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BACKGROUND AND PURPOSE: MR imaging studies and neuropathologic findings in individuals with 22q11.2 deletion syndrome show anomalous early brain development. We aimed to retrospectively evaluate cerebral abnormalities, focusing on gray matter heterotopia, and to correlate these with subjects’ neuropsychiatric impairments. MATERIALS AND METHODS: Three raters assessed gray matter heterotopia and other morphologic brain abnormalities on 3D T1WI and T2*WI in 75 individuals with 22q11.2 deletion syndrome (27 females, 15.5 [SD, 7.4] years of age) and 53 controls (24 females, 12.6 [SD, 4.7] years of age). We examined the association among the groups’ most frequent morphologic findings, general cognitive performance, and comorbid neuropsychiatric conditions. RESULTS: Heterotopia in the white matter were the most frequent finding in individuals with 22q11.2 deletion syndrome (n = 29; controls, n = 0; between-group difference, P < .001), followed by cavum septi pellucidi and/or vergae (n = 20; controls, n = 0; P < .001), periventricular cysts (n = 10; controls, n = 0; P = .007), periventricular nodular heterotopia (n = 10; controls, n = 0; P = .007), and polymicrogyria (n = 3; controls, n = 0; P = .3). However, individuals with these morphologic brain abnormalities did not differ significantly from those without them in terms of general cognitive functioning and psychiatric comorbidities. CONCLUSIONS: Taken together, our findings, periventricular nodular heterotopia or heterotopia in the white matter (possibly related to interrupted Arc cells migration), persistent cavum septi pellucidi and/or vergae, and formation of periventricular cysts, give clues to the brain development disorder induced by the 22q11.2 deletion syndrome. There was no evidence that these morphologic findings were associated with differences in psychiatric or cognitive presentation of the 22q11.2 deletion syndrome.

To figure out the spectra features of malformations of cortical development (MCDs) and the differences between MCDs subcategories. Twenty patients and 18 controls were studied. The patients included two subcategories: disorders of migration (DOM) and postmigration (DOPM). Spectra of patients were acquired from both the lesion and the normal-appearing contralateral side (NACS), and they were compared to those of the controls obtained from the frontal lobe. Compared to the controls, a decreased NAA (P = 0.002) was identified in MCDs. After dividing the MCDs into the DOM and DOPM, we found that NAA reduction was only notable in the DOM (P = 0.007). Moreover, Ins and Cr of the DOPM were higher than those of the controls (P = 0.017 and 0.013) and the DOM (P = 0.027 and 0.001). Compared to the NACS, a decreased NAA (P = 0.042) and an increased Ins (P = 0.039) were identified in the lesion of MCDs. After dividing the MCDs into the DOM and DOPM, we found no significant differences in the DOM, but Ins, Cr, and Glx of the lesion were higher than those of the NACS (P = 0.007, 0.005 and 0.047) in the DOPM. In addition, we found that Cr and Glx correlated positively to the seizure frequency (P = 0.003 and 0.016). Decreased NAA was the prominent abnormality confirmed in MCDs. Spectra of different MCDs subcategories were different: the DOM was characterized by decreased NAA, while the DOPM was characterized by increased Ins.

Background Hypothalamic hamartomas (HH) are rare, and it is even rare when combined with gray matter heterotopia (GMH) and polymicrogyria (PMG). Case Description A 5 years-old boy with HH, GMH and PMG were retrospectively evaluated. The clinical data which include the symptoms, examinations, diagnosis and treatment were collected. The patient had a chief complaint of gelastic seizures (GSs) and intellectual deficiency. Brain MRI showed HH, paraventricular nodular heterotopia and PMG. Video-electroencephalographys (V-EEGs) were normal. The patient underwent resection of the HH via transcallosal transseptal interforniceal approach. Seizures disappeared immediately after complete resection of HH, and the intellectual development was getting better. Conclusions In this extremely rare case, resection of the HH eliminates the symptoms. However, we still need to be cautious about the possible epilepsy that may be caused by GMH and PMG.

BACKGROUND AND PURPOSE: Fetal imaging is crucial in the evaluation of open neural tube defects. The identification of intraventricular hemorrhage prenatally has unclear clinical implications. We aimed to explore fetal imaging findings in open neural tube defects and evaluate associations between intraventricular hemorrhage with prenatal and postnatal hindbrain herniation, postnatal intraventricular hemorrhage, and ventricular shunt placement. MATERIALS AND METHODS: After institutional review board approval, open neural tube defect cases evaluated by prenatal sonography between January 1, 2013 and April 24, 2018 were enrolled (n = 504). The presence of intraventricular hemorrhage and gray matter heterotopia by both prenatal sonography and MR imaging studies was used for classification. Cases of intraventricular hemorrhage had intraventricular hemorrhage without gray matter heterotopia (n = 33) and controls had neither intraventricular hemorrhage nor gray matter heterotopia (n = 229). A total of 135 subjects with findings of gray matter heterotopia were excluded. Outcomes were compared with regression analyses. RESULTS: Prenatal and postnatal hindbrain herniation and postnatal intraventricular hemorrhage were more frequent in cases of prenatal intraventricular hemorrhage compared with controls (97% versus 79%, 50% versus 25%, and 63% versus 12%, respectively). Increased third ventricular diameter, specifically >1 mm, predicted hindbrain herniation (OR = 3.7 [95% CI, 1.5–11]) independent of lateral ventricular size and prenatal intraventricular hemorrhage. Fetal closure (n = 86) was independently protective against postnatal hindbrain herniation (OR = 0.04 [95% CI, 0.01–0.15]) and postnatal intraventricular hemorrhage (OR = 0.2 [95% CI, 0.02–0.98]). Prenatal intraventricular hemorrhage was not associated with ventricular shunt placement. CONCLUSIONS: Intraventricular hemorrhage is relatively common in the prenatal evaluation of open neural tube defects. Hindbrain herniation is more common in cases of intraventricular hemorrhage, but in association with increased third ventricular size. Fetal closure reverses hindbrain herniation and decreases the rate of intraventricular hemorrhage postnatally, regardless of the presence of prenatal intraventricular hemorrhage.

