Coexisting Trigeminal Autonomic Cephalalgias and Hemicrania Continua

Abstract

REFERENCES1. Ashkenazi A, Blumenfeld A, Napchan U, et al. Peripheral nerve blocks and trigger point injections in headache management -A systematic review and suggestions for future research. Headache. 2010;50:943-952. 2. Weatherall MW. Idiopathic trigeminal neuropathy may respond to greater occipital nerve injection. Cephalalgia. 2008;28:664-666. 3. Evans RW. Greater occipital neuralgia can cause facial paraesthesias. Cephalalgia. 2009;29:801. 4. Han KR, Kim C, Chae YJ, Kim DW. Efficacy and safety of high concentration lidocaine for trigeminal nerve block in patients with trigeminal neuralgia. Int J Clin Pract.We thank Dr. Evans for his comment and interest in our review. We agree that there are currently insufficient data to support the use of greater occipital nerve (GON) block in the treatment of trigeminal neuralgia (TN) or of idiopathic trigeminal neuropathy. Until more data are available, attempting to relieve the pain associated with these conditions using trigeminal nerve blocks appears to be a more reasonable approach. It should be noted, however, that there is compelling evidence from both animal and human studies for functional connectivity between the greater occipital nerve and the trigeminal system. 1,2 These data, together with some evidence for efficacy of GON block in other trigeminally driven headaches (eg, migraine), raise the question of whether GON block may also be effective in the treatment of TN. This hypothesis needs to be addressed in future well-designed controlled studies. In these future studies, patients who have idiopathic TN and those who have secondary TN should preferably be evaluated separately, since the responses of these two groups to GON block may differ. We would expect patients with an underlying structural lesion to do less well than those who have idiopathic TN.

Response: Coexisting Trigeminal Autonomic Cephalalgias and Hemicrania Continua

“…We thank Drs. Prakash and Lakhani for their comments 1 on our recent case report and literature review concerning coexisting trigeminal autonomic cephalalgias and hemicrania continua (HC) 2 . Their scrutiny of the fine details of our patient's headache semiology and caution directed to us regarding the diagnosis of 2 rare primary headache disorders is appreciated.…”