A Case of Lateral Medullary Infarction with Cardiovascular Autonomic Dysfunction: An Unusual Presentation

Objective: To report an unusual presentation of lateral medullary syndrome. Background: Lateral medullary syndrome is classically characterized with vertigo, dissociated crossed sensory deficits, ipsilateral ataxia, bulbar palsy, and Horner’s syndrome. Although presentations vary depending on the location of the lesion, the sensory and motor manifestations of lateral medullary infarctions are the most well recognized, with rare reports of associated autonomic dysfunctions. We report the case of a gentleman with an unusual presentation of lateral medullary syndrome with orthostatic hypotension and pre-syncope. Design/Methods: Case report. Results: A 67 year-old man presented with pre-syncope and ataxia without vertigo. Initial CT and MRI of the head were normal. Neurological evaluation revealed right-beating nystagmus with left gaze, vertical binocular diplopia, right upper extremity dysmetria, truncal ataxia, right-facial and lower extremity hypoesthesia, and positive bedside orthostatic hypotension. Echocardiogram was normal with EF of 65%. Telemetry revealed a normal sinus rhythm. A repeat MRI showed an acute right dorsolateral medullary infarct. Autonomic nervous system testing demonstrated the following - Deep breathing: blunted heart rate variation (trial one: 4 beats/min, trial two: 3.8; 5th percentile: 7. Valsalva maneuver: blunted heart rate variation (ratio one: 1.03, ratio two: 1.15; 5th percentile 1.29), and no late phase II blood pressure response. Tilt-table test: 25–50 Torr fall in blood pressure at the end of a 10-minutes tilt-table test with no significant change in heart rate. These results are consistent for dysautonomia with sympathetic and parasympathetic dysfunction. He was discharged to acute rehabilitation a week later with residual right dysmetria and ataxia. Conclusions: Dorsolateral medullary infarctions are usually reported as fragmentary presentation of classic lateral medullary syndrome with accompanying unusual symptoms ranging from trigeminal neuralgias to hiccups. Presyncope and orthostatic hypotension is a rare presentation of dorsolateral medullary infarctions. Physicians should be aware of this presentation as early diagnosis and treatment would lead to a good outcome. Disclosure: Dr. Huynh has nothing to disclose. Dr. Decker has nothing to disclose. Dr. Tunguturi has nothing to disclose.