|Year : 2018 | Volume
| Issue : 1 | Page : 63-65
Partial corpus callosal agenesis with ventriculomegaly and sulcal anomaly in a 10-year-old child
Austine Abebe Osawe, Saleh M Kabir, Anas Ismail
Department of Radiology, Aminu Kano Teaching Hospital and Bayero University, Kano, Nigeria
|Date of Web Publication||17-Apr-2018|
Dr. Austine Abebe Osawe
Department of Radiology, Aminu Kano Teaching Hospital, Zaria Road, Kano
Source of Support: None, Conflict of Interest: None
Agenesis of the corpus callosum is a heterogeneous, congenital neurodevelopmental condition that can be observed either in isolation or in combination with other brain abnormalities. Patients often present early with characteristic neurologic and physical manifestations. This case discusses a 10-year-old boy who presented to a tertiary health facility in Northern Nigeria with 6-month history of seizure disorder, cognitive impairment and urinary incontinence and had classical magnetic resonance imaging (MRI) findings consistent with partial corpus callosum agenesis in combination with other brain abnormalities. He was placed on daily oral carbamazepine and has done well with supportive care from family.
Keywords: Corpus callosum agenesis, neuroimaging, ventriculomegaly
|How to cite this article:|
Osawe AA, Kabir SM, Ismail A. Partial corpus callosal agenesis with ventriculomegaly and sulcal anomaly in a 10-year-old child. Niger Postgrad Med J 2018;25:63-5
|How to cite this URL:|
Osawe AA, Kabir SM, Ismail A. Partial corpus callosal agenesis with ventriculomegaly and sulcal anomaly in a 10-year-old child. Niger Postgrad Med J [serial online] 2018 [cited 2021 Mar 9];25:63-5. Available from: https://www.npmj.org/text.asp?2018/25/1/63/230199
| Introduction|| |
The corpus callosum is a major axonal commissure of the brain connecting the two cerebral hemispheres and providing communication between the cortical and subcortical neurons which connect one hemisphere with the corresponding part of the other hemisphere. It comprises of four parts: rostrum, genu, splenium and the body. It is essential for learning, discrimination, sensory experience, memory and synchronicity of sleep.
Agenesis of the corpus callosum (ACC) is the failure of the callosal commissural fibres to cross the midline and form the major connection between the two cerebral hemispheres. ACC could be complete or partial. A variety of brain malformations including midline anomalies such as interhemispheric cyst, lipomas and craniocerebral midline defects have been found in association with ACC. Others are malformations of cortical development, brain white matter anomalies, abnormal morphology of the lateral ventricles, diencephalic and rhombencephalic abnormalities.
Most of the prevalence studies about corpus callosum agenesis were performed using neuroimaging techniques such as ultrasound and magnetic resonance imaging, especially during the prenatal and postnatal periods. The true incidence of ACC is difficult to determine because many isolated cases may be asymptomatic. However, reported incidence in children with developmental disabilities is 2–3 per 100. The rarity of this case in our environment prompted its reporting.
| Case Report|| |
C. U. is the 3rd of 4 children born in a monogamous setting to a 42-year-old para-5 homemaker. He presented in company of his parents to Aminu Kano Teaching Hospital in May 2016 on account of inability to walk since birth, recurrent seizures and urinary incontinence of about 6-year duration. The mother booked pregnancy in late second trimester and had a few antenatal visits before delivery. She had prenatal ultrasound scan twice before delivery but could not recall the findings. Delivery was through an uneventful spontaneous vertex form following term pregnancy. There was maternal history of significant alcohol consumption during the pregnancy but no history of diabetes mellitus or hypertensive disease. She had no febrile illness in the course of pregnancy. The parents reported child's poor performance in school.
Family history did not reveal similar ailment or any congenital deformity among his siblings. There was no positive history of similar ailment in maternal or paternal family members.
On examination, he was conscious, alert and well oriented in time, place and person but paralytic and chronically ill looking. He smelt of ammonia due to urinary incontinence. He was afebrile and mildly pale. His vital signs were normal with pulse rate of 72 beats per minute and blood pressure of 110/80 mmHg. Respiratory rate was 15 cycles/min. Positive findings on neurologic examination were hypertonia in the lower limbs that was worse on the right, speech impairment and psychomotor retardation. Other systemic examinations were essentially normal.
Laboratory investigations including full blood count, electrolytes, urea, creatinine and urinalysis were essentially normal but for low packed cell volume (28%). Patients' karyotype was normal.
