Department of Neurology, Lithuanian University of Health Sciences, Academy of Medicine, Mickevičiaus street 9, Kaunas, Lithuania.
BMC Neurol. 2012 Mar 8;12:12. doi: 10.1186/1471-2377-12-12.
Hyperechogenicity of the substantia nigra (SN+), detected by transcranial sonography (TCS), was reported as a characteristic finding in Parkinson's disease (PD), with high diagnostic accuracy values, when compared mainly to healthy controls or essential tremor (ET) group. However, some data is accumulating that the SN + could be detected in other neurodegenerative and even in non-neurodegenerative disorders too. Our aim was to estimate the diagnostic accuracy of TCS, mainly focusing on the specificity point, when applied to a range of the parkinsonian disorders, and comparing to the degenerative cognitive syndromes.
A prospective study was carried out at the Hospital of Lithuanian University of Health Sciences from January until September 2011. Initially, a TCS and clinical examination were performed on 258 patients and 76 controls. The General Electric Voluson 730 Expert ultrasound system was used. There were 12.8% of cases excluded with insufficient temporal bones, and 4.3% excluded with an unclear diagnosis. The studied sample consisted of the groups: PD (n = 71, 33.2%), ET (n = 58, 27.1%), PD and ET (n = 10, 4.7%), atypical parkinsonian syndromes (APS) (n = 3, 1.4%), hereditary neurodegenerative parkinsonism (HDP) (n = 3, 1.4%), secondary parkinsonism (SP) (n = 23, 10.8%), mild cognitive impairment (MCI) (n = 33, 15.4%), dementia (n = 13, 6.1%), and control (n = 71).
There were 80.3% of PD patients at stages 1 & 2 according to Hoehn and Yahr. At the cut-off value of 0.20 cm² of the SN+, the sensitivity for PD was 94.3% and the specificity - 63.3% (ROC analysis, AUC 0.891), in comparison to the rest of the cohort. At the cut-off value of 0.26 cm², the sensitivity was 90% and the specificity 82.4%.The estimations for the lowest specificity for PD, in comparison to the latter subgroups (at the cut-off values of 0.20 cm² and 0.26 cm², respectively) were: 0% and 33.3% to APS, 33.3% and 66.7% to HDP, 34.8% and 69.6% to SP, 55.2% and 82.8% to ET, 75% and 91.7% to dementia.
The high sensitivity of the test could be employed as a valuable screening tool. But TCS is more useful as a supplementary diagnostic method, due to the specificity values not being comprehensive.
经颅超声（TCS）检测到的黑质高回声（SN+）被报道为帕金森病（PD）的特征性发现，与主要与健康对照组或特发性震颤（ET）组相比，具有较高的诊断准确性值。然而，一些数据表明，SN+也可能在其他神经退行性疾病中甚至在非神经退行性疾病中被检测到。我们的目的是评估 TCS 的诊断准确性，主要关注特异性，当应用于一系列帕金森病时，并与退行性认知综合征进行比较。
这是一项于 2011 年 1 月至 9 月在立陶宛健康科学大学医院进行的前瞻性研究。最初，对 258 名患者和 76 名对照者进行了 TCS 和临床检查。使用了通用电气 Voluson 730 专家超声系统。由于颞骨不足，有 12.8%的病例被排除，4.3%的病例因诊断不明确而被排除。研究样本包括以下组别：PD（n=71，33.2%）、ET（n=58，27.1%）、PD 和 ET（n=10，4.7%）、非典型帕金森综合征（APS）（n=3，1.4%）、遗传性神经退行性帕金森病（HDP）（n=3，1.4%）、继发性帕金森病（SP）（n=23，10.8%）、轻度认知障碍（MCI）（n=33，15.4%）、痴呆（n=13，6.1%）和对照组（n=71）。
根据 Hoehn 和 Yahr，80.3%的 PD 患者处于 1 期和 2 期。在 SN+为 0.20cm²的截断值下，PD 的敏感性为 94.3%，特异性为 63.3%（ROC 分析，AUC 0.891），与其余队列相比。在 SN+为 0.26cm²的截断值下，敏感性为 90%，特异性为 82.4%。对于 PD 而言，与后一组相比（截断值分别为 0.20cm²和 0.26cm²），PD 的最低特异性估计值分别为：0%和 33.3%，APS；33.3%和 66.7%，HDP；34.8%和 69.6%，SP；55.2%和 82.8%，ET；75%和 91.7%，痴呆。
该测试的高灵敏度可作为有价值的筛查工具。但由于特异性值不全面，TCS 作为辅助诊断方法更有用。
