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. 2020 Dec;61(12):2785-2794.
doi: 10.1111/epi.16731. Epub 2020 Oct 28.

Seven-tesla quantitative magnetic resonance spectroscopy of glutamate, γ-aminobutyric acid, and glutathione in the posterior cingulate cortex/precuneus in patients with epilepsy

Ofer M Gonen  1   2   3 , Bradford A Moffat  2 , Patricia M Desmond  2   4 , Elaine Lui  2   4 , Patrick Kwan  1   2   3   5 , Terence J O'Brien  1   2   3   5
Affiliations

Seven-tesla quantitative magnetic resonance spectroscopy of glutamate, γ-aminobutyric acid, and glutathione in the posterior cingulate cortex/precuneus in patients with epilepsy

Ofer M Gonen et al. Epilepsia. 2020 Dec.

Abstract

Objective: The posterior cingulate cortex (PCC)/precuneus is a key hub of the default mode network, whose function is known to be altered in epilepsy. Glutamate and γ-aminobutyric acid (GABA) are the main excitatory and inhibitory neurotransmitters in the central nervous system, respectively. Glutathione (GSH) is the most important free radical scavenging compound in the brain. Quantification of these molecules by magnetic resonance spectroscopy (MRS) up to 4 T is limited by overlapping resonances from other molecules. In this study, we used ultra-high-field (7 T) MRS to quantify their concentrations in patients with different epilepsy syndromes.

Methods: Nineteen patients with temporal lobe epilepsy (TLE) and 16 with idiopathic generalized epilepsy (IGE) underwent magnetic resonance imaging scans using a 7-T research scanner. Single-voxel (8 cm3 ) MRS, located in the PCC/precuneus, was acquired via stimulated echo acquisition mode. Their results were compared to 10 healthy volunteers.

Results: Mean concentrations of glutamate, GABA, and the glutamate/GABA ratio did not differ between the IGE, TLE, and healthy volunteer groups. The mean ± SD concentration of GSH was 1.9 ± 0.3 mmol·L-1 in healthy controls, 2.0 ± 0.2 mmol·L-1 in patients with TLE, and 2.2 ± 0.4 mmol·L-1 in patients with IGE. One-way analysis of variance with post hoc Tukey-Kramer test revealed a significant difference in the concentration of GSH between patients with IGE and controls (P = .03). Short-term seizure freedom in patients with epilepsy was predicted by an elevated concentration of glutamate in the PCC/precuneus (P = .01). In patients with TLE, the concentration of GABA declined with age (P = .03).

Significance: Patients with IGE have higher concentrations of GSH in the PCC/precuneus than healthy controls. There is no difference in the concentrations of glutamate and GABA, or their ratio, in the PCC/precuneus between patients with IGE, patients with TLE, and healthy controls. Measuring the concentration of glutamate in the PCC/precuneus may assist with predicting drug response.

Keywords: MRS; default mode network; epilepsy; glutathione; posterior cingulate cortex; precuneus.

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References

REFERENCES

    1. Benarroch EE. Glutamate transporters: diversity, function, and involvement in neurologic disease. Neurology. 2010;74(3):259-64.
    1. Kocsis JD, Mattson RH. GABA levels in the brain: a target for new antiepileptic drugs. Neuroscientist. 1996;2(6):326-34.
    1. van Veenendaal TM, IJff DM, Aldenkamp AP, Hofman PAM, Vlooswijk MCG, Rouhl RPW, et al. Metabolic and functional MR biomarkers of antiepileptic drug effectiveness: a review. Neurosci Biobehav Rev. 2015;59:92-9.
    1. Rae CD, Williams SR. Glutathione in the human brain: review of its roles and measurement by magnetic resonance spectroscopy. Anal Biochem. 2017;529:127-43.
    1. Ono H, Sakamoto A, Sakura N. Plasma total glutathione concentrations in epileptic patients taking anticonvulsants. Clin Chim Acta. 2000;298:135-43.

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