[Respiratory chemosensitivity in dementia with Lewy bodies]

The incidence of dementia with Lewy bodies (DLB) is increasing rapidly due to the increasing longevity of the population. In DLB, autonomic dysfunction, such as sleep disorders, and cardiopulmonary arrest, together with unconsciousness, can occur. Such cases have poor prognosis and may have dysfunction of chemosensitivity in the respiratory center. We have assessed the function of the respiratory center, especially chemosensitivity to hypercapnia. Twelve probable DLB patients (Group 1) and twelve age-matched healthy subjects (Group 2) were examined. Chemosensitivities to hypercapnia expressed by delta expiratory volume/delta partial pressure of carbon dioxide/body surface area: mean 0.16 (1/min/Torr/m(2)) in Group 1 and 0.49 in Group 2. Thus, patients with DLB had a subnormal hypercapnic response in chemosensitivity of the respiratory center, suggesting dysfunction of the respiratory center. Respiratory center dysfunction may be related to cardiopulmonary arrest together with unconsciousness, so, patients with DLB should not use drugs affecting the respiratory center.