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AJNR. American Journal of Neuroradiology Feb 2015Polymicrogyria is a malformation of cortical development that is often identified in children with epilepsy or delayed development. We investigated in vivo the potential...
BACKGROUND AND PURPOSE
Polymicrogyria is a malformation of cortical development that is often identified in children with epilepsy or delayed development. We investigated in vivo the potential of 7T imaging in characterizing polymicrogyria to determine whether additional features could be identified.
MATERIALS AND METHODS
Ten adult patients with polymicrogyria previously diagnosed by using 3T MR imaging underwent additional imaging at 7T. We assessed polymicrogyria according to topographic pattern, extent, symmetry, and morphology. Additional imaging sequences at 7T included 3D T2* susceptibility-weighted angiography and 2D tissue border enhancement FSE inversion recovery. Minimum intensity projections were used to assess the potential of the susceptibility-weighted angiography sequence for depiction of cerebral veins.
RESULTS
At 7T, we observed perisylvian polymicrogyria that was bilateral in 6 patients, unilateral in 3, and diffuse in 1. Four of the 6 bilateral abnormalities had been considered unilateral at 3T. While 3T imaging revealed 2 morphologic categories (coarse, delicate), 7T susceptibility-weighted angiography images disclosed a uniform ribbonlike pattern. Susceptibility-weighted angiography revealed numerous dilated superficial veins in all polymicrogyric areas. Tissue border enhancement imaging depicted a hypointense line corresponding to the gray-white interface, providing a high definition of the borders and, thereby, improving detection of the polymicrogyric cortex.
CONCLUSIONS
7T imaging reveals more anatomic details of polymicrogyria compared with 3T conventional sequences, with potential implications for diagnosis, genetic studies, and surgical treatment of associated epilepsy. Abnormalities of cortical veins may suggest a role for vascular dysgenesis in pathogenesis.
Topics: Adolescent; Adult; Cerebral Angiography; Cerebral Cortex; Child; Child, Preschool; Epilepsy; Female; Humans; Imaging, Three-Dimensional; Infant; Magnetic Resonance Imaging; Male; Middle Aged; Neuroimaging; Polymicrogyria
PubMed: 25258368
DOI: 10.3174/ajnr.A4116 -
BMC Neurology Aug 2022Polymicrogyria refers to the disruption of normal cerebral cortical development late in neuronal migration or in early cortical organization. Although patients with...
BACKGROUND
Polymicrogyria refers to the disruption of normal cerebral cortical development late in neuronal migration or in early cortical organization. Although patients with polymicrogyria feature relatively favorable motor outcomes, polymicrogyric lesions accompanied by extensive unilateral hemispheric atrophy and ipsilateral brainstem atrophy may induce poorer motor outcomes. This study is the first to employ transcranial magnetic stimulation (TMS) and diffusion tensor imaging (DTI) to characterize changes to motor organization and white matter tracts induced by polymicrogyria.
CASE PRESENTATION
We document a case of a 16-year-old female with left hemiplegic unilateral polymicrogyria associated with ipsilateral brainstem atrophy. Magnetic resonance imaging (MRI) of the brain revealed unilateral polymicrogyria to have affected anterior cortical areas, including the perisylvian region on the right side. The right halves of the brain and brainstem were significantly smaller than the left halves. Although our patient was found to exhibit cortical dysplasia of the right frontoparietal and sylvian fissure areas and a decreased number of fibers in the corticospinal tract (CST) of the affected side on DTI, the connectivity of the CST was preserved up to the motor cortex. We also measured the cross-sectional area of the CST at the level of the pons. In TMS, contralateral motor evoked potentials (MEPs) were evoked from both hands, but the ipsilateral MEPs were evoked only from the left hand. The left hand featured a long duration, polyphasic pattern of contralateral MEPs.
DISCUSSION AND CONCLUSION
TMS revealed that the concurrent bilateral projections to the paretic hand from the affected and unaffected hemispheres and contralateral MEPs in the paretic hand were polyphasic, indicating delayed electrophysiological maturation or a pathologic condition of the corticospinal motor pathways. In DTI, the cross-sectional area of the CST at the level of the pons on the affected side was smaller than that on the unaffected side. These DTI findings reveal an inadequate CST volume. Despite extensive brain malformation and ipsilateral brainstem atrophy, our patient had less severe motor dysfunction and presented with involuntary mirror movements. Mirror movements in the paretic hand are considered to indicate ipsilateral corticospinal projections from the unaffected hemisphere and may suggest favorable motor outcomes in early brain injury.
Topics: Adolescent; Atrophy; Brain Stem; Diffusion Tensor Imaging; Evoked Potentials, Motor; Female; Functional Laterality; Humans; Motor Cortex; Movement Disorders; Nervous System Malformations; Polymicrogyria; Pyramidal Tracts; Transcranial Magnetic Stimulation
PubMed: 35982397
DOI: 10.1186/s12883-022-02795-y -
Developmental Medicine and Child... Oct 2019We aimed to systematically review the speech production, language, and oral function phenotype of bilateral perisylvian polymicrogyria (BPP), and examine the correlation...
