In vivo 1H magnetic resonance spectroscopy, T2-weighted and diffusion-weighted MRI during lithium–pilocarpine-induced status epilepticus in the rat
| Autor: | Klaas Nicolay, Robbert G. E. Notenboom, Pieter van Eijsden, Pierre N. E. De Graan, Ona Wu, Kees P.J. Braun, Onno van Nieuwenhuizen |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Male
Pathology medicine.medical_specialty Excitotoxicity Status epilepticus Lithium Muscarinic Agonists Hippocampal formation medicine.disease_cause Epileptogenesis Epilepsy Status Epilepticus Nuclear magnetic resonance medicine Animals Effective diffusion coefficient Rats Wistar Molecular Biology medicine.diagnostic_test Chemistry General Neuroscience Pilocarpine Brain Magnetic resonance imaging medicine.disease Rats Disease Models Animal Diffusion Magnetic Resonance Imaging nervous system Neurology (clinical) medicine.symptom Developmental Biology medicine.drug |
| Zdroj: | Brain Research, 1030(1), 11-18. Elsevier |
| ISSN: | 0006-8993 |
| Popis: | Temporal lobe epilepsy (TLE) is associated with febrile convulsions and childhood status epilepticus (SE). Since the initial precipitating injury, triggering epileptogenesis, occurs during this SE, we aimed to examine the metabolic and morphological cerebral changes during the acute phase of experimental SE noninvasively. In the rat lithium–pilocarpine model of SE, we performed quantified T2- and isotropic-diffusion-weighted (DW) magnetic resonance imaging (MRI) at 3 and 5 h of SE and acquired single-voxel 1H MR spectra at 2, 4 and 6 h of SE. T2 was globally decreased, most pronounced in the amygdala (Am) and piriformic cortex (Pi), in which also a significant decrease in apparent diffusion coefficient (ADC) was found. In contrast, ADC values increased transiently in the hippocampus (HC) and thalamus (Th). MR spectra showed a decrease in N-acetylaspartate (NAA) and choline (Cho) and an increase of lactate in a hippocampal voxel. Discussion: The T2 decrease, attributed to raised deoxyhemoglobin, and the presence of lactate both indicate a mismatch between oxygen demand and delivery. The ADC decrease, indicative of excitotoxicity, confirms that the amygdala and piriformic cortex are particularly vulnerable to lithium–pilocarpine-induced seizures. The transient ADC increase in the thalamus may reflect the breakdown of the blood–brain barrier (BBB), which is shown to occur in this region at these time points. Neuronal damage and failure of energy-dependent formation of NAA are likely causes of an observed decrease in NAA, while the decrease in Cho is possibly due to depletion of the cholinergic system. This study illustrates that relative hypoxia, excitotoxicity and concomitant neuronal damage associated with SE can be probed noninvasively with MR. These pathological phenomena are the first to contribute to the pathophysiology of spontaneous recurrent seizures in a later stage in this animal model. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect