Department of Neurology, Emory University School of Medicine, 12 Executive Park Atlanta, GA 30329, USA.
Arch Clin Neuropsychol. 2019 Oct 24;34(7):1192-1202. doi: 10.1093/arclin/acz028.
Performance Validity Testing (PVT) decision-making rules may be indeterminate in patients with neurological disease in which PVT characteristics have not been adequately studied. We report a patient with multiple sclerosis (MS) who failed computerized PVT testing but had normal memory scores with a neuropsychological profile consistent with expected MS disease-related weaknesses.
Neuropsychological testing was conducted on two occasions in a middle-aged woman with an established MS diagnosis to address concerns of possible memory decline. Testing was discontinued after PVT scores below recommended cut-points were obtained during the first evaluation. During the second assessment, subthreshold PVT scores on a different computerized PVT were obtained, but unlike the first assessment, the entire neuropsychological protocol was administered.
Despite subthreshold computerized PVT scores, normal learning and memory performance was obtained providing objective data to answer the referral question. Other neuropsychological findings included decreased processing speed, poor working memory, and poor executive function consistent with her MS diagnosis. Embedded PVT scores were normal.
We speculate that poor computerized PVT scores resulted from the disease-related features of MS, although we also discuss approaches to reconcile apparently contradictory PVT versus neuropsychological results if the contributions of disease-related variables on PVTs scores are discounted. This case demonstrates the value of completing the assessment protocol despite obtaining PVT scores below publisher recommended cutoffs in clinical evaluations. If subthreshold PVT scores are considered evidence of performance invalidity, it is still necessary to have an approach for interpreting seemingly credible neuropsychological test results rather than simply dismissing them as invalid.
在尚未充分研究 PVT 特征的神经疾病患者中，性能有效性测试 (PVT) 的决策规则可能不确定。我们报告了一例多发性硬化症 (MS) 患者，该患者计算机化 PVT 测试失败，但记忆评分正常，神经心理学特征与预期的 MS 疾病相关弱点一致。
对一位中年女性进行了两次神经心理学测试，以解决可能的记忆下降问题。在第一次评估中获得低于推荐截断值的 PVT 分数后，停止了测试。在第二次评估中，获得了不同计算机化 PVT 的阈下 PVT 分数，但与第一次评估不同的是，整个神经心理学方案都进行了测试。
尽管计算机化 PVT 分数低于阈限，但仍获得了正常的学习和记忆表现，为回答转诊问题提供了客观数据。其他神经心理学发现包括处理速度下降、工作记忆差和执行功能差，与她的 MS 诊断一致。嵌入式 PVT 分数正常。
我们推测，较差的计算机化 PVT 分数是由 MS 的疾病相关特征引起的，尽管我们也讨论了如果不考虑疾病相关变量对 PVT 分数的影响，如何调和明显矛盾的 PVT 与神经心理学结果的方法。这个案例表明，在临床评估中，尽管获得的 PVT 分数低于出版商推荐的截断值，仍有必要完成评估方案。如果阈下 PVT 分数被认为是表现无效的证据，那么仍然需要有一种方法来解释看似可信的神经心理学测试结果，而不仅仅是将其视为无效。
