<aside>
Schizencephaly is a rare neuronal migration disorder characterized by a full-thickness cleft extending from the ependymal lining of the lateral ventricle to the pial surface of the cerebral cortex, lined by gray matter (polymicrogyric cortex).
</aside>
It results from a prenatal disruption of cortical development, typically between 7–24 weeks of gestation.
| Type | Description |
|---|---|
| Type I (Closed-lip schizencephaly) | Cleft walls are in apposition or fused, forming a slit-like cleft |
| Type II (Open-lip schizencephaly) | Cleft walls are separated and filled with CSF, forming a wide communication between ventricle and subarachnoid space |
| Mixed | One hemisphere has closed-lip, the other has open-lip |
| Cause | Mechanism |
|---|---|
| Disruption of neuronal migration | During second trimester (around 8–16 weeks) |
| Ischemia/infarction | Especially in border zone of MCA territories |
| Congenital infections | CMV, Zika virus |
| Genetic mutations | EMX2 gene (rare and inconsistent) |
| Metabolic | Less common (e.g., mitochondrial disorders) |
| Symptom | Details |
|---|---|
| Seizures | Most common presentation (focal or generalized) |
| Motor deficits | Hemiparesis, quadriparesis, spasticity depending on cleft location and extent |
| Developmental delay | Global delay if bilateral or extensive clefts |
| Hydrocephalus | May occur with large open-lip clefts |
| Visual or cognitive impairment | If associated occipital or parietal involvement |
Symptoms depend on laterality and extent:
<aside>
Schizencephaly appears as a cleft with CSF signal intensity traversing the cerebral mantle, always lined by gray matter, and best evaluated on MRI, which distinguishes it from porencephalic cysts.
Imaging Planes