Objective A vast network involving the nodules and overlying cortices is believed to be responsible for the epileptogenicity in gray matter heterotopia with multiple nodules, which often associated with difficult‐to‐treat epilepsy. We sought to determine if functional magnetic resonance imaging (fMRI) could detect internodular functional connectivity (FC), and if this connectivity reflects an actual synchronized neuronal activity and partakes in epileptogenicity. Methods We studied 16 epilepsy patients with multiple heterotopic nodules; eight underwent subsequent intracerebral EEG. We examined the internodular FC using fMRI and its correspondence with internodular synchrony of intracerebral interictal activity. We then compared the spreading speed of ictal activity between connected and unconnected nodules; and the FC among possible combinations of nodule pairs in terms of their involvement at seizure onset. Results Seventy nodules were studied: 83% have significant connection to at least one other nodule. Among the 49 pairs studied with intracerebral EEG, (1) synchronized interictal activity is more prevalent in fMRI‐connected pairs (P

International audience; Objective: Malformations of cortical development are common causes of intellectual disability and epilepsy, yet there is a crucial lack of relevant preclinical models associating seizures and cortical malformations. Here, we describe a novel rat model with bilateral subcortical band heterotopia (SBH) and examine whether this model develops spontaneous epileptic seizures. Methods: To generate bilateral SBH in rats, we combined RNAi-mediated knockdown of Dcx and in utero electroporation with a tripolar electrode configuration enabling simultaneous transfection of the two brain hemispheres. To determine whether bilateral SBH leads to epileptiform activity, rats of various ages were implanted for telemetric electrocorticographic recordings and histopathologi-cal examination was carried out at the end of the recording sessions. Results: By 2 months, rats with bilateral SBH showed nonconvulsive spontaneous seizures consisting of spike-and-wave discharges (SWDs) with dominant frequencies in the alpha and theta bands and secondarily in higher-frequency bands. SWDs occurred during both the dark and the light period, but were more frequent during quiet awake state than during sleep. Also, SWDs were more frequent and lasted longer at older ages. No sex differences were found. Although frequencies and durations of SWDs were found to be uncorrelated with the size of SBH, SWDs were initiated in some occasions from brain hemispheres comprising a larger SBH. Lastly, SWDs exhibited absence-like pharmacological properties , being temporarily alleviated by ethosuximide administration. Significance: This novel model of bilateral SBH with spontaneous epilepsy may potentially provide valuable new insights into causality between cortical malfor-mations and seizures, and help translational research aiming at designing novel treatment strategies for epilepsy. K E Y W O R D S animal model, epilepsy, gray matter heterotopia, malformation of cortical development-This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Summary Hippocampal sclerosis (HS) is the most common neuropathologic findings in patients with intractable temporal lobe epilepsy (TLE). The international league against epilepsy has proposed a new classification of HS based on pyramidal cell loss on different subfields to facilitate the study of HS pathology in patients after anterior temporal lobectomy (ATL), and the influence of these HS patterns on the prognosis of patients with TLE is contradictory. This study aims to investigate the relationship between different HS subtypes and postoperative seizure outcomes for intractable patients with TLE. From January 2008 to December 2018, we retrospectively reviewed 198 TLE patients with ATL surgery, and all patients had a complete preoperative evaluation, a specimen of hippocampal tissue after surgery, cognitive test after surgery, and more than 2 years of postoperative follow-up. The main findings were as follows: 1) temporal neocortical gray matter heterotopia were more common in the no-HS group; 2) HS type 1 was associated with a longer duration of epilepsy; 3) history of meningitis was the independent predictor of HS type 1; 4) no-HS patients experienced worse postoperative seizure outcomes than those with HS type1 and type 2, whereas no difference in seizure outcomes was obtained between HS type 1 and type 2; 5) no-HS patients were at increased risk for verbal memory decline after left hippocampal resection. The HS subtypes were associated with the prognosis of patients with TLE, and other variables were the predictors of different HS types. `Further study was to identify the HS subtypes by noninvasive evaluation to approve better postoperative outcomes.

Objective To investigate the clinical characteristics and neuroimaging features of childhood presenting with gray matter heterotopia observed in a single tertiary Pediatric Department in Catania and compare the data with those reported in the literature. Methods A retrospectively review of the history, clinical findings, electrophysiological features and magnetic resonance images of 22 children presenting with gray matter heterotopia observed from January 2010 to January 2020. Results Among the 22 children included in the study, 17 presented with periventricular heterotopia (PVNH), two with Subcortical Band Heterotopia (SBH), and three with other subcortical heterotopia (SUBH). In the affected children, the ages at first diagnosis ranged from 3 months to 16 years with a mean age of 8.2 years (± 5.4); twelve (54.5%) suffered by developmental delay and intellectual deficit; eleven children (50%) complained of epileptic seizures, mostly focal to bilateral tonic–clonic seizure. In addition, in the periventricular heterotopia group (PVNH), cerebral and systemic malformations were reported in twelve (70%) and in ten (58%) children, respectively, out of seventeen. In the SBH plus SUBH group, epileptic seizures were recorded in 3 (60%) out of 5 children, cerebral malformations in one child and systemic malformations in two children. Conclusions Heterotopic gray matter malformations include a group of disorders that manifest with a variety of neurological implications, such as cognitive impairment and epilepsy, and often related with epilepsy, other cerebral malformations and systemic anomalies.

Teaching point: Since some minor congenital brain defects manifest long after birth, even in adults they should be kept in the differential of new epileptic seizures or focal neurologic deficits.

International audience; EML1 encodes the protein Echinoderm microtubule-associated protein-like 1 or EMAP-1 that binds to the microtubule complex. Mutations in this gene resulting in complex brain malformations have only recently been published with limited clinical descriptions. We provide further clinical and imaging details on three previously published families, and describe two novel unrelated individuals with a homozygous partial EML1 deletion and a homozygous missense variant c.760G>A, p.(Val254Met), respectively. From review of the clinical and imaging data of eight individuals from five families with biallelic EML1 variants, a very consistent imaging phenotype emerges. The clinical syndrome is characterized by mainly neurological features including severe developmental delay, drug-resistant seizures and visual impairment. On brain imaging there is megalencephaly with a characteristic ribbon-like subcortical heterotopia combined with partial or complete callosal agenesis and an overlying polymicrogyria-like cortical malformation. Several of its features can be recognized on prenatal imaging especially the abnormaly formed lateral ventricles, hydrocephalus (in half of the cases) and suspicion of a neuronal migration disorder. In conclusion, biallelic EML1 disease-causing variants cause a highly specific pattern of congenital brain malformations, severe developmental delay, seizures and visual impairment.

For general radiologists, congenital brain malformations pose substantial challenges in terms of recognition, description, and classification. This review describes a practical approach to imaging and classifying the most common supratentorial brain malformations. It begins with a discussion of embryology and optimal imaging technique and then summarizes distinguishing imaging features for several major categories of cerebral malformation, including holoprosencephaly, gray matter heterotopia, lissencephaly/pachygyria, focal cortical dysplasia, polymicrogyria, and cobblestone malformation. The importance of identifying abnormalities in the corpus callosum and basal ganglia is also discussed, both for detection and characterization of cerebral malformations.

International audience; Malformations of cortical development (MCDs), a complex family of rare disorders, result from alterations of one or combined developmental steps, including progenitors proliferation, neuronal migration and differentiation. They are an important cause of childhood epilepsy and frequently associate cognitive deficits and behavioral alterations. Though the physiopathological mechanisms of epilepsy in MCD patients remain poorly elucidated, research during the past decade highlighted the contribution of some factors that will be reviewed in this paper and that include: (i) the genes that caused the malformation, that can be responsible for a significant reduction of inhibitory cells (e.g., ARX gene) or be inducing cell-autonomous epileptogenic changes in affected neurons (e.g., mutations on the mTOR pathway); (ii) the alteration of cortical networks development induced by the malformation that will also involve adjacent or distal cortical areas apparently sane so that the epileptogenic focus might be more extended that the malformation or even localized at distance from it; (iii) the normal developmental processes that would influence and determine the onset of epilepsy in MCD patients, particularly precocious in most of the cases.

