Epilepsy

Factors Associated With Epilepsy in Children With Periventricular Leukomalacia

by Raywat Deonandan

Children with cerebral palsy associated with periventricular leukomalacia frequently develop unprovoked epileptic... more Children with cerebral palsy associated with periventricular leukomalacia frequently develop unprovoked epileptic seizures. This article reports an analysis of risk factors for epilepsy in children with radiologically confirmed periventricular leukomalacia. This cohort was screened for epilepsy and for an array of clinical and demographic factors. Of 154 subjects with radiologically confirmed periventricular leukomalacia, 40 (26.0%) had epilepsy. In the epileptic group, radiologic pathology other than periventricular leukomalacia was uncommon. Significant associations were found between epilepsy and cerebral palsy patterns other than spastic diparesis, mental handicap, cortical visual impairment, neonatal seizures, and severe periventricular leukomalacia. Only the presence of neonatal seizures was significantly associated with epilepsy once other risk factors were controlled in the regression model. Some previous studies have shown an association between neonatal seizures and later epilepsy for cerebral palsy in general. This is the first report of such an association for a single predominant type of cerebral pathology.

The development of intellectual abilities in pediatric temporal lobe epilepsy

by francesca cormack

Memory in paediatric temporal lobe epilepsy: effects of lesion type and side

by francesca cormack

Surface-based multi-template automated hippocampal segmentation: application to temporal lobe epilepsy

by Hosung Kim

Hosung Kim, Tommaso Mansi, Neda Bernasconi, Andrea Bernasconi
Manuscript accepted in Medical Image Analysis

In drug-resistant temporal lobe epilepsy (TLE), detecting hippocampal atrophy on MRI is crucial as it allows defining... more In drug-resistant temporal lobe epilepsy (TLE), detecting hippocampal atrophy on MRI is crucial as it allows defining the surgical target. In addition to atrophy, about 40% of patients present with malrotation, a developmental anomaly characterized by atypical morphologies of the hippocampus and collateral sulcus. We have recently shown that both atrophy and malrotation impact negatively the performance of single averaged- and multi-template volume-based techniques. Here, we propose a novel hippocampal segmentation algorithm (SurfMulti) that integrates deformable parametric surfaces, vertex-wise modeling of locoregional texture and shape, and multiple templates in a unified framework. To account for inter-subject variability, including shape variants, we used a library derived from a large database of healthy (n=80) and diseased (n=288) hippocampi. To quantify malrotation, we generated 3D models from manual hippocampal labels and automatically extracted collateral sulci. The accuracy of SurfMulti was evaluated relative to manual labeling and segmentation obtained through a volume-based multi-template approach (Vol-multi) using the Dice similarity index and surface-based shape mapping, for which we computed vertex-wise displacement vectors between automated and manual segmentations. We then correlated segmentation accuracy with malrotation features and atrophy. SurfMulti outperformed Vol-multi and achieved a level of accuracy in TLE patients (Dice=86.9%) virtually identical to healthy controls (Dice=87.5%). Vertex-wise shape mapping showed that SurfMulti had an excellent overlap with manual labels, with sub-millimetric precision. Its performance was not influenced by atrophy or malrotation (|r|<0.20, p>0.2), while Vol-multi was hampered by both anomalies (|r|>0.28, p<0.05). The magnitude of atrophy detected using SurfMulti was the closest to manual volumetry (Cohen's d: manual=1.71, t=7.6; SurfMulti=1.60, t=7.0; Vol-multi=1.38, t=6.1). The high performance of SurfMulti regardless of cohort, atrophy and shape variants identifies this algorithm as a robust segmentation tool for hippocampal volumetry.

Aversion to patterns and cortical hyperexcitability in migraine.

by Sarah M Haigh

Haigh, S. M., Karanovic, O., Wilkinson, F., and Wilkins, A. J. (2011). Aversion to patterns and cortical hyperexcitability in migraine. Cephalalgia, 32, 236-240.

