Usefulness of proton MR spectroscopy in the evaluation of temporal lobe epilepsy.

Thompson, Jill E.; Castillo, Maurício; Kwock, Lester; Walters, Bradford L.; Beach, Robert L.

doi:10.2214/ajr.170.3.9490972

Cited by 20 publications

(28 citation statements)

References 13 publications

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“…[15][16][17][18] NAA is present in high concentration in neurons, but its exact role in the brain is unknown. NAA is considered a marker of neuronal attenuation and viability, and its concentration decreases in response to various types of insults to the brain.…”

Section: Controls Patientsmentioning

confidence: 99%

Multivoxel Proton MR Spectroscopy in Malformations of Cortical Development

Leite¹,

Lucato²,

Sato³

et al. 2007

American Journal of Neuroradiology

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BACKGROUND AND PURPOSE:Malformations of cortical development (MCD) are traditionally considered as a cause of epilepsy. Our aim was to study patients with focal MCD, by using multivoxel proton MR spectroscopy; we focused not only on the lesion but also on the normal-appearing contralateral side (NACS). Our hypothesis was that the metabolic abnormality extends to the NACS; therefore, it would be inadequate to consider NACS as an internal control.

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Section: Controls Patientsmentioning

confidence: 99%

Multivoxel Proton MR Spectroscopy in Malformations of Cortical Development

Leite¹,

Lucato²,

Sato³

et al. 2007

American Journal of Neuroradiology

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“…However, in studies of neurodegenerative diseases, other areas of the brain, such as the basal ganglia and medial temporal lobe, could be interesting as these are known to be sites of early biochemical changes and therefore potentially enable the early detection of the disease (7). As an example, MRS of the temporal lobe has been used extensively in studies of epilepsy (7)(8)(9)(10)(11), schizophrenia (12) and, in particular, Alzheimer's disease (13)(14)(15)(16)(17). However, obtaining high-quality 1 H MRS from this region is highly challenging.…”

Section: Introductionmentioning

confidence: 99%

Improvements in high‐field localized MRS of the medial temporal lobe in humans using new deformable high‐dielectric materials

et al. 2010

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The intrinsic nonuniformities in the transmit radiofrequency field from standard quadrature volume resonators at high field are particularly problematic for localized MRS in areas such as the temporal lobe, where a low signal-to-noise ratio and poor metabolite quantification result from destructive B₁⁺ field interference, in addition to line broadening and signal loss from strong susceptibility gradients. MRS of the temporal lobe has been performed in a number of neurodegenerative diseases at clinical fields, but a relatively low signal-to-noise ratio has prevented the reliable quantification of, for example, glutamate and glutamine, which are thought to play a key role in disease progression. Using a recently developed high-dielectric-constant material placed around the head, localized MRS of the medial temporal lobe using the stimulated echo acquisition mode sequence was acquired at 7 T. The presence of the material increased the signal-to-noise ratio of MRS by a factor of two without significantly reducing the sensitivity in other areas of the brain, as shown by the measured B₁⁺ maps. An increase in the receive sensitivity B₁⁻ was also measured close to the pads. The spectral linewidth of the unsuppressed water peak within the voxel of interest was reduced slightly by the introduction of the dielectric pads (although not to a statistically significant degree), a result confirmed by using a pad composed of lipid. Using LCmodel for quantitative analysis of metabolite concentrations, the increase in signal-to-noise ratio and the slight decrease in spectral linewidth contributed to statistically significant reductions in the Cramer-Rao lower bounds (CRLBs), also allowing the levels of glutamate and glutamine to be quantified with CRLBs below 20%.

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“…Amplamente descrita na literatura e com resultados variáveis a maioria dos estudos nos relatam que os pacientes com EMT sofrem uma diminuição significativa na concentração de NAA e da razão NAA/Cr, [11][12][13][14][15][16] outros apresentaram apenas diminuição na concentração NAA sem alterações de Cr ou NAA/Cr, 18,19 porém alguns nos mostraram um aumento de Cr no hipocampo ipsilateral. 11 A concentração de NAA se encontra significativamente diminuída nos hipocampos ipsilaterais quando comparados com indivíduos controles em todos os estudos.…”

Section: Resultsunclassified

“…Diferente dos resultados de Thompson et al 18 o hipocampo contralateral dos pacientes de ambos os grupos do estudo não se apresentou semelhante ao grupo controle. No entanto a relação NAA/Cr ipsi apresentou redução significativa apenas para o grupo de concordantes enquanto que a relação NAA/ Cr contra estava diminuída apenas no grupo de pacientes discordantes.…”

