F. Kerling

Prediction of postoperative outcome with special respect to removal of hemosiderin fringe: A study in patients with cavernous haemangiomas associated with symptomatic epilepsy

PURPOSE In this study 30 patients with symptomatic epilepsy caused by cavernomas were investigated in a postoperative follow up study to assess predictors for postoperative outcome with respect to indications, time and approach of surgery. METHODS Thirty patients with cavernomas refractory to medical treatment were scheduled for surgery based on the findings of high-resolution MR imaging and intensive EEG-video monitoring. Postoperative outcome of epilepsy was assessed by follow-up examinations based on the basis of classification by Engel and the International League against epilepsy (ILAE). RESULTS The following variables were associated with good postoperative outcome: (1) complete resection of hemosiderin fringe surrounding the cavernoma was correlated to less postoperative seizure frequency versus incomplete resection of the hemosiderin fringe according to the outcome protocol of ILAE. (2) Lower duration of epilepsy at the time of operation was correlated to a better postoperative outcome with a benefit for recovery. (3) Absence of hemorrhage before surgery and unifocal seizure onset was a predictor for a favorable outcome, whereas bilateral or multifocal seizure onset zones showed poorer postoperative outcomes. (4) In patients with dual pathology (hippocampal sclerosis in addition to a cavernoma), lesionectomy plus hippocampectomy as opposed to lesionectomy only, had a better outcome than single lesionectomy. CONCLUSION Postoperative outcome in patients with cavernomas should be the topic of further prospective multicenter studies involving a large number of patients. In addition to the ideal operation time and handling of dual pathology the role of extended resection including perilesional hemorrhages should be taken into account.

When do patients forget their seizures? An electroclinical study

Accurate knowledge of the frequency of epileptic seizures is a precondition for evaluating the efficacy of pharmacotherapy. It is a well-known fact that the information provided by epilepsy patients about the number of seizures they experience is often unreliable. In the present study, we aimed to identify predictors of a higher risk of unrecognized events. Thirty patients who underwent presurgical evaluation in a video/EEG monitoring unit were recruited. As soon as the patient became aware of a seizure, he or she completed a standardized questionnaire on the subjective perception of the seizure, which was then compared with the video/EEG findings. Of the 138 seizures recorded, 49.3% were reliably detected by the patient, whereas 44.2% went unnoticed; the remainder were incompletely or uncertainly perceived. Subjects in whom events occurred during sleep or originated in (or propagated to) the left temporal lobe had a significantly higher percentage of unrecognized events.

Autonomic auras: Left hemispheric predominance of epileptic generators of cold shivers and goose bumps?

Summary:  Purpose: Autonomic seizures in temporal lobe epilepsies associated with “cold shivers and goose bumps” as a principal ictal sign or aura have only rarely been studied.

Influence on ictal seizure semiology of rapid withdrawal of carbamazepine and valproate in monotherapy

Summary:  Purpose: To quantify changes in ictal seizure semiology during rapid withdrawal of carbamazepine (CBZ) and valproate (VPA) from a monoregimen in presurgical evaluation.

Onset of action of levetiracetam: a RCT trial using therapeutic intensive seizure analysis (TISA).

Summary:  Objectives: To correlate the onset of clinical effects of add‐on levetiracetam (LEV) therapy with daily serum LEV concentration, in pharmacoresistant focal epilepsies, using the TISA method.

Identifying the affected hemisphere by 1H-MR spectroscopy in patients with temporal lobe epilepsy and no pathological findings in high resolution MRI

Up to 30% of patients with temporal lobe epilepsy (TLE) remain without remarkable changes in MRI. In this study we investigated the role of 1H‐MR spectroscopy (1H‐MRS) in lateralizing the affected hemisphere in the mentioned patient group. Twenty‐two consecutive patients diagnosed with TLE were investigated by high resolution MRI and 1H‐MRS. We examined the incidence and diagnostic accuracy of temporal metabolite alterations determined by Linear Combination of Model Spectra (LCModel) via water reference. Metabolite values of each hemisphere of TLE patients were compared with healthy controls. Results of metabolite alterations were related to intensive video EEG focus localization. Reduction of N‐acetylaspartate + N‐acetylaspartyl‐glutamate (tNAA) in the affected hemisphere revealed identification in six of nine patients (66%) with unilateral TLE. Group comparison revealed a significant reduction of tNAA (6.1 ± 0.8 * ) in the involved temporal lobe compared with controls (6.67 ± 0.4 * , P = 0.026). Choline levels were significantly increased in the affected hemisphere (1.42 ± 0.17 * ) compared with healthy controls (1.22 ± 0.17 * , P = 0.035). The results of our study show that 1H‐MRS is able to identify the affected hemisphere of MRI negative TLE patients and can be used as an additive tool in multimodal focus localization.

Influence of levetiracetame on ictal and postictal EEG in patients with partial seizures.

