Trigeminal neuralgia due to pontine infarction: A case report

Brain stem lesions are known to cause facial pain. But, trigeminal neuralgia (TN) due to ischemic lesion of the pons are very rare. We report a case with a pontine infarct at the root entry zone (REZ) of the right trigeminal nerve resulting with a classical trigeminal neuralgia. C.M.A. is an old woman (75 years) that suddenly presented an acute symptomatology typical of classical trigeminal neuralgia. Neurological examination revelead only slight hypoesthesia on the right V2 dermatomes. There was a trigger point at the right upper lip. Magnetic Resonance cranial investigation showed a hyperintesity in the FLAIR and DP/T2 and a hypontensity in T1 sequences latero-pontine dx, at the root entry zone (REZ) of the right trigeminal nerve. The patients was treated with pregabalin at dosage of 150 mg/die/os in two administrations and antiaggregant drugs. The resolution of symptomatology was registered later three weeks. Isolated trigeminal neuralgia is a rare debut form of pontine in-farct and the mechanism of TN in these cases is still a matter of debate. Central theories on the etiology of TN mainly focus on the increased neuronal activity in the trigeminal nucleus. The treatment of secondary TN is a symptomatic control of pain with anti-epileptic agents. Besides, in a patient with pontine infarct, prevention of further strokes should be done. In our patient was obtained a complete resolution of the symptomatology with pregabalin and was effected a preventive stroke therapy with acetilsalicilic acid.