Background: Patients with migraine are averse to certain visual stimuli, such as flicker and striped patterns that... more Background: Patients with migraine are averse to certain visual stimuli, such as flicker and striped patterns that evoke paroxysmal EEG activity in patients with photosensitive epilepsy. Migraineurs demonstrate a hyper-responsiveness to such stimuli, and there is debate as to whether the aversion and hyper-responsiveness are due to a hyperexcitability of the cortex similar to that in patients with photosensitive epilepsy. In these patients grating patterns with certain spatial characteristics can be epileptogenic, depending critically on their movement. If the contours of the grating drift continually, the grating is not epileptogenic, but if the contours are static or if their direction is repeatedly and rapidly reversed so as to vibrate, the grating then becomes highly epileptogenic.
Methods: We compared aversion to vibrating, drifting and static gratings in migraineurs and controls. The contrast of each grating was gradually increased, but only until the participant felt discomfort, so as to obtain a contrast threshold for aversion with minimal exposure.
Results: Migraineurs had lower thresholds than the Control Group, indicating greater aversion. For both groups the threshold was higher (aversion was lower) for static than for both types of moving gratings. The drifting gratings were more aversive than the vibrating gratings when both groups were combined.
Conclusion: The findings suggest that the aversion shown by migraineurs is not attributable to a cortical hyperexcitability similar to that in photosensitive epilepsy.

Asymmetric cortical surface area and morphology changes in mesial temporal lobe epilepsy with hippocampal sclerosis

by Lena Palaniyappan

Saud Alhusaini1, 2, Colin P Doherty3, Lena Palaniyappan4, Cathy Scanlon2, 5, Sinead Maguire6, Paul Brennan6, Norman Delanty1, 7, Mary Fitzsimons2, Gianpiero L Cavalleri1

Epilepsia, in press

1 Molecular and Cellular Therapeutics Department, Royal College of Surgeons in Ireland, Dublin.2, Ireland.
2 Brain Morphometry Laboratory, Neurophysics Department, Beaumont Hospital, Dublin.9, Ireland.
3 Neurology Department, St. James’s Hospital, Dublin.8, Ireland.
4 Division of Psychiatry, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom
5 Clinical Neuroimaging Laboratory, Department of Psychiatry, National University of Ireland, Galway, Ireland.
6 Radiology Department, Beaumont Hospital, Dublin.9, Ireland.
7 Neurology Department, Beaumont Hospital, Dublin.9, Ireland

Cognitive development in Dravet syndrome: A retrospective, multicenter study of 26 patients

by Alessio Toraldo

Ragona F., Granata T., Dalla Bernardina B., Offredi F., Darra F., Battaglia D., Morbi M., Brazzo D., Cappelletti S., Chieffo D., De Giorgi I., Fontana E., Freri E., Marini C., Toraldo A., Specchio N., Veggiotti P., Vigevano F., Guerrini R., Guzzetta F., Dravet C. (2011). Epilepsia, 52, 386-392.

PURPOSE:
To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients... more PURPOSE:
To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients with Dravet syndrome.
METHODS:
In this retrospective study, we reviewed the clinical history and cognitive development of 26 patients who had been followed with standardized evaluations since seizure onset. The cognitive outcome was quantified as differential general quotient (dGQ) between ages 12 and 60 months. Statistical analysis correlated the dGQ with genotype and epilepsy course.
KEY FINDINGS:
Epilepsy started at the mean age of 5.6 months. All patients experienced prolonged convulsive seizures, whereas absences and myoclonus were reported in 17. Cognitive outcome was poor in almost all patients; the mean dGQ was 33 points, varying from 6-77 points. The analysis of individual cognitive profiles identified seven patients in whom the dGQ was <20 points; the main clinical characteristic in this subset of patients was lack of early absences and myoclonus. The statistical analysis of the whole series failed to reveal significant differences in cognitive outcome with regard to the presence of SCN1A mutations and their type. In particular, mutation-carrier patients with the best cognitive outcome harbored either missense or truncating mutations.
SIGNIFICANCE:
Dravet syndrome encompasses different epileptic and cognitive phenotypes that probably result from both genetic and epigenetic factors. In this series, early appearance of myoclonus and absences was associated with the worst cognitive outcome.

Cognitive development in Dravet syndrome: A retrospective, multicenter study of 26 patients

by Alessio Toraldo

Ragona F., Granata T., Dalla Bernardina B., Offredi F., Darra F., Battaglia D., Morbi M., Brazzo D., Cappelletti S., Chieffo D., De Giorgi I., Fontana E., Freri E., Marini C., Toraldo A., Specchio N., Veggiotti P., Vigevano F., Guerrini R., Guzzetta F., Dravet C. (2011). Epilepsia, 52, 386-392.

