Our findings suggest that severity of white matter ischemic changes is correlated with worse cognitive function, as well as advanced age and higher blood pressure.A higher vulnerability of frontal white matter to vascular disease seems to play an important role in executive dysfunction, mainly determined by impairment of attentional skills.DWI results suggest this could be true even for NAWM.
SUMMARYHypothalamic hamartomas (HHs) have been demonstrated as the cause of gelastic epilepsy, both by intracranial electrodes and functional imaging. The neocortex becomes secondarily involved, through poorly characterized propagation pathways. The detailed dynamics of seizure spread have not yet been demonstrated, owing to the limited spatial-temporal resolution of available functional mapping. We studied a patient with epilepsy associated with HH and gelastic epilepsy. Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) of several seizure events were obtained, with blood oxygen level dependent (BOLD) activation of the hamartoma, and left hemisphere hypothalamus, hippocampus, parietal-occipital area, cingulate gyrus, and dorsal-lateral frontal area. Integration of regional BOLD kinetics and EEG power dynamics strongly suggests propagation of the epileptic activity from the HH through the left fornix to the temporal lobe, and later through the cingulate fasciculus to the left frontal lobe. The EEG ⁄ fMRI method has the spatial-temporal resolution to study the dynamics of seizure activity, with detailed demonstration of origin and propagation pathways.
Summary:Purpose: Occipital lobe epilepsy (OLE) presents in childhood with different manifestations, age of onset and EEG features that form distinct syndromes. The ictal clinical symptoms are difficult to correlate with onset in particular areas in the occipital lobes, and the EEG recordings have not been able to overcome this limitation. The mapping of epileptogenic cortical regions in OLE remains therefore an important goal in our understanding of these syndromes.Methods: In this work, three patients with two types of idiopathic childhood OLE were studied with EEG source analysis and also with mapping of the BOLD effect associated with spikes in simultaneous EEG/fMRI recordings.Results: Two patients with late onset OLE provided EEG source localizations in the lateral parietal cortex and in the medial occipital areas. The BOLD activations were more consistent and restricted to the medial parietal-occipital cortex in both cases. One patient with photosensitive idiopathic OLE presented with dipole sources in the medial parietal cortex, but the BOLD activations were widespread over inferior and bilateral occipital areas and also posterior temporal ones. There was little spatial overlap between the EEG and BOLD results, but the localizations suggested by the latter are more consistent with the ictal clinical manifestations of each type of epileptic syndrome.Conclusions: Overall, the BOLD effect associated with interictal spikes maps epileptogenic areas to different localizations than the ones suggested by EEG source analysis. These maps are similar in two patients with late onset idiopathic OLE, but different from a case of photosensitive idiopathic OLE. Key Words: Epilepsy-Occipital lobe-BOLD.The occipital lobe epilepsies (OLEs) of childhood are a heterogeneous group of diseases with diverse clinical symptoms, age of onset and prognosis (1). The EEG helps in the localization of epileptic activity to the occipital lobes, but it is not syndrome-specific and very often the abnormalities also involve the parietal and temporal areas (1). The topography of spikes rarely points to the particular region in the occipital lobes originating the seizures and the few attempts to do source analysis did not improve the generally poor electroclinical correlation (2). In the case of idiopathic epilepsies, where brain imaging is normal, the particular regions of seizure onset remain unknown, despite the consistent clinical picture of each syndrome.The detection of the BOLD effect associated with the occurrence of interictal spikes in simultaneous EEG/fMRI recordings offers a promising way to detect the epileptic neuronal dysfunction with high spatial resolution (3). Some studies with this method have been done in symp- METHODS AND SUBJECTSThree patients with the diagnosis of idiopathic OLE from the outpatient clinic of the Pediatric Neurology Department of Hospital Dona Estefânia were submitted to a 60-min EEG recording outside the scanner, including a sleep period, with a cap of 36 AgCl electrodes
Objectives. To test the relation between white matter lesions (WML) location and physical performance, in aged patients. Methods. Subjects: 29 patients (17 males), aged >65 (mean age 72.6 ± 5.2), with leukoaraiosis. WML was quantified with a visual scale; Apparent Diffusion Coefficient (ADC) was measured bilaterally in frontal periventricular lesioned white matter and frontal and parieto-occipital normal appearing white matter (NAWM). Motor performance was studied using the Short Physical Performance Battery (SPPB), single leg stand time, finger tapping and grooved pegboard tests (GPT). Results. There were significant correlations between the frontal region visual scale scores and SPPB chair stands (r = −0.379; P = .039) and Grooved Pegboard (r = 0.393; P = .032); frontal NAWM ADC values and SPPB standing balance (r = −0.450; P = .014) and SPPB 4 meter walk (r = −0.379; P = .043). Conclusion. Frontal WML are negatively related to motor performance in patients with leukoaraiosis. DWI results suggest that this may be true even for NAWM.
