A 37-year-old woman with a 5-year history of multiple sclerosis is reported. She began having recurrent syncope even in the sitting position; other neurological features included hiccup, faciooro-lingual flushing and clumsiness of the hands. She had alternating Horner's syndrome, mild hypoalgesia of the right face, exaggerated deep tendon reflexes of the upper extremities, decreased deep sensation and ataxia of the upper extremities, and incomplete transverse myelopathy with a T4 sensory level. Head-up tilt testing confirmed orthostatic hypotension with relative preservation of the heart rate increase. Magnetic resonance imaging indicated abnormal intensities in the paramedian tegmentum and base of the medulla, which may have been additionally responsible for orthostatic hypotension. Steroid pulse therapy and L-threo-3,4-dihydroxyphenylserine caused regression of brainstem signs and reduced syncopal attacks.