Clinical Neuroscience

[Prolonged EEG-monitoring]


SEPTEMBER 23, 2011

Clinical Neuroscience - 2011;64(09-10)

[Prolonged EEG monitoring and video-EEG monitoring are basic methods on the level of epilepsy centers. These methods are able to make differences between epilepsy and non epileptic paroxysmal manifestations like psychogenic non epileptic seizures, parasomniac phenomena, narcolepsy. The application of the method, at least the video-EEG variant, needs team work, high level organisation, highly educated staff and high tech electrographic devices. Running the method even with these requirements is beneficial from the cost-benefit aspect as well.]



Further articles in this publication

Clinical Neuroscience

[The methodology and objectives of registrating high frequency oscillation in epilepsy]


[Technological advances in digital EEG allowed the recording the full frequency band of the EEG. Activity beyond the traditional 0.3-70 Hz band reflects both physiological and pathological processes. High frequency activity recorded from the epileptic brain has been related to both epileptogenicity and epileptogenesis. The article reviews research avenues, clinical applications, and the methodology of detecting and quantifying high frequency activity.]

Clinical Neuroscience

[Congress calendar]

Clinical Neuroscience

[The clinical utility of genetic testing in epilepsy]


[We summarize those epilepsies, in which genetic testing has clinical significance. Different types of genetic tests are presented. Na-channel epilepsies include different clinical entities, the exact genetic diagnosis is relevant in the prognosis, genetic counseling, as well in the therapeutic decision - as Na-channel blockers may worsen them. Molecular genetic tests are available for most of the malformations of cortical development, important for genetic counseling and prenatal diagnosis. Molecular genetic testing of progressive myoclonic epilepsies, which may be difficult to differentiate clinically is almost complete. For some neonatal/infantile epileptic encephalopathies, for most of the neurometabolic disorders, molecular genetic tests are available, so are cytogenetic tests for chromosomal abnormalities accompanied with epilepsy. The clinical significance of the genetic diagnostic of rare, focal inherited epilepsies is limited, their importance is mostly in epilepsy pathophysiology research. The genetic background of the common idiopathic generalized epilepsies is unrevealed so far.]

Clinical Neuroscience

[New antiepileptic drugs, and therapeutic considerations]


[Epilepsy is not a singular disease, but a variety of disorders. It is affects up to 0.5% of the population. Over the past decade, the researchers have been made great advances in the field of epilepsy. These have been accompanied by the licensing of a great number of antiepileptic drugs. However, despite these efforts, up to 15-20% of patients have refractory epilepsy. The novel antiepileptic drugs must suit several requirements: higher efficacy, especially in resistant cases, better tolerability, and improved pharmacokinetic properties. Recently, three new drugs have been introduced for the medication. The retigabine is a carbamic derivate, and the anticonvulsive properties are largely due to its ability to prolong the opening of neuronal voltage-gated potassium Kv7.2 and Kv7.3 channels. The lacosamide is a functionalized amino acid, and selectively enhances voltage-gated sodium channel slow inactivation. The eslicarbazepine acetate is a new member of the dibenzazepine family, and blocks the fast inactivated voltage-gated sodium channel. All three of them differ from the foregoing agents in several important ways, including new mechanism of action (retigabine, lacosamide), or pharmacokinetics (eslicarbazepine acetate). These novel anticonvulsants appears to be a safe and effective addition to the armamentarium for the treatment of patients with refractory epilepsy. However, it must take some new approaches into consideration, in the therapeutic algorithm.]

Clinical Neuroscience

[Functional magnetic resonance imaging for cortical mapping in epilepsy]

KOZÁK Lajos Rudolf, TÓTH Vivien, BARSI Péter, RUDAS Gábor

[It is not only the total curative resection of pathological tissue or the minimization of symptoms to be considered in epilepsy surgery or other neurosurgical procedures, it is equally desirable to maintain the best possible quality of life. Cortical mapping methods can help achieve this goal by delineating eloquent areas, i.e. brain regions that are vital for providing an acceptable quality of life, albeit not prone to compensatory reorganization. These areas include among others the Broca and Wernicke regions for speech, the primary motor, sensory and visual cortices. Functional MRI gained importance in the last decade as a non-invasive clinical cortical mapping technique. This method is capable of localizing cortical areas selectively activated by a given task condition. Thus, selecting appropriate tasks can help mapping eloquent brain regions. Using functional MRI provides information that is complementary to other mapping methods. Moreover, it can replace invasive methods such as the Wada test. Here, we explain the background of functional MRI, compare it to other clinical mapping methods, explain the intricacies of paradigm selection, and show the limitations of the technique while also pointing out alternative uses.]