PURPOSE:
To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients... more PURPOSE:
To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients with Dravet syndrome.
METHODS:
In this retrospective study, we reviewed the clinical history and cognitive development of 26 patients who had been followed with standardized evaluations since seizure onset. The cognitive outcome was quantified as differential general quotient (dGQ) between ages 12 and 60 months. Statistical analysis correlated the dGQ with genotype and epilepsy course.
KEY FINDINGS:
Epilepsy started at the mean age of 5.6 months. All patients experienced prolonged convulsive seizures, whereas absences and myoclonus were reported in 17. Cognitive outcome was poor in almost all patients; the mean dGQ was 33 points, varying from 6-77 points. The analysis of individual cognitive profiles identified seven patients in whom the dGQ was <20 points; the main clinical characteristic in this subset of patients was lack of early absences and myoclonus. The statistical analysis of the whole series failed to reveal significant differences in cognitive outcome with regard to the presence of SCN1A mutations and their type. In particular, mutation-carrier patients with the best cognitive outcome harbored either missense or truncating mutations.
SIGNIFICANCE:
Dravet syndrome encompasses different epileptic and cognitive phenotypes that probably result from both genetic and epigenetic factors. In this series, early appearance of myoclonus and absences was associated with the worst cognitive outcome.

Beneficial effects of desacyl-ghrelin, hexarelin and EP-80317 in models of status epilepticus

by Fabio Gualtieri

Explicit and implicit emotional processing modifications in pharmacoresistant left temporal lobe epilepsy and anxiodepressive disorders

by Nathalie Bedoin

We examined whether anxiodepressive patients with left temporal lobe epilepsy could be differentiated from those with... more We examined whether anxiodepressive patients with left temporal lobe epilepsy could be differentiated from those with depression but without epilepsy on tasks that investigate attentional bias toward and explicit judgment of emotional stimuli. Eight depressive patients, eight anxiodepressive patients with epilepsy, and eight controls participated in the present study. Anxiodepressive with epilepsy and depressive patients had comparable depression scores and the same cognitive profile. Two distinct emotional tasks were used: the decision lexical task and the number comparison task. Three emotional connotations were presented: neutral, positive, and negative. The pattern of results showed an attentional bias toward negative words and pictures in depressive patients and only toward negative words in anxiodepressive patients with epilepsy. Moreover, depressive patients explicitly judged negative stimuli with lower intensity and anxiodepressive patients judged neutral stimuli with higher intensity. The present study specifies the emotional functioning in depression with or without left temporal lobe epilepsy.

Atypical hemispheric asymmetries for the processing of phonological features in children with rolandic epilepsy

by Nathalie Bedoin

We assessed language lateralization in 177 healthy 4- to 11-year-old children and adults and atypical
asymmetries... more We assessed language lateralization in 177 healthy 4- to 11-year-old children and adults and atypical
asymmetries associated with unilateral epileptic foci in 18 children with benign epilepsy with centrotemporal
spikes (BECTS). Dichotic listening results revealed two indices of immature functional asymmetry when the
focus was left-sided (BECTS-L). First, children with BECTS-L did not show left hemisphere dominance for the
processing of place of articulation, which was recorded in children with BECTS-R and control children. On the
contrary, healthy children exhibited a gradual increase in left hemisphere dominance for place processing
during childhood, which is consistent with the shift from global to finer-grained acoustic analysis predicted by
the Developmental Weighting Shift model. Second, children with BECTS-L showed atypical left hemisphere
involvement in the processing of the voiced value (+V), associated with a long acoustic event in French stop
consonants, whereas right hemisphere dominance increased with age for +V processing in healthy children.
BECTS-L, therefore, interferes with the development of left hemisphere dominance for specific phonological
mechanisms.

