Evaluation of mesencephalic diameter using MRI in the diagnostic differentiation of progressive supranuclear palsy (PSP) from parkinson disease (PD)

Abstract

Diagnostic differentiation of progressive supranuclear palsy (PSP) from Parkinsons disease (PD) is difficult task in early stages. MR image based diagnosis plays a vital role in differentiation of parkinsonian syndromes because of its effective depiction of tissue anatomy. This study was designed to evaluate mesencephalic diameter using MRI in the differentiation of PSP from PD. A total 40 cases (20 cases clinically diagnosed with PSP and 20 cases with PD) and 20 healthy control subjects> 45 years were included. Cases were undergone with MRI (SEIMENS 1.5 Tesla) to detect antero-posterior diameter and superior profile of midbrain, tegmental hyper intensity, putamen intensity, Middle cerebellar peduncle width. AP diameter of midbrain was < 15mm in all the PSP cases, but none of the PD cases and control subjects. It has 100% sensitivity and specificity in differentiating PSP from PD and control subjects. The abnormal superior profile has 81% sensitivity, 80% specificity and 88% accuracy in identification of PSP from PD and control subjects. The measurement of mesencephalic diameter on standard routine T2 W MR images can be accurate to differentiate PSP cases from PD cases. Including this simple measure in the diagnostic criteria of PSP give effective outcome.