Medical treatment: The most common drug used is carbamazepine. The effective daily dose can be as small as 300mg to as large as 2000 mg. The principle of treatment is to administer the smallest single dose to control the pain. The frequency is adjusted to relieve the pain completely. Once achieved, the schedule is continued for 6-8 weeks without decreasing the dose to achieve stable remission. Following this the drug can be gradually tapered and stopped. In case of resurgence of pain this can be restarted. Over a period of time, the recurrences become less responsive, necessitating introduction of other drugs. Carbamazepine is usually well tolerated; however, some patients may experience ataxia, GI upset, leucopenia, hyponatremia, drowsiness or mental confusion. In these patients Oxcarbamazepine can be used (it has lesser side effects). Other drugs like Gabapentin, Phenytoin, Baclofen, etc. are also used, but their therapeutic efficacy is much less than Carbamazepine.
Role of peripheral Neurectomies: The common practice of peripheral neurectomies of mandibular and maxillary of the trigeminal nerve is highly discouraged. Peripheral neurectomies carry a high rate of recurrence. Beside , they also have a very high incidence of causing deafferentation pain which is one of the worst pain to manage ,requiring aggressive therapies like gasserian ganglion stimulation or motor cortex stimulation .The only place a peripheral neurectomy should be performed is in a case of V1 neuralgia as other therapies have higher incidence of side effect.
Surgical treatment: The two most common forms of surgical treatments are (a) Microvascular Decompression (MVD) and (b) Radiofrequency thermocoagulation (RFTC)
Microvascular Decompression: This is highly controversial as in one paper Janetta noted that in cadaver dissection of patients who never suffered from TN there was no vascular compression, but the same group later on published an incidence of 35% of vascular compression in asymptomatic patients. The MVD surgery involves posterior fossa exploration through a small table 1Comparison of Results of MVD and RFTC thermocoagulation (RFTC).
opening next to the mastoid process. Under magnification, the offending vascular loop is dissected free of the root entry zone and a Teflon graft is interposed. It has been found that in patients in whom arterial compression is identified the recurrence rate is 30% but in those patients where the conflict was either venous or none, the recurrence rate was high as 70%. The side effects of this surgery include damage to 7th and 8th nerve, and other complications like CSF leak, infection, haematoma etc (Table 1).
|10 years after!!!!||MVD||RFTC|
|Serious morbidity||More common||rare|
|Cost and Hospitalisation||More||Significantly small|
Table 1 – Tronnier, Neurosurgery, 2001; Young RF, J Neurosurg, 1988