Brain magnetic resonance imaging (MRI) (non-contrast T1 Weighted) revealed asymmetry of the cerebral hemispheres (right hemisphere being relatively larger) [Figure 1] with focal area of hypointensity at the temporoparietal region (toward the vertex) and prominent left cerebral sulci [Figure 2]. The absence of the splenium and rostrum of the corpus callosum [Figure 2] with grossly dilated posterior horn of the left lateral ventricle [Figure 1] was also present. The patient was managed with long-term anti-seizure medication (tablet carbamazepine 100 mg daily) with psychosocial support from his parents and relatives. He however remained stable.
|Figure 1: Midsagittal non-contrast T1-weighted magnetic resonance image of the brain showing focal area of cerebral hypointensity in the temporoparietal region, toward the vertex with adjacent areas of prominent sulci. Absence of the splenium and rostrum of the corpus callosum is also noted|
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|Figure 2: Axial non-contrast T1-weighted magnetic resonance image of the brain showing asymmetry of the cerebral hemispheres with prominent left cerebral sulci and Sylvian fissure. Gross dilatation of the posterior horn of the left lateral ventricle is also present|
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| Discussion|| |
ACC, a commissural (white matter) anomaly, is mostly congenital and occurs either in isolation or in combination with other central nervous system (CNS) or systemic malformations. The defect is more common in males than in females with a sex ratio approaching 2:1. The index case is a male with partial ACC occurring in combination with focal cerebral atrophy, sulcal anomaly and left ventricular enlargement.
The aetiology is extremely heterogeneous being attributed to disturbances of embryogenesis in the first trimester of pregnancy. Its occurrence has been well documented in foetal alcohol syndrome, maternal diabetes, CNS infectious conditions and inborn errors of metabolism. Positive maternal history of significant alcohol consumption during pregnancy of the index patient may have contributed to the occurrence of the multiple brain anomalies.
Although karyotyping in the index case did not reveal an abnormality, current evidences suggest that a combination of genetic mechanisms including single-gene Mendelian, single-gene sporadic mutations and complex genetics may be involved in the aetiology of ACC.
It is also established that a few cases (15%) of ACC with multiple brain malformations could have normal chromosomes. This possibly explains the negative karyotype result obtained in the index case.
The white matter contributes to normal sulcation. Decreased cerebral white matter volume is reportedly associated with defect in sulcation and consequent ventricular abnormalities such as ventriculomegaly and colpocephaly. This explains the associated neuroanatomical (sulcal and ventricular) abnormalities that were found in this patient.
The clinical manifestations of callosal agenesis have been described under two headings: non-syndromic and syndromic. Non-syndromic forms are more common. Clinical signs and symptoms in the non-syndromic variety vary widely from normal in some cases of isolated ACC to diverse in the presence of other CNS abnormalities. Findings on physical examination may include dysmorphic facial features (hypertelorism and a broad nose), hypotonia to severe spasticity, ataxia, autistic behaviour, learning disabilities and behavioural disorders. The index patient presented with motor and cognitive abnormalities, speech impairment and urinary incontinence.
Documented syndromes associated with ACC include Arnold– Chiari malformation More Details, Dandy–Walker syndrome, Aicardi's syndrome, Andermann syndrome, Acrocallosal syndrome, schizencephaly, holoprosencephaly and several of the trisomies.
MRI remains the best modality for establishing the diagnosis of ACC and for delineating associated anomalies of the CNS. Increasingly, patients with ACC are being identified at birth because of findings noted on prenatal ultrasonography. Prenatal diagnosis of this malformation is now routinely made by ultrasonography at 20th week and on MRI at 30th week of gestation.
Imaging findings may include upward elevation of the third ventricle, absence or alteration of the cavum septum pellucidum, high-riding third ventricle, widening of the interhemispheric fissure and posterior ventriculomegaly or colpocephaly. Absence of the splenium and rostrum of corpus callosum with ventriculomegaly and right cerebral hemispheric anomalies were found on MR image of the index patient. Focal area of cerebral ischaemia, an uncommon finding in ACC, was also noted at left temporoparietal region of the brain of this patient.
Treatment is mostly symptomatic. Anti-epileptic treatment for seizures, psychomotor support, speech therapy and psychotherapy in the presence of psychomotor disorder may be required. The index patient was treated with long-term anti-epileptics and psychomotor support. Early detection of this malformation, achievable by prenatal imaging, is important for appropriate prenatal counselling and postnatal care plan of patients.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]