Clinical and neuroimaging study of patients with Parkinson’s disease using transcranial sonography and neuromelanin-sensitive magnetic resonance imaging

Abstract

Background. Parkinson’s disease (PD) is one of the most common neurodegenerative diseases and aff ects 1% of the population above 60 years. The leading pathological features of PD include degeneration of neuromelanin (NM) containing dopaminergic neurons and iron deposition in the substantia nigra (SN) of the midbrain. Various neuroimaging methods sensitive to NM and iron can be clinically important for diagnosing and monitoring disease progression. Examples of such neuroimaging methods include transcranial sonography (TCS) and neuromelanin-sensitive magnetic resonance imaging (NM-MRI) fi rst and foremost.Aims. To compare the diagnostic signifi cance and eff ectiveness of TCS and NM-MRI in diff erentiating patients with PD from the norm and to elucidate the magnetic resonance- (MR-) morphological representation of the hyperechogenicity (HE) on midbrain during TCS by NM-MRI.Material and methods. 40 patients with PD were included in the main group, and 20 healthy volunteers of gender and age comparable with the main group were included in the control group. In the case of HE detection during TCS, this area was manually traced and automatic calculated. NM-MRI images were pre-processed using image processing program Image-J (USA) with subsequent automatic calculation of SN area. Based on the data obtained, clinical, demographic and neuroimaging correlations were estimated.Results. The sensitivity and specifi city of TCS in diff erentiating PD from the norm were 70 and 100% respectively, the sensitivity and specifi city of NM-MRI were 90.0 and 92.5% respectively. An analysis of the relationship between the HE area and the area of the SN according to NM-MRI data on the ipsilateral side showed a noticeable inverse correlation (for the right side: ρ = –0.606, p < 0.001; for the left side: ρ = –0.550; p < 0.001). Thus, in the case of an increase in the HE area, a decrease in the area of SN measured using NM-MRI is expected.Conclusion. TCS and NM-MRI are reliable biomarkers allowing highly eff ective diff erentiation of PD from normal. The pathophysiological and neuroimaging correlates of PD changes in neurodegenerative process remain not completely clear and require further clarifi cation in multicenter prospective studies.