Imaging biomarkers for the diagnosis of corticobasal ganglia syndrome: DaTSCAN and [18F]FDG PET

Corticobasal syndrome is a complex neurodegenerative disorder with clinical features that overlap with other Parkinsonian syndromes, posing significant diagnostic challenges. Biomarkers are essential for differentiating corticobasal syndrome from other parkinsonian syndromes and identifying underlying pathologies. This review aims to evaluate the diagnostic utility of DaTSCAN and [ 18 F]FDG PET in corticobasal syndrome, focusing on their roles in identifying biomarkers such as dopaminergic activity, cerebral glucose metabolism, and tau protein deposition to enhance diagnostic accuracy. A literature search was conducted on PubMed using the keywords “DaTSCAN,” “[ 18 F]FDG,” and “corticobasal syndrome.” Studies were included if they were published in English within the last 10 years and were not reviews or case reports. A total of 10 studies were included in the final analysis, involving patients clinically diagnosed with corticobasal syndrome who may have had underlying pathologies, including Alzheimer's disease, corticobasal degeneration, progressive supranuclear palsy, and frontotemporal dementia. DaTSCAN was used to assess dopaminergic activity, revealing reduced dopamine transporter activity in the basal ganglia, particularly in the posterior putamen, of patients with corticobasal syndrome. [ 18 F]FDG PET was performed to evaluate cerebral glucose metabolism, showing asymmetric hypometabolism in cortical and subcortical regions, especially in the parietal and frontal lobes of patients with corticobasal syndrome. Additionally, one study using [ 18 F]AV-1451 tau imaging found that the tau deposition pattern in patients with corticobasal syndrome differed from that observed in patients with Alzheimer's disease and other parkinsonian syndromes. These biomarkers aid in distinguishing the potential pathologies of corticobasal syndrome, such as Alzheimer's disease, corticobasal degeneration, progressive supranuclear palsy, and frontotemporal dementia. DaTSCAN and [ 18 F]FDG PET are valuable tools for identifying the underlying pathologies of corticobasal syndrome, particularly in detecting dopaminergic activity, cerebral glucose metabolism, and tau protein deposition. However, due to the heterogeneity of corticobasal syndrome, these techniques are better suited for differentiating potential diagnoses rather than directly diagnosing corticobasal syndrome. Future research should focus on optimizing imaging standards and integrating multimodal approaches to improve diagnostic accuracy for corticobasal syndrome.