To investigate the influence of levetiracetame (LEV) treatment on the interhemispheric seizure pattern propagation and postictal recovery of electroencephalography (EEG) background activity. Twenty‐three adult patients (age > 16 years) with pharmacoresistant focal epilepsies presenting at the Epilepsy Center Erlangen for pre‐surgical evaluation were enrolled in the study. Those eligible patients receiving only one antiepileptic drugs were recruited to the 48‐h baseline phase and, after at least two seizures, were randomized to the 7‐day treatment phase with either LEV (n = 11) or placebo (n = 12). All participants were submitted to continuous day‐and‐night video‐EEG monitoring. The daily dose of LEV was 1000 mg (500 mg bid.) on the first treatment day and was increased to 2000 mg (1000 mg bid.) from the second day onward. The EEG changes relating to the time delay of the interhemispheric seizure pattern propagation and to the postictal recovery of the background activity were analysed by computerized video‐EEG recording and compared using the non‐parameter Mann–Whitney U‐exact test (α = 0.05). A prolonged latency of the contralateral seizure pattern propagation was observed in the LEV group, whereas a more rapid propagation was observed in the placebo group (P = 0.009). Postictal generalized slowing of the background activity was recorded in 21 patients during the baseline phase. More rapid postictal recovery of the EEG background activity was observed in the LEV, but not in the placebo group (P = 0.03). This study demonstrated that LEV not only prevented the seizure pattern propagation but also helped the speedy recovery of the postictal background activity in the EEG.

Effect of epileptic seizures on the cerebrospinal fluid — A systematic retrospective analysis

OBJECTIVE Analyses of the cerebrospinal fluid (CSF) are obligatory when epileptic seizures manifest for the first time in order to exclude life-threatening causes or treatable diseases such as acute infections or autoimmune encephalitis. However, there are only few systematic investigations on the effect of seizures themselves on CSF parameters and the significance of these parameters in differential diagnosis. METHODS CSF samples of 309 patients with epileptic and 10 with psychogenic seizures were retrospectively analyzed. CSF samples were collected between 1999 and 2008. Cell counts, the albumin quotient, lactate and Tau-protein levels were determined. Findings were correlated with seizure types, seizure etiology (symptomatic, cryptogenic, occasional seizure), and seizure duration. RESULTS Pathological findings were only observed in patients with epileptic but not with psychogenic seizures. The lactate concentration was elevated in 14%, the albumin quotient in 34%, and the Tau protein level in 36% of CSF samples. Cell counts were only slightly elevated in 6% of patients. Different seizure types influenced all parameters except for the cell count: In status epilepticus highest, in simple partial seizures lowest values were seen. Symptomatic partial and generalized epileptic seizures had significantly higher Tau-protein levels than cryptogenic partial seizures. In patients with repetitive and occasional epileptic seizures, higher Tau-protein levels were seen than in those with psychogenic seizures. Duration of epileptic seizures was positively correlated with the albumin quotient, lactate and Tau-protein levels. High variability of investigated CSF parameters within each subgroup rendered a clear separation between epileptic and psychogenic seizures impossible. SIGNIFICANCE Elevated cell counts are infrequently observed in patients with epileptic seizures and should therefore not uncritically be interpreted as a postictal phenomenon. However, blood-CSF barrier disruption, increased glucose metabolism and elevation of neuronal damage markers are observed in considerable percentages of patients and depend on many factors such as etiology, seizure type and duration.

Clinical effects of topiramate against secondarily generalized tonic–clonic seizures

OBJECTIVE Intensive and quantitative evaluation of the duration, intensity and frequency of tonic and clonic signs of secondarily generalized tonic-clonic seizures (GTCS) in patients with pharmacoresistant partial seizures during topiramate (TPM) treatment. METHODS Thirty patients suffering from refractory partial seizures with secondarily GTCS undergoing presurgical evaluation were randomized into a low dosage (100 mg daily) and a parallel medium dosage (200 mg daily) group of TPM add-on medication (15 patients for each group). Study phases included a 3 days baseline video-EEG phase, a 10 days TPM titration phase without video-EEG and a 3 days TPM dose maintenance phase with video-EEG. During the baseline and the dose maintenance phase seizures were recorded using video-EEG monitoring and the following parameters were measured for each recorded secondarily generalized tonic and clonic signs: duration (lasting seconds), intensity (on a 0-3 scale), frequency (numbers per 24 h). RESULTS A total of 46 complex partial seizures with secondarily generalized tonic-clonic signs during the baseline phase and 20 during the dose maintenance phase were intensively analyzed. More patients in the medium dosage group than in the low dosage groups were free from secondarily GTCS during the dose maintenance phase (nine vs. two, P<0.05). Intergroup comparison suggested that the duration of all tonic signs decreased more in the medium dosage group computing the reduction from baseline to the dose maintenance phase (P<0.05). There were statistically more significant reductions in the duration and intensity of clonic signs in the medium dosage group (P<0.05). CONCLUSION TPM has an early dose-dependant effect on secondarily GTCS in patients with pharmacoresistant partial seizures. SHORT COMMUNICATION The present study intensively analyzed the duration, intensity, and frequency of secondarily generalized tonic and clonic signs in patients with pharmacoresistant partial seizures. The quantitative data suggested that TPM had a robust early inhibitory effect on secondarily generalized tonic-clonic signs; effects were more prominent in the medium dosage group (200 mg daily) than in the low dosage group (100 mg daily).

Pitfalls in diagnosing limbic encephalitis - a case report.

Background –  The syndrome of limbic encephalitis (LE) is characterized by subacute onset of temporal lobe epilepsy, loss of short‐term memory, cognitive confusion and psychiatric symptoms.