GH Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
Taub Institute for Research on Alzheimer's Disease and The Aging Brain, College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA.
Parkinsonism Relat Disord. 2014 May;20(5):541-4. doi: 10.1016/j.parkreldis.2014.01.021. Epub 2014 Feb 7.
Tremor is a common feature of a variety of neurological disorders. In genetic studies of essential tremor (ET), investigators need to screen potential enrollees by mail or telephone to exclude those with other neurological conditions, especially dystonia. In clinical settings, the differentiation of ET and dystonia may also be very challenging. We hypothesized that the spiral axis, described below, is a useful screening tool to distinguish ET cases from dystonia cases.
We analyzed the hand-drawn spirals of 135 individuals enrolled in a genetics study at Columbia University Medical Center. Each of the four spirals was assessed for the presence of a single identifiable tremor orientation axis, and a spiral axis score (range = 0-4) [a single axis on all 4 spirals] was assigned to each enrollee.
There were 120 ET cases and 15 cases with dystonic tremor. Most (101/120, 84.2%) ET cases had an axis score ≥1 vs. only half (8/15, 53.3%) of the dystonia cases (p = 0.02). Receiver Operator Curve (ROC) analysis revealed that the use of a spiral axis score ≥2 as a cut off would exclude 60.0% of dystonia cases while including 67.5% of ET cases.
Handwritten spirals appear to have a single predominant axis in more ET than dystonia cases. The evaluation of this axis has moderate diagnostic validity as a screening tool to distinguish ET cases from those with dystonia. Although this study did not assess the utility of this tool in clinical practice settings, future studies should do so.
震颤是多种神经障碍的常见特征。在原发性震颤（essential tremor，ET）的遗传研究中，研究人员需要通过邮件或电话对潜在的参与者进行筛查，以排除其他神经疾病，尤其是肌张力障碍。在临床环境中，区分 ET 和肌张力障碍也可能极具挑战性。我们假设，下面描述的螺旋轴是一种有用的筛选工具，可以将 ET 病例与肌张力障碍病例区分开来。
我们分析了哥伦比亚大学医学中心遗传学研究中纳入的 135 名个体的手绘螺旋。对每个个体的四条螺旋中的每一条螺旋评估是否存在单一可识别的震颤方向轴，并为每个入组者分配一个螺旋轴评分（范围为 0-4）[四条螺旋上均存在单一轴]。
有 120 例 ET 病例和 15 例伴张力障碍性震颤的病例。大多数（101/120，84.2%）ET 病例的轴评分≥1，而肌张力障碍病例中只有一半（8/15，53.3%）（p=0.02）。接收器操作曲线（ROC）分析显示，使用螺旋轴评分≥2 作为截断值可排除 60.0%的肌张力障碍病例，同时纳入 67.5%的 ET 病例。
手写螺旋似乎在 ET 病例中比肌张力障碍病例更具有单一的主导轴。该轴的评估作为一种筛选工具，具有中等的诊断有效性，可用于区分 ET 病例与伴有肌张力障碍的病例。尽管本研究并未评估该工具在临床实践环境中的实用性，但未来的研究应进行这方面的评估。
