Expanding Ventricular Diverticulum Overlying the Cerebral Hemisphere through an Open-Lip Schizencephalic Cleft: A Report of Two Pediatric Cases.

INTRODUCTION: Open-lip-type schizencephaly is characterized by trans-cerebral clefts filled with cerebrospinal fluid (CSF) between the subarachnoid space at the hemisphere surface and the lateral ventricles. Disorders related to CSF retention, including hydrocephalus and arachnoid cysts, have reportedly been associated with open-lip schizencephaly and have induced intracranial hypertension in some cases. However, detailed neuroimaging and surgical treatment findings have rarely been described. CASE PRESENTATION: We report 2 cases of open-lip schizencephaly with an expanding CSF-filled cavity overlying the ipsilateral cerebral hemisphere that manifested as signs of intracranial hypertension. Detailed three-dimensional heavily T2-weighted imaging revealed thin borders between the CSF-filled cavity and the subarachnoid space, but no separating structures between the cavity and the lateral ventricle, suggesting that the cavity was directly connected to the lateral ventricle through the schizencephalic cleft but not to the subarachnoid space. Neuroendoscopic observation in case 1 confirmed this finding. Endoscopic fenestration of the cavity to the prepontine cistern was ineffective in case 1. Shunting between the lateral ventricle (case 1) or CSF-filled cavity (case 2) and the peritoneal cavity slightly decreased the size of the CSF-filled cavity. DISCUSSION: We speculate that the thin borders along the margin of the CSF-filled cavity are membranes that previously covered the schizencephalic cleft and are now pushed peripherally. In addition, we believe that the cavity is a ventricular diverticulum protruding through the cleft and that shunting operation is effective against such expanding cavity. Detailed magnetic resonance imaging can be useful for evaluating patients with schizencephaly associated with CSF retention disorders.

Intracranial arachnoid cysts.

PURPOSE: The purpose of this review article is to outline the natural history, pathogenesis, anatomic considerations and surgical decision-making in caring for patients with intracranial arachnoid cysts. METHODS: A review of the literature for intracranial arachnoid cysts was performed using Embase, PubMed, and Web of Science databases, including review of the bibliographies of eligible articles and the author's own experience. RESULTS: Among those reviewed, 59 relevant original articles were included as well as illustrative cases from the authors own experience. CONCLUSIONS: Arachnoid cysts are congenital lesions characterized by split arachnoid membrane, thick collagen in the cyst wall, absent traversing trabecular processes within the cyst, and hyperplastic arachnoid cells in the cyst wall. The underlying etiology is not entirely known, and they occur in greater proportion in males and in greater incidence with various genetic conditions including Down syndrome, mucopolysaccharidosis, schizencephaly, neurofibromatosis, autosomal dominant polycystic kidney disease (ADPKD), acrocallosal syndrome, and Aicardi syndrome. Most intracranial arachnoid cysts are incidentally found and occur in the middle cranial fossa, with the remaining occurring in the cerebellopontine angle, suprasellar cistern, quadrigeminal cistern, convexity, and posterior fossa/cisterna magna. The current article outlines the natural history, prevalence, demographic factors, and treatment decisions in managing patients with intracranial arachnoid cysts.

Stereo-EEG for Epileptogenic Focus Localization in Schizencephaly: A Single-center Experience in Four Patients.

OBJECTIVE: Schizencephaly is a congenital cerebral malformation characterized by clefts in the hemispheres of the brain, where variations in semiology often make it difficult to localize epileptogenic focus. Here, we report on a series of patients who underwent stereo-encephalography (SEEG) for epileptogenic focus localization and subsequent SEEG-guided surgical intervention. METHODS: Four patients (ages 27, 33, 27, 25 years) with a mean seizure history of 16 years (range 8-22 years) were analyzed. Data pertaining to semiology, video encephalography (EEG), magnetic resonance imaging, positron emission tomography, and invasive EEG studies, surgical intervention and post-surgery outcome were collected and analyzed. RESULTS: All seizure onset zones were within the extent of schizencephaly; however, the limbic system (including the hippocampus, amygdala, cingulate gyrus, or insula) was involved in early spreading. Two patients underwent SEEG-guided radiofrequency thermo-ablation (RFTA) in the seizure onset zone, 1 patient underwent lesionectomy via craniotomy, and 1 underwent neither RFTA nor lesionectomy. At 2 years post-surgery, the outcomes were as follows: Engel grade Ia (n = 2), Ib (n = 1), and III (n = 1). CONCLUSIONS: This article reports on a precise approach to treating patients with schizencephaly dependent of seizure onset zone and functional cortex mapping. Subsequent SEEG-guided surgical interventions (radiofrequency thermo-ablation and lesionectomy) were shown to reduce seizure frequency, while preserving the neurologic functions in drug-resistant epilepsy patients with schizencephaly.

