PubMed Health⌕ Search

Biomedical subjects

R M Debets

Publications and source records attributed to R M Debets.

13 recordsLinked to original sources
PubMed2001

[Dutch Collaborative Epilepsy Surgery Program: reduction of seizures, operative complications and tapering of medication in 338 patients, 1973-1998].

OBJECTIVE: To determine the results of surgical treatment in patients with drug-resistant epilepsy, referred to the Dutch Epilepsy Surgery Program, who were treated in the University Medical Centre Utrecht, the Netherlands, in the period January 1973-December 1998. DESIGN: Retrospective descriptive. METHOD: A total of 338 patients were operated on; 269 underwent temporal lobe resection, 41 extratemporal resection, 12 a functional hemispherectomy and 10 callosotomy. Six patients were treated with vagus nerve stimulation. For seven of the patients no follow-up data was available. RESULTS: After a minimum follow-up of 1 year class I or class II results (in accordance with the University of California in Los Angeles classification (UCLA) where class I = seizure-free and class II < or = 3 seizures per year) were obtained in 91% of patients who underwent temporal lobe resections, 67% of patients who underwent extratemporal resections, 81% of patients who underwent functional hemispherectomy and 10% of patients who underwent anterior callosotomy. In five of these patients an improvement in their behaviour occurred. Of the 6 patients who underwent vagus nerve stimulation only I experienced a beneficial seizure reduction (UCLA class III). Transient physical complications occurred in 4% of the patients treated and permanent damage in 1%. Postoperative psychiatric complications occurred almost exclusively following temporal resections; in 11% of which 7% de novo. After 4 postoperative years this had decreased to 5%. In a group of 143 patients who were seizure-free for 2 or more years, post-surgery medication was tapered in 75 cases, stopped in 33 cases and remained unchanged in 35 cases. The relapse rate following a tapering or stopping of the medication was 30% and with unchanged medication 17%. Although the majority of patients were once again seizure-free upon restarting the medication, a significant number continued to experience seizures. CONCLUSION: For a number of carefully selected epilepsy patients with intractable seizures, surgery is a successful treatment with few serious complications.

Anticonvulsants↗
PubMed1997

Is 11C-flumazenil PET superior to 18FDG PET and 123I-iomazenil SPECT in presurgical evaluation of temporal lobe epilepsy?

OBJECTIVE: To determine the contribution of 18FDG PET, 11C-flumazenil PET, and 123I-iomazenil SPECT to the presurgical evaluation of patients with medically intractable complex partial seizures. METHODS: Presurgical evaluation was performed in 23 patients, who were considered candidates for temporal lobe resective surgery (14 females and nine males with a median age of 34 (range 13 to 50) years). The presurgical diagnosis was based on seizure semiology as demonstrated with ictal video recording, ictal and interictal scalp EEG recordings, and MRI. RESULTS: Eighteen patients had convergent findings in clinical semiology, interictal and ictal EEG with scalp and sphenoidal electrodes, and MRI that warranted surgery without depth EEG (DEEG). In five patients with insufficient precision of localisation, DEEG with intracerebral and subdural electrodes was performed. MRI showed abnormalities in 22 out of 23 patients. Of these 22, 18 had mesial temporal sclerosis. This was limited to the mesial temporal lobe in four and more widespread in the temporal lobe in 14 patients. In one patient only enlargement of the temporal horn was found and in three others only white matter lesions were detected. 18FDG PET showed a large area of glucose hypometabolism in the epileptogenic temporal lobe, with an extension outside the temporal lobe in 10 of 23 patients. Only in one of these patients DEEG showed extratemporal abnormalities that were concordant with a significant extratemporal extension of hypometabolism in 18FDG PET. 18FDG PET was compared with the results of scalp EEG: in none of the patients was an anterior temporal ictal onset in scalp EEG related to a maximum hypometabolism in the mesial temporal area. By contrast, the region of abnormality indicated by 11C-flumazenil PET was much more restricted, also when compared with DEEG findings. Extension of abnormality outside the lobe of surgery was seen in only two patients with 11C-flumazenil and was less pronounced compared with the intratemporal abnormality. Both 18FDG PET and 11C-flumazenil PET reliably indicated the epileptogenic temporal lobe. Thus these techniques provide valuable support for the presurgical diagnosis, especially in patients with non-lesional MRI or non-lateralising or localising scalp EEG recordings. In those patients in whom phase 1 presurgical evaluation on the basis of classic methods does not allow a localisation of the epileptogenic area, PET studies may provide valuable information for the strategy of the implantation of intracranial electrodes for DEEG. Previous studies have suggested that 11C-flumazenil binding has a closer spatial relationship with the zone of ictal onset than the area of glucose hypometabolism, but this study suggests rather that the decrease in the 11C-flumazenil binding simply reflects a loss of neurons expressing the benzodiazepine-GABA receptor. 11C-flumazenil PET did not prove to be superior to 18FDG PET. CONCLUSION: In 21 patients sufficient material was obtained at surgery for a pathological examination. In 17 mesial temporal sclerosis, in one an oligodendroglioma grade B, in another a vascular malformation and in two patients no abnormalities were found. Although all 21 patients with pathological abnormality showed hypometabolic zones with 18FDG PET and a decreased uptake in 11C-flumazenil binding, there was no strong correlation between pathological diagnosis and functional abnormal areas in PET. Grading of medial temporal sclerosis according to the Wyler criteria showed no correlation with the degree of hypometabolism in either 18FDG or 11C-flumazenil PET. The interictal 123I-iomazenil SPECT technique was highly inaccurate in localising the lobe of surgery.

