Unilateral Cerebral Atrophy: Severe Neuroimaging Feature of Incontinentia Pigmenti without Acute Encephalopathic State

Incontinentia pigmenti (IP) is a rare X-linked multisystem disease caused because of mutation in the IKBKG (inhibitor of kappa-B kinase gamma, previously NEMO) gene. Involvement of central nervous system is seen in approximately one-third of these patients. Ischemic strokes, symptomatic seizures, and encephalopathy can be seen during neonatal or early infancy age group. Typically, early bilateral brain involvement is seen with periventricular white matter injury, hemorrhagic infarction, and multifocal cortical injury. We reported a patient who did not have early encephalopathic presentation, but presented with right hemiparesis and intellectual impairment. Magnetic resonance imaging of the brain revealed extensive left cerebral white matter volume loss and encephalomalacia with Wallerian degeneration of the left cortical spinal tract. This case highlights a rare presentation of unilateral cerebral atrophy with no definite episode of acute encephalopathy during infancy to suggest pure intrauterine injury. Microvascular occlusion, inflammatory cerebral vasculopathy, and recurrent silent strokes possibly produced this extensive neurologic manifestation antenatally. We also reviewed the complex pathogenic mechanisms involved in IP.