Sensory and Motor Systems
Author: Ivonne Cruz | Email: ivonnecruzx@gmail.com
Ivonne Cruz1°, Miguel Wilken1°, Gonzalo Álvarez2°, Mirta Villarreal3°, Marcelo Merello1°3°
1° Servicio de Movimientos Anormales, Departamento de Neurología, FLENI, Buenos Aires, Argentina
2° Centro Atómico Bariloche, CONICET, CNEA, S. C. de Bariloche, Argentina
3° Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
Microstructural differences between tremor phenotypes in Parkinson’s Disease (PD) have not been explored. In this study, we aim to identify microstructural differences in the cerebello-thalamo-cortical circuit (CTC) among four groups of PD patients: those with no tremor (N=19 hemispheres), those with isolated rest tremor (RT=14), those with rest tremor that re-emerges after a pause when changing position (RET=12), and those with continuous tremor without pause during position change (CT=16). Diffusion Magnetic Resonance Images were acquired and each brain hemisphere was classified based on contralateral tremor. Voxelwise statistical analysis of diffusion parameters was carried out (p-value≤0.05). CT hemispheres presented increased mean and radial diffusivity (≥20.48%) in the whole CTC, as compared to NT and RT hemispheres; also decreased fractional anisotropy was observed. RET hemispheres present changes (≥39.34%) in the superior corona radiata as compared to NT and RT hemispheres. Our findings indicate that the hemispheres associated with RET and CT exhibit greater demyelination in the hemisphere opposite to the tremorous side of the body compared to RT and NT. Specifically, the hemispheres linked to RET display changes primarily in the thalamo-cortical section of CTC, whereas those associated with CT show alterations throughout the entire CTC. This suggests a potential correlation between the extent of CTC alterations and the degree of tremor attenuation during movement.