Standardized computer-based organized reporting of EEG: SCORE.

The electroencephalography (EEG) signal has a high complexity, and the process of extracting clinically relevant features is achieved by visual analysis of the recordings. The interobserver agreement in EEG interpretation is only moderate. This is partly due to the method of reporting the findings in free-text format. The purpose of our endeavor was to create a computer-based system for EEG assessment and reporting, where the physicians would construct the reports by choosing from predefined elements for each relevant EEG feature, as well as the clinical phenomena (for video-EEG recordings). A working group of EEG experts took part in consensus workshops in Dianalund, Denmark, in 2010 and 2011. The faculty was approved by the Commission on European Affairs of the International League Against Epilepsy (ILAE). The working group produced a consensus proposal that went through a pan-European review process, organized by the European Chapter of the International Federation of Clinical Neurophysiology. The Standardised Computer-based Organised Reporting of EEG (SCORE) software was constructed based on the terms and features of the consensus statement and it was tested in the clinical practice. The main elements of SCORE are the following: personal data of the patient, referral data, recording conditions, modulators, background activity, drowsiness and sleep, interictal findings, "episodes" (clinical or subclinical events), physiologic patterns, patterns of uncertain significance, artifacts, polygraphic channels, and diagnostic significance. The following specific aspects of the neonatal EEGs are scored: alertness, temporal organization, and spatial organization. For each EEG finding, relevant features are scored using predefined terms. Definitions are provided for all EEG terms and features. SCORE can potentially improve the quality of EEG assessment and reporting; it will help incorporate the results of computer-assisted analysis into the report, it will make possible the build-up of a multinational database, and it will help in training young neurophysiologists.

Postictal inhibition of the somatosensory cortex.

Transient suppression of the motor cortex and of the speech areas cause well-described postictal phenomena following seizures involving the respective cortical areas. Pain is a rare symptom in epileptic seizures. We present a patient with painful tonic seizures in the left leg. The amplitude of the cortical component of the somatosensory evoked potential following stimulation of the left tibial nerve was reduced immediately after the seizure. Our findings suggest that the excitability of the sensory cortex is transiently reduced following a seizure involving the somatosensory area.

Ketogenic diet in the treatment of refractory continuous spikes and waves during slow sleep.

PURPOSE: To evaluate the effect of the ketogenic diet on electroclinical characteristics and cognitive function in children with continuous spikes and waves during slow sleep (CSWS). METHODS: Five children (four boys, one girl) aged between 8 and 13 years with CSWS refractory to conventional antiepileptic drugs (AEDs), including levetiracetam, and steroids were included. The prospective electroclinical assessment was performed prior to the ketogenic diet and once every 6 months post initiation during the 2-year period. All children underwent neuropsychological testing prior to the ketogenic diet and four of the children again 12 months after the diet's introduction. In case 4 the testing has been performed after 7 months and the diet was withdrawn after 9 months because of the lack of efficacy and the parent's wishes. In two patients the cognitive functions were also evaluated after 24 months since the diet's initiation. During the period on the ketogenic diet the concomitant AED treatment was unchanged. RESULTS: Electrographic evaluation after 24 months on the ketogenic diet showed CSWS resolution in one patient, mild decrease of the spike-wave index in one, and lack of response in three patients. The ketogenic diet did not influence the neuropsychological outcome, and intelligence quotient (IQ) scores remained low at the end of the follow-up period. However, in two patients an improvement in attention and behavior was demonstrated. DISCUSSION: This is the first study evaluating the efficacy of the ketogenic diet in children with CSWS. Five presented cases were refractory to AEDs and steroids. Only one case responded with complete CSWS disappearance; in one the effect of the ketogenic diet was partial and intermittent, whereas in three patients no response has been observed. These results show that the ketogenic diet did not appear to influence the neuropsychological outcome; however, the absence of a control group makes it impossible to conclude with certainty.

Large inter-rater variability on EEG-reactivity is improved by a novel quantitative method.

