Non-invasive detection of hippocampal sclerosis: correlation between metabolite alterations detected by (1)H-MRS and neuropathology.
We assessed (1)H-MRS as a screening tool for detection of hippocampal sclerosis in patients with temporal lobe epilepsy (TLE). (1)H-MRS was carried out in the hippocampus of 23 patients with unilateral TLE. Metabolite alterations detected by (1)H-MRS correlated with degree of segmental neuronal cell loss and amount of astrogliosis. Positive correlation was found between total N-Acetylaspartate (tNAA) reduction and neuronal density in hippocampal CA1 (P < 0.001), CA3 (P = 0.015), and CA4 subfields (P = 0.031) and the dentate gyrus (P = 0.006). Neuronal cell loss in CA1 turned out to be the most predictive and only significant variable for tNAA reduction (P = 0.027). The association between myo-inositol (m-Ins) and astroglial glial fibrillary acidic protein (GFAP) expression revealed significantly increased m-Ins concentrations associated with diffuse astrogliosis (m-Ins = 6.4 +/- 1.1 institutional units) compared with gliosis restricted to isolated sectors of the hippocampus (i.e. hilus) (m-Ins = 5.2 +/- 1.2 institutional units) (P = 0.039). A negative correlation was found between m-Ins and neuronal loss in the CA4 subfield of the hippocampus (P = 0.028). Our results support (1)H-MRS as a suitable non-invasive method for preoperative identification of hippocampal sclerosis in patients with TLE. The extent of tNAA reduction correlates with hippocampal neuronal cell density. Furthermore, m-Ins is associated with the extent of hippocampal astrogliosis.
Hammen
Thilo
T
Center Epilepsy Erlangen (ZEE), Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany. thilo.hammen@uk-erlangen.de
Hildebrandt
Michelle
M
Stadlbauer
Andreas
A
Doelken
Marc
M
Engelhorn
Tobias
T
Kerling
Frank
F
Kasper
Burkhard
B
Romstoeck
Johann
J
Ganslandt
Oliver
O
Nimsky
Christopher
C
Blumcke
Ingmar
I
Doerfler
Arndt
A
Stefan
Hermann
H
D000293:Adolescent; D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007223:Infant; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011522:Protons; D015203:Reproducibility of Results; D012598:Sclerosis / Q000175:diagnosis* / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014018:Tissue Distribution
D015415:Biomarkers; D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate