Visual analysis of nigrosome-1 in the differential diagnosis of Parkinson's disease and essential tremor

• Published in: Bulletin of RSMU 2022-01 (2022(1))
• Main Authors: Moskalenko, AN, Filatov, AS, Fedotova, EYu, Konovalov, RN, Illarioshkin, SN
• Format: Article
• Language: English
• ISSN: 2500-1094; 2542-1204
• DOI: 10.24075/brsmu.2022.002

Differentiation between Parkinson’s disease, especially in its early stages, and essential tremor, which is a phenotypically similar movement disorder, still remains an unsolved challenge for neurology. The aim of this study was to assess the diagnostic significance of nigrosome imaging (nigrosomes are dopaminergic neuron clusters in the substantia nigra of the midbrain) using 3T high-resolution SW-MRI. The study was conducted in 20 patients with Parkinson’s disease and 10 patients with essential tremor. Visual analysis of the acquired nigrosome-1 images was performed using a 4-point ordinal rating scale. Differences in sex, age and duration of the disease were calculated using the Fisher exact test and the Mann–Whitney U test. The diagnostic value of the method was assessed using Pearson’s chisquared test. Nigrosome-1 was bilaterally or unilaterally absent in 70% of parkinsonian patients. Less specific changes to the substantia nigra (SN) were observed in two more parkinsonian patients (10%), whose nigrosome-1 appeared reduced in size. By contrast, nigrosome-1 was bilaterally intact in all patients (100%) with essential tremor (p < 0.001). Our preliminary findings demonstrate the high potential of noninvasive nigrosome-1 imaging in the differential diagnosis of Parkinson’s disease and essential tremor.