[Acute confusional syndrome of unknown cause. Prospective study in the emergency room]

In a prospective study conducted in the Emergency Area of a general hospital during a period of 6 months, the Neurology Service was consulted in 45 cases of acute confusional syndrome. Twenty nine of these patients had no immediate apparent etiology. Among the studied patients 5 had a subarachnoid hemorrhage, 4 suffered a central nervous system infection, 3 had a cerebral infarction, 3 presented a metabolic encephalopathy, and the remaining patients had variate etiologies. Clinical signs and symptoms were insufficient to establish the diagnosis and in several cases complementary tests were required (cerebral tomography and cerebrospinal liquid examination). Even in these cases the diagnosis could not be obtained in some patients. The clinical implications of the present findings were discussed.