Transcranial Sonography In The Diagnosis Of Parkinson Disease

Background:Parkinson disease is first described by James Parkinson in 1817. The cause of PD is not yet clear. A correct diagnosis of PD can be made according to the clinical manifestations, but in the early stage of PD, the patient's history or clinical findings were atypical. With the aging of people, its incidence increased year by year, as a result it burden the families of patients and our society. It is conceivable that diagnosis and therapy starting at an early stage of the disease can stop the degenerative process. Therefore, the identification of patients at risk and at earlier stages of the disease is essential for successful neuroprotection. Transcranial sonography as a non-invasive approach, has detected hyperechogenicity of the substantia nigra. The method has been used in clinical diagnosis of PD abroad. At present, there is few study about TCS in the diagnosis of PD in our country. In this paper we verify that hyperechogenicity of the SN, as determined by TCS, is characteristic of PD and estimate the value of TCS in diagnosis of PD according to clinical research. The research lay a foundation to continue the study of TCS in PD diagnosis and differential diagnosis in the future.Methods:Our study was performed on 83 individuals, including 40 PD patients (21 men, 19 women) and 43 age- and gender-matched healthy controls. Each over 50 years old, and every PD patients comply with a standard of UK Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria. All PD patients underwent UPDRS-III, and Hoehn & Yahr Rating Scale (H&Y), UPDRS-V and Webster Rating Scale .Transcranial sonography of substantia nigra were performed on 40 PD patients and 43 matched controls throughout both temporal bone windows on intact skull in axial plain. Afterwards, manually marked, calculated and presented in cm2 with own software instruments of Philips-IE33. According to Berg's standard: the one whose SN size exceeding 0.20 cm2 was considered (SN+) and the one below 0.20 cm2 was (SN-). The test results were statistically analyzed.Results:1 SN hyperechogenicity over margin of 0.20 cm2 was found in 34 of PD patients,4 of healthy subjects ; SN hyperechogenicity size of patients with PD was significantly different from controls group (P < 0.001). The sensitivity of TCS in PD was 91.2% and the specificity was 89.5%; the positive predictive value was 88.6% and the classification accuracy was 90.3%.2 There was no correlation between the size of SN hyperechogenicity and patients'age(P=0.32), duration of illness(P=0.15) and the severity of condition .ConclusionsSubstantia nigra hyperechogenicity on TCS is a highly specific finding of PD. The sensitivity of TCS in PD was 91.2% and the specificity was 89.5%; the positive predictive value was 88.6% and the classification accuracy was 90.3%. There was no correlation between the size of SN hyperechogenicity and patients'age, duration of illness, the severity of condition. TCS is an easy to implement, non-invasive, and inexpensive technique that could help in the diagnosis of PD. TCS can be used for early diagnosis and screening.