Paroxysmal Sympathetic Hyperactivity after Traumatic Brain Injury: Clinical and Prognostic Implications

Abstract A proportion of patients surviving severe traumatic brain injury (TBI) have symptoms suggestive of excessive sympathetic discharge, here termed paroxysmal sympathetic hyperactivity (PSH). The goals of this study were: (1) to describe the clinical associations and radiological findings of PSH, its incidence, and features in subjects with severe TBI in the intensive care unit (ICU); (2) to investigate the potential role of increased intracranial pressure in the pathogenesis of PSH; and (3) to determine the prognostic influence of PSH during the ICU stay, on discharge from the ICU, and at 12 months post-injury. A prospective cohort study was undertaken of all ICU admissions with severe TBI older than 14 years over an 18-month period. The PSH symptoms consisted of paroxysmal increases in blood pressure, respiratory rate, and heart rate; worsening level of consciousness; muscle rigidity; and hyperhidrosis. Subjects demonstrating PSH episodes were compared with a group of non-PSH consecutive subjects s...