[Septo optic dysplasia plus: about a case]. / Dysplasie septo optique plus: à propos d'un cas.

Septo optic dysplasia plus is a rare disease seen in children. Its diagnosis is radiological, based on brain magnetic resonance imaging (MRI). We report the case of a child aged 2 years and 4 months, with no particular pathological history; who consulted for psychomotor retardation, strabismus and low vision behavior. An endocrine biological assessment exploring the hypothalomo-pituitary function was carried out, revealing no abnormality. The diagnosis of septo-optic dysplasia plus was retained on the brain MRI data, in front of the agenesis of the septum pellucidum and of the splenium of the corpus callosum, the hypoplasia of the optic pathways and of the pituitary stalk as well as in front of the agenesis of the posterior pituitary. It was associated with a closed schizencephaly. Septo-optic dysplasia is a rare congenital malformation. Our objective is to recall its semiology in imaging and to underline the importance of MRI to establish the diagnosis. Septo-optic dysplasia is a rare clinical entity typically involving midline brain abnormalities, optic nerve hypoplasia, and pituitary insufficiency. The association with cortical malformations such as schizencephaly and polymicrogyria denotes the term septo-optic dysplasia plus. Advances in imaging currently allow early diagnosis, which is essential for adequate management. Antenatal ultrasound may suspect dysplasia, and brain MRI confirms the diagnosis.

Hypothesis: By-products of vascular disruption carried in the CSF affect prenatal brain development.

Prenatal CNS disruptions can be associated with physically separate findings. Examples include cognitive issues in septo-optic dysplasia and sporadic and WNT1-related unilateral cerebellar hypoplasia, and physical findings such as thinning of the corpus callosum, ventriculomegaly, hippocampal abnormalities, olfactory tract and bulb hypoplasia, and distant cortical dysplasias with schizencephaly. Similar effects to toxicities with intraventricular hemorrhage in prematurity could occur earlier in development. CSF transportation of disruption by-products would provide access to vulnerable areas through inflammatory effects on blood-brain barrier permeability. Outcomes are influenced by location and volume of byproducts in the CSF, timing, transport, and inflammatory responses. A particular association of vermis disruption with cognitive issues may be related to CSF flow distortions that avoid toxin dilutions in the third ventricle. Symmetrical contralateral cortical dysplasia with schizencephaly may reflect immunovascular field-related vulnerabilities seen in situations such as vitiligo.

Schizencephaly and the Neurodevelopmental Model of Psychosis.

Background: Schizencephaly is a rare congenital disorder of cerebral cortical development. Clinical features vary based on the areas and severity of cortical involvement. The most prominent manifestations being motor deficits, seizures, and cognitive impairment. MRI has been the diagnostic modality of choice. Till now, a handful of case reports associating schizencephaly with psychiatric manifestations have been reported. Methods: In this brief report, we review the available literature and present the summary of a 50-year-old gentleman who presented with paranoia, irritability, impulsive spending, emotional lability, and circumstantial speech with perseveration of themes. Results: MRI findings are suggestive of closed lip schizencephaly. Conclusion: This case helps us in understanding the neurodevelopmental model and functional neuroanatomy of psychiatric symptom dimensions.

Cleft size and type are associated with development of epilepsy and poor seizure control in patients with schizencephaly.

PURPOSE: To investigate the relationship between the anatomical features of schizencephaly and characteristics of epilepsy. METHODS: We retrospectively evaluated patients diagnosed with schizencephaly using brain magnetic resonance imaging. Seizure outcomes were evaluated as drug-resistant epilepsy and frequent seizures (more than once a month) during the previous year. Development of epilepsy, seizure outcomes, and clinical variables were compared according to the anatomical features of schizencephaly, such as cleft type, size, bilaterality, presence of cortical dysplasia, and temporal lobe involvement. RESULTS: Of the 76 patients with schizencephaly-related epilepsy, 28 (36.8%) had open lip clefts, and 13 (17.1%) had bilateral clefts. The development of epilepsy was related to a larger cleft size and the presence of cortical dysplasia. The patients with medium-to-large clefts were younger at seizure onset than those with small clefts (9.7±7.8 vs. 20.8±10.4 years). Among the 64 patients whose outcomes were evaluated, 31 (48.4%) had drug-resistant epilepsy, and 21 (32.8%) met our definition of frequent seizures. In the univariate analysis, open lip, larger clefts, and the presence of cortical dysplasia were associated with poor seizure outcomes. Even after adjustment for covariates, open lip clefts were significantly related to drug-resistant epilepsy (odds ratio=13.036, P=0.001) and frequent seizures (odds ratio=7.682, P=0.008). CONCLUSION: Open lip clefts were associated with poor seizure outcomes. Further, a larger cleft was related to an earlier development of epilepsy. The anatomical features of schizencephaly should be considered in the treatment of epilepsy.

