Advertisement

Topics

Epilepsy: Ever-changing states of cortical excitability.

Summary of "Epilepsy: Ever-changing states of cortical excitability."

It has been proposed that the underlying epileptic process is mediated by changes in both excitatory and inhibitory circuits leading to the formation of hyper-excitable seizure networks. In this review we aim to shed light on the many physiological factors that modulate excitability within these networks. These factors have been discussed extensively in many reviews each as a separate entity and cannot be extensively covered in a single manuscript. Thus for the purpose of this work in which we aim to bring those factors together to explain how they interact with epilepsy, we only provide brief descriptions. We present reported evidence supporting the existence of the epileptic brain in several states; interictal, peri-ictal and ictal, each with distinct excitability features. We then provide an overview of how many physiological factors influence the excitatory/inhibitory balance within the interictal state, where the networks are presumed to be functioning normally. We conclude that these changes result in constantly changing states of cortical excitability in patients with epilepsy.

Affiliation

Department of Clinical Neurosciences, St Vincent's Hospital, Fitzroy, Australia; Department of Medicine, The University of Melbourne, Parkville, Australia; Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville, Austra

Journal Details

This article was published in the following journal.

Name: Neuroscience
ISSN: 1873-7544
Pages: 89-99

Links

DeepDyve research library

PubMed Articles [8541 Associated PubMed Articles listed on BioPortfolio]

Cortical involvement in celiac disease before and after long-term gluten-free diet: A Transcranial Magnetic Stimulation study.

Transcranial Magnetic Stimulation in de novo patients with Celiac Disease previously revealed an imbalance in the excitability of cortical facilitatory and inhibitory circuits. After a median period o...

Epilepsy prevalence and severity predictors in MRI-identified focal cortical dysplasia.

To determine the prevalence of epilepsy and drug-resistant epilepsy in pediatric patients with focal cortical dysplasia (FCD) identified by magnetic resonance imaging (MRI). To determine clinical and ...

Excitability of the motor cortex in patients with migraine changes with the time elapsed from the last attack.

Motor-evoked potentials (MEPs) produced by single-pulse transcranial magnetic stimulation (TMS) of the motor cortex can be an objective measure of cortical excitability. Previously, MEP thresholds wer...

High frequency activity overriding cortico-cortical evoked potentials reflects altered excitability in the human epileptic focus.

We aimed to clarify that high frequency activity (HFA) of cortico-cortical evoked potentials (CCEPs), elicited by single pulse electrical stimulation (SPES), reflects cortical excitability.

The role of genetic testing in epilepsy diagnosis and management.

Epilepsy is a common neurological disorder characterized by recurrent unprovoked seizures. More than 500 epilepsy-associated genes have been described in the literature. Most of these genes play an im...

Clinical Trials [2187 Associated Clinical Trials listed on BioPortfolio]

Cortical Excitability Assessment Using Paired Pulses

The identification of the epileptogenic zone (EZ) during pharmacoresistant focal epilepsy presurgical assessment frequently requires intracranial recordings like stereo-electroencephalogra...

Transcranial Magnetic Stimulation and Anti-Epileptic Effect: Optimization and Evaluation With Electrophysiology.

Epileptic disease is characterised by enhanced brain excitability. Low frequency repetitive transcranial magnetic stimulation (rTMS) can be an effective treatment for refractory frontal ep...

RESET Treatment of Epilepsy

The goal of the present clinical trial is to determine whether low frequency (.5 Hz) rTMS can induce long term depression in epileptogenic cortex and thus suppress cortical excitability at...

Cortical Excitability Using Transcranial Magnetic Stimulation and Neuronavigation Device

This study has two main goals : - to investigate the impact of aging on cortical excitability (CE) - to investigate the impact of "state dependency" on CE, using a cognitive task a...

Neuronal Excitability of HCN1 Channel Mutations in Dravet Syndrome

This study addresses the changes in the axonal excitability parameters. It will compare these changes in patients with early infantile epileptic encephalopathy with HCN1 channel mutation a...

Medical and Biotech [MESH] Definitions

Measurable changes in activities in the CEREBRAL CORTEX upon a stimulation. A change in cortical excitability as measured by various techniques (e.g., TRANSCRANIAL MAGNETIC STIMULATION) is associated with brain disorders.

Heterogeneous disorders of cortical malformation characterized by excessive and small fused gyri and shallow sulci of the CORTEX with abnormal cortical lamination. It is considered a malformation secondary to abnormal post-migrational development of the neurons during cerebral cortical development and is associated with EPILEPSY and learning difficulties.

A neurosurgical procedure that removes or disconnects the epileptogenic CEREBRAL CORTEX of a hemisphere. Hemispherectomy is usually performed for patients with intractable unilateral EPILEPSY due to malformations of cortical development or brain lesions. Depending on the epileptogenic area in the hemisphere, cortical removal can be total or partial.

Cortical malformations secondary to abnormal cortical maturation after CELL MIGRATION in NEUROGENESIS. This group includes injury to the cortex during later stages of cortical development such as POLYMICROGYRIA and focal cortical dysplasias.

A disorder characterized by recurrent partial seizures marked by impairment of cognition. During the seizure the individual may experience a wide variety of psychic phenomenon including formed hallucinations, illusions, deja vu, intense emotional feelings, confusion, and spatial disorientation. Focal motor activity, sensory alterations and AUTOMATISM may also occur. Complex partial seizures often originate from foci in one or both temporal lobes. The etiology may be idiopathic (cryptogenic partial complex epilepsy) or occur as a secondary manifestation of a focal cortical lesion (symptomatic partial complex epilepsy). (From Adams et al., Principles of Neurology, 6th ed, pp317-8)

Quick Search
Advertisement
 


DeepDyve research library

Relevant Topics

Epilepsy
Epilepsy is defined as a disorder of brain function characterized by recurrent seizures that have a sudden onset.  (Oxford Medical Dictionary).  A seizure is caused by a sudden burst of excess electrical activity in the brain, causing a tempora...

Alzheimer's Disease
Of all the types of Dementia, Alzheimer's disease is the most common, affecting around 465,000 people in the UK. Neurons in the brain die, becuase  'plaques' and 'tangles' (mis-folded proteins) form in the brain. People with Al...


Searches Linking to this Article