Amyloid- and FDG-PET imaging in amyotrophic lateral sclerosis.
OBJECTIVE
We aimed to study brain metabolism and presence of beta-amyloid deposits using positron emission tomography (PET) in patients with amyotrophic lateral sclerosis (ALS).


METHODS
This prospective cross-sectional study included 18 patients with definite or probable ALS according to the revised El Escorial diagnostic criteria, and 24 healthy controls. Patients underwent neurological and neuropsychological assessments, PET with (18)F-fluorodeoxyglucose (FDG), and amyloid-PET with (18)F-florbetaben.


RESULTS
Patients with ALS showed hypometabolism in the frontal area and hypermetabolism in the cerebellum compared to healthy controls. Four patients (22 %) displayed cognitive impairment and decreased metabolism in the frontal area extending bilaterally to the parietal regions, and increased metabolism in the posterior area of the cerebellum. In patients with no cognitive impairment, metabolism was lower in the left superior frontal gyrus and higher in the anterior and posterior lobes of the cerebellum. In the individual analysis, six patients (35 %) displayed more anterior involvement with hypometabolism affecting the superior frontal, medial, and inferior gyri; six patients (35 %) exhibited a more posterior pattern with hypometabolism in the precentral and postcentral gyri and in the superior and inferior parietal lobules; two patients (11 %) showed a mixed pattern; and three patients (17 %) showed no alterations in brain metabolism. Three (16 %) showed increased (18)F-florbetaben uptake compared to controls.


CONCLUSIONS
We have identified two main patterns of brain metabolism with an association to cognitive status. Only a subgroup of patients showed an increased uptake of the amyloid tracer. Our results suggest that ALS is heterogeneous from a clinical, metabolic, and molecular standpoint.
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain. jordimatiasguiu@hotmail.com.
Jordi A
JA
Matías-Guiu
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
Vanesa
V
Pytel
Department of Nuclear Medicine, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
María Nieves
MN
Cabrera-Martín
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
Lucía
L
Galán
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
María
M
Valles-Salgado
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
Antonio
A
Guerrero
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
Teresa
T
Moreno-Ramos
Department of Neurology, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
Jorge
J
Matías-Guiu
Department of Nuclear Medicine, Hospital Clínico San Carlos, San Carlos Institute for Health Research (IdISSC), Universidad Complutense de Madrid, C/ Profesor Martín Lagos, s/n, 28040, Madrid, Spain.
José Luis
JL
Carreras
D000682:Amyloid / Q000378:metabolism*; D000690:Amyotrophic Lateral Sclerosis / Q000000981:diagnostic imaging / Q000378:metabolism*; D000814:Aniline Compounds / Q000493:pharmacokinetics; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001928:Brain Diseases, Metabolic / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D057054:Molecular Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013267:Stilbenes / Q000493:pharmacokinetics
D000682:Amyloid; D000814:Aniline Compounds; D019275:Radiopharmaceuticals; D013267:Stilbenes; D019788:Fluorodeoxyglucose F18; C527756:4-(N-methylamino)-4'-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)stilbene
Alzheimer’s disease; Amyloid; Amyotrophic lateral sclerosis; Brain metabolism; Cognitive impairment; Positron emission tomography