Correlation Between Substantia Nigra Features Detected by Sonography and Parkinson Disease Symptoms

An enlarged and hyperechoic SN existed in 84.0% of patients with bilateral rigidity but in only 70.6% of patients with unilateral rigidity (P < .05). Similarly, 85.0% of patients with bilateral bradykinesia in comparison with 65.7% of patients with unilateral bradykinesia had an enlarged and hyperechoic SN (P < .05). A significant correlation was shown between the SN echogenicity and area (r = 0.705; P < .01). Conclusions. An enlarged and hyperechoic SN seems to be a marker of structural involvement of the SN in patients with PD. This structural involvement is expressed more in patients with bilateral rigidity and bradykinesia.