What is increasingly clear is that there is no catch-all medical or surgical intervention that is effective for all patients with trigeminal neuralgia, likely reflective of the fact that TN is likely a heterogenous group of disorders that jointly manifests in facial pain. The first-line treatment for TN remains anticonvulsant medical therapy. Patients who fail this have a range of surgical options available to them. In general, microvascular decompression is a safe and effective procedure with immediate and durable outcomes. Patients who are unable to tolerate general anesthesia or whose medical comorbidities preclude a suboccipital craniectomy may benefit from percutaneous methodologies including glycerol or radiofrequency ablation, or both. For patients with bleeding diathesis due to blood thinning medications who are ineligible for invasive procedures, or for those who are unwilling to undergo open surgical procedures, radiosurgery may be an excellent option-provided the patient understands that maximum pain relief will take on the order of months to achieve. Finally, peripheral neurectomies continue to provide an inexpensive and resource-sparing alternative to pain relief for patients in locations with limited economic and medical resources. Ultimately, elucidation of the molecular mechanisms underlying trigeminal neuralgia will pave the way for novel, more effective and less invasive therapies.