Graduate Program in Medicine and Health Sciences, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil; Epilepsy Surgery Program, Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil.
Assistant Professor, Psychology Program, Universidade do Vale dos Sinos (UNISINOS), São Leopoldo, Brazil.
Seizure. 2021 Jul;89:65-72. doi: 10.1016/j.seizure.2021.04.025. Epub 2021 May 9.
The differential diagnosis between epileptic and psychogenic nonepileptic seizures (PNES) is challenging, yet suspicion of PNES is crucial to rethink treatment strategies and select patients for diagnostic confirmation through video EEG (VEEG). We developed a novel scale to prospectively suspect PNES.
First, we developed a 51-item scale in two steps, based upon literature review and panel expert opinion. A pilot study verified the applicability of the instrument, followed by a prospective evaluation of 158 patients (66.5% women, mean age 33 years) who were diagnosed for prolonged VEEG. Only epileptic seizures were recorded in 103 patients, and the other 55 had either isolated PNES or both types of seizures. Statistical procedures identified 15 items scored between 0 and 3 that best discriminated patients with and without PNES, with a high degree of consistency.
Internal consistency reliability of the scale for suspicion of PNES was 0.77 with Cronbach's Alpha Coefficient and 0.95 with Rasch Item Reliability Index, and performance did not differ according to the patient's gender. For a cut-off score of 20 (of 45) points, area under the curve was 0.92 (95% IC: 0.87-0.96), with an accuracy of 87%, sensitivity of 89%, specificity of 85%, positive predictive value of 77%, and negative predictive value of 94% (95% IC) for a diagnosis of PNES.
The scale for suspicion of PNES (SS-PNES) has high accuracy to a reliable suspicion of PNES, helping with the interpretation of apparent seizure refractoriness, reframing treatment strategies, and streamlining referral for prolonged VEEG.
癫痫性和心因性非癫痫性发作（PNES）的鉴别诊断具有挑战性，但对 PNES 的怀疑对于重新思考治疗策略至关重要，并通过视频脑电图（VEEG）选择患者进行诊断确认。我们开发了一种新的量表来前瞻性怀疑 PNES。
首先，我们基于文献回顾和小组专家意见分两步开发了一个 51 项的量表。一项初步研究验证了该工具的适用性，随后对 158 名（66.5%为女性，平均年龄 33 岁）接受长时间 VEEG 诊断的患者进行了前瞻性评估。103 名患者仅记录癫痫发作，另 55 名患者既有孤立性 PNES，也有两种类型的发作。统计程序确定了 15 个评分在 0 到 3 之间的项目，这些项目最好地区分了有无 PNES 的患者，一致性很高。
用于怀疑 PNES 的量表的内部一致性信度为 0.77，克朗巴赫α系数为 0.95，Rasch 项目可靠性指数为 0.95，且性能不因患者性别而异。对于 20 分（45 分）的截断值，曲线下面积为 0.92（95%可信区间：0.87-0.96），诊断为 PNES 的准确率为 87%，灵敏度为 89%，特异性为 85%，阳性预测值为 77%，阴性预测值为 94%（95%可信区间）。
PNES 怀疑量表（SS-PNES）具有较高的准确性，可以可靠地怀疑 PNES，有助于解释明显的癫痫发作难治性，重新制定治疗策略，并简化长时间 VEEG 的转诊。
