SPG BLOCK TO TREAT CLUSTER HEADACHE
WHAT IS CLUSTER HEADACHE?
Cluster headache is a severe, neurovascular pain in the head that comes in paroxysms (sharp bouts of pain), accompanied by lacrimation (tears) and a runny nose. It is a unilateral head pain, typical in young men, that is associated with autonomic cranial symptoms and usually follows circadian and circannual patterns (it usually appears in autumn and in spring). Chronic cluster headache, which accounts for approximately 10% to 15% of patients with cluster headache, lacks the circadian pattern and is often resistant to pharmacological management. The first treatment of chronic cluster headache is medical, but, if it does not respond, surgery can be considered.
The sphenopalatine ganglion (SPG) is located in the pterygopalatine fossa, just behind the middle nasal turbinate and directly in front of the pterygoid canal. Its size is no bigger than 5mm and it is involved in the physiopathology of cluster headache, so an SPG block may be used to treat chronic cluster headaches or atypical facial neuralgia. Percutaneous RF lesioning of the SPG was shown to have encouraging results in those patients with refractory cluster headaches.
WHAT HAPPENS DURING THIS SURGICAL PROCEDURE?
You will lie on your back with your head extended. The skin on your cheek will be sterilised using iodine, and some local anaesthetic will be injected into your cheek where the special radiofrequency needle is to be inserted. Once the needle is inserted, X-rays will be used to identify the SPG and check that the needle is exactly on that location. RF will then be applied to the ganglion.
This procedure may be uncomfortable but is usually not painful. After it you can eat and drink, and normal medication can be resumed.
RF lesioning of the sphenopalatine ganglion
WILL THE PROCEDURE HAVE TO BE REPEATED?
The effects of this procedure may be temporary for some people, and the degree and duration of pain relief may vary from person to person. Some feel the relief for weeks, whereas others feel it for years. Fortunately, this procedure is a low-risk one and if it is unsuccessful the first time, it will most likely continue to provide pain relief when it is carried out a second time.
WHAT ARE THE RISKS POSSIBLE SIDE EFFECTS?
The risks of this procedure are very low. As with any procedure that involves a local anaesthetic, there is a risk of the patient being allergic to the local anaesthetic and a risk of the anaesthetic entering into the bloodstream. Lastly, with the penetration of skin and soft tissues there is always the risk of infection.
The most common side effects are developing a bitter taste in the mouth or developing a slight numbness in the back of the throat, both due to the local anaesthetic and both temporary. Occasionally, a nose bleed, which will eventually spontaneously stop, may develop. Some patients may also experience a slight dizziness which will disappear 20-30 minutes after the procedure.
WHAT ARE THE RESULTS?
After the procedure, the pain may be gone or significantly decrease. It is normal to have some mild nose bleeding and slight numbness on the palate.