Brain Gray Matter Declines In Sleep Apnea Patients

Researchers have shown that the volume of gray matter in the brains of patients with obstructive sleep apnea (OSA) was reduced by up to 18 percent compared with normal controls. The amount of the reduction increased as the syndrome became more severe.

The investigators analyzed three-dimensional images done on the brains of 21 patients with OSA and 21 healthy control subjects. They reported that OSA patient gray matter losses occurred in such brain regions as the left frontal cortex, in an area that modulates upper airway motor function, and the cerebellum, which is a brain structure that plays a major role in cardiovascular and respiratory control. The researchers said that a portion of the volume changes may have been present before the onset of OSA and may have contributed to the characteristics of the syndrome.

In an editorial in the same issue on the research, David Gozal, M.D., of Kosair Children's Hospital Research Institute, University of Louisville, Louisville, Kentucky, noted that these research findings "raise the tantalizing possibility that changes in gray matter hint at mechanisms for the genesis of the sleep disordered breathing syndrome, likely in concert with anatomic features but certainly playing a role in the progression of a compromised oral airway environment leading to a condition of certain upper airway failure." He points out that, to date, neural deficits have been justifiably assumed to represent a consequence of sleep-disordered breathing rather than to precede the syndrome. "Perhaps the time has come to reverse our thinking," he said.

The research and editorial appear in the second issue for November 2002 of the American Journal of Respiratory and Critical Care Medicine.

Source: Medwire