Trigeminal neuralgia triggered by auditory stimuli in multiple sclerosis

Objectives: To describe a patient with a demyelinating brainstem lesion who developed right-sided trigeminal neuralgia triggered by auditory stimuli a nd to discuss the pathophysiological mechanisms underlying this unusual phe nomenon. Design: Case report. Setting: Referral center. Patient A 27-year-old man who presented with clinical signs of a brainstem lesion developed right-sided trigeminal neuralgia triggered by auditory sti muli to the right ear. Magnetic resonance imaging and electrophysiological studies demonstrated a demyelinating lesion in the pens affecting the right lateral lemniscus and the right trigeminal pathway. This phenomenon comple tely subsided within 4 days. After a relapse, the diagnosis of clinically d efinite multiple sclerosis was made. Conclusion: Lateral spread of impulse activity within the demyelinating pon tine lesion is the likely explanation for the unusual phenomenon of trigemi nal neuralgia triggered by auditory stimuli.