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W Van Paesschen

Publications and source records attributed to W Van Paesschen.

At least 19 recordsLinked to original sources
PubMed2006

Correlations of interictal FDG-PET metabolism and ictal SPECT perfusion changes in human temporal lobe epilepsy with hippocampal sclerosis.

BACKGROUND: The pathophysiological role of the extensive interictal cerebral hypometabolism in complex partial seizures (CPS) in refractory mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS) is poorly understood. Our aim was to study ictal-interictal SPECT perfusion versus interictal fluorodeoxyglucose (FDG)-PET metabolic patterns. METHODS: Eleven adults with refractory unilateral mTLE-HS, who were rendered seizure free after epilepsy surgery, were included. All had an interictal FDG-PET and an interictal and ictal perfusion SPECT scan. FDG-PET data were reconstructed using an anatomy-based reconstruction algorithm, which corrected for partial volume effects, and analyzed semi-quantitatively after normalization to white matter activity. Using Statistical Parametric Mapping (SPM), we compared interictal metabolism of the patient group with a control group. We correlated metabolic with ictal perfusion changes in the patient group. RESULTS: Global cerebral grey matter glucose metabolism in patients was decreased 10-25% compared with control subjects. Interictal PET hypometabolism and ictal SPECT hypoperfusion were maximal in the ipsilateral frontal lobe. Ictal frontal lobe hypoperfusion was associated with crossed cerebellar diaschisis. The ipsilateral temporal lobe showed maximal ictal hyperperfusion and interictal hypometabolism, which was relatively mild compared with the degree of hypometabolism affecting the frontal lobes. CONCLUSION: Interictal hypometabolism in mTLE-HS was greatest in the ipsilateral frontal lobe and represented a seizure-related dynamic process in view of further ictal decreases. Crossed cerebellar diaschisis suggested that there is a strong ipsilateral frontal lobe inhibition during CPS. We speculate that surround inhibition in the frontal lobe is a dynamic defense mechanism against seizure propagation, and may be responsible for functional deficits observed in mTLE.

Adult↗
PubMed2005

A novel susceptibility locus at 2p24 for generalised epilepsy with febrile seizures plus.

Generalised epilepsy with febrile seizures plus (GEFS+) is a clinically and genetically heterogeneous epilepsy syndrome. Using positional cloning strategies, mutations in SCN1B, SCN1A, and GABRG2 have been identified as genetic causes of GEFS+. In the present study, we describe a large four generation family with GEFS+ in which we performed a 10 cM density genome-wide scan. We obtained conclusive evidence for a novel GEFS+ locus on chromosome 2p24 with a maximum two point logarithm of the odds (LOD) score of 4.22 for marker D2S305 at zero recombination. Fine mapping and haplotype segregation analysis in this family delineated a candidate region of 3.24 cM, corresponding to a physical distance of 4.2 Mb. Linkage to 2p24 was confirmed (p = 0.007) in a collection of 50 nuclear and multiplex families with febrile seizures and epilepsy. Transmission disequilibrium testing and association studies provided further evidence (p < 0.05) that 2p24 is a susceptibility locus for febrile seizures and epilepsy. Furthermore, we could reduce the candidate region to a 2.14 cM interval, localised between D2S1360 and D2S2342, based upon an ancestral haplotype. Identification of the disease gene at this locus will contribute to a better understanding of the complex genetic aetiology of febrile seizures and epilepsy.

Chromosomes, Human, Pair 2↗
PubMed2004

Ictal SPECT.

The localizing value of ictal single-photon emission computed tomography (SPECT) performed with cerebral blood flow agents in patients with epilepsy is based on cerebral metabolic and perfusion coupling. Ictal hyperperfusion is used to localize the epileptogenic zone noninvasively, and is particularly useful in magnetic resonance (MR)-negative partial epilepsy and focal cortical dysplasias. Subtraction ictal SPECT coregistered with MRI (SISCOM) improves the localization of the area of hyperperfusion. Ictal SPECT should always be interpreted in the context of a full presurgical evaluation. Early ictal SPECT injections minimize the problem of seizure propagation and of nonlocalization due to an early switch from ictal hyperperfusion to postictal hypoperfusion during brief extratemporal seizures. The degree of thresholding of SISCOM images affects the sensitivity and specificity of ictal SPECT. Ictal hypoperfusion may reflect ictal inhibition or deactivation. Postictal and interictal SPECT studies are less useful to localize the ictal-onset zone. Statistical parametric mapping analysis of groups of selected ictal-interictal difference images has the potential to demonstrate the evolution of cortical, subcortical, and cerebellar perfusion changes during a particular seizure type, to study seizure-gating mechanisms, and to provide new insights into the pathophysiology of seizures.

Brain↗
PubMed2003

SPECT perfusion changes during complex partial seizures in patients with hippocampal sclerosis.

