Role of sphenopalatine ganglion block in the management of cluster headache
Cluster head ache (suicide headache) is one of the most painful of all headache syndromes. It is characterized by very severe orbital / temporal pain occuring usually on the same side lasting between 15-150 minutes if not treated. Cluster headache attacks are usually associated with rhinorrohea, lacrimation, conjunctival injection, perspiration and psychomotor agitation. These clusters usually occurs during “cluster periods” which range between 6-12 weeks with painless intervel inbetween.
Current views suggest that cluster headaches are caused by central mechanisms which are triggered by reflex arc involving the sphenopalatine ganglion. Hypothalamus has been suspected to play an important role in the pathophysiology of cluster headaches. That is the reason for using deep brain stimulation of the posterior nucleus of hypothalamus in managing drug resistant cases of cluster headaches.
Role of sphenopalatine ganglion block:
Recent studies have shown promising results when sphenopalatine ganglion is blocked. This can be carried out transnasally with minimal intervention under endoscopic vision. This can easily be achieved by a mixture of local anesthetics and steroids. These drugs should be delivered as close to sphenopalatine ganglion as possible. After decongesting and anesthetizing the nasal cavity a solution of triamcinolone acetonide (40 mg), 1% bupivacaine (4 mL), and 2% mepivacaine with 1/100,000 adrenaline (2 mL) in an average of three (range 2– 4) weekly sessions . Injection is usually administered with a 20 gauge needle close to the tail of the middle turbinate (this is the approximate location of sphenopalatine ganglion). Care is taken not to damage the sphenopalatine artery. Two to three injections may be adminstered in a space of 4 – 6 weeks.