The "band heterotopia" or "double cortex" is a brain anomaly that is presumed to result from a premature arrest of neuronal migration. Patients with this anomaly are reported to have a variable clinical course that has been, heretofore, unpredictable. The clinical records and magnetic resonance (MR) imaging studies of 27 patients with band heterotopia were retrospectively reviewed in an attempt to determine whether imaging findings are useful in predicting clinical outcome of affected patients. Statistical analyses revealed the following correlations: (1) severity of T2 prolongation in the brain with motor delay (p = 0.03); (2) degree of ventricular enlargement with the age of seizure onset (p = 0.04), and with development and intelligence (p = 0.04); (3) severity of pachygyria with the age of seizure onset (p = 0.01), seizure type (p = 0.03), and an abnormal neurologic examination (p = 0.002); (4) parietal involvement with delayed speech development (p = 0.05); (5) occipital involvement with age of seizure onset (p = 0.006); (6) age of seizure onset with development and intelligence (p = 0.03) and with an abnormal neurologic examination (p = 0.04); and (7) severity of the pachygyria and thickness of band with development of symptomatic generalized epilepsy (p = 0.002 and p = 0.02, respectively) and Lennox-Gastaut syndrome (p = 0.002 and p = 0.01, respectively).

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Purpose: Recent data suggest that methylation of the DNA repair gene O 6 -methylguanine DNA methyltransferase (MGMT), by increasing the chemosensitivity of glioblastoma multiforme, is significantly associated with improved prognosis. Results in contradiction with these findings, however, are present in the literature and the clinical and genetic context framing MGMT methylation is poorly characterized. Experimental Design: To address these issues, we have investigated the MGMT methylation status, clinical and magnetic resonance imaging characteristics, and relevant genetic features (loss of heterozygosity on17p and19q, EGFR amplification, and p53 mutations) in a retrospective study on 86 patients affected by glioblastoma multiforme: 72 patients had a clinical history indicating de novo insurgence of the tumor and the remaining 14 were secondary glioblastoma multiforme. Results: MGMT methylation was detected by methylation-specific PCR in 41 of 86 cases (47.7%; Meth+). Progression-free survival and overall survival were significantly longer in Meth+ than in Meth-patients [10 versus 7 months (P = 0.003, log-rank test) and 18 versus 14 months (P = 0.0003, log-rank test), respectively]. Mixed-nodular enhancement at magnetic resonance imaging was significantly more frequent in Meth+ and secondary glioblastoma multiforme and ring enhancement in Meth-and primary glioblastoma multiforme (P < 0.005). MGMT methylation was more present in secondary glioblastoma multiforme (P = 0.006) and associated with loss of heterozygosity on 17p and/or 19q (P = 0.005). Conclusions: These observations suggest that MGMT methylation is part of a genetic signature of glioblastomas that developed from lower-grade gliomas.

Summary:Purpose. Periventricular nodular heterotopia (PNH) is among the most common malformations of cortical development, and affected patients are frequently characterized by focal drug-resistant epilepsy. Here we analyzed clinical, MRI, and electrophysiologic findings in 54 PNH patients to reevaluate the classification of PNH, relate the anatomic features to epileptic outcome, and ascertain the contribution of PNH nodules to the onset of epileptic discharges.Methods: The patients were followed up for a prolonged period at the Epilepsy Center of our Institute. In all cases, we related MRI findings to clinical and epileptic outcome and analyzed interictal and ictal EEG abnormalities. In one patient, EEG and stereo-EEG (SEEG) recordings of seizures were compared.Results: We included cases with periventricular nodules, also extending to white matter and cortex, provided that anatomic continuity was present between nodules and malformed cortex.Based on imaging and clinical data, patients were subdivided into five PNH groups: (a) bilateral and symmetrical; (b) bilateral single-noduled; (c) bilateral and asymmetrical; (d) unilateral; and (e) unilateral with extension to neocortex. The latter three groups were characterized by worse epileptic outcome. No differences in outcome were found between unilateral PNH patients regardless the presence of cortical involvement. Interictal as well as ictal EEG abnormalities were always related to PNH location.Conclusions: The distinctive clinical features and epileptic outcomes in each group of patients confirm the reliability of the proposed classification. Ictal EEG and SEEG recordings suggest that seizures are generated by abnormal anatomic circuitries including the heterotopic nodules and adjacent cortical areas.

Objective: Understanding residual brain function in disorders of consciousness poses extraordinary challenges, and imaging examinations are needed to complement clinical assessment. The default-mode network (DMN) is known to be dysfunctional, although correlation with level of consciousness remains controversial. We investigated DMN activity with resting-state functional magnetic resonance imaging (rs-fMRI), alongside its structural and metabolic integrity, aiming to elucidate the corresponding associations with clinical assessment. Methods: We enrolled 119 consecutive patients: 72 in a vegetative state/unresponsive wakefulness state (VS/UWS), 36 in a minimally conscious state (MCS), and 11 with severe disability. All underwent structural MRI and rs-fMRI, and a subset also underwent 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET). Data were analyzed with manual and automatic approaches, in relation to diagnosis and clinical score. Results: Excluding the quartile with largest head movement, DMN activity was decreased in VS/UWS compared to MCS, and correlated with clinical score. Independent-component and seed-based analyses provided similar results, although the latter and their combination were most informative. Structural MRI and FDG-PET were less sensitive to head movement and had better diagnostic accuracy than rs-fMRI only when all cases were included. rs-fMRI indicated relatively preserved DMN activity in a small subset of VS/UWS patients, 2 of whom evolved to MCS. The integrity of the left hemisphere appears to be predictive of a better clinical status. Interpretation: rs-fMRI of the DMN is sensitive to clinical severity. The effect is consistent across data analysis approaches, but heavily dependent on head movement. rs-fMRI could be informative in detecting residual DMN activity for those patients who remain relatively still during scanning and whose diagnosis is uncertain.

We describe two brothers aged 8 and 10 affected by severe bilateral schizencephaly, carrying an identical point mutation of the homeobox gene EMX2. Both children had severe neurologic deficits and mental retardation, although they differed in the anatomic extent of the brain malformation and in the severity of the clinical picture. The present findings, together with the reported cases of schizencephaly associated with EMX2 mutations, support the hypothesis that, at least in some cases, schizencephalies are determined by deleterious mutations of this homeobox gene. The different morphoclinical pictures suggest that, besides the EMX2 mutation, other factors are relevant in determining the severity of the brain malformation and clinical picture.

We suggest that white matter abnormalities in type IIb FCD are due to defects of the myelination processes and maturation, impaired by the presence of balloon cells. To reveal the presence and the border of type II cortical dysplasia on MRI, a quantitative ROI-based analysis (coefficient of variation) is also proposed.

L-2-hydroxyglutaric aciduria is a rare metabolic encephalopathy displaying a subcortical leukoencephalopathy on MRI. Diagnosis rests on detection of an abnormal accumulation of L-2-hydroxyglutaric acid in body fluids. The authors report on four patients who developed a malignant brain tumor during the course of the disease. This association points to a possible role of L-2-hydroxyglutaric aciduria in predisposing to brain tumorigenesis.