To investigate the clinical and imaging features of gray matter heterotopia (GMH) and improve the clinicians’ understanding of the disease. A retrospective study was performed on 15 patients with GMH diagnosed at The Affiliated Hospital of Xuzhou Medical University from November 2014 to November 2016. Their clinical and imaging features are also summarized. The proportion of male and female patients was 2:1. The age of onset was 2~45 years and the average age was 19.1 years. There were 13 patients with epilepsy who also had cognitive decline (5 cases) and neurological deficit (3 cases). There were 2 patients with headache or dizziness. The imaging findings of GMH are unilateral or multiple spots in the periventricular or subependymal, subcortical, and centrum semiovale and are often accompanied by other cerebral malformations. We found that 10 patients had the subcortical type of GMH and 5 patients had the subependymal type or periventricular nodular heterotopia type. There were 8 cases of ventricular compression, 5 cases of ventriculomegaly, 5 cases of cerebral fissure malformation, 3 cases of pachygyria, 1 case of callosal agenesis, and 1 case of undeveloped septum pellucidum. All the patients were given symptomatic and supportive therapies and 3 patients were treated with antiepileptic drugs. Seizures were, however, poorly controlled. GMH should also be suspected in patients with juvenile onset of seizures, cognitive decline, and neurological deficits. Magnetic resonance scans may show lesions in the white matter of the brain with signals similar to the normal gray matter.

Background Vestibular schwannomas and meningiomas account for the great majority of lesions arising in the cerebellopontine angle. In this report, we present a case of glioneuronal heterotopia, also known as glioneuronal hamartoma, arising from cranial nerve VIII, which is an extremely uncommon lesion. Important radiologic and surgical aspects are reviewed, which may help in early recognition and intraoperative decision making when these lesions are encountered. Case Description A healthy 29-year-old female presented with intermittent right facial numbness. Magnetic resonance imaging showed an incidental, minimally enhancing cerebellopontine angle lesion on the right cranial nerve VII–VIII complex. The patient declined serial observation and opted for operative intervention for resection. Intraoperatively, the lesion resembled neural tissue and was continuous with the VIII cranial nerve. Pathologic analysis demonstrated mature glioneuronal tissue consistent with hamartomatous brain tissue. The patient maintained normal hearing and facial nerve function after surgery. Radiologic, surgical, and pathologic characteristics are described. Conclusions Ectopic glioneuronal tissue of cranial nerve VIII is a rare non-neoplastic lesion and should be considered in the differential diagnosis of unusual-appearing intracanalicular and cerebellopontine angle lesions. The congenital and benign nature of this entity makes observation a valid option for these cases, although they are so infrequent that they are often presumptively managed as vestibular schwannomas. Attempts to radically resect these lesions may result in higher rates of hearing loss or facial palsy due to their continuity with cranial nerves.

OBJECT Surgical exposure of the peritrigonal or periatrial region has been challenging due to the depth of the region and overlying important functional cortices and white matter tracts. The authors demonstrate the operative feasibility of a contralateral posterior interhemispheric transfalcine transprecuneus approach (PITTA) to this region and present a series of patients treated via this operative route. METHODS Fourteen consecutive patients underwent the PITTA and were included in this study. Pre- and postoperative clinical and radiological data points were retrospectively collected. Complications and extent of resection were reviewed. RESULTS The mean age of patients at the time of surgery was 39 years (range 11–64 years). Six of the 14 patients were female. The mean duration of follow-up was 4.6 months (range 0.5–19.6 months). Pathology included 6 arteriovenous malformations, 4 gliomas, 2 meningiomas, 1 metastatic lesion, and 1 gray matter heterotopia. Based on the results shown on postoperative MRI, 1 lesion (7%) was intentionally subtotally resected, but ≥ 95% resection was achieved in all others (93%) and gross-total resection was accomplished in 7 (54%) of 13. One patient (7%) experienced a temporary approach-related complication. At last follow-up, 1 patient (7%) had died due to complications of his underlying malignancy unrelated to his cranial surgery, 2 (14%) demonstrated a Glasgow Outcome Scale (GOS) score of 4, and 11 (79%) manifested a GOS score of 5. CONCLUSIONS Based on this patient series, the contralateral PITTA potentially offers numerous advantages, including a wider, safer operative corridor, minimal need for ipsilateral brain manipulation, and better intraoperative navigation and working angles.

Summary Background Gray matter heterotopia (GMH) is a malformation of the central nervous system characterized by interruption of normal neuroblasts migration between the 7th and 16th week of fetal development. The aim of the study was the analysis of clinical symptoms, prevalence rate and the most common concurrent central nervous system (CNS) developmental disorders as well as assessment of characteristic morphological changes of gray matter heterotopia in children hospitalized in our institution between the year 2001 and 2012. Material/Methods We performed a retrospective analysis of patients’ data who were hospitalized in our institution between the year 2001 and 2012. We assessed clinical data and imaging exams in children diagnosed with gray matter heterotopia confirmed in MRI (magnetic resonance imaging). Results GMH occurred in 26 children hospitalized in our institution between the year 2001 and 2012. Among children with gray matter heterotopia most common clinical symptoms were: epilepsy, intellectual disability and hemiparesis. The commonest location of heterotopic gray matter were fronto-parietal areas of brain parenchyma, mostly subependymal region. Gray matter heterotopia occurred with other developmental disorders of the central nervous system rather than solely and in most cases it was bilateral. Schizencephaly and abnormalities of the corpus callosum were the most often developmental disorders accompanying GMH. Conclusions 1. Subependymal gray matter heterotopia was more common than subcortical GMH. Subependymal GMH showed tendency to localize in the region of the bodies of the lateral ventricles. The least common was laminar GMH. 2. Gray matter heterotopia occurred more often with other developmental disorders of the central nervous system rather than solely. The most frequent concurrent disorders of the central nervous system were: schizencephaly, developmental abnormalities of the corpus callosum, arachnoid cyst, abnormalities of the septum pellucidum and the fornix. 3. GMH foci were more often bilateral than unilateral. 4. In the diagnostics of cell migration abnormalities, gray matter heterotopia included, MR imaging remains the method of choice.