Cerebral perfusion changes reliably reflect changes in neuronal activity. Our aim was to obtain new insights into the pathophysiology of complex partial seizures (CPS) in patients with hippocampal sclerosis (HS) using interictal and ictal single photon emission computed tomography (SPECT). We studied 24 patients with refractory temporal lobe epilepsy (TLE) associated with HS. All had an interictal and ictal SPECT with early injection during a CPS. Images were normalized and co-registered. Using statistical parametric mapping (SPM99), brain regions with significant ictal perfusion changes were determined. To assess possible interrelationships between these regions, Pearson correlation coefficients were calculated. The temporal lobe ipsilateral to the seizure focus, the border of the ipsilateral middle frontal and precentral gyrus, both occipital lobes and two small regions in the contralateral postcentral gyrus showed ictal hyperperfusion. The frontal lobes, contralateral posterior cerebellum and ipsilateral precuneus showed hypoperfusion. Further exploratory analysis suggested an association between ipsilateral temporal lobe hyperperfusion and ipsilateral frontal lobe hypoperfusion, and an inverse association between seizure duration and hyperperfusion in the ipsilateral anterior cerebellum and contralateral postcentral gyrus. We conclude that there is a network of perfusion changes during CPS in patients with HS. Studying a particular seizure type in patients with HS with peri-ictal SPECT performed during a defined time window will allow further analysis of the cerebral network activities, and excitatory, inhibitory and gating mechanisms during seizures associated with HS.

Adult↗
PubMed2003

De novo cryptogenic refractory multifocal febrile status epilepticus in the young adult: a review of six cases.

BACKGROUND: Status epilepticus (SE) is a common neurological emergency. In around 10 percent, the etiology of SE is not clear, i.e. cryptogenic SE. AIM: To describe six young adult patients with de novo cryptogenic multifocal febrile SE with poor outcome. METHODS: Retrospective chart review. RESULTS: We describe six patients who presented with de novo SE. All were young adults with an unremarkable previous medical history. In all except one, the family history for epilepsy was negative. All had a febrile illness in the week preceding SE. Investigations were unable to reveal the underlying etiology. SE proved refractory to conventional antiepileptic drug treatment (AED) and anesthesia was required to control seizures. Seizures during SE or ensuing epilepsy were multifocal. Brain pathology in four patients was normal in two and showed changes secondary to seizures in two. Outcome was poor in all cases: one patient died during the course of SE, another patient remained with severe mental and physical disability as well as refractory epileptic seizures, the other four developed refractory multifocal epilepsy. One of these patients died a sudden unexpected death in epilepsy (SUDEP) and one drowned during a seizure. CONCLUSIONS: Six patients were reviewed who presented with de novo cryptogenic multifocal refractory febrile SE. The possible etiologies are discussed. Based on the similarities in these cases, a distinct refractory SE syndrome might be assumed. Further prospective studies will, however, be required to validate this hypothesis as well as to elucidate its etiology and optimize treatment.

Adolescent↗
PubMed2002

Familial temporal lobe epilepsy with febrile seizures.

Described are the clinical, EEG, MR, and genetic characteristics of 106 members of a family with autosomal dominant temporal lobe epilepsy (TLE) and febrile seizures (FS), with 22 affected individuals. Eleven patients had a history of FS, and 10 patients had TLE. EEG showed epileptic activity in five. None had hippocampal sclerosis. There was no evidence for linkage to 13 candidate loci. This large family with autosomal dominant TLE has a distinct phenotype and shows no linkage to known candidate regions for familial partial epilepsy and FS.

Adolescent↗
PubMed2001

The amygdala and temporal lobe simple partial seizures: a prospective and quantitative MRI study.

PURPOSE: To determine whether specific temporal lobe simple partial seizures (SPSs) are associated with an abnormal amygdala T2 (AT2) ipsilateral to the seizure focus in patients with intractable unilateral temporal lobe epilepsy (TLE). AT2 relaxation time mapping is a sensitive method for the detection of abnormal tissue in the amygdala in patients with refractory TLE. The relation between an abnormal AT2 in the epileptic temporal lobe and amygdala seizure onset has not been established. METHODS: Fifty patients with intractable unilateral TLE and concordant data during presurgical evaluation were included. Patients with a foreign-tissue lesion on standard magnetic resonance imaging (MRI) were excluded. All had AT2 mapping. Fifteen types of SPSs were ascertained prospectively, systematically, and blinded to the results of AT2 mapping. The SPSs of patients with a normal AT2 (n = 25) were compared with those of patients with an abnormal AT2 ipsilateral to the seizure focus (n = 25). RESULTS: The group of patients with an abnormal AT2 reported a median of six types of SPSs (range 1-11), in comparison with a median of three types of SPSs (range, 0-7) for the group with a normal AT2 (p<0.01). Déjà vu, a warm sensation, an indescribable strange sensation, a cephalic sensation, and fear were associated with an abnormal AT2. The combination of déjà vu, a cephalic sensation, a warm sensation, a gustatory hallucination, and an indescribable strange sensation discriminated best between the 25 patients with a normal and the 25 patients with an abnormal AT2. CONCLUSIONS: A high number and the types of different SPSs provide clinical evidence for early involvement of the amygdala during seizures in patients with refractory unilateral TLE and an abnormal AT2 in the epileptic temporal lobe

Adolescent↗
PubMed2000

Self-injection ictal SPECT during partial seizures.

