Brain5-HT1AReceptor Binding in Multiple System Atrophy: An [18F]-MPPF PETStudy

Background Loss of medullary serotonin (5-hydroxytryptamine) neurons has been linked to respiratory disturbances in multiple system atrophy (MSA). Broader 5-hydroxytryptamine dysfunction may contribute to additional motor/nonmotor symptoms in MSA. The objective of this study was to compare brain 5-hydroxytryptamine(1A)receptor binding between MSA and healthy controls. Secondary objectives were to compare 5-hydroxytryptamine(1A)receptor binding between MSA and Parkinson's disease (PD) and to assess potential associations with motor/nonmotor symptoms in MSA. Methods 2 '-Methoxyphenyl-(N-2 '-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine positron emission tomography was performed in matched MSA patients (n = 16), PD patients (n = 15), and healthy controls (n = 18). Results 2 '-Methoxyphenyl-(N-2 '-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine distribution volume ratios were lower in MSA patients versus healthy controls in several brain regions including the caudate, raphe nuclei, thalamus, and brain stem. Distribution volume ratios were also lower in brain stem and amygdala in MSA versus PD. Moderate associations were found between 2 '-methoxyphenyl-(N-2 '-pyridinyl)-p-18F-fluoro-benzamidoethylpiperazine distribution volume ratios and fatigue, pain, and apathy in MSA. Conclusion Our results demonstrate 5-hydroxytryptamine dysfunction in several brain regions in MSA, which may contribute to fatigue, pain, and apathy. (c) 2020 International Parkinson and Movement Disorder Society

Automated summary

This study compared brain 5-hydroxytryptamine(1A) receptor binding between multiple system atrophy (MSA) patients, Parkinson's disease (PD) patients, and healthy controls. The findings showed dysfunction in several brain regions in MSA patients, which may contribute to symptoms like fatigue, pain, and apathy.