Summary:The Panayiotopoulos type of occipital lobe epilepsy has generated great interest, but the particular brain areas involved in the peculiar seizure manifestations have not been established. We studied a patient with the syndrome, using highresolution EEG and simultaneous EEG and functional magnetic resonance imaging (fMRI). Resolution of the scalp EEG was improved using a realistic spline Laplacian algorithm, and produced a complex distribution of current sinks and sources over the occipital lobe. The spike-related blood oxygen level dependent (BOLD) effect was multifocal, with clusters in lateral and inferior occipital lobe and lateral and anterior temporal lobe. We also performed regional dipole seeding in BOLD clusters to determine their relative contribution to generation of scalp spikes. The integrated model of the neurophysiologic and vascular data strongly suggests that the epileptic activity originates in the lateral occipital area, spreading to the occipital pole and lateral temporal lobe. Key Words: Epilepsy-Occipital lobe-BOLD-Childhood.The most common syndrome of idiopathic occipital lobe epilepsy (IOLE) has been a source of puzzling questions since its description by Panayiotopoulos (Panayiotopoulos, 1989). The cardinal ictal manifestations of vomiting, eye deviation and long periods of interruption of consciousness, with rare visual symptoms, constitutes an unusual constellation of symptoms and up to now very little is known about the particular cortical structures involved in their generation. The consistent clinical picture in affected children suggests that a common epileptic network is at work and persists with little change throughout the evolution of the syndrome. The variability of the EEG (Panayiotopoulos, 2002) CASE REPORTA healthy 11-year-old boy, with no previous history of seizures, was found with the eyes turned to one side, not responding to verbal stimulation and a pale face, while resting in the beach. He recovered normal behavior after a few minutes. Hours later, while resting in a sofa, he repeated the symptoms, which also lasted for a few minutes. Medical evaluation at an emergency department half an hour later failed to find any abnormality and he was discharged with an EEG booked for the next day.The EEG revealed almost continuous spike activity over the left posterior areas, and he was admitted to the Intensive Care Unit for vigilance, despite the fact that he remained alert and with a normal neurological status. No evidence supporting persisting clinical seizures was found.An ambulatory device using the full 10-20 system was used to monitor continuously the EEG (24 h). The prominent left posterior spike activity with the eyes closed was confirmed, as well as its striking decrease while recording with the eyes open, which led to he diagnosis of IOLE. The patient was medicated with sodium valproate and remains seizure-free after 6 months. 1179
Cerebellar apparent diffusion coefficient (ADC) was found to be increased after acute cerebral hemispheric stroke. There are no data on cerebellar ADC changes in patients with chronic, age-related white matter lesions (ARWML). We aimed to determine longitudinal ADC variations on cerebral hemispheric and cerebellar white matter regions of patients with ARWML in order to study relations between ADC changes in both regions. ADC was measured serially (1-year interval) on lesioned periventricular frontal white matter, frontal and parietoccipital normal appearing white matter and middle cerebellar peduncles, on 19 aged patients with ARWML, which also underwent gait assessment. We compared regional ADC at 0 and 1 year and calculated variation percentages for each region. Correlation analysis was made between ADC variation in cerebellar regions and in contralateral hemispheric regions and between cerebellar ADC at 1 year and walking speed. After 1 year, ADC was higher on lesioned periventricular frontal white matter and lower on cerebellar regions. ADC variations on these regions were negatively correlated. Cerebellar ADC measured after 1 year was positively correlated with walking speed. This suggests a link between vascular disease progression inside frontal lesions and ADC reduction in contralateral cerebellar peduncles. Chronic ischemia in frontal white matter could have interrupted frontal-cerebellar circuits, producing hypometabolism in cerebellar regions (and worse performance on motor tasks), decreased perfusion and hence ADC reduction.
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