Brainstem reflexes in patients with Wallenberg's syndrome

Clinical and radiological examinations of patients with Wallenberg's syndrome (WS) show slight differences. We have investigated whether interindividual differences were also present in neurophysiological studies of 22 consecutive patients with WS. We obtained abnormal blink reflexes to stimulation of the supraorbital nerve in 81.8% of patients, of the infraorbital nerve in 35.7%, and of the mandibular nerve in 28.5%. Abnormal masseteric inhibitory reflexes to electrical stimulation of the mental nerve were found in 45.4% of patients. Abnormal sudomotor skin responses to trigeminal nerve stimulation were found in 36.4% of patients. In 4 patients (18.2%), abnormalities of the SSR were limited to the side ipsilateral to the infarct. There was a poor correlation between neurophysiological results and clinical or MRI features. The results of this study suggest that patients with WS have subtle differences in their neurophysiological manifestations. The identification of different subgroups of patients with WS may be relevant for clinical outcome.