Schizencephaly of open and closed lip type in the same patient: An extremely rare occurrence.

Neuronal migration defects are rare causes of seizure disorder and developmental problems. Schizencephaly the most severe form is an extremely rare entity. Here a rare case of bilateral schizencephaly (open and closed type in the same patient) is reported.

Introduction

Neuronal migration defects are rare causes of seizure disorder and developmental problems.[1] The spectrum of these disorders ranges from gyral abnormalities, i.e. disturbances in the formation of cortical surface to complete focal agenesis of an entire region of the cerebral cortex as in schizencephaly[2] (most severe form).

Here we report an extremely rare case of bilateral schizencephaly: left side (type I) and right side (type II), presenting as seizure disorder and inability to speak since birth. Recent estimates show the overall prevalence of 1.54 per 100,000 population.[3] The literature from the Indian subcontinent is very scarce. Features of our case were relatively benign as compared to few published cases from India.[4-6]

Case Report

A 10-year-old male child presented to our pediatric outpatient department, with complaints of inability to speak since birth and seizures since 5 years of age (generalized tonic and clonic type). He was born at term, by vaginal delivery, to a nonconsanguineous couple. Antenatal, natal, and postnatal periods were uneventful. There was delay of language milestones since birth. Other fields of development were normal. No other abnormality was present on examination. Hearing was normal. We investigated the child for the cause of seizures and speech delay. Routine blood investigations, electrolytes, and liver function tests were normal. Electroencephalography showed isolated bursts of sharp waves occurring independently on either side. Magnetic resonant imaging (MRI) of brain done in our hospital on Philips Achieva (1.5 T, Philips, Holland) showed grey matter lined cerebrospinal fluid (CSF) filled clefts, in bilateral frontal regions, extending from the pial surface of brain through the white matter to ependymal surface of bodies of lateral ventricles. On the left side, the cleft was communicating with the ventricle [Figure 1a, b]. On the basis of MRI findings, diagnosis of bilateral schizencephaly was made.

Figure 1

Coronal T1 inversion recovery (a) and coronal T2 sequence images (b), respectively, are showing closed lip CSF cleft lined by grey matter on the right side and open lip CSF cleft communicating with lateral ventricle lined by grey matter on the left side

For seizures, he was taking oral phenytoin but seizures were poorly controlled. The patient was started on tab sodium valproate (@10 mg/kg/day dose) and was discharged on the same dose. The patient is regularly being followed up, and there has been no episode of seizure till 6 months of treatment of our follow-up. The patient has made very small progress regarding speech, despite speech therapy.

Discussion

Schizencephaly is an extremely rare congenital brain anomaly and is the most severe form of neuronal migration defects. This disorder was originally described by Yakovlev and Wadsworth.[7] Two types have been described. Type I or closed lip type is characterized by a pial ependymal seam lined by grey matter with both the lips apposed to each other. There is no intervening CSF cavity.[8] Type II or open lip type is a defect characterized by clefts, which are separated and communicates with the lateral ventricles and is usually accompanied by hydrocephalus.[8] Our patient had both the types, but there was no hydrocephalus. Only one-half of the schizencephaly cases are bilateral and when bilateral, only 20% are of mixed type.[9]

The presence of schizencephalic clefts lined by grey matter suggests that these defects occur early in the second to fifth month gestation, prior to the end of neuronal migration. Etiologies include in utero infections, cytomegalovirus and herpes virus, maternal trauma of several types, teratogens, alcohol and drug abuse, warfarin, and monozygotic twin interactions.[10] Role of gene EMX-2 mutations is controversial.[11] In our case, there were no stigmata of congenital infections. The antenatal profile was normal. The spine and cranium were normal. Parents of the child were also phenotypically normal.

Clinical presentation depends on the size and location of the lesion. It can have varying effects on neurological development and overall development. Bilateral clefts are generally associated with quadriparesis and severe cognitive impairment.[9] In our patient however, there was no history of delay in other fields of development (except speech) and there was no cognitive delay. Motor system was essentially normal. Features of our case were relatively benign as compared to few published pediatric cases from India.[4-6]

MRI examination is definitive and is the imaging modality of choice. MRI identifies the anomalous grey matter along the cleft as well as the associated abnormalities such as heterotopias.[12] Pediatric cases reported in India had severe complex associated brain abnormalities.[3-5] Except hypoplastic cavum septum pellucidum, there were no other abnormal findings in our case on MRI.

Our case highlights the possibility of a very rare entity associated with seizures and speech delay. MRI, being a modality able to pick these abnormalities, is thus advisable in all cases of childhood seizures and developmental delays. There is very scant literature on schizencephaly in Indian pediatric population. Carefully maintained patient records can help us build the database in Indian pediatric population.