Despite pharmacological and surgical interventions, some children with periventricular nodular heterotopia (PNH) remain refractory to treatment, which suggests more diffuse pathology potentially involving perilesional white matter. The purpose of this study was to evaluate MR diffusion tensor imaging (MRDTI) metrics within perilesional white matter in children with PNH. Six children with PNH (four boys; average age 3.2 years, range 2 months to 6 years) were studied with MRDTI at 3 T. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) were quantified within perilesional white matter at distances of 5 mm, 10 mm, 15 mm, and 20 mm from focal areas of PNH and compared to location-matched ROIs in six healthy control patients (two boys, average age 3.3 years, range 2–6 years). Statistical significance was set at an overall level of α = 0.05, corrected for multiple comparisons. Perilesional white matter showed significantly decreased fractional anisotropy and elevated mean and radial diffusivity at all evaluated distances. No significant differences in axial diffusivity were detected at any distance. PNH is associated with microstructural white matter abnormalities as indicated by abnormal perilesional MRDTI metrics detectable at least 20 mm from visible nodular lesions.

Various etiologic diagnoses are put forward for certain forms of infant epilepsy. We report four cases illustrating a rare cause: gray matter heterotopia. There were three girls and one boy, aged 3 months to 4 years at onset of seizures and 8 to 30 years at diagnosis of gray matter heterotopia. All patients sought healthcare because of repeated seizures. One patient also presented severe mental retardation. No consanguinity was noted. Magnetic resonance imaging showed the interposition of an ectopic ribbon of gray matter within the white matter in all cases. Ectopic gray matter formed bilateral subependymal nodules in one patient and bilateral nodules in the subcortical region suggestive of concentric laminar organization in another. The two other patients presented both of these forms. Other anomalies were associated: partial agenesis of the corpus callosum associated with colpocephaly causing cortical atrophy in one patient and hippocampal sclerosis in another.

We report on a child with Chudley-McCullough syndrome and re-evaluate the spectrum of imaging findings (in 15 previously reported patients) which appear to be variable and, to some extent, ambiguous in the literature. Magnetic resonance imaging of the brain revealed asymmetric colpocephaly with agenesis of the splenium corporis callosi, ribbon-like subcortical gray matter heterotopia along the cingulate gyri, malrotation of both hippocampi, and dysplasia of the cerebellum. Macrocrania together with sensorineural hearing loss, colpocephaly, and posterior or complete agenesis of the corpus callosum can be considered the hallmarks of the autosomal recessive Chudley-McCullough syndrome. These may be variably associated with interhemispheric arachnoid cyst, cortical dysplasia, gray matter heterotopia, and cerebellar dysplasia. While early support with hearing aids may lead to improved language and cognitive outcome, shunting of ventricular dilatation is not indicated in the Chudley-McCullough syndrome.

A 25-year-old woman with intractable seizures underwent FDG PET/MRI for seizure focus localization. MRI demonstrated bilateral carpetlike nodular subependymal gray matter and asymmetrical focal dilatation in the right temporal horn. PET/MRI showed increased FDG within subependymal gray matter with significant hypometabolism in right anterior temporal lobe. EEG and ictal semiology confirmed the right temporal seizure origin. This case highlights the importance of identification of gray matter heterotopia on FDG PET/MRI.

BACKGROUND AND PURPOSE: Malformations of cortical development (MCD) are traditionally considered as a cause of epilepsy. Our aim was to study patients with focal MCD, by using multivoxel proton MR spectroscopy; we focused not only on the lesion but also on the normal-appearing contralateral side (NACS). Our hypothesis was that the metabolic abnormality extends to the NACS; therefore, it would be inadequate to consider NACS as an internal control. MATERIALS AND METHODS: We studied 16 patients with focal MCD. MR spectroscopy was performed by using a point-resolved spectroscopy sequence technique, including the MCD area and the NACS. In each volume of interest, a smaller volume of interest of 2.25 cm 3 centered on the MCD was selected to study the N- acetylaspartate/creatine (NAA/Cr) ratio. In NACS, this ratio was studied by placing a symmetric voxel in comparison with the smaller MCD volume of interest. A control group ( n = 30) was also studied to evaluate both white and gray matter by using the same MR spectroscopy protocol. RESULTS: From 16 analyzed volumes of interest with MCD, 9 were composed of gray matter heterotopia and 7 of cortical dysplasia. MR spectroscopy of both MCD lesions and NACS ( n = 10) showed decreased NAA/Cr compared with that of the control group. NACS in these patients did not present significant differences regarding NAA/Cr in comparison with the affected side. CONCLUSIONS: MR spectroscopy demonstrated abnormal NAA/Cr in both MCD lesions and NACS in patients harboring focal MCD, giving support to the hypothesis that in MCD metabolic abnormalities extend far away from the limits of the lesion, reaching the contralateral side.

We present the results of a retrospective study on 10 patients operated on for intractable epilepsy associated with nodular heterotopia as identified by high resolution MRI. Seven patients had unilateral heterotopia, one patient had symmetric bilateral heterotopia and two patients had asymmetric bilateral heterotopia. By stereo-electroencephalogram (SEEG) (nine patients) interictal activity within nodules was similar in all cases, and ictal activity never started from nodules alone but from the overlying cortex or simultaneously in nodules and cortex. Excellent outcomes ([Engel class Ia, 1987][1]) were achieved in the seven patients with unilateral heterotopia, showing that surgery can be highly beneficial in such cases when the epileptogenic zone is carefully located prior to surgery by MRI and particularly SEEG. For the bilateral cases surgical outcomes were Engel IIa (one patient) or Engel IIIa (two patients). Histological/immunohistochemical studies of resected specimens showed that all nodules had similar microscopic organization, even though their extent and location varied markedly. The overlying cortex was dysplastic in nine patients, but of normal thickness. We suggest that nodule formation may be the result of a dual mechanism: (i) failure of a stop signal in the germinal periventricular region leading to cell overproduction; and (ii) early transformation of radial glial cells into astrocytes resulting in defective neuronal migration. The intrinsic interictal epileptiform activity of nodules may be due to an impaired intranodular GABAergic system. [1]: #ref-5

Parietal cephaloceles are rare congenital anomalies usually associated with significant underlying brain anomalies. Further investigations with cranial magnetic resonance examination and MR venography is important to reveal associated intracranial anomalies and to show the relationship of the cephalocele sac with the dural venous sinuses. These examinations are also crucial to predict the prognosis before surgical correction of the encephalocele. We present MR findings of an infant with a parietal meningoencephalocele associated with microcephaly and multiple other congenital central nervous system anomalies including partial callosal agenesis, gray matter heterotopia, ventricular dysplasia, and right retrocerebellar arachnoid cyst.

We describe two brothers with Chudley-McCullough syndrome who are 5 and 17 years old. They were born to healthy consanguineous parents of Pakistani descent. They had severe sensorineural deafness and neuroimaging showed corpus callosum agenesis and other structural brain abnormalities. The Chudley-McCullough syndrome is an autosomal recessive disorder, first described by Chudley et al. [1997: Am J Med Genet 68:350-356]. The original description of the syndrome includes hydrocephalus due to obstruction of the foramen of Monro and early-onset severe to profound sensorineural deafness. We review the findings in the two patients we describe, four children reported in the literature and two patients reported by Hendriks et al. [1999: Am J Med Genet 86:183-186] with sensorineural deafness, corpus callosum agenesis, and interhemispheric cysts, who may well have Chudley-McCullough syndrome. All patients had sensorineural deafness. The neuroimagings of all eight patients showed colpocephaly, which is most likely caused by corpus callosum agenesis. Three patients had other structural brain abnormalities: cortical dysplasia and gray matter heterotopia. We suggest a revision of the clinical description since the most likely basic developmental defect is corpus callosum agenesis and not foramen of Monro obstruction.

