Temporal schizencephaly MRI

A 16 yo male for epilepsy evaluation. EEG report mentions left temporo parietal abnormal spikes.
MRI Brain:

Axial and coronal T2w images of Brain shows:
A cleft iso intense to Csf , extending from left temporal horn towards the caudal surface of left temporal lobe.
Imaging diagnosis : Left temporal schizencephaly, the site of cleft is unusual.

Schizencephaly

A congenital brain malformation characterized by cleft extending from pial surface of cerebral hemisphere to the adjacent ventricle.
Imaging wise best diagnostic clue is a gray matter lined cleft iso dense to Csf on CT and iso intense on all pulse sequences of MRI .
Location wise usually involves insula, adjoining pre or post central cortex. Temporal and occipital are atypical and very uncommon locations.

Types:
Type I (Closed lip) : Fused pial - ependymal seam lined by gray matter forms "furrow" in cortex.
Type II (Open lip) : Large or wide gray matter lined, fluid filled cleft.

Incidence: Unilateral more common than bilateral in live patient series where as bilateral clefts reported more commonly than unilateral in neuropathological series. Exact incidence not known.
Associated findings may be deformity of ventricle at the site of cleft, 'points' towards the cleft. Heterotrophia. Associated anomalies may be Pituitary or Optic pathway hypoplasias, Hippocampal malformation / mal orientation. Septum pellucidum may be absent, partially deficient or present. In temporal or occipital schizencephaly, an associated absence of septum pellucidum not expected.
MRI is preferred investigation of choice due to its multi planner capability and excellent grey white matter differentiation.

General pathological comments: Insult or inherited mutations lead to same pathologic / imaging features typically in MCA distribution  Intra uterine insult include infection, maternal trauma or toxin exposure. Reported with alloimmune thrombocytopenia.
Genetics: Mutation in homeobox gene Emx 2 in some (not all) cases, particularly type ii Schizencephaly. Emx 2 is the first identified mutation.

Clinical presentation: Patient with type I cleft may be near normal or may have seizures, motor deficit "congenital" hemi paresis.
Unilateral variety often present with seizures, or motor deficit "congenital" hemi paresis where as bilateral variety is associated with severe disability may present with hemi or quadraparesis, microcephaly, hydrocephalus, Spasticity, severe deveolpmental delay, mental retardation etc.
Age at the diagnosis depends on onset of symptoms like seizures or when the motor deficit / developmental delay is noticed by parents.

Reference : Diagnostic imaging Osborn.