Subcortical heterotopia: a distinct clinicoradiologic entity

Area of Science:

• Neurology
• Developmental Neuroscience
• Neuroradiology

Background:

• Subcortical heterotopia is a rare congenital brain malformation characterized by the presence of gray matter nodules in the white matter beneath the cerebral cortex.
• Understanding the clinical spectrum and associated neuroimaging findings is crucial for diagnosis and management.

Purpose of the Study:

• To investigate the clinical syndrome and associated brain anomalies in patients diagnosed with subcortical heterotopia.
• To characterize the typical presentation and neurological deficits associated with this condition.

Main Methods:

• Retrospective review of clinical data, including seizure history, developmental milestones, family history, electroencephalography (EEG), and neuroimaging (MRI/CT).
• Pathological findings were analyzed where available.
• Study included 13 patients with subcortical heterotopia, ranging in age from 1 month to 39 years.

Main Results:

• Fifteen affected hemispheres were identified across 13 patients.
• Associated anomalies included thin cerebral cortex overlying heterotopia, smaller affected hemispheres, and abnormalities of the corpus callosum (hypogenesis/agenesis) and basal nuclei (dysplasia/hypoplasia).
• Clinical manifestations comprised developmental delay, contralateral hemiplegia/hemihypesthesia, and partial epilepsy, with EEG showing slow background activity and epileptiform discharges in the affected hemisphere.

Conclusions:

• Subcortical heterotopia presents with characteristic clinical, electrophysiological, and neuroimaging findings.
• These consistent manifestations suggest that patients with subcortical heterotopia can be effectively grouped for further research into treatment outcomes.