Recreational scuba diving has become a popular sport in the United States,
with almost 9 million certified divers. When severe diving injury occurs, t
he nervous system is frequently involved. In dive-related barotrauma, compr
essed or expanding gas within the ears, sinuses and lungs causes various fo
rms of neurologic injury. Otic barotrauma often induces pain, vertigo and h
earing loss. In pulmonary barotrauma of ascent, lung damage can precipitate
arterial gas embolism, causing blockage of cerebral blood vessels and alte
rations of consciousness; seizures and focal neurologic deficits. In patien
ts with decompression sickness, the vestibular system, spinal cord and brai
n are affected by the formation of nitrogen bubbles. Common signs and sympt
oms include vertigo, thoracic myelopathy with leg weakness, confusion, head
ache and hemiparesis. Other diving-related neurologic complications include
headache and oxygen toxicity.