Clinical spectrum of postviral fatigue syndrome.

Many different neurological and psychiatric syndromes follow viral infections, but their clinical pictures and pathogeneses are poorly understood. The syndromes include acute disseminated encephalomyelitis (post-infectious encephalomyelitis), the Guillain-Barre syndrome (post-infectious neuritis) and Reye's syndrome. Recently, attention has been focused on another common postviral neurological syndrome, i.e. the postviral fatigue syndrome (PVFS)--termed myalgic encephalomyelitis (ME) and a host of other designations. PVFS occurs both sporadically and in epidemics, with cases being reported from all over Europe, the United States, Australasia and South Africa. It is difficult to make the diagnosis and this has meant, in the past, that it is not until an epidemic has occurred that random cases which presented in the preceding years are realised to represent the same condition. With renewed interest in the syndrome and greater attention from physicians, however, diagnosis of sporadic cases is now becoming more common.