Transient Postictal Hemispheric Hypoperfusion Associated With Human Coronavirus NL63 in a Child.

Human coronavirus NL63 (HCoV-NL63) is typically associated with mild upper-respiratory infections, but rare neurological manifestations have been reported. These presentations may closely mimic acute vascular or epileptic events in children. We describe an 8-year-old previously healthy girl who developed vomiting followed by ocular deviation, limb tremors, and brief altered consciousness. On arrival, she was afebrile and hemodynamically stable, with right gaze deviation, miosis, and suspected right hemiparesis. Brain computed tomography (CT) and angiography revealed marked left-hemispheric hypoperfusion consistent with a postictal state. A multiplex respiratory viral panel was positive for HCoV-NL63, while cerebrospinal fluid, microbiological, and toxicological studies were unremarkable. Magnetic resonance imaging (MRI) performed 48 hours later demonstrated complete normalization of perfusion. The patient recovered fully without further seizures. This case highlights a temporal association between HCoV-NL63 infection and transient postictal hemispheric hypoperfusion, underscoring the importance of integrating clinical, radiologic, and virologic data to avoid misdiagnosis of stroke in pediatric patients.