Trigeminal neuralgia (tn)
Trigeminal Neuralgia (TN)
TN is caused by irritation of the trigeminal nerve at its origin. Over 95% of cases are due
to blood vessel compression. The rest are either from tumour around that region, or from
demyelinating disease such as multiple sclerosis.
Typical presentation: lightning like pain affecting any spot or area on one half of face.
Some points are highly sensitive to touch, shaving, eating, talking or even wind blowing.
These are called trigger points. Attacks of pain come in clusters. There may be bad times
and not so bad times. In severe cases, patients may be undernourished, suffering from
poor dental hygiene, and assume a rather unkempt appearance (cannot shave).
Medical treatment is usually highly effective. If not, the diagnosis may be wrong. Most
patients will respond to Tegretol, an anti-epileptic. Dosages varies individually but may
escalate with time. Other medications have been tried and claimed relief: Dilantin,
About 10% of patients' symptoms become refractory to drugs in the course of time,
usually 5 to 10 years. To provide pain relief, there are several options to consider:
1. Percutaneous Procedures
The trigeminal nerve is located by passing a long needle through the face towards the
skull base and is either destroyed by heat (radiofrequency), sclerosing agent (Glycerol or
alcohol), or compressed by a small balloon. All these procedures can be uncomfortable.
But in experienced hands, ~90% pain relief can be achieved. The downside is: pain
recurrence is high and repeated procedures are often required. In addition, the incidence
of facial numbness is higher than other treatment modalities.
The procedure is called microvascular decompression (MVD). It is a major complex
surgery involving general anaesthesia, opening of skull, retraction of brain, exposure of
the trigeminal nerve at its origin from the brain stem, finding the offending blood vessel
and relieving the nerve from direct irritation by the offending artery or vein. In expert
hands, MVD is the most effective method to achieve immediate pain relief. Facial
numbness is rare, although some patients experience deafness, and or facial weakness
as a result of excessive retraction of the cerebellum. MVD also carries a small but
definitive death rate: 0.5 to 1% even in best hands. Since majority of TN patients are
older than 60 and may have other medical problems such as heart disease, hypertension,
diabetes mellitus, etc, MVD may not be so desirable from patient's perspective.
3. Gamma Knife Surgery
The target is the same as in MVD, except that the procedure is non-invasive. The success
rate is at 90%, slightly lower than MVD. It also takes longer (average 1 months from
time of treatment) to achieve pain relief. However, there is no fear of operative death or
dreadful complications such as facial paralysis or deafness, and may well be the
treatment of choice in elderly or medically unfit patients.
TN caused by tumours are best treated by any effective measure against the tumour,
TN caused by multiple sclerosis may also respond to Gamma Knife surgery even though
the results are usually less favourable.
Comité Consultatif de Bioéthique Avis n° 39 du 18 décembre 2006 relatif aux traitements hormonaux des auteurs de délit(s) sexuel(s) Demande d'avis du 13 octobre 2006, de L. Onkelinx, Ministre de la Justice, relative aux traitements hormonaux des auteurs de délit(s) sexuel(s) A. Demande d’avis Madame la ministre Laurette Onkelinx a posé la question suivante
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