TITLE

Increased thalamus levels of glutamate and glutamine (Gix) in patients with idiopathic generalised epilepsy

AUTHOR(S)
Helms, G.; Ciumas, C.; Kyaga, S.; Savic, I.
PUB. DATE
April 2006
SOURCE
Journal of Neurology, Neurosurgery & Psychiatry;Apr2006, Vol. 77 Issue 4, p489
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Objective: Abnormal thalamo-cortical oscillations underlie idiopathic generalised epilepsy (IGE). Although thalamic involvement has long been indicated by electrophysiological data, it has only recently become feasible to test this with independent methods. In this magnetic resonance (MR) study, we investigated the metabolic and structural integrity of the thalamus. Possible changes in glutamine and glutamate concentrations and signs of neuronal damage were of particular interest. Method: Forty three IGE patients and 38 age and sex matched healthy controls were investigated. Quantitative single volume MR spectroscopy (MRS, 1.5 T) was used to measure concentrations of glutamate and glutamine (Glx) and N-acetyl aspartate (NAA) in thalamus and occipital cortex. We also measured thalamic volumes on high resolution gradient-echo images and estimated fractions of thalamic grey and white matter with voxel based morphometry (VBM). Results: IGE patients showed elevated Glx and reduced NAA concentrations in the thalamus compared to controls (12.2±2.6 v 8.9±4.1 mM, p=0.0022 for Glx, and 9.9±1.0 v 10.7±0.9 mM, p=0.017 for NAA). Thalamic grey matter fraction was reduced in IGE patients, and white matter fraction was increased with the greatest increase in the dorso-medial thalamus. Mean thalamic volume was reduced in patients (6.7±0.7 v 7.2±0.6 ml in controls, p=0.0001), as was mean cerebral volume (1163±128 v 1250±102 ml, p=0.0003). Patients' thalamus/whole brain ratios were normal. Conclusion: Quantitative MRS and VBM provide further evidence for involvement of the thalamus in IGE. The observed elevation of Glx levels together with reductions in NAA levels and grey matter fractions are consistent with epilepsy related excitoxicity as a possible underlying mechanism.
ACCESSION #
20737384

 

Related Articles

  • Catastrophe Theory Enables Moves to be Detected Towards and Away from Self-Organization: The Example of Epileptic Seizure Onset. Cerf, Roger // Biological Cybernetics;Jun2006, Vol. 94 Issue 6, p459 

    Macroscopic systems with many interacting subunits, when driven far from equilibrium, exhibit self-organization, for example when a pathological rhythm appears suddenly in an epileptic patient. Sudden changes occurring while conditions vary smoothly have, in cases of interest, underlying...

  • Classification Control for Discrimination between Interictal Epileptic and Non -- Epileptic Pathological EEG Events. Papavlasopoulos, Sozon H.; Poulos, Marios S.; Bokos, George D.; Evangelou, Angelos M. // International Journal of Biomedical Sciences;2006, Vol. 1 Issue 1, p34 

    In this study, the problem of discriminating between interictal epileptic and non- epileptic pathological EEG cases, which present episodic loss of consciousness, investigated. We verify the accuracy of the feature extraction method of autocross-correlated coefficients which extracted and...

  • Coherence Analysis for Epilepsy Patients: An MEG Study. Ge, S.; Wu, T.; Tang, H. Y.; Xiao, X.; Iramina, K.; Wu, W. // World Academy of Science, Engineering & Technology;Aug2011, Issue 56, p517 

    It is crucial to quantitatively evaluate the treatment of epilepsy patients. This study was undertaken to test the hypothesis that compared to the healthy control subjects, the epilepsy patients have abnormal resting-state connectivity. In this study, we used the imaginary part of coherency to...

  • A Glossary of Terms Used for PLEDs (Periodic Lateralized Epileptiform Discharges) and Related EEG Patterns. Sazgar, Mona; Westmoreland, Barbara F.; Sharbrough, Frank W.; Klass, Donald W. // American Journal of Electroneurodiagnostic Technology;Sep2003, Vol. 43 Issue 3, p185 

    Since the term periodic lateralized epileptiform discharges (PLEDs) was first coined by Chatrian et al. in 1964, there has been an evolution of terms used to describe variants of this EEG pattern. This article is an attempt to collect and define various terms used to describe these patterns.

  • Spike—wave Discharges: Absence or Not, a Common Finding in Common Laboratory Rats. Kelly, Kevin M. // Epilepsy Currents;Sep/Oct2004, Vol. 4 Issue 5, p176 

    Presents a study which focused on the behavioral detection of tactile stimuli during cortical oscillations. Purpose of the use of spike-wave discharge (SWD) as a model of absence seizures; Assessment of perception and auditory information processing during SWD; Association of behavioral...

  • Pusher Syndrome – a frequent but little-known disturbance of body orientation perception. Karnath, Hans-Otto // Journal of Neurology;Apr2007, Vol. 254 Issue 4, p415 

    Disturbances of body orientation perception after brain lesions may specifically relate to only one dimension of space. Stroke patients with “pusher syndrome” suffer from a severe misperception of their body's orientation in the coronal (roll) plane. They experience their body as...

  • WAVEFORM WINDOW.  // American Journal of Electroneurodiagnostic Technology;Sep2005, Vol. 45 Issue 3, p200 

    Analyzes the elecroencephalographic pattern taken from a female patient who experienced episodes of staring and unresponsiveness. Examples of the patient's alpha background; Description of the mu rhythm of the brain; Comparison between mu and posterior alpha rhythm.

  • Some Highlights on Epileptic EEG Processing. Wang, Jing; Xu, Guanghua // Recent Patents on Biomedical Engineering;Jan2009, Vol. 2 Issue 1, p48 

    Abstract: Epilepsy is one of the most serious neurological diseases, second only to stroke, with a prevalence of approximately 1% of the world's population. Electroencephalogram (EEG), a summation of electrical activities generated by cortical neurons, was first recorded in 1924 by Hans Berger....

  • An investigation of the phase locking index for measuring of interdependency of cortical source signals recorded in the EEG. Sazonov, Andrei V.; Chin Keong Ho; Bergmans, Jan W. M.; Arends, Johan B. A. M.; Griep, Paul A. M.; Verbitskiy, Evgeny A.; Cluitmans, Pierre J. M.; Boon, Paul A. J. M. // Biological Cybernetics;Feb2009, Vol. 100 Issue 2, p129 

    The phase locking index (PLI) was introduced to quantify in a statistical sense the phase synchronization of two signals. It has been commonly used to process biosignals. In this article, we investigate the PLI for measuring the interdependency of cortical source signals (CSSs) recorded in the...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sign out of this library

Other Topics