Laterality of specific binding ratios on DAT-SPECT for differential diagnosis of degenerative parkinsonian syndromes

Taro Shigekiyo,Shigeki Arawaka

doi:10.1038/s41598-020-72321-y

Taro Shigekiyo, Shigeki Arawaka

Open Access

https://doi.org/10.1038/s41598-020-72321-y

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Journal: Scientific Reports	Publication Date: Sep 25, 2020
Citations: 23	License type: open-access

Affiliation: Osaka Medical and Pharmaceutical University

Abstract

Motor symptoms of Parkinson’s disease (PD) occur unilaterally and progress with asymmetry, while progressive supranuclear palsy (PSP) and multiple system atrophy of the parkinsonism subtype (MSA-P) lack this tendency. We assessed the laterality of specific binding ratios (SBRs) on dopamine transporter single-photon emission computed tomography (DAT-SPECT) for the differential diagnosis of these diseases in 311 PD, 33 PSP, 20 MSA-P, and 137 control patients. The average SBR in PD was higher than that in PSP (P = 0.035). Compared with Hoehn–Yahr (HY) stages, the average SBR in PD with HY stage I was only higher than that in PSP (P < 0.001). SBR laterality in PD with HY stage I was significantly higher than that in PSP (P = 0.001). This difference was not observed in PD with HY stage II. The average and laterality of SBRs in MSA-P were similar to those in PD and PSP. The asymmetry indices were similar among PD, PSP, and MSA-P. These data suggest that PSP shows a pattern of SBRs different from that in PD, attributed to HY stage I in PD. The limited usefulness of DAT-SPECT may be explained by the low discrimination between PD with bilateral motor symptoms and PSP.

Highlights

Motor symptoms of Parkinson’s disease (PD) occur unilaterally and progress with asymmetry, while progressive supranuclear palsy (PSP) and multiple system atrophy of the parkinsonism subtype (MSA-P) lack this tendency
A previous study showed that striatal 123I‐Ioflupane accumulation is reduced in PD, PSP, and MSA-P, and the striatal reduction is more significant in PSP with no statistical difference between that in PD and MSA-P15,16
We found that the average specific binding ratios (SBRs) in MSA-P showed no difference from that in PD and PSP

Summary

Introduction

Motor symptoms of Parkinson’s disease (PD) occur unilaterally and progress with asymmetry, while progressive supranuclear palsy (PSP) and multiple system atrophy of the parkinsonism subtype (MSA-P) lack this tendency. The diagnosis of definite PD requires three or more of the following items: unilateral onset, rest tremor, progressive course, persistent asymmetry affecting the side of onset, excellent response to levodopa, severe levodopa-induced dyskinesia, levodopa response for more than 5 years, or a clinical course of more than 10 years As indicated in these diagnostic criteria, the motor symptoms of PD are clinically characterised by asymmetry of the affected limbs observed at any time. Pirker et al demonstrated that asymmetry of striatal 123I‐Ioflupane binding seemed to be less pronounced in MSA and PSP than in PD with no statistical d ifference[14] It is unclear how the asymmetry of motor symptoms in different stages of PD is reflected on DAT-SPECT imaging and whether asymmetric reduction in striatal 123I‐Ioflupane accumulation on DAT-SPECT is useful to differentiate PD from PSP and MSA-P. We assessed the average and laterality of SBRs on DAT-SPECT for the differential diagnosis of PD, PSP, and MSA-P

Methods

Results

Conclusion