Respiratory paralysis as a presenting symptom in Japanese encephalitis--a case report.

In the literature there are rare reports on Japanese encephalitis (JE) mimicking poliomyelitis or presenting as respiratory paralysis. A case of JE presenting as respiratory paralysis is described. The 22-year-old male was well until five days earlier, when he experienced the acute onset of headache and fever. Four days after onset he developed dysphagia and respiratory difficulty, and a tracheotomy was performed. The following day he lapsed into semicoma and the respiration had to be maintained by an artificial ventilator. He regained consciousness by the 10th day after onset. He became able to comprehend questions and express himself by gestures. But the respiration was still paralytic, and assisted ventilation via a tracheotomy had to be continued. The case was clinically diagnosed as encephalitis. Bulbar poliomyelitis was initially considered due to the clinical features of aseptic meningitis, respiratory paralysis, pharyngeal paralysis with pooling secretions in the pharynx, tachycardia and elevated blood pressure. But poliovirus culture obtained from stool and appropriate serological studies were negative. The diagnosis of encephalitis due to JE virus was confirmed by hemagglutination inhibition test (acute phase HI titer 1:320; convalescent phase HI titer 1.1280).