@Douglas Ward i want to post something from Dr Shevels post a few years ago , seems he changed his theory of what causes clusters
The medical rationale for my treatment of cluster headache is as follows:
Primary headaches, including cluster headache, are exceedingly complex conditions and difficult to treat due to the great number of anatomical structures in the head and neck, which are all interlinked in some way. These structures include the brain and nervous system, arteries, muscles, tendons, sinuses, joints, and teeth. Many of these structures are innervated by the trigeminal nerve, which is widely accepted as the main conduit for primary headache pain, including cluster.
There is widespread agreement among headache specialists that many cluster symptoms occur due to the involvement of what is called the sphenopalatine ganglion (also known as the pterygopalatine Ganglion). One of the therapies being used at present to minimize the severity of cluster is sphenopalatine ganglion stimulation (Lainez, MA et al.Sphenopalatine ganglion stimulation for the treatment of cluster headache. Ther Adv Neurol Disord. 2014 May; 7(3): 162-168). The sphenopalatine ganglion is situated behind the upper jaw under the eye, and the maxillary artery is very close to it. When the maxillary artery dilates, it gives off pain producing neuropeptides – in patients where the dilated maxillary artery is very close to the sphenopalatine ganglion, the ganglion is without doubt affected.
Migraine can in no way be compared with cluster – but there is one vitally important similarity, and that is that they both respond to sumatriptan. Sumatriptan was developed as a vasoconstrictor to treat migraine, but as it transpired, it is far more efficacious in the treatment of cluster than it is in the treatment of migraine.
As the members of Clusterbusters are very aware, Imitrex (Imigran in some countries) injections are the most reliable and effective way of aborting cluster attacks for most cluster sufferers.
Remember, the only action of Imitrex is to constrict the painfully dilated extracranial terminal branches of the external carotid artery. It has no other action. This leads to the logic that if Imitrex works in cluster, then in cluster the painfully dilated EXTRACRANIAL TERMINAL BRANCHES OF THE EXTERNAL CAROTID ARTERY are INVOLVED IN THE PAIN.
The rationale and aim of my surgery is to achieve a permanent Imitrex effect. When the maxillary artery is permanently closed surgically, it no longer gives off pain-producing neuropeptides or impacts the collection of nerves of the sphenopalatine ganglion which generate the intense pain.
An illustration appeared on the cover of Cephalalgia in 2012, entitled “Location of maximum pain intensity in 209 patients with chronic and episodic cluster headache”. It is no coincidence that the precise area depicted is supplied by the maxillary artery. I am unable to post images here, but these can be referenced at http://www.theheadacheclinic.net/cluster-headache-treatment/
In my treatment of cluster, the most important element is permanent closure of the maxillary artery on the affected side. The major difference between the symptoms of cluster and migraine is because in cluster, not only are the scalp arteries involved, but the maxillary artery is also involved.
All the arteries that I close, including the maxillary, are done through small superficial incisions. These procedures are done in a day care facility and patients are discharged the same day.
It is important to note that these same arteries are closed by Neurosurgeons, Maxillo-Facial Surgeons, Plastic surgeons and ENT surgeons every day for a variety of other reasons. In spite of this there has never been a report of the blood supply being compromised as a result. A small number of patients have had temporary numbness of the skin or the cheek lining, most of whom recovered within a month or two. In the few cases where the numb patch persists, it is a relatively small price to pay for being pain free.
If it was only the maxillary artery that was responsible for cluster, the procedure would be done in a day and the patient would be able to fly home a few of days later. Frequently however, other anatomical structures are also involved in generating the pain. The most common are other terminal branches of the external carotid artery in the scalp, but the jaw and neck muscles and the three branches of the trigeminal nerve may also become painful.
