Association of heterotopic gray matter with seizures: MR imaging. Work in progress.

Smith, A S; Weinstein, Mark D.; Quencer, R M; Muroff, Lawrence R.; Stonesifer, Kurt J.; Li, F C; Wener, L; Soloman, Marc; Cruse, Robert P.; Rosenberg, Logan

doi:10.1148/radiology.168.1.3132731

Cited by 77 publications

(32 citation statements)

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“…Human malformations are normally identified in vivo during neuroimaging (66)(67)(68), or after neuropathologic analysis of resected tissue ( I 1,69,70), or after death by histologic analysis (7 1). Although there is a strong association between malformations and epilepsy, it is possible to have a cortical malformation in the absence of an epileptic phenotype.…”

Section: From Epilepsy To Malformation: Clinical Featuresmentioning

confidence: 99%

Cortical Malformations and Epilepsy: New Insights from Animal Models

et al. 1999

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Summary:In the last decade, the recognition of the high frequency of cortical malformations among patients with epilepsy especially children, has led to a renewed interest in the study of the pathophysiology of cortical development. This field has also been spurred by the recent development of several experimental genetic and non-genetic, primarily rodent, models of cortical malformations. Epileptiform activity in these animals can appear as spontaneous seizure activity in vivo, in vitro hyperexcitability, or reduced seizure susceptibility in vitro and in vivo. In the neonatal freeze lesion model, that mimics human microgyria, hyperexcitability is caused by a reorganization of the network in the borders of the malformation. In the prenatal methylazoxymethanol model, that causes a diffuse cortical malformation, hyperexcitability is associated with alteration of firing properties of discrete neuronal subpopulations together with the formation of bridges between normally unconnected structures. In agreement with clinical evidence, these expenmental data suggest that cortical malformations can both form epileptogenic foci and alter brain development in a manner that causes a diffuse hyperexcitability of the cortical network. Key Words: Neocortex-Hippocampus-Development-Neuronal migration-Methylazoxymethanol.As early as the end of the nineteenth century, neuropathologists began to report an association between cortical malformations and epilepsy (1-3). Until recently, however, clinical and experimental research yielded few insights into the pathophysiology of this distinct class of epilepsies. In fact, the last decade has seen three major scientific advances that have directly contributed to the "rediscovery" and renewed interest in examining the cause of epilepsy in patients with cortical malformations: mation and epilepsy. Moreover, neuropathologic analysis of resected tissue has frequently demonstrated the presence of more subtle malformations that were not identified in vivo. 3. Recent progress in human molecular genetics has allowed the identification of several genes whose mutations lead to both malformations and epilepsy. In parallel, several genetic and nongenetic rodent models of cortical malformations were shown to be associated with either spontaneous seizures or hyperexcitability .Our goal is to review the contributions of these animal models to our understanding of the pathophysiology of cortical malformations and to discuss their possible link with epilepsy. CORTICAL MALFORMATIONS IN HUMANSHuman cortical malformations have been the subject of several reviews (4-8) and the histology of the major types of cortical malformations encountered is fairly well established (see Fig. 1). In addition, classification of cortical malformations (based on neuropathology, radiology, etiology, or a combination of these elements) has 811

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Section: From Epilepsy To Malformation: Clinical Featuresmentioning

confidence: 99%

Cortical Malformations and Epilepsy: New Insights from Animal Models

et al. 1999

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“…ously described PNH cases (5,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)21) (Table 3), which also suggests a different etiology for bilateral and unilateral PNH. The clear female predominance (86%, including the present cases), the frequent familial occurrence of symmetrically diffuse cases (13)(14)(15)(16)(17)19), and the positive family history for epilepsy (19, present study), all suggest that genetic factors may play a role in determining the brain malformation in at least some bilaterally affected patients.…”

