In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy

Robert C. Knowlton, K. D. Laxer, G. Klein, S. Sawrie, G. Ende, R. A. Hawkins, O. S. Aassar, K. Soohoo, S. Wong, Nicholas Barbaro

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

Background: The appearance of decreased 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake in the mesial temporal region in temporal lobe epilepsy may simply reflect loss of gray matter due to hippocampal atrophy. Increased partial volume effects due to atrophic hippocampi may further increase appearance of hypometabolism. Methods: The authors used a combination of MRI-PET coregistration, with MRI-based gray matter segmentation, and partial volume correction to improve the examination of hippocampal specific glucose uptake in FDG PET. The goal was to determine 1) if relative mesial temporal hypometabolism is an artifact of gray matter (hippocampal) atrophy, 2) whether hippocampal metabolism correlates with atrophy evaluated on MRI, and 3) if MRI-based partial volume correction influences measurement of hippocampal metabolic-volume relationships, including epilepsy lateralization. Results: Findings showed that ipsilateral hippocampi of mesial temporal lobe epilepsy (MTLE) are relatively hypometabolic per unit of gray matter volume, and that hippocampal metabolism directly correlates with hippocampal volume. Specifically, partial volume corrected hippocampal metabolism correlated strongly (r = 0.613, p <0.001) with hippocampal volume. Without partial volume correction, a weaker, but still significant, correlation was present (r = 0.482, p <0.001). Degree of asymmetry was consistently greater and provided higher sensitivity of lateralization with partial volume vs non-partial volume corrected metabolic measurements. Conclusions: Although, decreased metabolism may occur in the absence of neuronal cell loss, hippocampal atrophy and presumed degree of neuronal cell loss appears to be a primary factor involved in the cause of decreased metabolism in epileptogenic hippocampi. Partial volume correction is recommended for optimal interpretation of hippocampal structure and function relationships.

Original languageEnglish (US)
Pages (from-to)1184-1190
Number of pages7
JournalNeurology
Volume57
Issue number7
StatePublished - Oct 9 2001
Externally publishedYes

Fingerprint

Temporal Lobe Epilepsy
Atrophy
Glucose
Hippocampus
Fluorodeoxyglucose F18
Deoxyglucose
Temporal Lobe
Artifacts
Epilepsy
Gray Matter

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Knowlton, R. C., Laxer, K. D., Klein, G., Sawrie, S., Ende, G., Hawkins, R. A., ... Barbaro, N. (2001). In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy. Neurology, 57(7), 1184-1190.

In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy. / Knowlton, Robert C.; Laxer, K. D.; Klein, G.; Sawrie, S.; Ende, G.; Hawkins, R. A.; Aassar, O. S.; Soohoo, K.; Wong, S.; Barbaro, Nicholas.

In: Neurology, Vol. 57, No. 7, 09.10.2001, p. 1184-1190.

Research output: Contribution to journalArticle

Knowlton, RC, Laxer, KD, Klein, G, Sawrie, S, Ende, G, Hawkins, RA, Aassar, OS, Soohoo, K, Wong, S & Barbaro, N 2001, 'In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy', Neurology, vol. 57, no. 7, pp. 1184-1190.
Knowlton RC, Laxer KD, Klein G, Sawrie S, Ende G, Hawkins RA et al. In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy. Neurology. 2001 Oct 9;57(7):1184-1190.
Knowlton, Robert C. ; Laxer, K. D. ; Klein, G. ; Sawrie, S. ; Ende, G. ; Hawkins, R. A. ; Aassar, O. S. ; Soohoo, K. ; Wong, S. ; Barbaro, Nicholas. / In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy. In: Neurology. 2001 ; Vol. 57, No. 7. pp. 1184-1190.
@article{509ff1a020e9488ab28c2841cb72f6dd,
title = "In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy",
abstract = "Background: The appearance of decreased 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake in the mesial temporal region in temporal lobe epilepsy may simply reflect loss of gray matter due to hippocampal atrophy. Increased partial volume effects due to atrophic hippocampi may further increase appearance of hypometabolism. Methods: The authors used a combination of MRI-PET coregistration, with MRI-based gray matter segmentation, and partial volume correction to improve the examination of hippocampal specific glucose uptake in FDG PET. The goal was to determine 1) if relative mesial temporal hypometabolism is an artifact of gray matter (hippocampal) atrophy, 2) whether hippocampal metabolism correlates with atrophy evaluated on MRI, and 3) if MRI-based partial volume correction influences measurement of hippocampal metabolic-volume relationships, including epilepsy lateralization. Results: Findings showed that ipsilateral hippocampi of mesial temporal lobe epilepsy (MTLE) are relatively hypometabolic per unit of gray matter volume, and that hippocampal metabolism directly correlates with hippocampal volume. Specifically, partial volume corrected hippocampal metabolism correlated strongly (r = 0.613, p <0.001) with hippocampal volume. Without partial volume correction, a weaker, but still significant, correlation was present (r = 0.482, p <0.001). Degree of asymmetry was consistently greater and provided higher sensitivity of lateralization with partial volume vs non-partial volume corrected metabolic measurements. Conclusions: Although, decreased metabolism may occur in the absence of neuronal cell loss, hippocampal atrophy and presumed degree of neuronal cell loss appears to be a primary factor involved in the cause of decreased metabolism in epileptogenic hippocampi. Partial volume correction is recommended for optimal interpretation of hippocampal structure and function relationships.",
author = "Knowlton, {Robert C.} and Laxer, {K. D.} and G. Klein and S. Sawrie and G. Ende and Hawkins, {R. A.} and Aassar, {O. S.} and K. Soohoo and S. Wong and Nicholas Barbaro",
year = "2001",
month = "10",
day = "9",
language = "English (US)",
volume = "57",
pages = "1184--1190",
journal = "Neurology",
issn = "0028-3878",
publisher = "Lippincott Williams and Wilkins",
number = "7",

