Differentiating Paroxysmal Sympathetic Hyperactivity From Seizures in Medically Complex Children

Mark Timothy Bleazard


Pediatr Nurs. 2019;45(2):67-70. 

In This Article

Abstract and Introduction


Background: Paroxysmal sympathetic hyperactivity and seizures may co-occur in the medically complex child with autonomic instability. Distinguishing one from the other can be difficult for the clinician due to an overlap in presentation. As a result, signs of paroxysmal sympathetic hyperactivity are frequently misinterpreted as seizures, leading to delays in appropriate care.

Purpose: To provide nurses caring for medically complex children with neurologic impairment an overview of physiology, symptomatology, and management to differentiate paroxysmal sympathetic hyperactivity from seizures.

Methods: A literature review was conducted using the keywords "autonomic storming," "paroxysmal sympathetic hyperactivity," "seizures," "seizure presentation," and "medically complex children" in Ovid Medline, EBSCOhost, and ClinicalKey online databases. Limits included articles and texts published between 2008–2017 and limited to English. Pediatric and adult literature were included in the review. Nineteen sources were selected for inclusion in the review.

Findings: Diaphoresis, hyperthermia, hypertension, tachycardia, and tachypnea are uniquely associated with paroxysmal sympathetic hyperactivity, whereas unusual ocular and oral movements, cyanosis, salivation, desaturations, and pupillary dilation characterized by a post-ictal period have been more commonly associated with seizures, particularly generalized tonic-clonic seizures of childhood.

Conclusion: Nurses caring for medically complex children may be required to differentiate paroxysmal sympathetic hyperactivity from seizure activity. Accurate assessment, identification, and appropriate intervention are imperative in reducing complications from uncontrolled symptoms. Further research on paroxysmal sympathetic hyperactivity specific to medically complex children and outside of the intensive care unit is indicated.


Neurologic findings in medically complex children can be a challenge for clinicians to interpret. Various neurologic phenomena may occur at baseline for children with severe neurologic impairment (Russell & Simon, 2014). Paroxysmal sympathetic hyper activity (PSH) and seizures are two disorders that may co-occur with one another in medically complex children with neurologic impairment. This can be difficult for the clinician to recognize due to the overlap in presenting symptoms of hypertonicity, alterations from neurologic baseline, involuntary muscle contractions, or dystonia (Choi, Jeon, Samuel, Allison, & Lee, 2013; Sharma, 2013). Further-more, neurologic baselines are individualized to each medically complex child, providing uncertainty when a change from baseline has occurred. Care givers, though often valuable partners in the care of medically complex children, may not always be present to provide insight into the child's condition. A review of PSH and seizure physiology, symptomatology, and management will assist clinicians in improving patient care outcomes in medically complex children.