Whole-brain analysis of amyotrophic lateral sclerosis by using echo-planar spectroscopic imaging.
OBJECTIVE
To detect regional metabolic differences in amyotrophic lateral sclerosis (ALS) with whole-brain echo-planar spectroscopic imaging.


METHODS
Sixteen patients with ALS (nine men, seven women; mean age, 56.6 years), five persons suspected of having ALS (four men, one woman; mean age, 62.6 years), and 10 healthy control subjects (five men, five women; mean age, 56.1 years) underwent echo-planar spectroscopic imaging after providing informed consent. The study was approved by the institutional review board and complied with HIPAA. Data were analyzed with the Metabolic Imaging and Data Analysis System software, and processed metabolite maps were coregistered and normalized to a standard brain template. Metabolite maps of creatine (Cr), choline (Cho), and N-acetylaspartate (NAA) were segmented into 81 regions with Automated Anatomical Labeling software to measure metabolic changes throughout the brains of patients with ALS. Statistical analysis involved an unpaired, uncorrected, two-sided Student t test.


RESULTS
The NAA/Cho ratio across six regions was significantly lower by a mean of 23% (P ≤ .01) in patients with ALS than in control subjects. These regions included the caudate, lingual gyrus, supramarginal gyrus, and right and left superior and right inferior occipital lobes. The NAA/Cr ratio was significantly lower (P ≤ .01) in eight regions in the patient group, by a mean of 16%. These included the caudate, cuneus, frontal inferior operculum, Heschl gyrus, precentral gyrus, rolandic operculum, and superior and inferior occipital lobes. The Cho/Cr ratio did not significantly differ in any region between patient and control groups.


CONCLUSIONS
Whole-brain echo-planar spectroscopic imaging permits detection of regional metabolic abnormalities in ALS, including not only the motor cortex but also several other regions implicated in ALS pathophysiologic findings.
Department of Radiology, Hospital of the University of Pennsylvania, B6 Blockley Hall, 423 Guardian Dr, Philadelphia, PA 19104, USA.
Gaurav
G
Verma
John H
JH
Woo
Sanjeev
S
Chawla
Sumei
S
Wang
Sulaiman
S
Sheriff
Lauren B
LB
Elman
Leo F
LF
McCluskey
Murray
M
Grossman
Elias R
ER
Melhem
Andrew A
AA
Maudsley
Harish
H
Poptani
D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism* / Q000473:pathology*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline