Perimesencephalic subarachnoid hemorrhage triggered by hypoxic training during swimming.

INTRODUCTION

Perimesencephalic subarachnoid hemorrhage is a rare neurologic condition of unclear etiology. Multiple mechanisms have been postulated as potential triggers, but none are universally accepted.

METHODS

Single observational case report and review of the literature.

RESULTS

We describe a patient who developed perimesencephalic subarachnoid hemorrhage in the setting of "hypoxic training" (breath-holding while swimming). We describe the plausible pathophysiologic events that caused the hemorrhage.

CONCLUSION

The occurrence of perimesencephalic subarachnoid hemorrhage during hypoxic training suggests that acute venous congestion may be a triggering factor. The increasing popularity of hypoxic training demands vigilance from health care providers.