161 Microscopically, the gray matter lining the clefts of SCZ is consistent with PMG, often indistinguishable from other forms of PMG. Figure 9. Imaging features of schizencephaly. Coronal T1 – (left) and axial T1 (right)-weighted MRI scans. Both images show full-thickness clefts lined by irregular gray matter (arrows). The image on the left shows bilateral closed-lip schizencephaly (SCZ) and … The clinical features of SCZ are well described in the literature, and depend on two factors: (i) unilateral vs bilateral SCZ and (ii) open vs. closed-lipped SCZ. Patients with closed-lipped SCZ typically present with hemiparesis or motor

delay whereas patients with open-lipped SCZ typically Inhibitors,research,lifescience,medical present with hydrocephalus or seizures.162 In a large series of 47 children

with different, types of SCZ, Packard et al found a prevalence of epilepsy in 57% and moderateto-sevcre developmental delay in 83%. The median age for seizure onset was 13 months, although those with openlipped SCZ generally had seizure onset Inhibitors,research,lifescience,medical at an earlier age than those with closed-lipped SCZ. The most common seizure type was complex partial, although infantile spasms, tonic, atonic, and tonic-clonic seizures were also reported. The severity and type of seizures does not. appear to correlate with the topography of the SCZ.162,163 Outcome is worst, for those with bilateral open-lipped SCZ and best for Inhibitors,research,lifescience,medical those with unilateral Inhibitors,research,lifescience,medical closed-lip SCZ.162,164 A large PI3K inhibitor number of patients have associated brain abnormalities which may account for the severity of some cases. These included agenesis of the septum pellucidum, focal cortical dysplasia, and dysgenesis of the corpus callosum.162-165

An interesting finding is that some patients with SCZ have relatively minor clinical problems relative to the appearance of their malformation. 166-169 Routine structural MRI scanning is usually sufficient to diagnose SCZ and determine whether the SCZ is open- or closed-lipped. Subtle SCZ may recognizable by a “puckering” or “dimple” Inhibitors,research,lifescience,medical outwards of the lateral ventricle at the point at which the cleft reached the ventricular margin (seen in Astemizole the left, image in figure 9). The cleft, is lined by gray matter. The presence of white matter or T2 signal increase suggestive of gliosis lining the cleft suggests that the lesion is porencephaly rather than SCZ. The gray matter lining the cleft has the imaging appearance of PMG with apparent, cortical thickening, an irregular surface, and stippling of the gray-white interface. SCZ may be asymmetric, and the contralateral hemisphere should be closely evaluated for the presence of a milder SCZ or PMG of another form. Agenesis of the septum pellucidum is a common finding and hypoplasia of the optic nerves may be present, in up to 30% of cases, placing some forms of SCZ in the septo-optic dysplasia spectrum.136,170 The etiology of SCZ remains highly controversial, and there are likely both genetic and non-genetic causes.