Micturitional disturbances are associated with impaired breathing control in multiple sclerosis

Study objectives: To investigate whether the localization of multiple scler osis (MS), the duration of the disease, and the level of neurologic functio ning in patients with MS predispose them to disturbed breathing control. Design: Case-control study. Setting: Outpatient pneumology department of a university hospital. Patients: Twenty-three MS patients and 51 healthy control subjects, Measurements and results: Resting mouth occlusion pressure at 0.1 s after o nset of inspiratory effort (P-0.1) was measured during the hypercapnic resp onse (HCR) and the hypoxic response (HR) in all subjects. The Kurtzke expan ded disability status scale and the functional system score were used to de scribe the level of neurologic functioning of the MS patients. Predictors o f HCR and HR were assessed by multiple regression analysis. Low maximal ins piratory pressure (MIP) values correlated with low resting P-0.1 values (r = 0.44; p = 0.05), although in neuromuscular diseases, high resting P-0.1 v alues are usually found to compensate for low MIPs. Detrusor-sphincter dyss ynergia (DSD) was the only predictor for lower ventilator? HCR (p = 0.006; r(2) = 0.52), lower P-0.1 HCR (p = 0.004; r(2) = 0.47), lower ventilatory H R (p = 0.04; r(2) = 0.28), and lower P-0.1 HR (p = 0.04; r(2) = 0.10); low MIPs and pyramidal tract involvement had no role. Conclusions: (1) Impaired control of breathing in some MS patients is relat ed mainly to central defects. (2) DSD is the most important predictor of di sturbed ventilatory control, presumably because the micturition and pneumot axic center are closely related and located in the rostral pens. (3) No rel ationship with the duration of the MS disease could be demonstrated, which can be explained by the variable course of MS itself.