Adolescent↗
PubMed1994

Temporal lobe epilepsy: the various MR appearances of histologically proven mesial temporal sclerosis.

PURPOSE: To determine the frequency of appearance of various MR signs in mesial temporal sclerosis, to determine the optimal scanning planes for their visualization, and to propose a histologic explanation for the diminished demarcation between gray and white matter in the temporal lobe, a frequent MR finding in patients with mesial temporal sclerosis. METHODS: MR scans of 14 surgically treated patients with epilepsy and histologically proven mesial temporal sclerosis were assessed for the presence of six features: feature 1, high signal intensity in the hippocampus; 2, reduced hippocampal size; 3, ipsilateral atrophy of the hippocampal collateral white matter; 4, enlarged temporal horn; 5, reduced gray-white matter demarcation in the temporal lobe; and 6, decreased temporal lobe size. RESULTS: Feature 1 was present in 14 patients and was best appreciated on the T2-weighted images in planes parallel to the long axes of the hippocampi. Feature 2, present in 12 patients, and feature 6, present in 9 patients, were optimally seen in the coronal planes and on the inversion-recovery sequences in particular. Feature 3, present in 12 patients, was optimally seen on the coronal T2-weighted images. Feature 4, seen in 11 patients, was equally well seen in all planes (transverse, coronal, and parallel to the long axes of the hippocampi). Feature 5, seen in 10 patients, was best appreciated on the T2-weighted images in the planes of the long axes of the hippocampi. Histologic investigation of the temporal lobe white matter in the 10 patients with feature 5 demonstrated on the MR scan showed abnormalities in 7 cases. Oligodendroglia cell clusters were found in 6, with concomitant corpora amylacea in 1 case and perivascular macrophages with pigment a sole finding in another case. CONCLUSION: Of the six features found in cases of mesial temporal sclerosis on MR, increased hippocampal signal intensity is the most consistent. A decreased gray-white matter demarcation in the temporal lobe parenchyma is also a frequent feature of this disease. A combination of multiple scanning planes results in an optimal demonstration of lesions.

Adolescent↗
PubMed1993

Functional neurosurgery in the treatment of epilepsy in The Netherlands. Aspects of presurgical evaluation and the contribution of subdural and stereotactically implanted depth electrodes in the Dutch Workgroup for Functional Surgery.

In the Netherlands all patients who are considered candidates for surgical treatment of their epilepsy are referred to the Dutch Workgroup for Functional Neurosurgery. Resective neurosurgery in partial epilepsy is a focus of special interest of national health authorities. Annually 15-20 patients can now be operated upon. Presurgical evaluation includes a.o. 18/FDG PET. For depth-EEG recording a specially designed method of "Combined Subdural and Depth-EEG Recording" is used which has been described previously. 70 patients underwent depth-EEG recording with the combined method. In 4.2% of the patients there were transient complications, in 1.4% there was a possibly permanent slight neurological deficit caused by the method. Fifty-six patients were evaluated at least one year after their surgical treatment (median follow-up 3 years). In the frontal lobe group comprising 9 patients 56% were seizure-free, 76% benefited from the treatment. In the temporal lobe group with 47 patients 68% were seizure-free and 92% benefited. No patient deteriorated from the resection. Permanent morbidity was nil.

Brain Mapping↗
PubMed1992

Regional brain glucose metabolism in patients with complex partial seizures investigated by intracranial EEG.

We performed interictal 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET) studies in 57 patients with complex partial epilepsy (CPE), not controlled by medical treatment and considered for surgical resection of their epileptic focus. A precise localization of the epileptic focus was obtained in 37 of these patients with a combination of subdural and depth electrodes. We visually inspected the metabolic images; we also measured glucose consumption in a number of brain regions and compared the values with those obtained in 17 normal controls. Eighty-two percent of the 57 patients had an area of glucose hypometabolism on the 18FDG-PET images. Six patients had a frontal epileptic focus, 3 of them had a frontal lobe hypometabolism. Twenty-six patients had a unilateral temporal lobe focus and all of them displayed a temporal lobe hypometabolism. The asymmetry was more pronounced in the lateral temporal cortex (-20%) than in the mesial part of the temporal lobe (-9.6%). In each cortical brain region on the side of the epileptic focus (except the sensorimotor cortex), glucose consumption rate was lower than in the contralateral region or than in controls. No differences could be found between patients with a seizure onset restricted to the hippocampus and patients with a seizure onset involving the hippocampus and the adjacent neocortex. Divergent metabolic patterns were obtained in 5 patients with bilateral temporal seizure foci. Combined with other non invasive techniques (EEG, neuroradiology), PET contributes increasingly to the selection of patients with CPE who could benefit from surgical treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Quantitative analysis of 18/FDG-PET in the presurgical evaluation of patients suffering from refractory partial epilepsy. Comparison with CT, MRI, and combined subdural and depth. EEG.

