Multiple Sclerosis Revealed by Intrapontine Axial Lesion of Peripheral Nerves

Multiple sclerosis(MS) is most often revealed by motor, sensitive symptoms with paresthesia, ocular symptoms, and more seldom by symptoms with rapidly installed hearing loss and vertigo.We report an observation with initialsymptoms of a peripheral pathology mimicking a meningo-neuritis. A 22 years old young woman was addressed as anemergency for a sudden peripheral symptomatology associating a sudden right hearing loss with ear fullness,vertigo with vomiting and a right peripheral facial palsy. The patient had a spontaneous nystagmus beating toward the left side suppressed by fixation and sensory neural hearing loss on low frequencies. The Fukuda tests initially deviated toward the right side. The caloric test showed a right hypofunction at 75% and a correlated consistent left preponderance. The head shaking test (HST) and skull vibration induced nystagmus test (SVINT) revealed a left nystagmus. Blood samples results andcervical vestibular evoked myogenic potentials (cVEMP) were normal. Brainstem evoked response audiometry (BERA) demonstrated a retrocochlear disease with a Wave V prolonged latency on the right side. A CSF lumbar puncturerevealedaoligoclonal band on electrophoresis and the MRI a pons intra-axial nodular image on the VII and VIIIth nerve pathway in the immediate vicinity of the right vestibular nucleus (hyper signal T2 and T1 Gadolinium contrast fixation). The evolution surveyed in neurology was totally regressive. A further disease relapseconfirmed dissemination in time and location of the pathology. Conclusion: Inaugural vestibular symptoms are seldom in MS. The ensnaring initial pseudo-peripheral presentation of this case is explained by the plaquelocation in close vicinity on the pons intra-axial cranial nerves pathway route. BERA are essential to reveal a neuronal conduction impairment on auditory nerve related to a demyelination process.