The authors compared ictal SPECT injection performed by medical personnel with self-injection ictal SPECT in six patients with refractory temporal lobe epilepsy. Self-injection was safe and started faster. Self-injection subtraction ictal SPECT coregistered to MRI (SISCOM) was localizing in three patients who had a complex partial seizure, but only one of three patients who had a simple partial seizure, which may limit its usefulness in clinical practice. The localizing information of self-injection was better in three patients, and obviated the need for depth-EEG studies in one patient.

Adult↗
PubMed1998

In vivo [11C]flumazenil-PET correlates with ex vivo [3H]flumazenil autoradiography in hippocampal sclerosis.

By using [11C]flumazenil-positron emission tomography ([11C]FMZ-PET), we have previously shown that reductions of central benzodiazepine receptors (cBZRs) are restricted to the hippocampus in mesial temporal lobe epilepsy (mTLE) caused by unilateral hippocampal sclerosis (HS). Receptor autoradiographic studies on resected hippocampal specimens from the same patients demonstrated loss of cBZRs that was over and above loss of neurons in the CA1 subregion. Here, we report the first direct comparison of in vivo cBZR binding with [11C]FMZ-PET and ex vivo binding using [3H]FMZ autoradiography. We applied a magnetic resonance imaging-based method for partial volume effect correction to the PET images of [11C]FMZ volume of distribution ([11C]FMZ Vd) obtained in 10 patients with refractory mTLE due to unilateral, histologically verified HS. Saturation autoradiography was performed on the hippocampal specimens obtained from the same patients, allowing calculation of receptor availability ([3H]FMZ Bmax). After correction for partial volume effect, [11C]FMZ Vd in the body of the epileptogenic hippocampus was reduced by a mean of 42.1% compared with normal controls. [3H]FMZ Bmax, determined autoradiographically from the same hippocampal tissue, was reduced by a mean of 42.7% compared with control hippocampi. Absolute in vivo and ex vivo measurements of cBZR binding for the body of the hippocampus were significantly correlated in each individual. Our study demonstrates that reduction of available cBZR on remaining neurons in HS can be reliably detected in vivo by using [11C]FMZ-PET after correction for partial volume effect.

Adult↗
PubMed1998

A test of spatial memory and its clinical utility in the pre-surgical investigation of temporal lobe epilepsy patients.

Deficits in memory for figurative detail, spatial composition and the spatial location of objects in a scene have been reported postoperatively in right temporal lobectomy patients. The aim of this study was to examine whether these deficits can be used as a sign of lateralised dysfunction in pre-surgical temporal lobe epilepsy (TLE) patients. Sixty-nine patients with lateralised TLE (27 right, 42 left) were assessed on a battery of neuropsychological tests, including tests of general intellectual functioning and psychomotor speed and standardised memory tests involving the learning and recall of verbal and non-verbal material. A new task, the "Aspects of Spatial Memory Test" (AoSMT), based on the experimental tasks developed by Pigott and Milner [39] was also administered. The RTLE and LTLE groups did not differ in their overall level of intellectual function or on measures of cognitive and motor speed. On the AoSMT the LTLE group recognised significantly more figurative detail changes than the RTLE group. In addition, the RTLE group took significantly longer than the LTLE group to identify changes in orientation, figurative detail and filled/unfilled spaces. Poor scores on the AoSMT were significantly correlated with quantitative MRI measures of right hippocampal pathology. The clinical and theoretical implications of these findings are discussed.

Adult↗
PubMed1998

A comparison of the neuropathological effects of vigabatrin and carbamazepine in patients with newly diagnosed localization-related epilepsy using MR-based cerebral T2 relaxation time measurements.

BACKGROUND: Magnetic resonance (MR)-based T2 relaxation time measurement is a sensitive technique to detect neuropathological changes such as intramyelinic edema in vivo. OBJECTIVE: To determine whether vigabatrin (VGB) causes an increase in T2 relaxation time in patients with newly diagnosed localization-related epilepsy over 1 year. METHODS: Patients with newly diagnosed localization-related epilepsy who participated in a VGB-carbamazepine (CBZ) monotherapy trial were included. All were scanned on a 1.5 T Siemens SP63 Magnetom scanner. T2 maps of the brain were obtained at baseline and at follow-up 1 year later. Nine control subjects had repeated hippocampal T2 maps with a median interval of approximately 2 years. RESULTS: 23 patients (12 on VGB and 11 on CBZ) were included. There were no increased T2 relaxation times in the VGB treated group at follow-up and no significant differences between the two antiepileptic drug groups. There was a trend for the temporal and frontal white matter T2 relaxation times to be lower on follow-up in the patients compared to the control subjects. CONCLUSION: The findings do not suggest that intramyelinic edema occurs in patients taking monotherapy VGB for 1 year.

Adolescent↗