OBJECTIVE: To assess inter-rater agreement on EEG-reactivity (EEG-R) in comatose patients and compare it with a quantitative method (QEEG-R). METHODS: Six 30-s stimulation epochs (noxious, visual and auditory) were performed during EEG on 19 neurosurgical and 11 cardiac arrest patients. Six experts analysed EEGs for reactivity using their habitual methods. QEEG-R was defined as present if ≥2/6 epochs were reactive (stimulation/rest power ratio exceeding noise level). Three-months patient outcome was assessed by the Cerebral Performance Category Score (CPC) dichotomized in good (1-2) or poor (3-5). RESULTS: Agreement among experts on overall EEG-R varied from 53% to 83% (κ: 0.05-0.64) and reached 100% (κ: 1) between two QEEG-R calculators. For the experts, absence of EEG-R yielded sensitivities for poor outcome between 40-85% and specificities between 20-90%, for QEEG-R sensitivity was 40% (CI: 23-68%) and specificity 100% (CI: 69-100%). CONCLUSIONS: There is a large inter-rater variation among experts on EEG-R assessment in comatose patients. QEEG-R is a promising objective prognostic parameter with low inter-rater variation and a high specificity for prediction of poor outcome. SIGNIFICANCE: Clinicians should be cautious when using the traditional, qualitative method, in particular in end-of-life decisions. Implementation of the quantitative method in clinical practice may improve reliability of reactivity assessments.

[Cognitive deficits are underestimated in children with benign epilepsy with centro-temporal spikes].

Benign epilepsy with centro-temporal spikes (BECTS) is, as the name suggests, usually considered benign. However, there is a growing awareness that this is not the case in all instances. Many of the children with BECTS have neuropsychological and linguistic dysfunctions, even after remission of the disease. In patients with classic BECTS, an association with GRIN2A-mutations is reported by several groups, suggesting a possible placement of BECTS at the mild end of an epileptic-aphasia spectrum. Awareness of the possible neuropsychological consequences of BECTS should be considered when treating these children.

A prospective study of levetiracetam efficacy in epileptic syndromes with continuous spikes-waves during slow sleep.

PURPOSE: To evaluate the add-on effect of levetiracetam (LEV) treatment on the EEG and clinical status of children with continuous spikes-waves during slow sleep (CSWS). METHODS: 20 children with CSWS refractory to other conventional antiepileptic drugs (AEDs) received LEV 45-50 mg/kg/day as add-on treatment, and were prospectively followed for a minimum period of 18 months. The patient population comprised seven cryptogenic, seven symptomatic and six idiopathic cases (atypical benign partial epilepsy, aBECTs). The electrographic evaluation included 24 h EEG recordings taken every six months (minimum of three per child). Electrographically children were categorised as responders, partial responders or non-responders by comparing changes in the spike index (SI) during NREM-sleep with baseline SI before initiation of LEV. The clinical efficacy of LEV was assessed by comparing seizure frequency at the end of follow up with the baseline. The follow up duration varied from 18 to 53 months. RESULTS: Electrographic response was observed in 11 patients. Eight patients demonstrated a lasing response (more than 12 months): five from symptomatic, two--cryptogenic and one--idiopathic group respectively. Three children showed a partial response (6-12 months): one from symptomatic and two from idiopathic group. Eleven out of the 20 children were seizure free at baseline and during the whole follow up. The rest, six-symptomatic and three-cryptogenic patients, had seizures prior to LEV treatment initiation. Six became seizure free after add-on therapy with LEV, and in three children a significant reduction of seizure frequency was observed. CONCLUSION: This study suggests that add-on therapy with LEV is more effective in children with CSWS resulting from a known underlying structural brain lesion (the symptomatic group).

Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study.

Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were recruited. Cathodal tDCS and sham stimulation were applied to the epileptic focus, before sleep (1 mA; 20 min). Cathodal tDCS did not reduce the spike-index in any of the patients.