Paroxysmal sympathetic hyperactivity after acquired brain injury: a review of diagnostic criteria

Primary objective: To evaluate the development and usage of diagnostic criteria for paroxysmal sympathetic hyperactivity (PSH) following acquired brain injury (ABI), then comparatively analyse published criteria. Research design: Systematic literature review. Methods and procedures: Literature published in English language prior to 30 November 2008 was reviewed for dysautonomic syndromes following ABI, characterized by simultaneous paroxysmal autonomic hyperactivity and motor over-activity. Main outcome and results: Sixty papers presenting 349 cases of PSH were identified, with a further 21 papers providing additional information regarding the condition. Only 27 of these 81 papers (33%) utilized diagnostic criteria. There were nine novel or substantially modified diagnostic criteria sets, which were analysed further. Criteria showed strong agreement on core clinical features of PSH—heart rate (HR), blood pressure, respiratory rate, temperature, sweating, and motor hyperactivity. Most criteria sets utilized a polythetic diagnostic system and all but one indicated severity thresholds, e.g. HR >120 beats per minute. Two papers specified a minimum episode frequency and four papers required a minimum syndrome duration. Conclusions: Of necessity, diagnostic criteria have been developed ad hoc. The differences between criteria complicate both clinical diagnosis and the process of comparing research cohorts. These findings demarcate the need for a single set of PSH diagnostic criteria and provide the substrate for scientific consensus