Section: Classification and Possible Origin Of Pnhmentioning

confidence: 99%

“…In the last 10 years, a number of reports have been published concerning patients affected by periventricular nodular heterotopia (PNH), diagnosed by computed to-mography (CT) (7) or magnetic resonance imaging (MRI) (5,(8)(9)(10)(11)(12). These studies have stressed the predominance of females, the possible occurrence in members of the same family (13)(14)(15)(16)(17), the absence of any major neurological or mental deficits, and the frequent incidence of epilepsy.…”

mentioning

confidence: 99%

Periventricular Nodular Heterotopia: Epileptogenic Findings

Battaglia¹,

Granata²,

Farina³

et al. 1997

Epilepsia

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Summary: Purpose:We studied 17 patients with periventricular nodular heterotopia (PNH) to further investigate the electroclinical pictures and semiology of the associated seizures.Methods: PNH was diagnosed by means of magnetic resonance imaging (MRI). The patients' clinical and familial histories were carefully analyzed, and their electroclinical features and course of epilepsy followed for periods ranging from 10 months to 22 years. The electroclinical data were compared with those of previously reported PNH cases.Results: The patients were subdivided into those with bilateral (7) and unilateral (10) PNH. The former were mainly characterized by structural abnormalities in the posterior cerebral fossa and multiple seizure types; the latter were characterized by the paratrigonal location of the malformation and, frequently, by elementary seizures with a visual or auditory onset. Focal seizures were drug resistant in most cases. The interictal EEG abnormalities were always focal and consistent with the location of the PNH. A previously unreported photic driving of posterior background activity was observed in all patients and was always consistent with the PNH location.Conclusions: Our present findings and previously reported data show that bilateral and unilateral PNH cases are different in their morphological and electroclinical features and may be determined by different etiologies. The female predominance, frequent familial occurrence, and positive family history for epilepsy suggest that genetic factors may be involved in the genesis of bilateral and symmetrical PNH, whereas the presence of prenatal risk factors and its location in the watershed paratrigonal area suggest that vascular mechanisms may determine unilateral PNH.

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“…Several studies have shown a consistently unfavourable neurological outcome of band heterotopias (Smith et al 1988, Barkovich and Kjos 1992, Huttenlocher et al 1994. Bilateral periventricular nodular heterotopia, on the other hand, generally has a more favourable outcome (Dobyns et al 1996).…”

Section: Discussionmentioning

confidence: 99%

“…The cerebral whitematter heterotopias can be focal, bilateral (diffuse) nodular, or diffuse laminar (band heterotopias) in distribution (Barkovich et al 1989). Seizures are present in all three types of heterotopias (Smith et al 1988, Barkovich and Kjos 1992, Huttenlocher et al 1994. These children frequently have abnormalities of motor function and cognitive development, particularly those with band heterotopias who have had the most consistently unfavourable neurological outcome (Barkovich and Kjos 1992).…”

Section: *Correspondence To Author At Above Addressmentioning

confidence: 99%

Outcome of bilateral periventricular nodular heterotopia in monozygotic twins with megalencephaly

Jan

1999

Develop Med Child Neuro

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Bilateral periventricular nodular heterotopia (BPNH) is a neuronal migration disorder, characterized by grey‐matter cellular rests in the periventricular regions. Patients frequently present with seizures during childhood or later in life. Monozygotic twin sisters were found to have enlarged head circumferences (>95th centile) during a routine medical visit at 6 months of age. A brain CT scan revealed grey‐matter cellular rests in the subependymal regions extending to the subcortical white matter. In some areas these cell aggregates had nodular margins, consistent with the diagnosis of BPNH. At 6 years of age they are cognitively and neurologically normal. They have not had any seizures and their heads continue to grow along the 95th centile.

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Association of heterotopic gray matter with seizures: MR imaging. Work in progress.

Cited by 77 publications

References 0 publications

Cortical Malformations and Epilepsy: New Insights from Animal Models

Cortical Malformations and Epilepsy: New Insights from Animal Models

Periventricular Nodular Heterotopia: Epileptogenic Findings

Outcome of bilateral periventricular nodular heterotopia in monozygotic twins with megalencephaly

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