A 48-day-old girl presented to the emergency department with a first-time seizure. Immediately after breastfeeding, she vomited and became unresponsive. Her head and eyes deviated to the left, followed by bilateral arm and leg shaking for 20 minutes. A 20 mg/kg fosphenytoin load was given. Neurological examination showed mildly decreased axial tone with mild head lag and slip-through on vertical suspension. There was a hypopigmented lesion on the right forehead with irregular borders ( Fig. 19.1 ).

Hypomelanosis of Ito. Hypopigmentation may appear as striations, swirls, patches, or whorls at birth or during the first year of life. Lesions can involve the trunk, limbs, and/or head.

The patient was otherwise healthy and born following an uncomplicated full-term pregnancy at 39 weeks via elective cesarean section to a G3P2 mother with no complications during delivery. Development was appropriate for age. The parents were originally from Ethiopia, with two other healthy children and no family history of consanguinity, seizures, or developmental delay.

The patient’s seizures were refractory to levetiracetam bolus, requiring loading doses of lorazepam and fosphenytoin. Intermittent and at times prolonged seizures continued, requiring daily lorazepam rescue doses and maintenance of levetiracetam, phenobarbital, and lacosamide. Despite all antiseizure medications, she required a brief midazolam infusion in the pediatric intensive care unit.

Initial labs, cultures, and CSF analysis were unremarkable. Head CT was also normal. Brain MRI showed subtle right hemispheric asymmetry of T1, T2, and diffusion signal with cortical thickening ( Fig. 19.2 ). Repeat brain MRI 20 days later showed more prominent gray-white differentiation suggestive of diffuse cortical dysplasia ( Fig. 19.3 ). Additional investigations and prolonged video-EEG monitoring were performed ( Fig. 19.4 ).

Hemimegalencephaly. Brain MRI shows asymmetric right cerebral signal with cortical thickening and white matter signal abnormality ( arrows ).

Hemimegalencephaly. Brain MRI on day 2 and day 20 of admission show persistent asymmetric right cerebral findings ( arrows ). There is mild interval volume loss with more prominent cortical irregularity on the follow-up examination.

1-hour epoch of EEG trends ( left ) and 7-second epoch of regular EEG ( right ) at 2 months of age showing ongoing seizures despite aggressive antiseizure therapy. Frequent seizures were recorded over the right hemisphere ( red rectangle ). These were often brief and minimally noticeable on the EEG trends ( arrowheads ), but other episodes were very prolonged and almost 1 hour in length ( arrows ). EEG , Electroencephalography.

The patient proceeded to neurosurgery for a right functional hemispherotomy at 69 days of life. Pathology reported extensive cortical dysplasia including cortical thinning with radial and tangential dyslamination, numerous enlarged dysmorphic neurons with extension into subcortical white matter, and extensive gliosis.

Seizures in the neonatal and early infant period can show stereotyped features, forced posturing, and lack of improvement with repositioning. There are multiple causes including inborn errors of metabolism, intracranial or intraparenchymal hemorrhage, cerebral ischemia, infections, congenital brain malformations, genetic epilepsy syndromes, and developmental or epileptic encephalopathies.

Seizure mimics include gastro-esophageal reflux disorder, benign neonatal sleep myoclonus, excessive startle, and benign clonic movements.

Careful history and physical examination, laboratory testing, EEG, and neuroimaging should be performed to identify etiology and guide appropriate management.