CT, MRI, 18/FDG-PET and Depth. EEG, performed with subdural and depth electrodes were part of the presurgical evaluation in 22 patients. Statistical analysis of 18/FDG-PET was performed to compare cerebral utilization of glucose to that of normal age matched controls. The findings of CT, MRI, and quantitative analysis of PET are compared with those of ictal Depth. EEG. A positive correlation between CT and Depth. EEG was obtained in 23% of the patients and between MRI and Depth. EEG. in 50%. For both imaging techniques a negative correlation was found in 5%. Regional abnormalities were found with quantified PET in 95% of the patients and were concordant with Depth. EEG. for side of onset in 77% of the patients and for lobe of onset in 59%. A possibly false localising PET result for lobe of onset was obtained in 8 patients (36%). Limitations of PET were most apparent in patients with regional mesiolimbic or bilateral seizure onset. A favourable outcome of surgery was associated usually with positive convergence of both methods. PET may be a valuable contribution to the research and management of partial complex epilepsy, but at present cannot be considered a reliable alternative to invasive EEG methods in patients without clear unilateral focus localization on surface EEG.

Adolescent↗
PubMed1990

Combined use of subdural and intracerebral electrodes in preoperative evaluation of epilepsy.

For intracranial recording of partial seizures considered to originate from one of the temporal or frontal lobes, the team in the Utrecht Academic Hospital has used subdural, multicontact, flexible electrodes since 1972. These are introduced through bilateral, frontocentral trephine holes and are manipulated under fluoroscopy to cover most of the cerebral convexity. It became evident that in many patients, additional placements to record from intracerebral structures were indispensable. Therefore, using the same trephine holes, an additional 2 to 4 depth electrodes were stereotactically implanted in the mesial temporal and/or frontal structures, as appropriate. An extensive intra- and extracerebral spatial representation of the epileptogenic zone was thus obtained. We report here the methods for manufacturing and applying these electrodes and our clinical experience with 28 patients. The results obtained so far stress the value of combining subdural and depth electroencephalographic monitoring in the presurgical selection of patients suffering from medically refractory complex partial seizures. By miniaturizing the electrodes, extensive areas of the brain can be investigated without craniotomy or multiple burr holes.

Adult↗
PubMed1987

Seven day administration of lamotrigine in epilepsy: placebo-controlled add-on trial.

A double-blind placebo-controlled trial of 7 days administration of lamotrigine as add-on therapy was performed in 10 patients with frequent therapy-resistant, chiefly partial, seizures. Dosage was adjusted on the basis of estimated half-life. Six patients showed a 50% seizure reduction on lamotrigine and two an increase. Side effects (ataxia, dizziness and apathy) occurred in 3 patients, but only at blood levels above 3 micrograms/ml, and were rapidly relieved when the dose was reduced in two. EEG spike counts were significantly reduced on lamotrigine. There was no evidence of interactions with co-medication.

Adolescent↗
PubMed1984

Epileptic nystagmus.

"Epileptic nystagmus" unaccompanied by other ictal phenomena is rare. We report four new cases confirmed by ictal EEG and video or cine recording in which nystagmus was a prominent and sometimes the only clinical manifestation of the seizures. The ictal EEG showed a parietal focus in three instances and generalized spike-wave activity in one.

Adolescent↗
PubMedDate not supplied

Double-blind crossover trial of lamotrigine (Lamictal) as add-on therapy in intractable epilepsy.

A double-blind, placebo-controlled trial is reported of lamotrigine as add-on treatment in therapy-resistant epilepsy. A within-patients serial design was used, with two 3-month treatment periods and an intervening 6-week washout/crossover period. An unblinded investigator adjusted lamotrigine dosage to achieve a plasma concentration within a previously predicted therapeutic range. All patients had therapy-resistant partial seizures, some in combination with other seizure types and were without serious neurological or intellectual deficit. Of 34 patients recruited only one was withdrawn because of an adverse experience (maculo-papular rash) probably related to the experimental drug and 30 completed the trial. The other 3 withdrawals were due to default during baseline, dispensing error and cholecystectomy. There was a modest statistically significant reduction in total and partial seizures on lamotrigine compared to placebo treatment. There was no difference in adverse experiences or abnormal biochemical or haematological findings between the lamotrigine and placebo periods. The plasma concentrations of concomitantly administered antiepileptic drugs were not affected by lamotrigine treatment. It is concluded that lamotrigine shows promise as an antiepileptic drug with low toxicity.

Adolescent↗