Cerebral White-Matter Lesions in Asymptomatic Military Divers

Abstract

There is some concern that over a period of years, diving may produce cumulative neurological injury even in divers who have no history of decompression sickness. We evaluated asymptomatic divers and controls for cerebral white-matter lesions using magnetic resonance imaging (MRI). The study enrolled 113 male military divers (34.4 +/- 5.6 yr) and 65 non-diving men (33.1 +/- 9.0 yr) in good health. Exclusion criteria included any condition that might be expected to produce neurological effects. Patent foramen ovale was not assessed. A questionnaire was used to elicit diving history. A 1.5-T MRI device was used to acquire T1, T2-weighted, and fluid attenuated inversion recovery (FLAIR) images of the brain. A lesion was counted if it appeared hyperintense on both T2-weighted and FLAIR images. MRI revealed brain lesions in 26 of 113 divers (23%) and in 7 of 65 (11%) controls, a difference that was statistically significant. There was no significant difference between the groups with respect to blood pressure, smoking history, or alcohol consumption, and no subject reported a history of head trauma or migraine. There was no relationship between MRI findings and age, diving history, or lipid profile in divers. The higher incidence of lesions in the cerebral white matter of divers confirms the possibility that cumulative, subclinical injury to the neurological system may affect the long-term health of military and recreational divers.