}

TY - JOUR

T1 - In vivo hippocampal glucose metabolism in mesial temporal lobe epilepsy

AU - Knowlton, Robert C.

AU - Laxer, K. D.

AU - Klein, G.

AU - Sawrie, S.

AU - Ende, G.

AU - Hawkins, R. A.

AU - Aassar, O. S.

AU - Soohoo, K.

AU - Wong, S.

AU - Barbaro, Nicholas

PY - 2001/10/9

Y1 - 2001/10/9

N2 - Background: The appearance of decreased 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake in the mesial temporal region in temporal lobe epilepsy may simply reflect loss of gray matter due to hippocampal atrophy. Increased partial volume effects due to atrophic hippocampi may further increase appearance of hypometabolism. Methods: The authors used a combination of MRI-PET coregistration, with MRI-based gray matter segmentation, and partial volume correction to improve the examination of hippocampal specific glucose uptake in FDG PET. The goal was to determine 1) if relative mesial temporal hypometabolism is an artifact of gray matter (hippocampal) atrophy, 2) whether hippocampal metabolism correlates with atrophy evaluated on MRI, and 3) if MRI-based partial volume correction influences measurement of hippocampal metabolic-volume relationships, including epilepsy lateralization. Results: Findings showed that ipsilateral hippocampi of mesial temporal lobe epilepsy (MTLE) are relatively hypometabolic per unit of gray matter volume, and that hippocampal metabolism directly correlates with hippocampal volume. Specifically, partial volume corrected hippocampal metabolism correlated strongly (r = 0.613, p <0.001) with hippocampal volume. Without partial volume correction, a weaker, but still significant, correlation was present (r = 0.482, p <0.001). Degree of asymmetry was consistently greater and provided higher sensitivity of lateralization with partial volume vs non-partial volume corrected metabolic measurements. Conclusions: Although, decreased metabolism may occur in the absence of neuronal cell loss, hippocampal atrophy and presumed degree of neuronal cell loss appears to be a primary factor involved in the cause of decreased metabolism in epileptogenic hippocampi. Partial volume correction is recommended for optimal interpretation of hippocampal structure and function relationships.

AB - Background: The appearance of decreased 2-[18F]fluoro-2-deoxy-D-glucose (FDG) uptake in the mesial temporal region in temporal lobe epilepsy may simply reflect loss of gray matter due to hippocampal atrophy. Increased partial volume effects due to atrophic hippocampi may further increase appearance of hypometabolism. Methods: The authors used a combination of MRI-PET coregistration, with MRI-based gray matter segmentation, and partial volume correction to improve the examination of hippocampal specific glucose uptake in FDG PET. The goal was to determine 1) if relative mesial temporal hypometabolism is an artifact of gray matter (hippocampal) atrophy, 2) whether hippocampal metabolism correlates with atrophy evaluated on MRI, and 3) if MRI-based partial volume correction influences measurement of hippocampal metabolic-volume relationships, including epilepsy lateralization. Results: Findings showed that ipsilateral hippocampi of mesial temporal lobe epilepsy (MTLE) are relatively hypometabolic per unit of gray matter volume, and that hippocampal metabolism directly correlates with hippocampal volume. Specifically, partial volume corrected hippocampal metabolism correlated strongly (r = 0.613, p <0.001) with hippocampal volume. Without partial volume correction, a weaker, but still significant, correlation was present (r = 0.482, p <0.001). Degree of asymmetry was consistently greater and provided higher sensitivity of lateralization with partial volume vs non-partial volume corrected metabolic measurements. Conclusions: Although, decreased metabolism may occur in the absence of neuronal cell loss, hippocampal atrophy and presumed degree of neuronal cell loss appears to be a primary factor involved in the cause of decreased metabolism in epileptogenic hippocampi. Partial volume correction is recommended for optimal interpretation of hippocampal structure and function relationships.

UR - http://www.scopus.com/inward/record.url?scp=0035833917&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035833917&partnerID=8YFLogxK

M3 - Article

C2 - 11591833

AN - SCOPUS:0035833917

VL - 57

SP - 1184

EP - 1190

JO - Neurology

JF - Neurology

SN - 0028-3878

IS - 7

ER -