Histological Changes of Muscle ln a Patient with Pyruvate Dehydrogenase Deficiency

Hypoventilation during sleep in the absence of primary pulmonary, cardiac or neuromuscular disease, prompted us to make a diagnosis of Ondine's curse. This was confirmed by the immediate improvement in the blood gas level following voluntary hyperventilation, and by the lack of ventilatory response to high PC02 and low P02 levels in the blood [1]. Shannon et al reported that hypoventilation improved markedly during REM sleep in Ondine's curse [2]. On the other hand, Wells et al reported a case where ventilation was not improved during REM sleep [3]. In our case also, no significant improvement in blood gas levels was noted during REM sleep, as measured by a transcutaneous P02 monitor and PC02 monitor and by gas analysis of arterial blood. Contrary to the hypothesis of Shannon et aI, these cases suggest that non-chemoreceptor stimuli during REM sleep are not always enough to maintain normal respiration. Although some cases have been reported associated with other rare disorders [4], we have been unable to discover any previous report of a patient with both Ondine's curse and hypergonadotropic hypogonadism. Both disorders are rare, and we cannot find any explanation to link them. In the treatment of Ondine's curse respiratory stimulants seem the most applicable, although drugs such as ritalin, ethamivan, nikethamide, aminophylline and medroxyprogesterone have been tried with little success. Doxapram hydrochloride has been reported to be effective but it has to be administered parenterally and acts for only a brief period [5]. Compared with these drugs, dimfline has advantages in the treatment of Ondine's curse. It stimulates the respiratory center directly. It has a higher therapeutic index [6] and it can be administered orally. In the case reported here oral administration of dimefline brought about significant improvement of nocturnal hypoventilation. However, after the effective time of this drug PC02 elevated higher than that of no treatment. This may suggest the "exhaustion" of respiratory center. Therefore it should be tried with enough caution.