Cortical dysplasias or malformations due to abnormalities of cortical development are a well-recognized cause of intractable seizures. This study retrospectively examines the clinicopathologic features of 52 cases of extratemporal cortical dysplasia (from 135 total resections performed over a 16-year period). The study consists of 52 patients (27 males; 25 females) who underwent extratemporal resection for epilepsy at a mean age of 15.1 years (range, 3 months to 44.1 years). Seizure duration before surgery ranged from 7 to 372 months (mean duration, 129 months). Patterns of cortical dysplasia observed included diffuse architectural disorganization (n=48), neuronal cytomegaly (n=32), increased number of molecular layer neurons (n=32), balloon cells (n=19), gray matter heterotopia (n=3), neuronal glial clustering (n=3), and pial glial neuronal tissue (n=2). Five patients had coexistent nodular hamartomas. Coexistent tumors were present in five patients; including three dysembryoplastic neuroepithelial tumors, one ganglioglioma, and one low-grade fibrillary astrocytoma. Two patients had tuberous sclerosis. Follow-up was available in 50 patients (mean follow-up, 29 months). Thirty-eight patients (73%) had complete resolution or significant decrease in seizure frequency, 13 patients (25%) had increased seizures or no change in seizures, and one patient died in the postoperative period. In conclusion, (1). cortical dysplasia was identified in 38.5% of extratemporal resections for epilepsy; (2). the common cortical dysplasia patterns observed included diffuse cortical disorganization, neuronal cytomegaly, and increased molecular layer neurons; (3). 10% of extratemporal cortical dysplasia was associated with tumors; (4). improved seizure control was obtained in approximately three fourths of patients after resection; and (5). seizures associated with balloon cell dysplasia were less successfully managed with surgery.

I read with interest the original article by Kadom and colleagues [1] titled “Hippocampal Sclerosis in Children Younger than 2 years.” I congratulate the authors for highlighting these cases of hippocampal sclerosis (HS), or mesial temporal sclerosis (MTS), in an unexpectedly young patient group. While one cannot argue with the importance of MTS as a cause of refractory temporal lobe epilepsy in children and adults, I challenge the author’s statement that “an infectious trigger was present in all five patients.” In Table 1, the authors indicate that patient 1 had infection as the etiology of MTS and that patients 3–5 had complex febrile seizures. Unfortunately, there is no serological or CSF laboratory evidence or histopathological evidence to support the assertion that infection was the trigger leading to MTS. While the authors have increased our awareness of MTS in a younger-than-expected age group, their study raises several broader questions. An ongoing contention in epileptology is the proposed relationship between febrile seizures and the development of MTS. The prevalence of febrile seizures among developed countries is about 4% and it is thought to be even higher in poorer countries [2]. Some authors suggest that prolonged febrile seizures lead to direct injury of the hippocampus and adjacent structures, and ultimately to MTS [3]. There is strong retrospective evidence supporting this belief [4, 5]. There is increasing evidence from animal and human data that prolonged febrile seizures are associated with physiological and anatomical changes within the hippocampus that may lead to hippocampal injury, subsequent mesial temporal sclerosis and temporal lobe epilepsy in some cases [6]. More recent MR imaging studies suggest that up to 30–40% of children with prolonged febrile seizures will have acute changes within the hippocampus demonstrated on MRI [7, 8]. Additionally, the presence and the severity of temporal lobe MRI signal changes are predictive of mesial temporal sclerosis preceding the development of clinical seizures. Provenzale et al. [9] in their MRI study of 11 children (mean age of 25 months) who suffered from febrile status epilepticus reported a strong positive correlation between the conspicuity of hippocampal T2 hyperintensity and subsequent development of MTS. On the other side of the argument of MTS genesis are population-based prospective studies that have failed to find an association between febrile seizures and MTS [10–12]. In addition to the role that prolonged or complex febrile seizures may play in the genesis of hippocampal injury, clinical pathological studies have demonstrated other potential causes of mesial temporal sclerosis [7]. Dual pathology (gray matter heterotopia or focal cortical dysplasia + MTS) or “double hit” abnormality may be found in 15% of pediatric patients with mesial temporal sclerosis [7]. Genetics may play a role in hippocampal malformation and function, and ultimately in the development of clinical seizures of hippocampal origin. Familial cases of mesial temporal sclerosis have been reported [13]. Syndromespecific genes for febrile seizures (channelopathies) have been identified, as have mutations in the SOX2 gene that have been linked to mesial temporal malformation and clinical temporal lobe seizures [13, 14]. Human herpes virus G. L. Hedlund (*) Department of Radiology, Neuroradiology Division, Primary Children’s Medical Center, 100 N. Mario Capecchi Drive, Salt Lake City, UT 84113, USA e-mail: Gary.Hedlund@imail.org

Interhypothalamic adhesion is a newly described disease entity, characterized by an abnormal parenchymal band connecting the medial margins of the hypothalami across the third ventricle. Additional anomalies, including cleft palate, gray matter heterotopia, cerebellar hypoplasia, optic atrophy, hippocampal under-rotation, and white matter lesions, may coexist. The purpose of this clinical report is to describe the imaging findings from a series of 13 patients with interhypothalamic adhesions discovered on brain MR imaging.

This contribution presents a magnetic resonance imaging (MRI) acquisition technique named Tissue Border Enhancement (TBE), whose purpose is to produce images with enhanced visualization of borders between two tissues of interest without any post-processing. The technique is based on an inversion recovery sequence that employs an appropriate inversion time to produce images where the interface between two tissues of interest is hypo-intense; therefore, tissue borders are clearly represented by dark lines. This effect is achieved by setting imaging parameters such that two neighboring tissues of interest have magnetization with equal magnitude but opposite sign; therefore, the voxels containing a mixture of each tissue (that is, the tissue interface) possess minimal net signal. The technique was implemented on a 7.0 T MRI system. This approach can assist the definition of tissue borders, such as that between cortical gray matter and white matter; therefore, it could facilitate segmentation procedures, which are often challenging on ultra-high-field systems due to inhomogeneous radiofrequency distribution. TBE allows delineating the contours of structural abnormalities, and its capabilities were demonstrated with patients with focal cortical dysplasia, gray matter heterotopia, and polymicrogyria. This technique provides a new type of image contrast and has several possible applications in basic neuroscience, neurogenetic research, and clinical practice, as it could improve the detection power of MRI in the characterization of cortical malformations, enhance the contour of small anatomical structures of interest, and facilitate cortical segmentation.

