ATH has now its phase 2 MSA study going on. If we get a positive result, it is interesting to estimate if it has any value in other parkinsonian diseases. We know that there is a primate study going on to evaluate the dosage in Parkinson's disease and "a proof of concept study" in planning also in Parkinson's disease. So to me, it looks like the next study is the proof of concept for Parkinson's disease based on the results of the phase 2 MSA study. This paper below how similar and different these parkinsonian diseases are through imaging modalities.

I first post and underline here the conclusion of this new review paper.

"To our knowledge, this is the largest whole-brain ALE meta-analysis of parkinsonian disorders and the first to characterize brain regions implicated across disorders, and within multiple neuroimaging modalities. Localizations aligned with current diagnostic imaging markers, isolating the midbrain in PSP, and the brainstem in MSA. PET studies most consistently reported alteration to the middle temporal gyrus in Parkinson’s disease patients. Importantly, we also demonstrated several regions that were abnormal across these parkinsonian disorders, including the thalamus, caudate, inferior frontal, and middle temporal gyri. These findings help to illuminate the brain regions that are abnormal in parkinsonian disorders and highlight a set of common brain regions across disorders that may contribute to shared parkinsonian symptoms."




Here is the abstract of this free paper.

Brain Commun

. 2023 May 30;5(3):fcad172.

doi: 10.1093/braincomms/fcad172. eCollection 2023.

Large-scale activation likelihood estimation meta-analysis of parkinsonian disorders

Elizabeth G Ellis ¹, Juho Joutsa ^{2 3 4}, Jordan Morrison-Ham ¹, Ellen F P Younger ¹, Jacqueline B Saward ¹, Karen Caeyenberghs ¹, Daniel T Corp ^{1 2}

Affiliations expand

• PMID: 37324240

PMCID: PMC10265724 DOI: 10.1093/braincomms/fcad172

Abstract

Parkinsonism is a feature of several neurodegenerative disorders, including Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome and multiple system atrophy. Neuroimaging studies have yielded insights into parkinsonian disorders; however, due to variability in results, the brain regions consistently implicated in these disorders remain to be characterized. The aim of this meta-analysis was to identify consistent brain abnormalities in individual parkinsonian disorders (Parkinson's disease, progressive supranuclear palsy, corticobasal syndrome and multiple system atrophy) and to investigate any shared abnormalities across disorders. A total of 44 591 studies were systematically screened following searches of two databases. A series of whole-brain activation likelihood estimation meta-analyses were performed on 132 neuroimaging studies (69 Parkinson's disease; 23 progressive supranuclear palsy; 17 corticobasal syndrome; and 23 multiple system atrophy) utilizing anatomical MRI, perfusion or metabolism PET and single-photon emission computed tomography. Meta-analyses were performed in each parkinsonian disorder within each imaging modality, as well as across all included disorders. Results in progressive supranuclear palsy and multiple system atrophy aligned with current imaging markers for diagnosis, encompassing the midbrain, and brainstem and putamen, respectively. PET imaging studies of patients with Parkinson's disease most consistently reported abnormality of the middle temporal gyrus. No significant clusters were identified in corticobasal syndrome. When examining abnormalities shared across all four disorders, the caudate was consistently reported in MRI studies, whilst the thalamus, inferior frontal gyrus and middle temporal gyri were commonly implicated by PET. To our knowledge, this is the largest meta-analysis of neuroimaging studies in parkinsonian disorders and the first to characterize brain regions implicated across parkinsonian disorders.