[Slow posterior rhythm: electroclinical study of 100 new cases].

One hundred patients with slow rhythmical electro-encephalographic (EEG) activity in the posterior regions were classified according to their clinical symptomatology. Correlations were established between the occurrence of the slow posterior rhythm (SPR) and head injury, and psychological, autonomic or vascular disturbances. In contrast to most previous publications, the patients with head injury constituted only one-half of the series. Autonomic and psychological complaints were frequently encountered in this group. A second group of 11 patients had some type of vascular pathology. A third group of 39 patients had symptoms of anxiety and autonomic system disturbance. The importance of head injury as a factor responsible for SPR seems to have been overrated. Regardless of classification, psychological symptoms were found in 50% and autonomic dysfunction in 53% of all patients. It is apparent that the origin and significance of slow posterior rhythm have not yet been eludicated.