BACKGROUND AND PURPOSE Septo-optic dysplasia (SOD) is the triad of optic nerve hypoplasia, panhypopituitarism, and agenesis of septum pellucidum, and has been described previously to be associated with heterotopias and midline interhemispheric cyst. We describe a case of SOD with arachnoid cysts, persistent primary hyperplastic vitreous, and malformations of cortical development. METHODS Case report and review of literature. RESULTS Our patient was found to have SOD, bilateral ventriculomegaly, pachygyria, gray matter heterotopia, bilateral choroidal cysts near the brainstem, and persistent primary hyperplastic vitreous. She later developed infantile spasms and required enucleation of the abnormal eye and cyst fenestration. CONCLUSION Coincidence of seizures, SOD, bilateral choroid fissure cysts, heterotopias, and persistent primary hyperplastic vitreous is a unique constellation. It is unclear whether this represents a new syndrome or SOD spectrum variation. Patients with SOD and arachnoid cysts should be monitored for signs of herniation.

Gray matter heterotopia are common malformations of cortical development. From a clinical perspective, affected patients are best divided into three groups: subependymal, subcortical, and band heterotopia (also called double cortex). Symptomatic women with subependymal heterotopia typically present with partial epilepsy during the second decade of life; development and neurologic examinations up to that point are typically normal. Symptoms in men with subependymal heterotopia vary, depending on whether they have the X-linked or autosomal form. Men with the X-linked form more commonly have associated CNS and visceral anomalies; their development is typically abnormal. Symptomatic men with the autosomal variety have clinical courses similar to symptomatic women. Both men and women with subcortical heterotopia typically have congenital fixed neurologic deficits and develop partial epilepsy during the second half of the first decade of life. The more extensive the subcortical heterotopia, the greater the deficit; bilateral heterotopia are almost invariably associated with severe developmental delay or mental retardation. In general, band heterotopia are seen exclusively in women; men with a mutation of the related gene (called XLIS or DCX) usually die in utero or have a much more severe brain anomaly. Symptoms in affected women vary from normal to severe developmental delay or mental retardation; the severity of the syndrome is related to the thickness of the band of arrested neurons. Nearly all affected patients that come to medical attention have epilepsy, with partial complex and atypical absence epilepsy being the most common syndromes. Some of the more severely affected patients develop attacks.

The Chudley-McCullough syndrome, an autosomal recessive condition first reported by Chudley et al. [1997], comprises profound sensorineural hearing loss and hydrocephalus secondary to an obstruction of the foramen of Munro. We describe two more sibs with this condition. One girl had sensorineural hearing loss and hydrocephalus due to obstruction of the foramen of Munro. Incidentally she was also found to carry a full mutation in the FMR1 gene. The older sister had profound sensorineural hearing loss and hydrocephalus not due to obstruction of the foramen of Munro; she also had callosal dysgenesis, gray matter heterotopia, cortical dysplasia, and cerebellar dysgenesis. Thus, the Chudley-McCullough syndrome may include hydrocephalus not necessarily related to obstruction of the foramen of Munro and other structural brain abnormalities.

Many posterior fossa malformations are associated with other malformations particularly supratentorial ones, which tend to affect the prognosis of these patients. The role of the cerebellum in higher learning is just beginning to be understood, but it is obvious that cerebellar abnormalities may result in higher-cognition defects. Studies have demonstrated cerebellar abnormalities in patients with developmental encephalopathies, such as autism, mental retardation, and Rett syndrome. Disorders that affect cell life cycles and result in abnormal cell proliferation and abnormal cell migration disorders (hemimegalencephaly, dystroglicanopathy, lissencephaly, and gray matter heterotopia) can also be accompanied by posterior fossa malformations. In this article, we discuss hindbrain-midbrain malformations associated with developmental encephalopathies and with supratentorial brain abnormalities that result from abnormal cell proliferation and cell migration.

Vertex cephaloceles (VCs), also known as midline parietal cephaloceles, are among the most common midline scalp masses. Usually composed by a meningeal wall herniating from a vertex skull defect and covered by skin, VCs may also contain both anomalous vessels and neural elements. In spite of their harmless appearance, VCs often hide complex intracranial venous and/or brain malformations so that they represent a "tip of the iceberg". Vertical embryonic positioned straight sinus, elongation of the vein of Galen, persistence of the falcine sinus, fenestration of the superior sagittal sinus, corpus callosum agenesis, intracranial cysts, tentorial malformations, cerebellar vermis agenesis, hydrocephalus, and gray matter heterotopia are some of such associated anomalies.The treatment of VCs is surgical. It is indicated to prevent the rupture of the malformation or in case of pain or cosmetic impact. A careful preoperative radiological work up is mandatory to investigate the relationship between the VC and the sagittal sinus and/or the possible communication with the brain. The surgical procedure is usually carried out without significant complications.The prognosis of VCs is good even though the overall outcome is affected by the associated brain malformations.

Grey matter heterotopias, demonstrated by MRI, may present with a broad spectrum of clinical severity. We have studied 33 patients with periventricular nodular heterotopias (PNH); 19 (58%) had unilateral and 14 (42%) bilateral lesions. Thirteen of the 19 patients (68%) with unilateral subependymal nodules of grey matter had, in addition, unilateral focal subcortical heterotopias (SNH), comprising 39% of the entire group. Most had normal intellectual and motor function but some presented with mild mental retardation and neurological deficits. Recurrent seizures were described in 82%, mainly partial attacks with temporo-parieto-occipital auras. Nodular heterotopias led to unilateral or bilateral independent temporal epileptic discharges in 47% of epileptic patients with PNH alone and in 61% of those who had SNH in addition. Extratemporal or multilobar, unilateral or bilateral interictal spiking was present in 10 other patients (36%). Two first degree relatives of patients with seizures were affected but had no seizures, three were investigated for other apparently unrelated neurological symptoms: memory impairment, vertigo or transient ischaemic attacks in one person each. Contiguous ovoid nodules of grey matter, symmetrically lining both lateral ventricles, were described in nine patients. Seven of them were female, including four with familial incidence of PNH. Such lesions may explain the familial occurrence of epilepsy in some families. Seven patients underwent anterior temporal resection: two patients with unilateral subependymal and focal subcortical heterotopias were seizure free or significantly improved. Four patients, three with PNH alone and one with additional subcortical nodules, did not improve significantly after surgery. The remaining patient was followed for less than 6 months.

