Conditions treated and surgical results
Trigeminal Neuralgia
This is a severe facial pain which occurs in short sharp attacks often feeling like electric shocks. It is often caused by events which cause movement or stimulation of the skin of the mouth such as, eating, talking, cleaning teeth, washing or drying the face. If the pain occurs in the forehead, combing hair or taking a shower can also cause attacks.
Drug treatment - medication usually controls trigeminal neuralgia in the first instance but many sufferers find that the drugs eventually lose their effect or cause unpleasant side effects.
Injection treatment - years of relief can be given by an injection through the cheek carried out under a short general anaesthetic. One technique known as Radiofrequency Thermocoagulation produces a patch of permanent facial numbness (usually not too severe) and lasts for an average of 5 years. The other technique used for pain in the forehead involves injection of glycerol which does not produce numbness and lasts for 12 months on average.
Surgical therapy - having discussed details with their specialists most patients with trigeminal neuralgia opt for the operation known as Microvascular Decompression. This is carried out via a small incision behind the ear and in a good surgeon's hands is extremely safe giving a high chance of permanent cure without inflicting any facial numbness. In most cases the neuralgia is caused by a brain blood vessel which compresses the main part of the trigeminal nerve close to where it enters the brain stem. Using microsurgery the blood vessel is gently moved to a new position where it is fixed with a small Teflon sling. The operation requires 3/4 days in hospital with most patients being able to return to work 3 or 4 weeks afterwards.
Professor Coakham's results presented to 12th World Congress of Neurosurgery, Sidney, Australia 2001 - 359 patients with trigeminal neuralgia were operated on over a 20 year period and 84% remained pain-free, 9% had mild recurrence of pain and 6% developed recurrence requiring further treatment. 86% of patients were highly satisfied with their treatment. There were no serious complications. It has also been demonstrated that the results of this operation improve with a surgeon's experience.
Hemifacial Spasm
This condition is similar to trigeminal neuralgia but affects the nerves responsible for moving the facial muscles. Whilst it is not painful it is immensely troublesome - one side of the face twitches uncontrollably causing continual grimacing. It is caused by vein blood vessels compressing and irritating the facial nerve close to the brain stem.
Drug treatment does not help this condition.
Botulinum toxin injections - this treatment results in a temporary cure lasting only about 3 months. If this treatment is chosen then a lifetime of injections are needed.
Microvascular decompression - this treatment is now accepted as providing the best chance of permanent cure. Professor Coakham's results of treating 126 cases over 22 years have been analysed and surgery is very safe with a good chance of permanent cure. Satisfied patients have posted their results on the website
www.hfs-assn.org/survey.htm
Microvascular decompression for Hemifacial Spasm: long term follow up of surgical results and patient satisfaction 13th World Congress of Neurological Surgery 2005. 82% of patients were permanently cured, 11% had spasms improved but not totally relieved and 7% were not relieved of their spasms. 85% of patients were highly satisfied with the treatment. These results compare well with the results achieved in other countries. All surgeons carrying out this procedure report a 5% or 6% risk of causing deafness in one ear because the hearing nerve passes very close to the facial nerve. Professor Coakham is among the specialists who monitor hearing during the surgery with the help of neurophysiology colleagues who specialise in this (auditory brainstem response monitoring). This has reduced the risk of deafness in his patients.
Results can also he optimised by measuring an electrical phenomenon called lateral spread response, which is now available in Bristol.
Results of repeat surgery. Professor Coakham has now carried out repeat surgery on his own cases and also cases operated in other parts of the UK. In 11 repeat operations 10 patients were cured.
Acoustic neuroma (vestibular schwannoma)
This is a benign slowly growing tumour which affects the hearing in one ear and sometimes also the balance. The original name of acoustic neuroma has now been changed to vestibular schwannoma because it is known that the tumour grows from the balance nerve (vestibular) and arises from the cells of the nerve sheath (schwann cells). Surprisingly the balance is not usually too badly affected but about two thirds of people develop pronounced deafness because the auditory nerve is very close by, as is the facial nerve which causes facial expression.
The therapeutic challenge is to prevent the tumour growing large enough to cause serious brain compression and to preserve the function of the delicate nerves which are distorted by tumour growth.
Smaller tumours can be treated either with microsurgical removal or by a form of highly focused radiotherapy known as Gamma Knife. Larger tumours - over 2.5cm, require microsurgery.
Professor Coakham and his neuro-otology ENT colleagues have carried out 191 operations in the past 13 years and results have been published.
Link to CV publication list, Butler S, Coakham HB, Maw AR and Morgan MH. Physiological Identification of the Acoustic Nerve during Surgery for Acoustic Neuromas, Clinical Otolaryngology 1995: 420, pages 312-317.
Mulatti N, Coakham HB, Maw AR, Butler SR, Morgan MH, Intraoperative Monitoring during Surgery for Acoustic Neuroma, Benefits of an extra Tympanic Intrameatal Electrode. Journal of Neurology Nursery and Psychiatry, 1999; Vol 66, pages 591-599.
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The preservation of hearing and facial nerve function following surgery for vestibular schwannomas has been presented at the Fourth International Conference on Vestibular Schwannoma. Cambridge. July 2003. The results show that 95% of patients have completely normal facial movement after surgery and of those patients who have good hearing before surgery, virtually half (49%) have preservation of that hearing after surgery.