Neurologic manifestations of Legionnaires' disease.

The neurologic manifestations of Legionnaires' disease were reviewed in this paper. Nine (42.9%) of 21 patients seen at this institution had neurologic abnormalities during acute infection, comparable to 52% of patients found in the literature. Abnormal mentation was most common, occurring in all our patients and in 29.6% of patients in the literature. Encephalopathy disproportionate to metabolic disturbances varied from mild confusion to coma, was not associated with increased mortality, and tended to resolve with acute illness although some patients reported persistent memory defects. Rarely did these changes in mentation precede the development of pulmonary infiltrates. Headache occurred in two (22.2%) of our patients and in 28.7% of those in the literature. Headache, noted in many febrile illnesses, is common but nonspecific in Legionnaires' disease. Other neurologic abnormalities including cerebellar dysfunction and focal deficits were relatively infrequent and tended to persist beyond resolution of clinical infection. In some cases these neurologic derangements may have occurred coincidentally with Legionnaires' disease. Diagnostic evaluations and autopsies were frequently normal, nonspecific, or revealing of pathology unrelated to infection. Only two patients had evidence of direct invasion of the central nervous system by Legionella, and the cause of encephalopathy and neurologic abnormalities in most cases remains unclear. Patients with neurologic abnormalities and Legionnaires' disease deserve full evaluation to exclude other entities. Only encephalopathy appears to be a characteristic manifestation of Legionnaires' disease.

The protean manifestations of Legionnaires' disease.

The protean manifestations of Legionnaires' disease are described in an analysis of 12 sporadic cases. Two forms of the disease have been delineated. One variant (Group A) consisted of six patients who had a mild form of non-progressive pneumonia with minimum extra-pulmonary involvement. Six patients (Group B) were differentiated by rapidly progressive pulmonary infiltrates, severe hypoxia and respiratory failure, plus a higher frequency of band neutrophils and extra-pulmonary manifestations. Particularly notable were evidence of severe myositis (elevated creatinine phosphokinase and lactate dehydrogenase), anaemia, and neurological findings which included alterations in the sensorium, meningitis, and convulsions. Cerebrospinal fluid (CSF) abnormalities were seen frequently in patients with neurological manifestations, and necropsy findings in one patient suggested that the Legionnaires' bacillus was capable of producing a fatal leucoencephalitis. Renal findings included haematuria, proteinuria and oliguric renal failure. Hepatic transaminases (SGPT, SGOT) were elevated in six patients and serum bilirubin was abnormal in five. Alkaline phosphatase values were normal to minimally elevated. The gastrointestinal symptoms commonly considered to be a frequent initial manifestation of Legionnaires' disease were rare in this series. Recommendations for instituting empirical therapy, based upon recognition of a clinical syndrome which should suggest the diagnosis of Legionnaires' disease, are included.