Autosomal-recessive inheritance, severe to profound sensorineural hearing loss, and partial agenesis of the corpus callosum are hallmarks of the clinically well-established Chudley-McCullough syndrome (CMS). Although not always reported in the literature, frontal polymicrogyria and gray matter heterotopia are uniformly present, whereas cerebellar dysplasia, ventriculomegaly, and arachnoid cysts are nearly invariant. Despite these striking brain malformations, individuals with CMS generally do not present with significant neurodevelopmental abnormalities, except for hearing loss. Homozygosity mapping and whole-exome sequencing of DNA from affected individuals in eight families (including the family in the first report of CMS) revealed four molecular variations (two single-base deletions, a nonsense mutation, and a canonical splice-site mutation) in the G protein-signaling modulator 2 gene, GPSM2, that underlie CMS. Mutations in GPSM2 have been previously identified in people with profound congenital nonsyndromic hearing loss (NSHL). Subsequent brain imaging of these individuals revealed frontal polymicrogyria, abnormal corpus callosum, and gray matter heterotopia, consistent with a CMS diagnosis, but no ventriculomegaly. The gene product, GPSM2, is required for orienting the mitotic spindle during cell division in multiple tissues, suggesting that the sensorineural hearing loss and characteristic brain malformations of CMS are due to defects in asymmetric cell divisions during development.

Ritscher-Schinzel or “cranio-cerebello-cardiac“ (3C) syndrome is a rare autosomal recessive syndrome characterized by craniofacial, cerebellar and cardiac anomalies. Central nervous system anomalies include Dandy-Walker malformation, cerebellar vermis hypoplasia and enlargement of the cisterna magna. Ritscher-Schinzel syndrome is listed as a very rare disease by the Office of Rare Diseases (ORD) of the National Institutes of Health and so far only about 30 cases are reported all over the world, mostly from North America and Europe. We present a case of young male patient born in 1972, who was, soon after his birth, operated due to cleft palate, and afterwards because of ventricular septal defect. From 1989 he has been treated due to epilepsy with signs of psychomotor retardation. In 2008 brain CT revealed Dandy-Walker malformation. In March 2009 he was hospitalized in the Department of Neurology of the University Hospital Centre Zagreb, where brain MRI confirmed described malformation with enlargement of the posterior fossa by cystic formation and aplasia of the caudal part of cerebellar vermis, as well as extensive bilateral subependymal areas of gray matter heterotopia. He clinically presented with craniofacial dysmorphism, syndactylia of 1st and 2nd finger on his right foot, flexion contractures of the distal phalanges of 2nd and 3rd finger on the both hands, and thoracic scoliosis. X-ray examination also revealed hypoplasia of the 1st right rib, congenital block of C6-C7 vertebral bodies and sinistroconvex scoliosis of thoracal segment. Based on clinical examination, neuroradiologic and radiologic diagnostic procedures we believe that our patient fills all necessary criteria for the diagnosis of Ritscher-Schinzel syndrome. So far he is the oldest patient described in the literature, and first described patient in Croatia.

Magnetic resonance (MR) images and clinical records of 20 patients with gray matter heterotopias were retrospectively reviewed to correlate MR characteristics of the heterotopias with clinical findings. On the basis of the MR images, patients were divided into three groups: those with subependymal heterotopias (eight patients), focal subcortical gray matter heterotopias (six patients), and diffuse subcortical heterotopias (six patients). Patients with subependymal heterotopias had a significantly higher prevalence of normal development than patients in the other two groups (P = .02). When all patients with gray matter heterotopias were considered, patients with thick heterotopias and those with overlying cortical gyral anomalies, which correlated with one another, had a significantly higher prevalence of developmental delay (P = .002). Patients with thick focal gray matter heterotopias had a substantially increased prevalence of motor dysfunction. In three cases, gray matter heterotopias were associated with infoldings of dysplastic cortex containing blood vessels or cerebrospinal fluid. If not properly analyzed, these anomalies can be mistaken for vascular or cystic tumors.

With the advent of magnetic resonance imaging, there has been an increased recognition of schizencephaly during life, especially in epileptic patients. We report our experience with the assessment and treatment of three patients with medically intractable seizures associated with this condition. The three men were aged 24 to 37 years. Two had delayed developmental milestones and hemiparesis or hemiplegia. One had normal development and a normal neurological examination. Seizures began between the ages of 15 and 19 years and lasted for 5 to 22 years before surgery. All had partial simple or generalized seizures with predominant electroencephalographic and electrocorticographic epileptic activity localized to temporal and frontal lobes on the side of the lesion. Neuropsychological assessment indicated widespread dysfunction maximal at the areas of predominant electroencephalographic abnormality. Magnetic resonance imaging demonstrated anterior parasagittal, parietal, and Rolandic cerebral clefts, with ventricular diverticuli, gray matter heterotopia, polymicrogyria, and a true agenesis of the corpus callosum in individual patients. The patients underwent temporal (one patient) and frontotemporal (two patients) lobectomies without additional neurological deficits or neuropsychological deterioration. Postoperative follow-up showed reduction in seizure frequency. We conclude that the surgical treatment of epilepsy is well tolerated in such patients, and their seizures can be alleviated by resection of epileptogenic areas.

A 25-year-old woman underwent interictal F-18 FDG PET for evaluation of long-standing intractable epilepsy. She had no sign or family history of tuberous sclerosis, and she demonstrated no interictal neurologic deficit. PET showed periventricular and deep white matter FDG metabolism that was congruent anatomically to the pattern of nodular gray matter heterotopia (GMH) demonstrated on MRI. This case adds information concerning the spectrum of interictal FDG metabolism within GMH, when it is performed without activation task. It further illustrates the importance of recognizing GMH to avoid their misinterpretation as independent, subclinical ictal foci.

A 36-year-old right-handed woman with a 24-year history of medically refractory complex-partial seizures described as spells of staring and lip licking was referred for brain SPECT imaging. Tomographic imaging after intravenous administration of Tc-99m HMPAO and acetazolamide revealed abnormal focal areas of increased radiopharmaceutical accumulation in the white matter of the occipital region located at and above the level of the right lateral ventricle posteriorly. A magnetic resonance imaging (MRI) study performed for comparison showed multiple corresponding foci of ectopic gray matter. This report reveals the utility of SPECT imaging in the localization of double cortex in patients with longstanding seizure disorders.

