Interactive clinical case reports: Central nervous system infections in Viet Nam: ‘off legs—?cause’

Abstract

The management of children presenting with acute flaccid paralysis has received increasing attention since the WHO launched its campaign for the global eradication of polio by the year 2000. In this interactive case presentation based around a Vietnamese child, clinical pointers to the diagnosis, and the appropriate use of investigations were discussed. In broad terms, patients with acute flaccid paralysis can be divided into those who are otherwise well, and those whose flaccid paralysis is part of an acute febrile illness. The former presentation suggests Guillain Barré syndrome, either the ‘classical’ dernyelinating polyradiculopathy affecting both sensory and motor nerves, or the acute motor axonal neuropathy (AMAN). AMAN (also known as the Chinese paralytic syndrome) often follows infection with Campylobacter jejuni, and is associated with auto-antibodies directed against ganglioside components of motor axons. When flaccid paralysis occurs as part of an acute febrile illness, this suggests direct invasion of anterior horn cells, especially if sensation is preserved. This presentation is typical of polio, other enteroviruses, and also the recently described Japanese encephalitis virus (JEV) myelitis. Like polio, JEV myelitis is characterized by a short febrile illness immediately followed by an acute onset asymmetrical flaccid paralysis. There is a cerebrospinal fluid pleiocytosis, and nerve conduction studies suggest damage to the anterior horn cells. The development of acute retention of urine and signs of encephalitis may be more common in JEV myelitis than polio. Residual weakness and wasting are common in JEV myelitis, and in JEV-endemic areas it should be included in the differential of children with suspected polio.