Trigeminal Neuralgia

Trigeminal neuralgia also known as tic douloureaux is a condition consisting of excruciating pain affecting one or other side of the face. It most frequently involves the lower lip and lower teeth or upper lip and cheek, but can also involve the nose and the area above the eye.

It usually occurs in people older than 60 years of age and slightly more often in females. Pain occurs in attacks lasting from seconds to minutes to hours and can be brought on by stimuli such as light, touch or a gentle breeze on the face or even chewing, talking or brushing of teeth.

As described by Walter Dandy in 1934 and Peter Jannetta of Pittsburg during the 1970's, the condition is most often caused by the hardening and unfolding of an artery at the base of the brain pressing into the origin of the trigeminal nerve from the brain stem.

Approximately 70% of patients respond reasonably well to drug therapy with either carbamazepine (Tegretol) Gabapentin (Neurontin), Pregabalin (Lyrica) or Baclofen (Lioresal). More invasive modalities of treatment consist of percutaneous injections of various substances into the nerve where it leaves the brain or even radiofrequency lesions in the same anatomical region.

Jannetta Procedure

The most successful form of treatment as shown by Peter Jannetta is a micro-vascular decompression of the nerve. A small window of bone is removed behind the ear under general anaesthetic to gain access to the lower brain stem and trigeminal nerve.

With the aid of the operating microscope the blood vessel causing the problem is teased from under the nerve and displaced away from the nerve and held in position with a small teflon cotton patch. Initial pain relief is as high as 90% and recurrence rate between 10 and 15%. Complications are rare and include cerebro-spinal leak, transcient deafness and other minor complications related to any surgical procedure.

Other conditions similar to Trigeminal Neuralgia

1. Hemifacial spasm

   Hemifacial spasm is a condition consisting of unvoluntary movements starting usually with the muscles around the eye on one side of the face and in severe cases spreading to the other facial muscles causing grimacing movements of the mouth. The condition is again caused by micro-vascular compression like in trigeminal neuralgia, but only affecting the 7th cranial nerve instead of the 5th. Medical treatment has not proved successful, but micro-vascular decompression as in the case of trigeminal neuralgia proves successful in a high percentage of cases.

2. Tinnitus

   Tinnitus is a condition describing a ringing or buzzing sound in one or both ears. When this occurs in one ear and has a pulsating quality synchronizing with the heart beat it can also be caused by an unfolding blood vessel at the base of the brain and in these cases micro-vascular decompression as for trigeminal neuralgia and hemi-facial spasm can also solve the problem.
   
   
3. Other conditions described caused by the same micro-vascular compression of a cranial nerve include hypertension, diabetes, cardiac arrhthymias and torticollis.

Special investigations:

In most of these patients (trigeminal neuralgia, hemifacial spasm and other cranial nerve dysfunctions) abnormal blood vessels can be visualised by special high resolution Magnetic Resonance Imaging which then of course also excludes other pathological conditions.

Dr Louis Wessels (M.B. Ch.B., M.Med. (Neur. Chir.))

Dr Louis Wessels is a neurosurgeon practising at the Vergelegen Medi-Clinic in Somerset West, South Africa. After reading Peter Jannetta's articles he performed his first micro-vascular decompression for trigeminal neuralgia in December 1980. Only two serious complications have occurred in a series of almost 700 cases with a success rate in the region of 85% and approximately 10% recurrence of pain.

Patients are admitted to hospital the night before their proposed operation which then takes about 2 to 2 ½ hours. The patient is kept in high care for observation overnight and usually discharged from hospital within 3 or 4 days.