Paroxysmal Sympathetic Hyperactivity in Critically Ill Children with Encephalitis and Meningoencephalitis

Autonomic dysfunction in pediatric patients with acquired brain injury is often encountered and greatly understudied. We sought to identify the incidence of Paroxysmal Sympathetic Hyperactivity (PSH) in critically ill pediatric patients with meningoencephalitis and encephalitis, associated risk factors and influence on outcome.

Children admitted to the pediatric intensive care unit (PICU) with a diagnosis of meningoencephalitis and/or encephalitis were identified from a single institution Neurocritical Care database. The patients were stratified as having a bacterial or non-bacterial cause of their meningoencephalitis/encephalitis. Data from their hospitalization was supplemented with a retrospective review of the electronic medical record. PSH was defined as episodic lability in heart rate and/or blood pressure, hyperthermia, diaphoresis, dystonic posturing, tachypnea and/or agitation without any other cause. Statistical analysis was performed using t-test and chi-squared to compare outcomes and risk factors between patients with PSH and without.

PSH was found in 41 % of children studied. Subgroup analysis revealed patients with non-bacterial encephalitis were more likely to experience PSH (51 %) as compared to those with bacterial causes (27 %). Fever and/or seizures on presentation and female gender were associated with higher occurrence of PSH but only in the non-bacterial etiology group. There were trends toward increased length of PICU and overall hospital stay for patients with PSH.

PSH was found in a high percentage of our patients with significant variation in risk factors and outcome noted between patients with bacterial and nonbacterial causes of their meningoencephalitis/encephalitis.