Imaging Approaches to Parkinson Disease

Abstract

Parkinson disease (PD) is associated with nigral degeneration and striatal dopamine deficiency. Demonstrating midbrain structural abnormalities with transcranial sonography or diffusionweighted MRI or showing striatal dopamine terminal dysfunction with PET or SPECT supports the diagnosis and rationalizes the use of dopaminergic medications. In atypical PD variants, transcranial sonography can detect striatal hyperechogenicity, and diffusion-weighted imaging can detect increased putamen water diffusion, whereas 18 F-FDG PET reveals reduced lentiform nucleus glucose metabolism. PET and SPECT can detect changes in striatal dopamine levels after levodopa administration and relate these to motor responses. Loss of cortical dopaminergic and cholinergic function is present in demented PD and, on occasion, amyloid deposits can be detected. Loss of cardiac sympathetic innervation can be sensitively detected in PD with 18 F-dopamine PET or 123 I-metaiodobenzylguanidine SPECT. Finally, PET can detect widespread brain inflammation in PD. This review discusses the role of structural and functional imaging for diagnosing and managing different parkinsonian syndromes.

Nuclear Medicine Applications in Movement Disorders

“…PH'de beyinde substansiya nigrada yer alan dopaminerjik nöronların ilerleyici kaybı söz konusudur (1,41). Hücre gövdeleri substansiya nigrada yer alan dopaminerjik nöronların aksonları beyinde bazal gangliada sonlanır.…”

“…Hücre gövdeleri substansiya nigrada yer alan dopaminerjik nöronların aksonları beyinde bazal gangliada sonlanır. Dolayısıyla presinaptik dopaminerjik terminali görüntülemek için kullanılan radyofarmasötiklerin bazal gangliada tutulumunda azalma olur (1,4,41). Buna karşılık PH'sinde postsinaptik dopaminerjik reseptörlerde benzer bir azalma söz konusu değildir.…”

Compartmental modeling of F-DOPA PET images from Parkinson’s patients

“…All images were evaluated qualitatively and semiquantitatively by two nuclear medicine physicians experts in neuroimaging according with the imaging algorithm described by D.J. Brooks [10].…”

Neuropeptide Receptors in Pain Circuitries: Useful Targets for CNS Imaging with Non-Peptide Ligands Suitable for PET?

“…β endorphins act via presynaptic µ opioid receptors mediating inhibition of the release of GABA, which results in excess production of dopamine [53].…”

“…Dynorphin binds κ opioid sites and inhibits glutamate release in the globus pallidus interna from subthalamic projections [53].…”