Transcranial sonography image characteristics in different Parkinson's disease subtypes

Recently, Parkinson's disease (PD) has been classified into three subtypes: postural instability gait difficulty (PIGD), tremor dominate (TD), and indeterminate PD. Transcranial sonography (TCS) is considered to be an important tool to diagnose PD. However, it is uncertain that whether there are differences in TCS image characteristics in different PD subtypes, so 373 idiopathic PD (188 PIGD, 108 TD, 77 indeterminate PD) were registered and received TCS in our investigation; also, the association between clinical characteristics and TCS results in different PD subtypes was analyzed. In accordance with several previous studies, we detected substantia nigra (SN) by TCS in 85.4% of patients with idiopathic PD; we concluded that PIGD patients had more serious disease than TD and indeterminate PD group (p < 0.05). They always had larger SN hyperechogenicity areas on TCS (p < 0.05), and we found that there was no correlation between SN hyperechogenicity and disease duration or severity (p > 0.05). Similarly, abnormal brainstem raphe signal was also more often in PIGD group than in TD and indeterminate PD group (p < 0.05), which might imply that PIGD group was vulnerable to suffer from depression in the future.