Correlation of substantia nigra hyperecho with essential tremor and Parkinson disease

Abstract

Objective To investigate the correlation of substantia nigra hyperecho with essential tremor (ET) and Parkinson disease (PD). Methods The clinical data of 158 patients with ET or PD who underwent transcranial ultrasonography in Tongji Hospital from March 2016 to March 2018 were retrospectively analyzed. There were 35 patients with ET (ET group), 113 patients with PD who had no previous history of ET (PD group), and 10 PD patients with previous history of ET (ET-PD group). And 58 healthy subjects served as controls (control group). The hyperechoic area of substantia nigra in different groups was compared. Results The hyperechoic areas of the substantia nigra were [0 (0, 0)]cm2 (control group), [0.27(0, 0.41)]cm2 (ET group), [0.33(0.21, 0.40)]cm2 (ET-PD group) and [0.35(0.29, 0.45)]cm2 (PD group); the differences between control group and ET group, between the ET group and PD group were statistically significant (Z=-5.24, P=0.01; Z=-3.09, P=0.02), and there were no significant difference between the ET group and ET-PD group, between ET-PD group and PD group (Z=-0.98, P=0.32; t=-0.98, P=0.33). The ratio of substantia nigra hyperechoic positive to negative in ET-PD group was 9.00 (9/1), while that in ET group was 0.94 (17/18) (OR=9.53, 95% CI: 1.09-83.43, χ2=3.91, P=0.04). Conclusion Substantia nigra hyperecho is an objective imaging indicator for patients with ET and PD, and has a certain differential value for their diagnosis. Key words: Essential tremor; Parkinson disease; Substantia nigra; Ultrasonography, Doppler, transcranial