Paroxysmal apnea and vasomotor instability following medullary infarction.

BACKGROUND

Central hypoventilation and paroxysmal hypertension are uncommon complications of medullary infarction. To our knowledge, the combination of these autonomic complications of medullary stroke has not previously been reported.

OBJECTIVE

To describe a patient who experienced life-threatening paroxysmal attacks of central apnea and vasomotor instability 3 months after medullary infarction, a combination of symptoms that is unusual. PATIENT, METHODS, AND

RESULTS

Following a right lateral medullary infarction, an otherwise stable 70-year-old woman developed recurrent episodes of apnea (PCO2), > 100 mm Hg), blood pressure instability (systolic blood pressure, > 200 to < 100 mm Hg), and mental status changes (from agitation to coma) within hours of removal from mechanical ventilation. These attacks occurred repeatedly after removal from mechanical ventilation and were prevented by diaphragm pacing with a phrenic nerve pacemaker and nocturnal mechanical ventilation via a tracheostomy.

CONCLUSIONS

A syndrome of life-threatening central hypoventilation and vasomotor instability can occur after medullary infarction. Placement of a phrenic nerve pacemaker can prevent these complications, without the functional limitations imposed by continuous mechanical ventilation.