Assessment of brainstem function in Chiari II malformation utilizing brainstem auditory evoked potentials (BAEP), blink reflex and masseter reflex

Brainstem dysfunction was evaluated in 67 patients with myelomeningocele an d Chiari II malformation using brainstem auditory evoked potentials (BAEP), blink reflex (BR) and masseter reflex (MR). Signs and symptoms related to Chiari II malformation were observed in 18 patients while 49 patients had n ormal brainstem findings. BAEP and BR showed a higher sensitivity of brains tem involvement than MR (BAEP = 1.0, BR = 0.83, MR = 0.50). BR, and in part icular, MR were of higher accuracy (BR = 0.52, MR = 0.72) than BAEP (0.39) in separating patients with brainstem signs and symptoms related to Chiari II malformation. We feel that this is due to anatomic and physiologic pecul iarities of the brainstem structures mediating BR and MR. Our results sugge st that brainstem reflexes can support the decision of further treatment. ( C) 2000 Elsevier Science B.V. All rights reserved.