Unilateral right closed-lip schizencephaly.

Schizencephaly is a rare central nervous system (CNS) malformation secondary to neuronal migration defects. The pathogenesis is complex and is secondary to environmental and genetic factors. Clinically, the majority of patients present with varying degrees of motor and psychological disturbances. Imaging plays a cornerstone in the diagnosis by identifying the characteristic lesional features and recognising other associated abnormalities such as an absent septum pellucidum and corpus callosum dysgenesis. Here, we present a male paediatric case who presented with an interestingly asymptomatic unilateral right closed-lip schizencephaly and review the aetiology, clinical presentation and imaging characteristics of the disease and associated literature.

Latent Schizencephaly With Psychotic Phenotype or Schizophrenia With Schizencephaly? A Case Report and Review of the Literature.

OBJECTIVES: Although schizencephaly belongs to the class of neurodevelopmental disorders, which are a well-known predisposing factor for psychosis, there is a lack of relevant studies and diagnostic guidelines on this relationship. METHOD: A case report of first-episode psychosis with persistent negative symptoms associated with schizencephaly is described and compared with 7 other cases found in the literature. RESULTS: We found perinatal pathology, cognitive deficit, and EEG abnormality in a patient with atypical initial symptoms of psychosis such as olfactory hallucinations. Abnormal EEG findings (left frontal spikes and frontal intermittent rhythmic delta activity) called for magnetic resonance imaging, which revealed left parieto-occipital closed-lip schizencephaly. The patient exhibited a partial response to low-dose amisulpride treatment. CONCLUSION: We conclude that schizencephaly in our patient was at first asymptomatic and later developed into clinically manifest schizophrenia-like disorder. Both magnetic resonance imaging and EEG were essential tools for establishing this diagnosis.

A rare case of super-refractory epileptic status in pregnant woman: Schizencephaly.

Schizencephaly is an anomaly of the subtotal brain development, which occurs as the presence of a cleft lined with grey matter extending from subarachnoid space to the ventricles. It may be manifested by psychomotor retardation, paresis or partial seizures and drug-resistant convulsions. The clinical expression of schizencephaly depends on the bilaterality of the slit, its size and its seat. The diagnostic strategy of schizencephaly in the ante- and postnatal period has been revolutionised by MRI imaging, the only technique able to provide an accurate and complete lesional assessment, particularly in type I. We report the case of a 34-year-old pregnant woman at the 25th weeks of amenorrhea, who presented a super-refractory epileptic-status due to a right schizencephaly. The diagnosis of eclampsia was excluded. This case report is very particular cause of the late appearance of epileptic seizures in this pregnant woman who has never done so.

Schizencephaly: A Review of 734 Patients.

BACKGROUND: Schizencephaly is a rare congenital cerebral malformation associated with serious neurological manifestations. The number of studies regarding schizencephaly is limited. METHODS: We conducted a literature review and extracted data from the case reports. Of 199 articles retrieved, 156 articles (734 patients) met our inclusion criteria. RESULTS: Patient characteristics included microcephaly (41.5% of patients), seizures (74.1%), bilateral cleft (41.4%), open lip (61.3%), septo-optic dysplasia (69.1%), and ventricular dilation (60.5%). The majority of clefts were in the frontal and parietal lobes. When these potential association factors were assessed by univariate logistic regression microcephaly (OR = 21.75, P < 0.001), corpus callosum agenesis (OR = 9, P < 0.001), motor impairments (OR = 6.21, P < 0.001), and bilateral clefts (OR = 6.31, P < 0.001) seems to have the strongest association, but also age at diagnosis <10 years (OR = 1.05, P < 0.001), right (OR = 1.85, P = 0.001) or left (OR = 2.71, P < 0.001) side clefts and septum pellucidum (OR = 3.7, P = 0.002) agenesis were associated with neurocognitive dysfunctions. CONCLUSIONS: We describe novel findings with practical implications for predicting neurocognitive outcomes in patients with schizencephaly. Most patients had neurological impairments including motor (90.0%) or cognitive (77.5%) dysfunctions. Bilateral clefts, motor impairment, microcephaly, and corpus callosum agenesis were strongly associated with neurocognitive impairment. A lack of large cohorts of patients with schizencephaly prevented comparison of our results; most previous studies are case reports or small case series.

