Temporal lobe epilepsy: presurgical localization with proton chemical shift imaging.

Ng, Thian C.; Comair, Youssef G.; Xue, Ming; So, Norman K.; Majors, Anthony W.; Kolem, H.; Lüders, Hans; Modic, Michael T.

doi:10.1148/radiology.193.2.7972764

Cited by 145 publications

(101 citation statements)

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“…Most studies included only a small number of patients, controls, or almost exclusively patients with MRI evidence for MTS. Some studies included patients suspected or proved to have bilateral independent TLE, a finding used to explain discordant or nonlateralized MRSI results [8,14]. The 1 H-MRSI sensitivity (55-65%) reported in the series by Connelly and associates [11] and Cross and colleagues [12], including some discordant lateralization, is nearly identical to our results.…”

Section: Mri (Diagnostic and Hv)-hv Lateralized 2 Additional Patientssupporting

confidence: 86%

“…1 H-MRSI-Our relatively low sensitivity with 1 H-MRSI lateralization contrasts with the nearly 100% sensitivity reported in some earlier studies, including our own [7][8][9]14,30,31].…”

Section: Mri (Diagnostic and Hv)-hv Lateralized 2 Additional Patientscontrasting

confidence: 85%

“…[29]. The value of T2 remains for both clinical and research purposes because it is simple to perform, is highly reliable (low variance in normals), and can be performed in any ROI.1 H-MRSI-Our relatively low sensitivity with 1 H-MRSI lateralization contrasts with the nearly 100% sensitivity reported in some earlier studies, including our own [7][8][9]14,30,31].Most studies included only a small number of patients, controls, or almost exclusively patients with MRI evidence for MTS. Some studies included patients suspected or proved to have bilateral independent TLE, a finding used to explain discordant or nonlateralized MRSI results [8,14].…”

mentioning

confidence: 79%

“…Several groups have reported the ability of 1 H-MRSI to detect unilateral and bilateral metabolite abnormalities in TLE [7][8][9][10][11][12][13][14][15][16][17]. No studies have compared 1 H-MRSI lateralization results directly with FDG-PET and quantitative MRI techniques in patients with and without hippocampal atrophy.…”

mentioning

confidence: 99%

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Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy

Knowlton

Laxer

Ende

et al. 1997

Annals of Neurology

127

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The purpose of this study was to compare 2-[ 18 F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), hippocampal volumetry (HV), T2 relaxometry, and proton magnetic resonance spectroscopic imaging ( 1 H-MRSI) in the presurgical neuroimaging lateralization of patients with nonlesional, electroencephalogram (EEG)-defined unilateral temporal lobe epilepsy (TLE). Twenty-five patients were prospectively studied, along with age-matched controls. T2 relaxometry examinations were performed in 13 patients. Comparison of FDG-PET, HV, and 1 H-MRSI was possible in 23 patients. FDG-PET lateralized 87% of patients, HV 65%, N-acetyl aspartate (NAA)/(choline [Cho] + creatine [Cr]) 61%, and [NAA] 57%. Combined HV and NAA/(Cho + Cr) results lateralized 83% of the patients, a value similar to PET. Of 10 patients with normal magnetic resonance imaging (MRI) scans, 2 were lateralized with HV, 6 with FDG-PET, 4 with NAA/(Cho + Cr), and 3 with [NAA]. T2 relaxometry lateralized no patients without hippocampal atrophy. Bilateral abnormality was present in 29 to 33% of patients with 1 H-MRSI measures and 17% with HV. Only hippocampal atrophy correlated with postoperative seizure-free outcome. FDG-PET remains the most sensitive imaging method to correlate with EEG-lateralized TLE. Both FDG-PET and 1 H-MRSI can lateralize patients with normal MRI, but only the presence of relative unilateral hippocampal atrophy is predictive of seizure-free outcome. Bilaterally abnormal MRI and 1 H-MRSI measures do not preclude good surgical outcome.Multiple imaging methods are available to help lateralize temporal lobe epilepsy (TLE). To minimize the requirement for intracranial electrodes and to localize the epileptogenic zone with increased confidence, 2-[ 18 F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) are used to provide confirmatory localizing information. Relative temporal lobe (TL) hypometabolism on FDG-PET and hippocampal atrophy or prolonged T2 signal on MRI predict reliably lateralization of the epileptogenic temporal lobe [1][2][3][4][5]. Localized TL hypometabolism on FDG-PET is reported to be more sensitive than the detection of lateralized abnormality on MRI [3]; however, little has been published on the direct comparison of FDG-PET to advanced MRI and magnetic resonance spectroscopic imaging (MRSI) techniques. Gaillard and colleagues [6] compared FDG-PET with MRI-based hippocampal volumetry (HV) and showed that although FDG-PET was more Copyright © 1997 Patients and Methods Patients and Epilepsy EvaluationPatient selection commenced in April 1994 as part of a prospective imaging project with PET and MRSI at University of California, San Francisco (UCSF). Informed consent was obtained from all subjects according to guidelines of the UCSF Committee on Human Research. All surgical candidates suspected to have seizures arising from the TLs between April 1994 and June 1995 were screened for selection. After scalp-sphenoidal EEG/video telemetry, 36 patients were su...

