Clinical Neuroscience

[Diagnosis of epilepsy]


JUNE 10, 2004

Clinical Neuroscience - 2004;57(05-06)

[0.5-1% of the population suffers from epilepsy, while another 5% undergoes diagnostic evaluations due to the possibility of epilepsy. In the case of suspected epileptic seizures we face the following questions: Is it an epileptic seizure? The main and most frequent differential- diagnostic problems are the psychogenic non-epileptic seizures ("pseudo-seizures") and the convulsive syncope, which is often caused by heart disorders. Is it epilepsy? After an unprovoked seizure, the information on recurrence risk is an important question. The reoccurrence is more possible if a known etiological factor is present or the EEG shows epileptiform discharges. After an isolated epileptic seizure, the EEG is specific to epilepsy in 30-50% of cases. The EEG should take place within 24 hours postictally. If the EEG shows no epileptiform potentials, a sleep-EEG is required. What is the cause of seizures? Hippocampal sclerosis, benign tumors, and malformations of the cortical development are the most frequent causes of the focal epilepsy. Three potentially life-threatening conditions may cause chronic epilepsy: vascular malformations, tumors, and neuroinfections. The diagnosis in theses cases can usually be achieved by MRI, therefore, MRI is obligatory in all epilepsies starting in adulthood. The presence of epileptogenic lesion has a prognostic significance in treatment. If the MRI shows a circumscribed lesion then the pharmacological treatment will likely to be unsuccessful, while surgery may result in seizure freedom. The new and quantitative MRI techniques, such as volumetry, T2-relaxometry, MR-spectroscopy, and functional MRI play a growing role in the epilepsy diagnosis.]



Further articles in this publication

Clinical Neuroscience

[Dear Readers and Colleagues!]


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

[Questions of epileptogenesis and prevention in symptomatic epilepsies]

NIKL János

[Symptomatic epilepsies usually report themselves after a longer period of time after brain injury, after the so-called latent period. During this period progressive functional and structural changes occur which finally cause an increased excitatory condition. The process of epileptogenesis may be examined in animal models, such as in the kindling, status epilepticus, hypoxicischaemic models. Data gained from such sources support the hypothesis that the first injury results in a lower seizure threshold, but genetical and enviromental factors also contribute to the development of epilepsy and most probably further insults may be needed. The development of epilepsy can be traced back to several reasons. In spite of this, the latent period provides opportunity for the prevention of epilepsy or for the influence of epileptogenesis in such a manner that later treatment can become more succesful. Prevention should be an aim in clinical practice, as well. Medication used presently are more like to have anticonvulsive properties and their antiepileptogenic effect is questionable. Due to this fact, development of new drugs is necessary with new theoretical background. The most important influence on the incidence of epilepsy in recent years has been provided by the improvement in neonatal care. This highlights the fact that such optimal medical care should be provided in the acute period of brain injury which can terminate or lessen the risk of epilepsy.]

Clinical Neuroscience

[Antiepileptic drug treatment]


[Antiepileptic drug treatment is essential and provides excellent therapeutic effects in more than the two-third of the epileptic patients. The antiepileptic drugs influence the chronic hyperexcitability of the brain developed during the epileptogenesis. As an effect, it decreases the excitability and/or increases the inhibition of the pathological cells, which prevents the precipitation of the epileptic seizure (anticonvulsive effect). The anticonvulsive effect comes into operation by the influence of the transport of one ore more ion-channels. The anticonvulsive effect is only symptomatic and it doesn’t cure the disorder. The drug selection is based on the knowledge of the therapeutic markers and the effectiveness of the drug to be used. This can occure on the basis of the action of the drug or in syndromespecific way. The pharmacokinetic properties of the drugs determine how they can be used in the practice. The drug interactions can take place in several levels. Among them, the change of the metabolism is the most important. Acute dosedependent side effects, organ-specific chronic interactions and idiosyncratic reactions must be taken into consideration during the use of antiepileptic drugs. The patient's individual aspects must be considerably taken into account during the treatment. There are other medical areas that can benefit from the antiepileptic drugs. Among them, the most important diseases are: restless legs syndrome, neuropathic pain, trigeminal neuralgia, essential tremor, bulimia and bipolar disorders. There are other pharmacological (adrenocorticotropic hormone, immunoglobulins, neurosteroids) and dietary methods, which may be effective at certain epileptic syndromes. The principles of the pharmacotherapy have been changing continuously during the past decades and since. New drugs have been introduced into the marketing and new expectations are coming into the limelight concerning the treatment. As a consequence this will bring on the modification of antiepileptic drug therapeutic habits.]

Clinical Neuroscience

[Hungarian Epilepsy League]