Extensive lesions involving the posterior quadrant of the cerebral hemisphere (temporal, parietal, and occipital lobes) induce intractable epilepsy. These patients are potential candidates for surgical treatment[1]. Maintenance of isolated nerve tissue activity after surgery plays a crucial role in the neuroprotective effects of neurosurgery treatment. Disconnection surgery of the posterior quadrant is used to completely isolate nerve fibers, while blood supply at the isolated lobes is maintained. Subsequently, cavities caused by cystic or necrotic nerve tissues should be reduced as much as possible, to maintain the activity of isolated nerve tissue[1,2,3,4]. In this study, we selected two patients with temporal-parietal-occipital intractable epilepsy, from the Department of Neurosurgery, Tianjin Huanhu Hospital and Tianjin Neurological Institute (Tianjin, China), between February and May in 2012. The two cases underwent post quadrant disconnection. After surgery, activity of temporal-parietal-occipital nerve tissue and the control of epileptic seizures were observed. Case 1: An 11-year-old male, was admitted to Tianjin Huanhu Hospital in February, 2012, and received surgery 1 week later. Postoperative follow-up was performed every 6 months. The medical history showed mild head injury when he was 5 years old, resulting from a scalp laceration without loss of consciousness. The first seizure occurred 1 year later, with the head turning towards the left side, without limb and trunk spasms. He was conscious, and the seizure stopped after 2 minutes. After the second attack, he was diagnosed and treated for epilepsy. Control of seizures failed after 3 anticonvulsant treatments, became refractory, and he still had one seizure per week, while being treated with a combination of 3 anticonvulsants. Preoperative physical examination showed left homonymous hemianopsia. Video-electroencephalography monitoring showed interictal spikes and slow wave complexes in the right central occipital region (Figure 1A1). Magnetic resonance imaging (MRI) of the brain revealed right occipital congenital porencephaly (Figure 1A2). Based upon these findings, this case was diagnosed as simple partial epilepsy. The left hemisphere was not involved during the seizure, because language function was not affected. Video-electroencephalography monitoring and brain imaging results, as well as the clinical features, identified the epileptogenic region as the right post quadrant. A right post quadrant disconnection was therefore performed. Figure 1 Electroencephalogram (EEG) and MRI changes of case 1, an 11-year-old male patient with temporal-parietal-occipital epilepsy, before and after posterior quadrant disconnection. After surgery, the patient orally received 300 mg of oxcarbazepine, twice a day, for an extended period. Follow-up was performed every 6 months. Six month postoperative electroencephalogram showed no epileptic waves (Figure 1B1). MRI revealed complete resection of the right posterior temporal-parietal-occipital lobes, and the majority of isolated brain tissue produced normal signals (Figure 1B2). Case 1 was followed-up for 22 months, during which time no aura or seizure was observed. Case 2: A 28-year-old female was admitted to Tianjin Huanhu Hospital in April, 2012, and received surgery 1 week later. Medical history showed no remarkable features such as brain injury or infection. The first attack occurred 6 months before admission, involving generalized tonic-clonic seizures and disturbance of consciousness, which continued for 1–2 minutes, and then stopped. She was diagnosed with epilepsy and received anticonvulsant medication after a secondary seizure 2 months before admission. However, the seizures were not controlled, and a brain CT scan at a local hospital revealed suspicious “gray matter heterotopia”. Preoperative physical examination showed no seizure attacks during 3 days of video-electroencephalography monitoring. Interictal electroencephalogram showed interrupted short-range low and middle amplitude waves in the right hemisphere. There were also some interictal spikes and slow wave complexes, especially in the temporal and parietal regions (Figure 2A1). MRI of the brain showed an irregular and abnormal signal isodensity with gry matter subendymal at the atrium of the right ventricle. Similar signals were also observed in the temporal horn of the ipsilateral ventricle under the ventricular ependyma (Figure 2A2). The neuroimaging and electroencephalogram therefore showed an epileptogenic focus at the posterior right hemisphere, and posterior quadrant disconnection was performed with the same surgical procedures as case 1. Figure 2 Electroencephalogram (EEG) and MRI changes of case 2, a 28-year-old female patient with temporal-parietal-occipital epilepsy, before and after posterior quadrant disconnection. After surgery, the patient orally received 500 g of sodium valproate, twice a day, for an extended period. A 6 month postoperative electroencephalogram showed no epileptic waves (Figure 2B1). MRI revealed complete resection of the right posterior quadrant, but nerve tissue still survived (Figure 2B2). Case 2 was followed up for 20 months, during which time no seizures were observed. The involved two patients were informed of the experimental scheme and risk prior to treatment, and both patients signed informed consents. Disconnection surgery of the posterior quadrant is used to cut nerve fibers between the posterior quadrant and the resting region in the hemisphere, isolating the epileptogenic zone at the posterior quadrant. In this study, we only partially removed the superior temporal gyrus (tissue width < 5 mm), so that the tissue could be isolated with less incision. A careful macroscopic examination was made to preserve arteries and veins while the incision was made, therefore the isolated lobe maintained a blood supply and survived. MRI scans of the two epileptic patients showed that the disconnected brain tissue still survived, the activity of temporal-parietal occipital nerve tissue was maintained, and nerve fibers were completely disconnected. The involved patients were followed-up for over 1 year after surgery, during which time the epilepsy was completely controlled.

Imaging findings of morphology and regional cerebral blood flow in two patients suffering from epileptic seizures are presented. CT and MRI revealed heterotopic gray matter as a probable structural correlate, causing the seizure disorder. 99mTc hexamethyl-propylenamine oxime (HM-PAO) SPECT demonstrated focally increased regional cerebral blood flow in both patients in the areas of their heterotopic lesions. Heterotopic and orthotopic gray matter seem to have similar features in terms of regional perfusion. A focally increased brain perfusion in interictal epileptic patients may indicate an underlying migration anomaly.

Trichothiodystrophy was diagnosed in a 3-year-old male presenting with speech delay, brittle hair, chronic neutropenia, and a history of febrile convulsions. Cranial magnetic resonance imaging revealed a focal subcortical and periventricular gray matter heterotopia. An acute encephalopathy with status epilepticus and coma occurred when he was 4 years of age during an upper respiratory tract infection. Magnetic resonance imaging revealed multifocal T2-weighted hypersignal lesions involving mainly the thalami, hippocampi, midbrain, and pons. Analysis of cerebrospinal fluid revealed hyperproteinorachia without pleocytosis. Results of an extensive metabolic evaluation of this acute brain injury, resembling the syndrome of acute necrotizing encephalopathy of childhood described in Japan, were negative. Focal neuronal migration disorder and acute encephalopathy with symmetric thalamic involvement are newly described neurologic manifestations of syndromes with trichothiodystrophy, which suggests that these conditions may have a common genetic background.

Magnetic resonance imaging scans were visually inspected to investigate the incidence of gray matter heterotopia (GMH) in a group of 55 schizophrenic patients and a group of 75 control subjects. No GMHs were found in the control subjects. In the patient group, 1 GMH was found, an incidence of 1.8%.

Background: Subcortical nodular heterotopia is a neuronal migration disorder of uncertain etiology. This disorder occurs primarily in females and has a familial X-linked dominant inheritance pattern. The predominant symptom associated with heterotopia is seizures. Case: At 23 weeks’ gestation, prenatal sonography disclosed an isoechoic supratentorial intracranial mass causing right-sided shift of midline structures and compression of the contralateral cerebral ventricle. Serial ultrasound examinations of this mass were significant for the absence of invasion into surrounding structures, gross enlargement of cranial biometric parameters, and hydrocephalus and hydrops fetalis. Neonatal magnetic resonance imaging findings were consistent with gray matter heterotopia and were confirmed as such by brain biopsy. Conclusion: Subcortical nodular heterotopia manifested unique prenatal sonographic findings. This case suggests the possibility of prenatal diagnosis in families at risk for this lesion.