AIM
We aimed to systematically review the speech production, language, and oral function phenotype of bilateral perisylvian polymicrogyria (BPP), and examine the correlation between the topography of polymicrogyria and the severity of speech, language, and oral functional impairment.
METHOD
A systematic search of MEDLINE, Embase, and PubMed databases was completed on 26th October 2017 using Medical Subject Heading terms synonymous with BPP and speech, language, or oral motor impairment. In total, 2411 papers were identified and 48 met inclusion criteria.
RESULTS
Expressive and receptive language impairment and oral structural and functional deficits are frequent in BPP. Expressive deficits are frequently more severe than receptive. Only one study used formal assessments to demonstrate the presence of speech disorder, namely dysarthria. Seven studies reported an association between diffuse BPP and more severe language impairment.
INTERPRETATION
Findings confirmed that language deficits are common in BPP, though assessment of the specific speech phenotype is limited. The paucity of high quality studies detailing the specific communication phenotype of BPP highlights the need for further investigation. Improving understanding of this phenotype will inform the development of targeted therapies and lead to better long-term outcomes.
WHAT THIS PAPER ADDS
Speech, language, and oral functional impairments are common in individuals with bilateral perisylvian polymicrogyria. Posterior polymicrogyria is associated with a less severe language impairment than anterior polymicrogyria. Deeper investigation of speech is needed to understand implicated networks in this malformation.
Topics: Abnormalities, Multiple; Humans; Intellectual Disability; Language; Language Development Disorders; Malformations of Cortical Development; Phenotype; Severity of Illness Index; Speech
PubMed: 30680716
DOI: 10.1111/dmcn.14153 -
Acta Neurologica Belgica Jun 2021
Topics: Atrophy; Electromyography; Evoked Potentials, Somatosensory; Frontal Lobe; Humans; Male; Middle Aged; Muscle Spasticity; Paresis; Polymicrogyria
PubMed: 33151517
DOI: 10.1007/s13760-020-01537-6 -
Journal of Neurosurgical Sciences Apr 2017
Topics: Cerebral Cortex; Child; Cognition; Electroencephalography; Epilepsy; Female; Humans; Magnetic Resonance Imaging; Memory; Polymicrogyria
PubMed: 26112139
DOI: 10.23736/S0390-5616.16.03250-1 -
Scientific Reports Dec 2020GPR56, a member of the adhesion G protein-coupled receptor family, is abundantly expressed in cells of the developing cerebral cortex, including neural progenitor cells...
GPR56, a member of the adhesion G protein-coupled receptor family, is abundantly expressed in cells of the developing cerebral cortex, including neural progenitor cells and developing neurons. The human GPR56 gene has multiple presumptive promoters that drive the expression of the GPR56 protein in distinct patterns. Similar to coding mutations of the human GPR56 gene that may cause GPR56 dysfunction, a 15-bp homozygous deletion in the cis-regulatory element upstream of the noncoding exon 1 of GPR56 (e1m) leads to the cerebral cortex malformation and epilepsy. To clarify the expression profile of the e1m promoter-driven GPR56 in primate brain, we generated a transgenic marmoset line in which EGFP is expressed under the control of the human minimal e1m promoter. In contrast to the endogenous GPR56 protein, which is highly enriched in the ventricular zone of the cerebral cortex, EGFP is mostly expressed in developing neurons in the transgenic fetal brain. Furthermore, EGFP is predominantly expressed in GABAergic neurons, whereas the total GPR56 protein is evenly expressed in both GABAergic and glutamatergic neurons, suggesting the GABAergic neuron-preferential activity of the minimal e1m promoter. These results indicate a possible pathogenic role for GABAergic neuron in the cerebral cortex of patients with GPR56 mutations.
Topics: Animals; Animals, Genetically Modified; Base Sequence; Brain; Callithrix; Cell Movement; Cerebral Cortex; GABAergic Neurons; Gene Expression; Homozygote; Humans; Mutation; Neural Stem Cells; Polymicrogyria; Promoter Regions, Genetic; Receptors, G-Protein-Coupled; Sequence Deletion
PubMed: 33299078
DOI: 10.1038/s41598-020-78608-4 -
Epilepsia Dec 2016The role of resective surgery in the treatment of polymicrogyria (PMG)-related focal epilepsy is uncertain. Our aim was to retrospectively evaluate the seizure outcome...
OBJECTIVE
The role of resective surgery in the treatment of polymicrogyria (PMG)-related focal epilepsy is uncertain. Our aim was to retrospectively evaluate the seizure outcome in a consecutive series of patients with PMG-related epilepsy who received, or did not receive, surgical treatment, and to outline the clinical characteristics of patients who underwent surgery.
METHODS
We evaluated 64 patients with epilepsy associated with magnetic resonance imaging (MRI)-documented PMG. After presurgical evaluation, 32 patients were excluded from surgical treatment and 32 were offered surgery, which was declined by 8 patients. Seizure outcome was assessed in the 40 nonsurgical and 24 surgical patients.
