Hyperexcitability of the facial nerve in tuberculous meningitis

Facial myokymias (FM) are continuous, involuntary, undulating movements of the facial muscles associated with spontaneous electromyographic activity, such as fasciculations and myokymic discharges. They may occur in healthy individuals, or be secondary to multiple sclerosis, posterior fossa tumors, or an inflammatory process.

We describe the case of a 31-year-old man who presented with headache, vomiting, low fever, and disorientation. Cerebrospinal fluid findings included low glucose and high protein content and lymphocyte pleocytosis, with positive culture for Myobacterium tuberculosis. The patient was diagnosed with tuberculous meningitis. Magnetic resonance imaging showed high contrast enhancement in the basal meninges and a left frontal tuberculoma. Over the course of the disease, he experienced FM and persistent, involuntary contraction of the facial muscles. The electromyogram recorded myokymic discharges.

Tuberculous meningitis is a rare cause of FM. The presence of myokymic discharges on electromyography verified the peripheral origin of facial nerve hyperexcitability in this case, in contrast to persistent contraction of the facial muscles, which has a central origin. The phenomena were transitory and only positive symptoms were observed, with no facial nerve injury.

Tuberculous meningitis is a rare cause of facial nerve hyperexcitability, which can have a peripheral, nuclear, or supranuclear origin.