Urinary frequency in a case of Neuro-Behcet disease involving the brainstem - clinical, electrophysiological and urodynamic features.

Micturitional disturbances are reported in 5-20% of patients with Behcet disease (BD) affecting the central nervous system. However, corresponding data regarding urodynamic and electrophysiological findings are limited. A patient with known BD presented with dysarthria, diplopia and urinary frequency (36 times/day). MRI revealed an extensive lesion involving the lateral and tegmental pons, reaching the pontomedullary junction. Auditory evoked potentials indicated a left-side lesion between superior olivary nucleus and superior colliculus. Blink reflex examination indicated a location caudal to the left trigeminal root. Pudendal nerve somatosensory evoked potentials and transcranial magnetic stimulation of the perineal muscles were slightly affected. Bulbocavernosus reflex latencies were normal. EMG of the bulbocavernosus muscles showed a normal maximal voluntary contraction activity. Urodynamic studies revealed normal urine volume, maximum flow rate and residual volume. After intravenous administration of methylprednisolone diplopia and dysarthria resolved within 3 weeks. Urinary frequency remained almost unchanged for the first 8 weeks, but clearly improved during the following months. We assume that the present case of urinary frequency is the result of vasculitic lesion affecting the pontine micturition inhibitory area on the ground of Neuro-Behcet disease.