All articles in the issue

Related contents

Clinical Neuroscience

The yield of electroencephalography in syncope

NALBANTOGLU Mecbure, TAN Ozturk Ozlem

Introduction - Syncope is defined as a brief transient loss of consciousness due to cerebral hypoperfusion. Although the diagnosis of syncope is based on a thorough history and examination, electroencaphalography (EEG) is also an important investigational tool in the differential diagnosis in this group of patients. In this study we aimed to identify the diagnostic value of EEG in patients with syncope. Methods - We retrospectively examined EEG recordings of 288 patients with the diagnosis of syncope referred to the Cankiri State Hospital EEG laboratory, from January 2014 to January 2016. The EEG findings were classified into 6 groups as normal, epileptiform discharges (spike and sharp waves), generalized background slowing, focal slowing, hemispherical asymmetries, and low amplitude EEG tracing. The EEGs were separated according to gender and age. Results - Total of 288 patients were included in this study, 148 were females (51.4%) and 140 (48.6%) were males. Among all the EEG reports, 203 (70.5%) were normal, 8 of them (2.8%) showed generalized background slowing and 7 (2.4%) demonstrated focal slow waves. Epileptiform discharges occured among 13 patients (4.5%). Hemispherical asymmetries were detected in 10 patients (3.5%) and low amplitude EEG tracing in 47 patients (16.3%). There was no significant difference between age groups in EEG findings (p=0.3). Also no significant difference was detected in EEG results by gender (p=0.2). Discussion - Although the diagnosis of syncope, epilepsy and non-epileptic seizures is clinical diagnosis, EEG still remains additional method

Clinical Neuroscience

[Acute disseminated encephalomyelitis in childhood]

LIPTAI Zoltán, ÚJHELYI Enikő, MIHÁLY Ilona, RUDAS Gábor, BARSI Péter

[Background and purpose - Acute disseminated encephalomyelitis is a rare inflammatory demyelinating disorder often preceded by infection or vaccination. The purpose of the study was the systematic analysis of clinical, radiological and microbiological profiles of children treated at Szent László Hospital, and the comparison of findings with literature data. Methods - Demographic, infectological, clinical, radiological, laboratory and virological data of patients treated and followed-up between 1-Jan-1998 and 30-June-2008 were reviewed and analysed. Results - 19 children met diagnostic criteria. Their mean age was 6.8 years. A prodromal illness - mostly febrile viral infection, upper respiratory infection or chickenpox - preceded neurological symptoms in 17 patients. All had polysymptomatic encephalopathy, 2 children had spinal symptoms. The cerebrospinal fluid was abnormal in all but one. A viral etiology was definite in 7 and probable in 8 cases. MRI disclosed white matter changes in 18, cortical and deep gray matter in 16, cerebellar in 6, brain stem in 14 and spinal cord changes in 2 cases. Repeat MRI performed mean 4 months later showed complete resolution in 6 and partial resolution in 11 patients. 13 patients received high-dose methylprednisolone, 2 of whom were also treated with plasma exchange and 1 with immunoglobulin. 9 children required mechanical ventilation. 2 patients died, 10 recovered without and 7 with sequelae. 2 patients developed further demyelinating events: multiple sclerosis and multiphasic disseminated encephalomyelitis, respectively. Conclusion - Clinical, radiological and follow-up results were similar to those published in literature however, triggering viruses were identified in a larger proportion of cases.]

Lege Artis Medicinae

[Osteonercosis of the femoral head during pregnancy]

KISS-POLAUF Marianna, TAKÁCS János, TASI Róbert, RÁKÓCZI István

[Osteonecrosis of the femoral head associated with pregnancy is a rare condition. Approximately 40-50 cases have been reported, the first one by Pfeifer in 1957. Avascular osteonecrosis is usually caused by factors that impair the bone’s blood supply (intraosseous arterious or venous occlusion, venous stasis, hypertension in the bone marrow). Owing to the cautious use of radiological imaging techniques during pregnancy and the limited experience with this condition, the correct diagnosis is usually made only retrospectively. Thus, total hip replacement is required in most cases. In the third trimester, MRI examination is safe to perform, and in some cases a simple X-ray should be also considered, as timely avoidance of weight-bearing and other therapeutic interventions might help to prevent the arthroplasty. Here, we would like to present a case observed and treated by us, and to overview the options that could facilitate making the correct diagnosis and finding the appropriate therapeutic program.]

Hungarian Radiology

[Metal objects in the MR]


[During magnetic resonance imaging the patient is exposed to three different types of electromagnetic radiation: static magnetic field, gradient or time varying magnetic fields and radiofrequency electromagnetic fields. The potential risks associated with performing MRI in patients with ferromagnetic implants, materials, or devices are related to the possibility of movement or dislodgement, to the induction of electrical currents and to the heating. The majority of metallic implants are considered to be safe for MRI, but patients with cardiac pacemakers, ferromagnetic aneurysm clips, cochlear implants, implantable drug infusion pumps should not be examined by MRI.]

Clinical Neuroscience

[New applications of conventional EEG analysis ]


[Neurophysiological research suggests that the so-called “standard” EEG analysis has been confronted with new diagnostic challenges. The findings mainly concern the occurrence, the neurophysiological and clinical significance of epileptiform EEG discharges in several neurological and psychiatric disorders. In addition to well-known interictal and ictal discharges, a growing number of recently recognized epileptiform phenomena have been described. The first reports suggested that they might be relevant for the comprehensive description of epileptic dysfunction and might contribute to diagnosis and treatment as well. However, considerable improvement of present-day “standard” EEG technique is necessary to give an appropriate answer to most challenges. Reliable registration and quantitative assessment of well-known epileptiform transients require extended electrode coverage of the head (high-density EEG) and long-term recordings including waking and sleep states to estimate frequency and dyna­mics of targeted activities. Computer-based automatic event detection is preferable to spare time and cost of the evaluation. The authors review recent progress concerning epidemiology, neurophysiology and clinical impact of well-known epileptiform transients and candidate epileptiform activities in neurological and psychiatric conditions. However, recent results need confirmation in large patient populations; therefore, research should not be restricted to a few central laboratories.]