[Pickwickian syndrome and hypersomnia with periodic respiration]

A classical definition of Pickwickian syndrome associates alveolar hypoventilation, obesity and hypersomnia with periodic breathing. Obesity in itself is enough to explain the alveolar hypoventilation and some of the sleep disorders, but in fact all three elements of this syndrome are intricated. Obesity, whether associated with a Pickwickian syndrome or not, affects ventilatory mechanics similarly. With the cause of sleep disorders are associated central ventilatory pauses, appearing periodically followed by phases of apnoea secondary to buccopharyngial hypotony. The alveolar hypoventilation is therefore the consequence of obesity and periodic apnoea. It also results from a low respiratory frequency considering that the tidal volume is also decreased. These different elements suggest some disorder of the centers controling ventilation. One can describe different nosological forms, all having as a common factor hypersomnia with periodic respiration, the latter being a determining factor in the diagnosis. Therapy, including weight reduction and symptomatic treatment of alveolar hypoventilation, is now augmented by new drugs acting on the central nervous system.