Perception and Comprehension of Linguistic and Affective Prosody in Children with Landau-Kleffner Syndrome

by Emmanuel Ferragne

A novel prosody assessment test: Findings in three cases of Landau–Kleffner syndrome

by Emmanuel Ferragne

Atypical hemispheric asymmetries for the processing of phonological features in children with rolandic epilepsy

by Emmanuel Ferragne

Improved Neuronavigation through Integration of Intraoperative Anatomical and Diffusion Images in an Interventional MRI Suite

by Pankaj Daga

Integration of information from complementary imaging modalities in medical image registration schemes potentially... more Integration of information from complementary imaging modalities in medical image registration schemes potentially improves the registration accuracy. MRI is now being used for guidance of various neurosurgical procedures like anterior temporal lobe resection in patients with refractory temporal lobe epilepsy. Accurate localisation of critical white matter tracts, such as the optic radiation, during neurosurgery is critical in ensuring good patient outcome. Current commercial interventional MR scanners are capable of performing anatomical and diffusion weighted imaging. We propose a near real-time multivariate registration scheme that uses both anatomical and diffusion images from the pre and intraoperative imaging sessions. The registration framework is optimized for use on graphical processing units and we perform a full multivariate non-rigid registration in under three minutes making the proposed framework suitable for use under the stringent time constraints of neurosurgical procedures. We assess the accuracy of our algorithm using a numerical phantom and demonstrate accurate localisation of the optic radiation in clinical datasets. This work could be of significant utility in image guided interventions and facilitate effective surgical treatments.

Integrating structural and diffusion MR information for optic radiation localisation in focal epilepsy patients

by Pankaj Daga

Current state of the art neurosurgical systems do not exploit the complementary information provided by structural and... more Current state of the art neurosurgical systems do not exploit the complementary information provided by structural and diffusion MRI when aligning pre-operative and intra-operative images. We propose a multivariate registration scheme where structural and fractional anisotropy data are combined in a single similarity measure. We formulate the normalised mutual information expression for the multichannel scheme and compute its analytical derivative. The method was validated using both a numerical phantom and clinical data using pre and post-operative images from patients who had undergone surgery for treatment of refractory focal epilepsy and shows correlation between visual field deficit and predicted damage to the optic radiation. This work could be of significant utility in image-guided interventions and facilitate effective surgical treatments.

Basal temporal sulcal morphology in healthy controls and patients with temporal lobe epilepsy

by Hosung Kim

Hosung Kim, N. Bernasconi, B. Bernhardt, O. Colliot and A. Bernasconi
Neurology 2008; 70(22, Pt2), 2159-2165

Background: We previously demonstrated that shape variants of the hippocampal formation are more prevalent in patients... more Background: We previously demonstrated that shape variants of the hippocampal formation are more prevalent in patients with temporal lobe epilepsy (TLE) than in healthy individuals.

Objective: To categorize sulcal patterns of the basal temporal lobe in TLE compared to healthy controls.

Methods: We studied 51 healthy controls and 69 patients with TLE (37 left, 32 right TLE). Brain sulci were identified and labeled automatically on MRI using an algorithm based on a congregation of neural networks that allows mapping three-dimensional sulcal models on the cortical surface. We used four sulcal patterns classes to categorize the sulcal arrangement in the inferior surface of the temporal lobe in each subject: Type 1, i.e., single-branch, unbroken collateral sulcus (CS) connected with the rhinal sulcus (RS) anteriorly; Type 2, i.e., CS connected with the occipitotemporal sulcus (OTS), but separated from the RS; Type 3, i.e., CS separated from the OTS and RS, which are connected; and Type 4, i.e., CS, OTS and RS separated.

Results: In healthy controls, Type 1 and Type 2 were the patterns seen most frequently. Overall, 82% (42/51) of subjects had the same sulcal pattern in both temporal lobes. Inter-rater reliability for 35 randomly selected subjects indicated excellent agreement (Cohen's Kappa: 0.84). Compared to controls, we found an increased frequency of Type 1 CS in patients with TLE, both in the left (77% vs 47%, p = 0.004) and the right hemispheres (72% vs 41%, p = 0.002). On the other hand, we found a decreased frequency of Type 2 CS in patients with TLE, both in the left (4% vs 31%, p = 0.00002) and the right hemisphere (4% vs 35%, p < 0.00001).

Conclusions: A single-branch, unbroken collateral sulcus is the predominant sulcal pattern found in temporal lobe epilepsy. This “simplified” arrangement may be an indicator of neurodevelopmental deviance associated with this condition.

Disturbed dreaming in medical conditions (2004)

by Tore Nielsen

The human K-complex represents an isolated cortical down-state

by Nima Dehghani

Pattern of trauma determines the threshold for epileptic activity in a model of cortical deafferentation

by Vladislav Volman