Volume estimation of the subcortical structures in Parkinson’s disease using magnetic resonance imaging: A methodological study

ABSTRACT

Background & Objectives: Parkinson’s disease (PD) is the most prevalent neurodegenerative disorder, beginning in the in the substantia nigra and spreading to the subcortical structures to the limbic cortices, and eventually to the neocortex and is characterized clinically by tremor at rest, bradykinesia, and rigidity. Regional brain atrophy is found to be an important marker of PD’s pathology. The aim of the current study was to compare the volumes of subcortical brain structures between healthy subjects and patients with PD using stereological (point-counting) and semi-automated segmentation methods. Methods: Twenty-four patients with PD and 23 age matched healthy subjects free of any psychiatric, neurological or cognitive impairment were included in our study. Magnetic resonance images were analyzed by using two methods. Results: Both methods showed a decrease in volume of caudate nucleus and lentiform nucleus in PD group compared to the control group. (p˂0.05). However, no significant differences was found between patient and control groups for the volume of thalamus (p>0.05). Also, no significant difference was found between point-counting and semi-automated segmentation methods for the volumes of subcortical structures in both two groups (p>0.05). Conclusion: Magnatic resonance imaging is helpful to facilitate the diagnosis in vivo of patients with PD, revealing atrophy of specific brain regions such as caudate nucleus and lentiform nucleus.