Tadpole-shaped lateralized parietal atretic cephalocele associated with an ipsilateral lacrimal gland fistula and schizencephalic clefts.

BACKGROUND: Parietal atretic cephalocele (AC) and its associated intracranial venous anomalies, such as vertical embryonic positioning of the straight sinus (VEP of SS), have, in previous reports, been exclusively restricted to the midline. CLINICAL PRESENTATION: We report a patient with lateralized parietal AC on the right side. The AC was in the shape of a tadpole, with a large head and a long tail, extending to the proximity of the right external canthus, where a lacrimal gland fistula was observed. The superior sagittal sinus and VEP of SS were also displaced to the right side, although the sagittal suture was located at the midline. Schizencephalic clefts in the right posterior cortex were also observed. CONCLUSION: The parietal AC, which was initially located in the midline, could conceivably have been displaced to the right side by other developmental processes. However, the relationship between lateralized AC and associated multiple anomalies on the ipsilateral side is difficult to explain monogenetically. Our case study indicates that AC might have a broader spectrum of clinical symptoms than was once thought to be the case.

Successful surgery for refractory seizures associated with bilateral schizencephaly: two case reports and literature review.

Schizencephaly is a rare malformation of cortical development resulting from cell migration defects that occur unilaterally or bilaterally. The type of the schizencephalic cleft can be open lip or closed lip. Patients suffering from refractory seizures secondary to schizencephaly should be considered for surgical treatment. In this paper, we retrospectively analyzed two patients with confirmed schizencephaly and intractable seizures. The evaluation methods included a medical history assessment, a neurological examination and magnetic resonance imaging (MRI). Continuous intracranial video-electroencephalogram (vEEG) monitoring with surface electrodes and deep electrodes was evaluated to confirm the epileptogenic zones associated with the schizencephalic lesions. Cortical electrical stimulation was performed to evaluate the neurophysiology of the relevant brain regions. Epileptic focus resection was performed close to the schizencephalic cleft according to the results of intracranial EEG and stimulation while preserving neurological functions. MRI revealed bilateral open lip schizencephaly in one patient and closed lip schizencephaly in the other patient. The epileptogenic zones were localized close to the schizencephalic clefts. The seizure outcome was Engel's class Ia in both patients at 1-year follow-up. No significant neurological deficits were found, and their activities of daily life were significantly improved. We conclude that abnormal cortex near the schizencephalic clefts may display an extrinsic epileptogenicity. Accurate localization of the epileptogenic zones using intracranial EEG and electrical stimulation can lead to a seizure-free outcome in patients with refractory epilepsy associated with schizencephaly.

Location of Irritative Zone in Epileptic Brains of Schizencephalic Patients.

Although many schizencephaly patients suffer from epilepsy, the relationship between schizencephalic lesions and epileptic foci remains unclear. Previous studies have shown that schizencephalic lesions may be associated with, rather than contain, epileptogenic zones. Thus, the purpose of this study was to investigate the current source distribution (CSD) of epileptiform discharges in schizencephalic patients and to correlate this activity with existing structural lesions. A consecutive series of 30 schizencephalic patients who were diagnosed using brain magnetic resonance imaging (MRI) were selected retrospectively and prospectively. Of the original 30 subjects selected, 13 had epilepsy, and 6 of these patients exhibited schizencephaly, epilepsy, and interictal spikes on electroencephalograms (EEG) and were enrolled in the present study investigating the current source analysis of interictal spikes. The CSDs of the initial rising phases and the peak points of the interictal spikes were obtained using standardized low-resolution brain electromagnetic tomography (LORETA). Five patients exhibited a single focus of interictal spikes, while 1 patient showed 2 foci. Relative to the structural brain lesions, 5 patients displayed extrinsically localized CSDs, while 1 patient showed a partially intrinsically localized CSD. The present findings demonstrate that the CSDs of interictal spikes in schizencephalic patients are in general anatomically distinct from the cerebral schizencephalic lesions and that these lesions may display an extrinsic epileptogenicity.