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نمایش مقاله

Title:

Altered Cerebral Perfusion in the Epileptogenic Lobe of Patients with MRI-Negative Drug-Resistant Epilepsy: A Quantitative Perfusion MRI Study

Subject:

Brain Mapping Applications in Epilepsy – Across Pediatric and Adult Populations

Presenter Author:
Name:	Asieh Fatemidokht

Author:
Name 1:	Asieh Fatemidokht - Corresponding - Presenter
Affiliation 1:	Department of Radiology, Faculty of Allied Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran

Name 2:	Keyvan Hassanzadeh
Affiliation 2:	Mojtaba Asadi Non-Profit Institute, Rafsanjan, Iran

Name 3:	Mohammad Ali Oghabian
Affiliation 3:	Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran

Name 4:	Mohammad Hossein Harirchian
Affiliation 4:	Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran

Name 5:	Abbas Tafakhori
Affiliation 5:	Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran

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Abstract

Original Research

introduction :

Drug-resistant epilepsy may be associated with functional and microvascular alterations that are not necessarily detectable on conventional structural magnetic resonance imaging (MRI). In patients with MRI-negative epilepsy, identification of subtle abnormalities within the epileptogenic tissue remains challenging. Quantitative perfusion MRI can provide measurements of cerebral hemodynamics and blood-brain barrier-related parameters and may therefore contribute to the characterization of occult abnormalities. Intra-individual comparison with the contralateral non-epileptogenic lobe may be particularly useful because it reduces the influence of inter-individual variability. To investigate quantitative perfusion abnormalities in the epileptogenic lobe of patients with drug-resistant, MRI-negative epilepsy using an intra-individual comparison with the contralateral non-epileptogenic lobe

Methods:

Seven patients with drug-resistant epilepsy and no apparent structural abnormality on routine MRI were examined using a 3-T MRI system. The epileptogenic lobe was identified based on video-electroencephalography (VEEG). Multiple regions of interest (ROIs) were placed in corresponding gray- and white-matter regions of the epileptogenic and contralateral non-epileptogenic lobes. Quantitative dynamic contrast-enhanced (DCE) perfusion MRI was performed to obtain the transfer constant (Ktrans), rate constant (Kep), blood volume fraction (Vb), cerebral blood volume (CBV), and cerebral blood flow (CBF). Magnetization transfer ratio (MTR) was additionally evaluated as a quantitative tissue-related parameter. Epileptogenic and contralateral regions were compared using paired statistical analyses, with statistical significance defined as p<0.05.

Results:

In gray matter, Ktrans was significantly higher in the epileptogenic lobe than in the contralateral non-epileptogenic lobe (0.717 vs. 0.393 mL/g/min, p=0.003). Gray-matter CBF was also significantly increased in the epileptogenic lobe (34.14 vs. 21.51, p=0.048). In contrast, no statistically significant differences were observed for gray-matter Kep (3.46 vs. 3.34, p=0.841), Vb (0.165 vs. 0.184, p=0.291), or CBV (1.82 vs. 2.12, p=0.437). In white matter, none of the evaluated perfusion parameters differed significantly between the epileptogenic and contralateral regions: Ktrans (0.633 vs. 0.404, p=0.483), Kep (3.23 vs. 3.03, p=0.878), Vb (0.140 vs. 0.194, p=0.155), CBV (1.91 vs. 1.53, p=0.315), and CBF (33.64 vs. 29.06, p=0.420). MTR differences were also not statistically significant.

Conclusion:

Quantitative perfusion MRI demonstrated significantly increased Ktrans and CBF in the gray matter of the VEEG-defined epileptogenic lobe in patients with drug-resistant, MRI-negative epilepsy. The findings indicate that measurable perfusion and blood-brain barrier-related differences may exist within the epileptogenic lobe despite the absence of apparent structural abnormalities on routine MRI. The intra-individual quantitative approach may provide complementary information for characterizing occult abnormalities in MRI-negative drug-resistant epilepsy and warrants further investigation in larger patient populations.

Keywords:

Drug-resistant epilepsy; MRI-negative epilepsy; perfusion MRI; Ktrans; cerebral blood flow; blood-brain barrier.