Abstract
Schizencephaly arises from irregular neuronal migration leading to clefts development in the cerebral cortex. The condition is often detected in childhood and it is extremely rare to go unnoticed. This case highlights a 45-year-old male with no previous medical history who presented with a seizure for the first time in the emergency department after which an MRI was done and detected schizcenphaly which at this point was the first time for the patient to be diagnosed with this condition. The available data on schizcencphaly in the literature is very little and the data on the condition when diagnosed in adulthood is even less, hence our case report aims to shed light on this unthought etiology of adult-onset seizures which could have major potential risks if not detected. Adults who receive a diagnoses later in life may face prognosis issues hence imaging should be encouraged to be a part of seizure workup to avoid underdiagnoses of brain abnormalities that may go unnoticed in childhood.
Keywords: Schizencepahly, seizures, Brain abnormalities, Adult-onset seizures, Frontal lobe closed lip schizencephaly
Introduction
Schizencephaly was a term first pointed to by Yakovlev and Wadsworth back in 1946 during their study on cadavers and it is an exceptionally uncommon condition involving irregular neuronal migration, resulting in cerebrum malformation [1]. It is characterized by clefts in the cerebral cortex, which extends from the ependymal surface of the ventricle through the white matter to the pial surface [2]. The incidence of schizencephaly globally is approximately 1.5 in 1,000,000 live births. In the pediatrics population 1:1650 children with schizencephaly suffer from seizures. In the adults age group however, schizencephaly being a cause for seizures is very rare.
Case report
A 45 year old male patient with no history for past medical or surgical diseases developed generalized tonic-clonic seizures during sleep which was witnessed by his wife. The seizure lasted 90 seconds. Postictally, the patient was sleepy and drowsy after which an ambulance was called. When the ambulance arrived the patient had another tonic-clonic seizure after which the patient has arrived to our emergency department (ED). The patient retained consciousness in the emergency department after which he and his family denied history of any previous similar attacks. Febrile seizures were also excluded. The patient denied any drug abuse history and he isn't consuming any medications. A computed tomography (CT) scan has been done in the ED and showed no evidence of any trauma, hemorrhagic insult, strike or fractures. An MRI was subsequently done (Fig. 1) and showed left frontal lobe closed lip schizencephaly associated with localized periventricular grey matter heterotopia and anterior corpus callosum dysgenesis. Moreover, coronal cuts were also taken to further demonstrate the anatomical defect. Fig. 2 is a T2 FLAIR MRI and (Fig. 3) is a T1 MRI, both of which were coronal cuts further defining the schizencephaly defect. Additionally an EEG done on the same day and showed evidence of a left temporal epileptic discharge. The patient was back to his baseline level of alertness and mental status during the clinic visit. He had a tongue bite at that time noted on examination. However further assessment in the clinic showed no active bleeding, no headache, and no neck rigidity. In the clinic few days after the initial ED incident the patient turned out to not be aware of these 2 generalized tonic-clonic seizures that happened previously. The patient was kept ok Kepra 500 mg twice daily for 3 months and was advised to follow up again in the clinic after 3 months for a repeat EEG. Moreover the patient has been advised to avoid driving for at least 1 year.
Fig. 1.
T1 weighted sagittal MRI that shows left frontal lobe closed lip schizencephaly associated with localized periventricular grey matter heterotopia and anterior corpus callosum dysgenesis.
Fig. 2.
T2 FLAIR MRI coronal section showing left frontal lobe closed lip schizencephaly.
Fig. 3.
T1 MRI coronal section showing left frontal lobe closed lip schizencephaly.
Discussion
Previously only 5 cases of adult-onset seizures caused by schizencephaly were reported (Table 1) [[1], [2], [3], [4], [5]].
Table 1.
Summary of all previously reported cases of schizencephaly as a cause of seizures.
| Case number | References | Patient's age (Y) | Patient's gender | Reporting country | Imaging modality used | EEG findings | Area affected |
|---|---|---|---|---|---|---|---|
| 1 | Kamble et al. [2] | 48 | Male | India | MRI | N/A | Left parietal lobe |
| 2 | Okunlola et al. [3] | 66 | Female | Nigeria | CT | N/A | Left parietal lobe |
| 3 | Battah et al. [1] | 21 | Female | United States of America | CT | Asymptomatic right temporal seizure activity | Right temporal lobe |
| 4 | Khadka et al. [4] | 25 | Male | Nepal | MRI | N/A | Right frontoparietal region |
| 5 | Laasri et al. [5] | 43 | Male | Morocco | MRI | N/A | Right temporal lobe |
| 6 | Mousa et al. | 44 | Male | United Arab Emirates | CT | Focal sharp wave in the left temporal region indicating left temporal epileptic discharge | Left frontal lobe |
Etiology
The etiology of schizencephaly remains unclear but is often described in the literature as multifactorial with possible genetic factors being discussed. The main gene mutations identified in the literature were EMX2, COL4A1, SHH, and SIX3 [4]. Discrete genetic causes of schizencephaly have been very difficult to confirm hence no solid evidence yet exists for an individual genetic test. Other risk factors reported in the literature included cerebral artery stroke, maternal age, substance abuse, and lack of prenatal care [6].
Role of neuroimaging
Neuroimaging, particularly magnetic resonance imaging (MRI), plays a crucial role in the diagnosis of schizencephaly [3]. In our case, high-resolution MRI was instrumental in revealing the characteristic clefts extending from the lateral ventricles to the pial surface, confirming the diagnosis. Recent research has looked at the utilization of diffuse tensor imaging (DTI) in the diagnoses and treatment of various bran abnormalities as schizencephaly. DTI may provide valuable insights for the diagnosis and management of such conditions while genetic testing may aid in knowing the underlying genetic causes and potential treatment targets [4,5]. Imaging in schizencephaly shows a cleft that is linear and lined with heterotrophic gray matter and extends from the cortical surface to the ventricular system [7]. Some studies suggested that dysplastic gray matter could contribute to making up an epileptogenic zone [8].
Treatment and prognosis
The treatment used in our case was the standard epilepsy protocol with the patient being kept on Keppra after discharge. Due to that the accurate etiology and pathogenesis of this disorder is still unclear to date, controlling the symptoms serve as the mainstay of treatment [3].
Conclusion
This case underscores the rarity of adult-onset seizures attributed to schizencephaly and emphasizes the necessity for thorough evaluation and management in such instances. Rare congenital brain anomalies such as schizencephaly require more extensive testing to determine the underlying risks and ideal modalities to be utilized.
Patient consent
We confirm that a written informed consent for publication was obtained from the patient discussed in the case report.
Footnotes
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
References
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