All articles in the issue

Related contents

Clinical Neuroscience

[Surgical treatment of epilepsy]


[In this article the possibilities, indications, methods and results of surgery in epilepsy are summarized in general with the Hungarian experience emphasized. Surgery may provide effective treatment in about 5-10% of the epileptic population. Surgical solution nowadays became an essential treatment in medial temporal epilepsy, if hippocampal sclerosis or other lesion is present, in therapy resistent lesional extratemporal epilepsies and in catastrophic childhood epilepsies if the epileptic disorder is restricted to one hemisphere (Rasmussen syndrome, hemimegalencephaly, Sturge-Weber disease and posttraumatic or postencephalitic hemispherial epilepsies). The algorhythms of the presurgical evaluation and the current methods for study the pacemaker area, forbidden zones, and hemispherial functions are treated. The currently used type and techniques of surgery, such as lesionectomy, temporal lobe resections, hemispherotomy, callosotomy, multiple subpial transsections and their indications are described. The newest surgical approaches, as deep brain stimulation, vagal nerve stimulation, and irradiation techniques are also briefly touched. Lastly, we deal with prognostical factors of the surgical outcome, reasons of surgical failures and complications. In a brief chapter the importance of postsurgical rehabilitation is emphasized.]

Clinical Neuroscience

[10 years, 600 monitoring sessions - our experience with the video EEG monitoring of children]


[Introduction- The only Hungarian video EEG laboratorywhere children of ages 0-18 can be continuously monitoredfor several days was opened 1 June 2001 at Department ofNeurology of Bethesda Children’s Hospital.Objectives- Summarizing our 10 years of experience withthe video EEG monitoring (VEM) of children and defining theplace of VEM in the treatment of childhood epilepsy inHungary.Patients and methods- We have processed data from 597monitoring sessions on 541 patients between June 1, 2001and 31 May, 2011 based on our database and the detailedsummaries of the procedures. Results- 509 patients were under the age of 18. The average length of the sessions was 3.1 days. We haveobserved habitual episodes or episodes in question in 477(80%) sessions. 241 (40%) sessions were requested with anepilepsy surgery indication, and 74 patients had 84 opera-tions. 356 (60%) were requested with a differential diagnosisindication, and 191 (53%) cases of epilepsy werediagnosed. We most commonly diagnosed symptomaticgeneralized epilepsy (57 cases). In 165 sessions the episodein question was not diagnosed as epilepsy. Among theparoxysmal episodes we have identified events ofpsychogenic origin, movement disorders, sleep disordersand behavioral disorders. Only 3% of the differential diag-nosis procedures brought no additional clinical information.Discussion- The diagnostic efficiency in our VEM laborato-ry is in accordance with the data found in the literature.Besides epilepsy surgery VEM is recommended if suspectedepileptic episodes occur and interictal epileptiform signs arenot present or are not in accordance with the symptoms, ifthere is no explanation for therapy resistance and if paroxys-mal episodes of non-epileptic origin are suspected but theycannot be identified based on the anamnesis. VEM is also helpful in diagnosing subtle seizures. The procedure hasnumerous additional benefits in patient care and in trainingthe parents and hospital staff. ]

Clinical Neuroscience

EEG-based connectivity in patients with partial seizures with and without generalization

DÖMÖTÖR Johanna, CLEMENS Béla, EMRI Miklós, PUSKÁS Szilvia, FEKETE István

Objective - to investigate the neurophysiological basis of secondary generalization of partial epileptic seizures. Patients and methods - inter-ictal, resting-state EEG functional connectivity (EEGfC) was evaluated and compared: patients with exclusively simple partial seizures (sp group) were compared to patients with simple partial and secondary generalized seizures (spsg group); patients with exclusively complex partial seizures (cp group) were compared to patients with cp and secondary generalized seizures (cpsg group); the collapsed sp+cp group (spcp) was compared to those who had exclusively secondary generalized seizures (sg group). EEGfC was computed from 21-channel waking EEG. 3 minutes of waking EEG background activity was analyzed by the LORETA Source Correlation (LSC) software. Current source density time series were computed for 23 pre-defined cortical regions (ROI) in each hemisphere, for the 1-25 Hz very narrow bands (1 Hz bandwidth). Thereafter Pearson correlation coefficients were calculated between all pairs of ROI time series in the same hemisphere. Z-scored correlation coefficients were compared at the group level (t-tests and correction for multiple comparisons by local false discovery rate, FDR). Results - Statistically significant (corrected p<0.05) EEGfC differences emerged at specific frequencies (spsg > sg; cpsg > cp), and at many frequencies (sg > spcp). The findings indicated increased coupling between motor cortices and several non-motor areas in patients with partial and sg seizures as compared to patients with partial seizures and no sg seizures. Further findings suggested increased coupling between medial parietal-occipital areas (structural core of the cortex) and lateral hemispheric areas. Conclusion - increased inter-ictal EEGfC is associated with habitual occurrence of secondary generalized seizures.