Evidence for astrocytosis in ALS demonstrated by [11C](l)-deprenyl-D2 PET

ObjectiveTo use deuterium-substituted [11C](l)-deprenyl PET to depict astrocytosis in vivo in patients with amyotrophic lateral sclerosis (ALS).BackgroundIn human brain, the enzyme MAO-B is primarily located in astrocytes. l-deprenyl binds to MAO-B and autoradiography with 3H-l-deprenyl has been used to map astrocytosis in vitro. Motor neuron loss in ALS is accompanied by astrocytosis and astrocytes may play an active role in the neurodegenerative process. Deuterium-substituted [11C](l)-deprenyl PET provides an opportunity to localize astrocytosis in vivo in the brain of patients with ALS.MethodsDeuterium-substituted [11C](l)-deprenyl PET was performed in seven patients with ALS and seven healthy control subjects.ResultsIncreased uptake rate of [11C](l)-deprenyl was demonstrated in ALS in pons and white matter.ConclusionThis study provides evidence that astrocytosis may be detected in vivo in ALS by the use of deuterium-substituted [11C](l)-deprenyl PET though further studies are needed to determine whether deuterium-substituted [11C](l)-deprenyl binding tracks disease progression and reflects astrocytosis.