[Neuritis of multiple cranial nerves in idiopathic focal pachymeningitis]. / Multinévrite crânienne dans le cadre d'une pachyméningite focale idiopathique.

ABSTRACT

A 76 years old patient suffering from insulin dependent diabetes presents a multiple, bilateral and asymmetric cranial neuropathy involving on the left side the cranial nerves VIII, IX with a participation of the efferent autonomic fibers of the nerves VII and IX (xerostomia) and the nerve XII, and involving on both sides the nerves VII and X. Like it is known from literature the nerve XI was spared, probably because of the more caudal emergence from the brainstem. The disease was preceded by a violent otalgia on the left side which was initially interpretated as a malignant external otitis. This affection was associated with an inflammatory syndrome that was easily monitored by the blood sedimentation rate. The course was favorable but marked by fluctuations of the neurological deficits. The MRI shows a pachymeningitis localised at the beginning in the medial fossa and on the cerebellar tentorium, later on the left parieto-occipital convexity. The diagnosis of a focal idiopathic pachymeningitis was confirmed by excluding different other affections like inflammatory, tumoral and infectious diseases, by using MRI examinations, CSF analysis and especially meningeal biopsy. It is a rare inflammatory disease of unknown origin with potentially persistent neurological deficits. We discuss the differential diagnosis and the therapeutical possibilities, which consist in a long term immunosuppression with corticosteroids and azathioprine.