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Clinical Neuroscience

SEPTEMBER 30, 2019

[Newer studies on the strong link between sleep and epilepsy: Epilepsy as an epileptic transformation of sleep plastic functions]

HALÁSZ Péter

[Aims - Overview of the new data about the strong link of sleep and epilepsy and conjoining cognitive impairment. Methods - Search for relevant references and summary of our own research activity on the topic. Results - Strong interrealtionship exists between epilepsy and plastic brain functions (memory processing and synaptic homeostasis) and the working modes of NREM sleep. In the most frequent childhood and adult epilepsy networks responsible for plastic functions can be derailed to an epileptic level of excitability, and suffer a transitory or permanent epileptic transformation. Exampling on the three big epilepsies: absence epilepsy; medial temporal lobe epilepsy; and childhood idiopathic focal age dependent epilepsy spectrum we demonstrate the most important features of this epileptic transformation. The association of cognitive impairment to certain sleep dependent epilepsies gains explanation by the epilepsy caused interference with slow wave decline (ICFE) and memory consolidation (MTLE) during NREM sleep. This paper serves also to introduce the concept of sleep dependent system epilepsies. Conclusions - We provide evidences about shared mechanisms among sleep related epilepsies being the derailment of sleep plastic funcions toward exaggerated excitability determined by the inherent possibilities of the signal transduction properties. ]

Clinical Neuroscience

JULY 30, 2019

A case report of Morvan syndrome

AYTAC Emrah, ACAR Türkan

Morvan syndrome is a rare disease characterized by peripheral nerve hyperexcitability, encephalopathy, dys­autonomia and significant insomnia. The patient, who was included in the present study, was followed-up at our clinics for confusion, myokymia, hyperhidrosis, epileptic seizures, tachycardia, agitation, hypokalemia, and hyponatremia. The cranial MRI of the patient demonstrated hyperintensities at the T2 and FLAIR sections of the medial temporal lobe and insular lobes. Electromyography and neurotransmission examination results were concordant with peripheral nerve hyperreactivity. Contactin-associated protein-like 2 antibodies and leucine-rich glioma inactivated protein 1 antibodies were detected as positive. The patient was diagnosed with Morvan syndrome; intravenous immunoglobulin and corticosteroid treatment was started. Almost full remission was achieved. This very rare syndrome implies challenges in diagnosis and treatment; however, remission can be achieved during the follow-up. In addition, caution is needed in the long-term follow-up of these patients regarding the development of malignancies.

Clinical Neuroscience

NOVEMBER 30, 2009

[New vistas and views in the concept of generalized epilepsies]

HALÁSZ Péter, KELEMEN Anna

[The aim of this work is to show explicitly why the “idiopathic generalized epilepsy” concept becomes outfashioned and untenable. As the concept of “generalized epilepsies” is from long ago closely related to the thalamo-cortical system, we briefly summarize the functional anatomy, the double working mode of the thalamo-cortical system in different vigilance states and it’s role in development of the spike - wave pattern. The next part shows weaknesses of this concept from the EEG, seizure semiology, and neuroimaging point of view. Further experimental and clinical arguments are accumulated from the reflex epileptic features in IGE, indicating local/regional cortical hyperexcitability. A separate part is devoted to genetic aspects of the question. Lastly implications to epilepsy classification are shown and an outlook toward a unified epilepsy concept is provided. The epileptic disorder of the thalamo-cortical system is responsible for the development of “generalized", synchronous spike-wave paroxysms as the common neurophysiological background in “primary” - idiopathic and in “secondary” generalized epilepsies. This disorder is specifically related to the burstfiring working mode of the thalamo-cortical system during NREM sleep (is an epileptic exageration of it). The “generalized” epilepsy category should be abandoned, being misleading. Epilepsies are proposed to be classified according to their network properties and relations to different physiological systems of the brain. The different phenotypes, named earlier idiopathic (primary) generalized, or symptomatic (secondary) generalized (with encephalopathic features), should be delineated depending on the following factors: 1. speed and extent of syncronization within the thalamo-cortical system, 2. the way how the thalamo-cortical system is involved, 3. which kind of cortical triggers play role, 4. the degree and level of the disorder (restricted to the molecular level or extended to the level of structural alterations - in the cortex or more diffusely, 5. genetic targets and features.]

LAM Extra for General Practicioners

JUNE 20, 2010

[A holistic approach to neuropathic pain]

KISS Gábor

[Neuropathic pain is a chronic pain disorder due to a primary lesion and/or dysfunction of the peripheral or central nervous system. This tormenting condition causes a lot of distress to the patients, impairs their quality of life, and demands significant expenses. Chronic neuropathic pain is frequently under-diagnosed and mistreated. Explanations for these problems are the complex underlying pathomechanism, variability of symptoms, difficulties in diagnosis, and the differences between the treatment of this and other painful disorders. In addition, comorbid conditions such as anxiety, depression, and sleep disorders are often overlooked. Apart from the diagnostic difficulties, also treatment is usually unsatisfactory. Frequently NSAIDs are used, but they are usually not effective. Undoubtedly, even with the use of evidence-based treatment - such as duloxetine and pregabalin - complete pain relief is not always possible. Lack of proper medical education also contributes to problems in diagnosis and treatment. In western countries, diabetes is the most common cause of polyneuropathy. Painful diabetic neuropathy is the most intensely studied neuropathic pain condition; a lot of evidence comes from randomized controlled trials of this type of neuropathy. The same drugs as in the case of other neuropathic pain conditions are used for the symptomatic treatment of painful diabetic neuropathy. Etiological therapy is based on the best achievable glycemic control. A combination of etiological and symptomatic therapy can be a future treatment, but proving this will require further studies.]

Clinical Neuroscience

JUNE 10, 2004

[Antiepileptic drug treatment]

SZUPERA Zoltán

[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.]

Lege Artis Medicinae

APRIL 01, 2009

[A holistic approach to neuropathic pain]

KISS Gábor

[Neuropathic pain is a chronic pain disorder due to a primary lesion and/or dysfunction of the peripheral or central nervous system. This tormenting condition causes a lot of distress to the patients, impairs their quality of life, and demands significant expenses. Chronic neuropathic pain is frequently under-diagnosed and mistreated. Explanations for these problems are the complex underlying pathomechanism, variability of symptoms, difficulties in diagnosis, and the differences between the treatment of this and other painful disorders. In addition, comorbid conditions such as anxiety, depression, and sleep disorders are often overlooked. Apart from the diagnostic difficulties, also treatment is usually unsatisfactory. Frequently NSAIDs are used, but they are usually not effective. Undoubtedly, even with the use of evidence-based treatment - such as duloxetine and pregabalin - complete pain relief is not always possible. Lack of proper medical education also contributes to problems in diagnosis and treatment. In western countries, diabetes is the most common cause of polyneuropathy. Painful diabetic neuropathy is the most intensely studied neuropathic pain condition; a lot of evidence comes from randomized controlled trials of this type of neuropathy. The same drugs as in the case of other neuropathic pain conditions are used for the symptomatic treatment of painful diabetic neuropathy. Etiological therapy is based on the best achievable glycemic control. A combination of etiological and symptomatic therapy can be a future treatment, but proving this will require further studies.]