RESUMO
To correlate the signal intensity [SI] of the substania nigra [SN] on T2 weighted MR image with clinical findings and response to Levo-dopa in patients with idiopathic Parkinson's disease [IPD]. Prospective study was conducted upon 100 elderly patients with IPD [52 men, 48 women aged from 45 to 79 with mean age [58.8 +/- 8.82] and 25 age and sex matched volunteers. Thirty-seven of the patients were without treatment and 63 were under levo-dopa therapy. The patients were assessed according to Hoehn and Yahr rating scale. Routine T1 and T2 weighted MR imaging of the brain was done on 1.5 tesla unit [Symphony, Siemens]. The parameters used were TR/TE: 10000/38 msec. The SI of the SN on T2 weighted image was calculated. There was statistically significant difference in SI on T2 weighted image between patients with IPD and volunteers [P<0.001]. The SI correlated with disease onset [P = 0.252] and duration [P<0.001]. Also, there was correlation between SI of SN and disease severity [P < 0.001]. There was significant difference in the SI of SN between patients without treatment and patients with under levo-dopa therapy [T- 8.04, P<0.001]. We concluded that signal intensity on T2 weighted images is correlated with clinical score as well as with response for levo-dopa therapy