Trigeminal neuralgia is a neuropathic facial pain condition which is characterised by
unilateral paroxysmal pain which is excruciating, short lasting in the distribution territory
of trigeminal nerve.(1) Trigeminal neuralgia is oro-facial pain restricted to one or more
divisions of the trigeminal nerve. With the exception of Trigeminal Neuralgia caused by
Multiple sclerosis, the pain affects one side of the face. It is abrupt in onset and
typically lasts only a few seconds (2 min at maximum).Patients may report their pain as
arising spontaneously, but these pain paroxysms can always be triggered by innocuous
mechanical stimuli or movements. Patients usually do not experience pain between paroxysms.
If they do report additional continuous pain, in the same distribution and in the same
periods as the paroxysmal pain, they are considered to have Trigeminal Neuralgia with
continuous pain. (IASP)(1) Trigeminal neuralgia is mainly classified into three diagnostic
categories i.e. Classical, Secondary and Idiopathic. This classification is mainly based on
the etiology & pain characteristics. The etiology of Trigeminal Neuralgia is not well
understood, but various theories such as Compression of sensory root of trigeminal nerve by
arteries & bony exostoses.(4) ,focal demyelination of trigeminal afferents near the entry of
the trigeminal root into pons(2)and alteration in the central neural function followed by
injury to peripheral nerves (4) are widely accepted.
Trigeminal Neuralgia has a profound effect on quality of life of the patient & expenditure on
health (4). Due to the severe intensity of pain, patients avoid touching face, washing face,
thus making patient's life disturbing & miserable. Even after so many years of research, it
is still a challenge to treat patients suffering from Trigeminal Neuralgia. Treatment can be
sub- divided into pharmacological & invasive therapies .
The pharmacological therapy include drugs such as carbamazepine ( 200-1200mg) , oxcarbazepine
(300-1800mg) , lamotrigine, Gabapentin , baclofen, eslicarbazepine, sumatriptan, vixotrigine.
The pre- surgical procedures like botulinium toxin A & intranasal non-inhaled CO2 have also
been sporadically used (1).
A review study discussing the pharmacological options to treat trigeminal neuralgia concluded
that carbamazepine & oxcarbazepine are the first choice of drugs(1). Oxcarbazepine showed
equal efficacy in reducing pain attacks with better tolerability & less side effects (1) .
A recently conducted study found that carbamazepine is associated with serious side effects
including CNS disturbances, somnolence, unbalance, thrombocytopenia, increase level of
transaminases while OXC showed similar efficacy with less side effects. CNS disturbances
encountered in patients on CBZ were triple to those on OXC & withdrawal from the treatment
was also more in patients on CBZ(27%) than on OXC (18%)(12).
OXC has contemporarily been used as monotherapy in epileptic patients (8) & has proven
efficacy over the CBZ. In trigeminal neuralgia, though various studies have shown that OXC
produce lesser side effects, but none of the studies have compared the efficacy of
carbamazepine with oxcarbazepine .
Thus the present study intends to compare the efficacy of oxcarbazepine with carbamazepine as
monotherapy in patients suffering from trigeminal neuralgia.