[Chronic facial pain due to a brainstem cavernoma].

Idiopathic trigeminal neuralgia is almost always associated with pathological nerve/vessel contact. Symptomatic forms of trigeminal neuralgia include cases of multiple sclerosis, infratentorial tumours and postherpetic neuralgia. Vascular malformations causing neuralgia have rarely been reported. We present the case of a 55-year old woman, who suffered from facial pain and ptosis on her left side. Repeated neurological examinations as well as repeated magnetic resonance imaging did not lead to a definite diagnosis or therapy. The pain suddenly stopped three weeks before admission and only a slight left sided facial hypaesthesia persisted. Reevaluating the older MRI we found a small signal alteration of 2 mm in the caudal part of the left trigeminal nucleus. A new MRI showed a subacute haemorrhage into a small brainstem cavernoma, which must have caused the pain and later on the hypaesthesia. Small vascular malformations are a rare cause of neuropathic facial pain.