|Year : 2021 | Volume
| Issue : 2 | Page : 353-354
Posterior quadrantic dysplasia: An unusual cause of focal seizures
Krishnan Balagopal1, Jeyaseelan Nadarajah2, Jasica Joy Thottiyil2
1 Department of Neurology, MOSC Medical College, Kolenchery, Kochi, Kerala, India
2 Department of Radiology, MOSC Medical College, Kolenchery, Kochi, Kerala, India
|Date of Submission||06-Jul-2021|
|Date of Decision||06-Sep-2021|
|Date of Acceptance||09-Sep-2021|
|Date of Web Publication||29-Dec-2021|
Dr. Krishnan Balagopal
Department of Neurology, MOSC Medical College, Kolenchery, Kochi, Kerala
Source of Support: None, Conflict of Interest: None
Hemimegalencephaly (HME) is one of the rare malformations of cortical development that can present in children and in adults with refractory seizures. One of the localized forms of HME is posterior quadrantic dysplasia (PQD). This entity commonly involves hypertrophy of the parieto-temporo-occipital lobes with periventricular signal changes on imaging. Presentation is with focal seizures in children and in adults. We present here a 24-year-old man presenting with recurrent left focal seizures who was found to have PQD on imaging. He was started on anticonvulsants with improvement in his symptoms. This report aims to highlight the characteristic imaging findings and clinical features of PQD.
Keywords: Focal seizures, hemimegalencephaly, posterior quadrantic dysplasia
|How to cite this article:|
Balagopal K, Nadarajah J, Thottiyil JJ. Posterior quadrantic dysplasia: An unusual cause of focal seizures. Arch Med Health Sci 2021;9:353-4
| Introduction|| |
Hemimegalencephaly (HME) is one of the rare congenital malformations of cortical development seen in clinical practice. The main features of HME are enlarged and dysplastic overgrowth of one or all parts of a cerebral hemisphere. HME usually affects the entire hemisphere but localized forms have also been reported in the literature. One of the types seen is posterior quadrantic dysplasia (PQD) or hemi-HME with an enlargement of the parieto-occipito-temporal lobe, sparing the frontal lobe of a single hemisphere. Most patients who have PQD on imaging show dysmorphic ipsilateral occipital horn with high-signal posterior periventricular white matter and abnormal gyri with heterotopias. We present here a case of a 24-year-old patient with recurrent episodes of left focal seizures who was detected to have PQD on imaging.
| Report|| |
A 24-year-old patient with no prior comorbidities or significant history presented with a history of recurrent episodes of seizures over the past 2 years. These episodes were associated with sudden loss of awareness, involuntary posturing of left upper limb followed by fall to the ground, and loss of consciousness for around 5 min. Clinical examination revealed no focal deficits while laboratory values were within normal limits. Magnetic resonance imaging of the brain showed marked enlargement of the right parieto-temporo-occipital lobe and periventricular astrogliosis, sparing of frontal lobes, and polymicrogyria with blurred cortical-white matter junction that was consistent with a diagnosis of PQD [Figure 1] and [Figure 2]. The patient was subjected to an electroencephalogram which showed intermittent spike and slow-wave discharges from the right parieto-occipital regions. He was started on Levetiracetam and Clobazam at therapeutic doses. At follow-up, his seizures were under control and he was doing well on medications.
|Figure 1: (a) Magnetic resonance imaging T1-weighted image at the level of the pons shows focal posterior quadrantic dysplasia involving the parieto-occipital lobe on the right side (white thin straight arrow). (b) Axial T2-weighted image at the level of the thalamus shows focal megalencephaly of the right parietal lobe (thin straight arrow) and sparing of frontal lobes (white thick short arrows)|
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|Figure 2: Noncontrast axial TI-weighted fat-saturated images at the level of the thalamus (a) and coronal fluid-attenuated inversion recovery (b) show periventricular hyperintensity adjacent to the occipital horn of the right lateral ventricle (white arrows)|
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| Discussion|| |
PQD or hemi-HME is one of the malformations of cortical development which is a rare cause of focal seizures in children and adults. It is a sporadic cortical development malformation that involves the posterior three lobes of a single hemisphere and spares the frontal cortex. PQD is a rare condition, accounting for only 3% of cortical dysplasia diagnosed by imaging. Most common presentation is infantile spasms. Mental retardation, axial hypotonia, and mild contralateral hemiparesis are seen in older children. Many of the cases are refractory to anticonvulsants and may require surgical management. Early diagnosis and availability of motor-sparing neurosurgical disconnective procedures have led to dramatically reduced mortality and morbidity rates, apart from gifting the affected children a better quality of life.
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.
The authors wish to thank their friends and family.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]