Teaching Case

A 3 year-old male patient presented with partial complex epileptic seizures, motor mental retardation and right sided hemiparesia.

A 3 year-old male patient presented with partial complex epileptic seizures, motor mental retardation and right sided hemiparesia. MRI of the cranium with SE T1, FSE T2, IR T1 sequences was performed on 1.5 T MR scanner.

Schizencephaly is an uncommon disorder of cerebral cortical development, characterized by congenital clefts spanning the cerebral hemispheres from the pial surface to the lateral ventricles and lined by dysplastic cortical gray matter. The clefts can be open-lip or closed-lip. Closed-lip clefts have their gray matter lined walls in apposition at one or more points in more than one plane, while open-lip schizencephaly the walls are separated. Schizencephalic clefts can be unilateral or bilateral. Clefts may be located in any area of the brain, but most commonly in the frontal and frontoparietal regions. Either an antenatal environmental insult such as infection, ischemia or a genetic origin can be responsible for the development of schizencephaly, which occurs between the third and fourth month of gestation. The ages of the patients at the time of the first presentation ranges from 1 month to 10 years. Presenting findings vary with the size and location of the lesion, and include seizures, hydrocephalus, developmental delay, language impairment, and motor dysfunction (hypotonia, hemiparesis, quadriparesis). Patients with closed-lip schizencephaly commonly present with hemiparesis and motor retardation, whereas those with open-lip present with hydrocephalus, seizures. Bilateral forms are significantly associated with tetraparesis, whereas unilateral forms are associated with hemiparesis. When both hemispheres are involved, an absence of reorganization of the brain function between the two hemispheres leads to severe mental deficits, in addition to the cerebral anomaly itself. Most of the patients have associated anomalies such as neuronal migration disorders like as dysplasia or heterotopia, the absence of septum pellucidum, corpus callosum dysgenesis, septooptic dysplasia. Histopathologically a dysplastic (polymicrogyric ) gray matter-lined cleft extends from the ventricle through the full thickness of the hemisphere. MRI reveals schizencephaly clearly, the cleft extends from brain surface to ventricle and is lined by irregular polymicrogyric gray matter in open-lip defects, and a dimple is seen along the ventricular surface in closed-lip defects. Porencephalic cyst which is secondary to a destructive process, lined by gliotic white matter rather than dysplastic gray matter can be easily differentiated from schizencephalies. Treatment is mostly conservative for seizures, however medically intractable cases may undergo surgical resection. Prognosis depends on size, location, and uni- or bilaterallity of the schizencephaly. Patients with closed-lip schizencephaly are more likely to have a mild to moderate outcome than those with open-lip type, and patients with unilateral schizencephaly have a mild or moderate outcome more frequently than those with bilateral lesions.