Decreasing incidence of paroxysmal sympathetic hyperactivity syndrome in the vegetative state

To update knowledge of the incidence of paroxysmal sympathetic hyperactivity (PSH, also referred to as dysautonomia), an emergency condition tentatively attributed to sympathetic paroxysms or diencephalic-hypothalamic disarrangement associated with severe diffuse brain axonal damage or hypoxia. This condition is reportedly common in the vegetative state, threatens survival and affects outcome.

The results of a retrospective study on 333 subjects in a vegetative state admitted to a dedicated unit in 1998-2005 are compared with a survey on patients admitted to the same unit in 2006-2010.

In the 1998-2005 period, the incidence of PSH was 32% and 16% in post-traumatic and non-traumatic patients, respectively. It decreased to 18% and 7% in the 2006-2010 period. The PSH duration and the time spent in emergency units before admission and in the dedicated unit for the vegetative state after admission also decreased significantly. Incidence was greater among post-traumatic- patients; its effect on outcome does not appear to have changed.