Masseter reflex and blink reflex abnormalities in Chiari II malformation

Masseter reflex and blink reflex were evaluated in 64 patients with a myelo meningocele and Chiari II malformation. In 46 patients, no brainstem signs or symptoms were present. Brainstem dysfunction related to Chiari II malfor mation occurred in 18 patients. The masseter reflex was more frequently abn ormal in the symptomatic than asymptomatic patients (P = 0.02). Although th e blink reflex was similarly affected in the two groups of patients (P > 0. 1), it was very sensitive, being abnormal in 83% of symptomatic and 65% of asymptomatic patients. Concomitant abnormality of masseter reflex and the l ate contralateral blink reflex component (R2c) was almost exclusively found in symptomatic patients and reached the highest significance in separating the two groups (P = 0.002). (C) 2001 John Wiley & Sons, Inc.