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Section: Mri (Diagnostic and Hv)-hv Lateralized 2 Additional Patientssupporting

confidence: 86%

“…1 H-MRSI-Our relatively low sensitivity with 1 H-MRSI lateralization contrasts with the nearly 100% sensitivity reported in some earlier studies, including our own [7][8][9]14,30,31].…”

Section: Mri (Diagnostic and Hv)-hv Lateralized 2 Additional Patientscontrasting

confidence: 85%

mentioning

confidence: 79%

mentioning

confidence: 99%

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Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy

Knowlton

Laxer

Ende

et al. 1997

Annals of Neurology

127

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“…The reduction was reported either in absolute units or as a ratio to choline-containing compounds (Ch) and/ or creatine/phosphocreatine (Cr). Several recent reports have shown that NAA in the contralateral side is also reduced in many mTLE subjects [8,10,11], suggesting contralateral damage. Structural abnormalities of both hippocampi have also been detected in an autopsy study of TLE [12].…”

mentioning

confidence: 99%

Hippocampal N‐acetylaspartate in neocortical epilepsy and mesial temporal lobe epilepsy

Vermathen

Ende

Laxer

et al. 1997

Annals of Neurology

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Previous magnetic resonance spectroscopy (MRS) studies have shown that N-acetylaspartate (NAA) is reduced not only in the ipsilateral but also in the contralateral hippocampus of many patients with mesial temporal lobe epilepsy (mTLE). The reason for the contralateral damage is not clear. To test whether the hippocampus is also damaged if the focus is outside the hippocampus, we have measured patients with neocortical epilepsy (NE). Therefore, the goals of this study were to determine if hippocampal NAA is reduced in NE and if hippocampal NAA discriminates NE from mTLE. MRS imaging (MRSI) studies were performed on 10 NE patients and compared with MRSI results in 23 unilateral mTLE patients and 16 controls. The results show that, in contrast to mTLE, NAA was not reduced in the hippocampus of NE patients, neither ipsilateral nor contralateral to the seizure focus. These results suggest that repeated seizures do not cause secondary damage to the hippocampus. The absence of spectroscopic differences in NE may help to distinguish NE from mTLE.Approximately 30% of epilepsy patients have neocortical epilepsy (NE) [1] in which, in contrast to mesial temporal lobe epilepsy (mTLE), the focus is outside the hippocampus. Although these patients respond much less well than mTLE patients to medical treatment, neurosurgical removal is performed only rarely and with less success than in mTLE [2].This laboratory and others have previously shown that proton magnetic resonance spectroscopy ( 1 H MRS) can be used to lateralize the seizure focus in mTLE [3][4][5][6][7][8][9][10][11]. The correlation to the epileptogenic focus as defined by electroencephalography (EEG) was done on the basis of reduced N-acetylaspartate (NAA) in the hippocampus and/or the temporal lobe. The reduction was reported either in absolute units or as a ratio to choline-containing compounds (Ch) and/ or creatine/phosphocreatine (Cr). Several recent reports have shown that NAA in the contralateral side is also reduced in many mTLE subjects [8,10,11], suggesting contralateral damage. Structural abnormalities of both hippocampi have also been detected in an autopsy study of TLE [12]. Copyright © 1997 The following are the three possible explanations for the contralateral reduction of NAA in mTLE: (1) bilateral presence of mesial tempotal sclerosis, (2) seizures in one hippocampus causing secondary damage to the opposite hippocampus due to preferential pathways, and (3) damage to the contralateral hippocampus as a result of repeated seizure activity. If repeated seizure activity is responsible for reduced contralateral NAA, hippocampal NAA might also be reduced in NE. Therefore, the primary goal of our study was to determine if hippocampal NAA is reduced in NE. The finding may lead to a better understanding of contralateral damage in mTLE, or point to mechanistic differences between mTLE and NE.In some circumstances it can be difficult to distinguish NE from mTLE. Hence, a secondary goal was to test if hippocampal NAA results could be used to discrimina...

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The Value of PET Scan (and MRI and Wada Test) in Patients With Bitemporal Epileptiform Abnormalities

Benbadis

So²,

Antar³

et al. 1995

Archives of Neurology

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Temporal lobe epilepsy: presurgical localization with proton chemical shift imaging.

Abstract: NAA/Cho is an excellent marker for localizing the epileptogenic zone in TLE.

Cited by 145 publications

References 1 publication

Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy

Presurgical multimodality neuroimaging in electroencephalographic lateralized temporal lobe epilepsy

Hippocampal N‐acetylaspartate in neocortical epilepsy and mesial temporal lobe epilepsy

The Value of PET Scan (and MRI and Wada Test) in Patients With Bitemporal Epileptiform Abnormalities

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