The role of width of pars compacta of substantia nigra and the midbrain area in patients with Parkinson’s disease and progressive supranuclear palsy with healthy aged individuals

Abstract

Introduction and Aim: Though numerous image processing software exists to analyse the images, measurement of substantia nigra width and midbrain area are simple yet definite tools to distinguish and diagnose the Parkinson’s disease (PD) and progressive supranuclear palsy (PSP) when complimented with clinical findings. Comparing the brainstem parameters in healthy, (neurodegenerative) diseased, and during the treatment helps us to assess the disease monitoring i.e., severity and progress of the disease, and formulate the best treatment strategies.  This study aimed at comparison of the thickness of substantia nigra (SN) in Parkinson's disease (PD) and progressive supranuclear palsy (PSP) with aged healthy individuals by magnetic resonance (MR) imaging. Material and Methods: This observational study includes the evaluation of MR images of 50 aged healthy individuals with no obvious neurological diseases, 35 classical PD, and 15 PSP patients from the Department of Radiology. Quantitative planimetric evaluation of midbrain area was calculated and the width of substantia nigra (SN) was evaluated as per standard reference criteria with computer assisted image analysis and interpretation program. Results: The parameters like means of midbrain area and the pars compacta thickness on both right and left sides were compared both in PD and PSP patients with healthy individuals. MR image analysis showed significant decrease in the thickness of pars compacta of SN in PD patients than in PSP patients when compared with age matched healthy aged individuals. Conclusion: Parkinsonian diseases are always associated with the neuronal loss leading to volume alterations by causing midbrain atrophy. Magnetic resonance imaging of the thickness of SN is simple and reliable imaging markers to differentiate PD and PSP when combined with clinical symptomatology.