RESULTS
Of 40 nonsurgical patients, 8 (20%) were seizure-free after a mean follow-up of 91.7 ± (standard deviation) 59.5 months. None of the eight patients who declined surgical treatment was seizure-free (mean follow-up: 74.3 ± 60.6 months). These seizure outcomes differ significantly (p = 0.000005 and p = 0.0003, respectively) from that of the 24 surgical patients, 18 of whom (66.7%) were Engel's class I postoperatively (mean follow-up: 66.5 ± 54.0 months). Of the eight patients excluded from surgery for seizure control at first visit, two had seizure recurrence at last contact. At last contact, antiepileptic drugs (AEDs) had been withdrawn in 6 of 24 surgical and in one of 40 nonsurgical cases (p = 0.0092).
SIGNIFICANCE
The present study indicates that, at least in a subset of adequately selected patients with PMG-related epilepsy, surgery may provide excellent seizure outcomes. Furthermore, it suggests that surgery is superior to AEDs for achieving seizure freedom in these cases.
Topics: Adolescent; Adult; Child; Child, Preschool; Electroencephalography; Epilepsy; Female; Functional Laterality; Humans; Magnetic Resonance Imaging; Male; Neurosurgical Procedures; Polymicrogyria; Retrospective Studies; Treatment Outcome; Young Adult
PubMed: 27778326
DOI: 10.1111/epi.13589 -
Journal of Child Neurology May 2013This report describes a case of megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome in a 1-year-old boy, born to healthy nonconsanguineous parents....
This report describes a case of megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome in a 1-year-old boy, born to healthy nonconsanguineous parents. Megalencephaly and bilateral postaxial polydactyly of upper and lower limbs were noted at birth. He had profound developmental delay and moderate hypotonia. Magnetic resonance imaging (MRI) of the brain revealed hydrocephalus, polymicrogyria in both frontal lobes and perisylvian regions, and thin corpus callosum. Array-comparative genomic hybridization was normal. The patient's clinical and radiologic findings fit the classic description of megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome. The possible overlap between megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome and other similar conditions is discussed.
Topics: Abnormalities, Multiple; Brain; Cerebral Ventricles; Developmental Disabilities; Dominance, Cerebral; Frontal Lobe; Humans; Hydrocephalus; Infant; Magnetic Resonance Imaging; Male; Malformations of Cortical Development; Megalencephaly; Muscle Hypotonia; Polydactyly; Syndrome; Temporal Lobe
PubMed: 22859694
DOI: 10.1177/0883073812448530 -
Frontiers in Neurology 2021Polymicrogyria (PMG) is a common malformation of cortical development associated with a higher susceptibility to epileptic seizures. Seizures secondary to PMG are...
Polymicrogyria (PMG) is a common malformation of cortical development associated with a higher susceptibility to epileptic seizures. Seizures secondary to PMG are characterized by difficult-to-localize cerebral sources due to the complex and widespread lesion structure. Tracing the dynamics of interictal epileptiform discharges (IEDs) in patients with epilepsy has been shown to reveal the location of epileptic activity sources, crucial for successful treatment in cases of focal drug-resistant epilepsy. In this case series IED dynamics were evaluated with simultaneous EEG-fMRI recordings in four patients with unilateral peri-sylvian polymicrogyria (PSPMG) by tracking BOLD activations over time: before, during and following IED appearance on scalp EEG. In all cases, focal BOLD activations within the lesion itself preceded the activity associated with the time of IED appearance on EEG, which showed stronger and more widespread activations. We therefore propose that early hemodynamic activity corresponding to IEDs may hold important localizing information potentially leading to the cerebral sources of epileptic activity. IEDs are suggested to develop within a small area in the PSPMG lesion with structural properties obscuring the appearance of their electric field on the scalp and only later engage widespread structures which allow the production of large currents which are recognized as IEDs on EEG.
PubMed: 34149595
DOI: 10.3389/fneur.2021.658239 -
AJP Reports Dec 2011Fetal parvovirus B19 infection causes anemia, hydrops, and pregnancy loss but is generally not considered teratogenic. Nevertheless, disturbances of neuronal migration...
Fetal parvovirus B19 infection causes anemia, hydrops, and pregnancy loss but is generally not considered teratogenic. Nevertheless, disturbances of neuronal migration have been described with congenital parvovirus infection. We evaluated a term infant with congenital parvovirus disease and polymicrogyria. We compared this case with four other reports of central nervous system disease after birth to parvovirus-infected mothers. After an extensive diagnostic evaluation, this infant was found to have congenital parvovirus disease with severe anemia and nonimmune hydrops as well as extensive polymicrogyria. Although rare, this report and literature review suggest that parvovirus B19 has the potential to disrupt normal neurodevelopment. We suggest that infants with severe congenital parvovirus infection have close developmental surveillance and if symptomatic undergo neuroimaging to assess for disorders of neuromigration.
PubMed: 23705097
DOI: 10.1055/s-0031-1285984