Paroxysmal sympathetic hyperactivity after severe brain injury.

Paroxysmal sympathetic hyperactivity (PSH) is characterized by the rapid onset and paroxysmal cycling of agitation and dystonia in association with autonomic symptoms. These symptoms may include the following: tachycardia, hypertension, tachypnea, fever, pupil dilation, decreased level of consciousness, diaphoresis, and ventilator dyssynchrony. In a critically ill patient, these are all nonspecific symptoms that may reflect impending sepsis, seizure, or a number of other complications. This can confound and delay the diagnosis and treatment of PSH. While this phenomenon has been frequently observed in the traumatic brain injured population, management is highly variable, prompting this review of the literature. This article aims to outline the evidence base for the management of PSH, as well as to describe an algorithm for management developed at our institution.