Section: Resultsunclassified

“…Atualmente tem sido amplamente utilizada na avaliação pré-operatória de pacientes com epilepsia refratária, especialmente nos casos de EMT, pois pode detectar sutis mudanças na concentração dos metabólitos estudados que podem ser implicados na geração das crises. [11][12][13][14][15][16][17][18][19][20][21] OBJETIVO O objetivo desse estudo é verificar se as alterações metabólicas no hipocampo são diferentes para os grupos de pacientes concordantes e discordantes.…”

Section: Introductionunclassified

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Metabolic differences in the contralateral hippocampus of concordant and discordant mesial temporal sclerosis (MTS) patients: evaluation with proton magnetic resonance spectroscopy (1H-MRS)

Nascimento¹,

Ej²,

Lyra³

et al. 2012

J. epilepsy clin. neurophysiol.

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RESUMOObjetivo: Pacientes com esclerose mesial temporal (EMT) são clinicamente classificados como concordantes ou discordantes de acordo com a extensão da atividade epileptogênica. O objetivo desse estudo é verificar se as alterações metabólicas no hipocampo são diferentes nos dois grupos. Materiais e métodos: Foram avaliados 33 pacientes diagnosticados com EMT, 23 concordantes (33±9 anos) e 10 discordantes (33±10 anos), e 28 controles (33±10 anos). Foi obtida espectroscopia por ressonância magnética de ambos os hipocampos (ipsi e contralateral) com aparelho de 3T e com a sequência PRESS de vóxel único com TE/TR=135/1500ms. Os principais metabólitos foram quantificados com o LCModel. Para a comparação entre os grupos foram realizados testes estatísticos com nível de significância de 0,05. Resultados: Para todos os pacientes foi observada redução de NAA ipsi e Cr ipsi quando comparado com o lado contralateral, porém esta diferença foi significativa apenas para o grupo de pacientes concordantes. Quando comparado com o grupo controles houve uma redução significativa de Cr ipsi e NAA ipsi para os dois grupos e da relação NAA/Cr ipsi para o grupo de pacientes concordantes enquanto que a relação NAA/Cr contra estava diminuída apenas no grupo de pacientes discordantes. Conclusão: Nossos achados sugerem uma maior diminuição do NAA/Cr ipsi no grupo de pacientes concordantes e da relação NAA/Cr contra no grupo de pacientes discordantes apontando para um padrão diferente de alteração metabólica para os dois grupos. Porém é preciso aumentar o tamanho da amostra para confirmar estes resultados. Unitermos: ressonância magnética (RM), espectroscopia por ressonância magnética (ERM), esclerose mesial temporal (EMT), concordante, discordante. ABSTRACT Metabolic differences in the contralateral hippocampus of concordant and discordant mesial temporal sclerosis (MTS) patients: evaluation with proton magnetic resonance spectroscopy (1H-MRS)Purpose: Patients with mesial temporal sclerosis (MTS) are clinically classified as concordant or discordant according to the extent of epileptogenic activity. The aim of this study is to determine whether the metabolic changes in the hippocampus are different in the two groups. Materials and Methods: 33 patients diagnosed with MTS, 23 concordant (33±9 years old) and 10 discordant (33±10 years old) and 28 controls (33±10 years old) were evaluated. We obtained magnetic resonance spectroscopy of both hippocampi (ipsilateral and contralateral) on a 3T scanner with single voxel PRESS sequence with TE/TR=135/1500ms. The main metabolites were quantified with LC Model. For comparison between groups statistical tests were performed with a significance level of 0.05. Results: In all patients a reduction of NAA ipsi and Cr ipsi was observed, when compared to the contralateral side, but this difference was only significant for the group of concordant patients. In comparison with controls a significant reduction of Cr ipsi and NAA ipsi was observed for both groups and for Naa/Cr ipsi in the group of concordan...

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Usefulness of proton MR spectroscopy in the evaluation of temporal lobe epilepsy.

Cited by 20 publications

References 13 publications

Multivoxel Proton MR Spectroscopy in Malformations of Cortical Development

Multivoxel Proton MR Spectroscopy in Malformations of Cortical Development

Improvements in high‐field localized MRS of the medial temporal lobe in humans using new deformable high‐dielectric materials

Metabolic differences in the contralateral hippocampus of concordant and discordant mesial temporal sclerosis (MTS) patients: evaluation with proton magnetic resonance spectroscopy (1H-MRS)

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