Differentiating poor validity from probable impairment on the medical symptom validity test: a cross-validation study

Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.     

Pattern electroretinogram plus visual evoked potential: A decisive test in patients suspected of malingering

Along the processing chain in the visual pathway the pattern electroretinogram (PERG) is a better indicator of the peripheral function than the visual evoked potential (VEP). Therefore the PERG and the VEP will be impaired equally by disturbances before the ganglion cell layer (e.g., blurred image or retinal disease) and differently by further centrally located diseases (e.g., tumor compression of the optic nerve). Thus in patients complaining of reduced visual acuity who show disturbed VEP but a normal PERG, malingering can be definitely ruled out. Representative combinations of PERG and VEP findings are described.     

Immediate Post-Concussion and Cognitive Testing (ImPACT): a systematic review of the prevalence and assessment of invalid performance

Objective: Computerized neuropsychological assessment of concussion has rapidly expanded and Immediate Post-Concussion and Cognitive Testing (ImPACT) is among the most commonly used measures in this domain. ImPACT was primarily developed for use with athletic populations but continues to expand beyond athletics to settings such as the workplace and schools where motivational dispositions may vary. The purpose of the present study was to conduct a systematic review of existing research investigating the prevalence of invalid baseline results and the effectiveness of ImPACT’s embedded invalidity indicators in detecting suspect effort.Method: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in order to systematically structure a search across four databases and analysis of studies that presented data related to the prevalence of invalid performance and/or the effectiveness of ImPACT’s embedded invalidity indicators.Results: A total of 17 studies included prevalence rates of invalid performances or examined the effectiveness of ImPACT’s invalidity indicators. Of the 17 studies, 12 included prevalence rates of invalid baseline results; and across this group of studies (after removing an outlier), the weighted prevalence rate of invalid baseline results was 6%. Four of the 17 studies examined the effectiveness of ImPACT’s embedded invalidity indicators. ImPACT’s embedded invalidity indicators correctly identified suboptimal effort in approximately 80% of individuals instructed to perform poorly and avoid detection (‘coached’) or instructed to perform poorly (‘naïve’).Conclusions: These findings raise a number of issues pertaining to the use of ImPACT. Invalid performance incidence may increase with large group versus individual administration, use in nonclinical settings, and among those with Attention Deficit-Hyperactivity Disorder or learning disability. Additionally, the older desktop version of ImPACT appears to be associated with a higher rate of invalid performances than the online version. Although ImPACT’s embedded invalidity indicators detect invalid performance at a rate of 6% on average, known group validity studies suggest that these measures miss invalid performance approximately 20% of the time when individuals purposefully underperform.     

Recurrent Ethylene Glycol Poisoning with Elevated Lactate Levels to Obtain Opioid Medications

Background

Malingering is when a patient feigns illness for secondary gain. While most patients with malingering manufacture or exaggerate symptoms, some patients may induce illness. Previous reports of malingering patients inducing illness include sepsis, kidney pain, migraine, and chest pain. However, acute poisoning as a manifestation of malingering appears to be rare.

伪装与非伪装脑外伤患者数字再认测验结果分析

目的：探讨二项数字再认测验（二项测验）对赔偿性脑外伤患者伪装智力低下的判定作用。方法：分析57例赔偿性脑外伤伴有伪装智力低下者与66例非赔偿性脑外伤患者二项测验结果的各统计参数，计算出伪装与非伪装的划界分。并作判定分析。结果：伪装组与非伪装组二项测验容易条目分，困难条目分，总分的得分及偏应商数差异有显著性；容易条目的回答正确数小于等于11分，或者困难条目的回答正确数小于等于7，或总分小于，等于18分可判定为伪装；判定的总正确率92.7%-100%，总错误率0%-7.3%。二项测验总分对伪装智力低下的判断正确率最高。结论：二项必选数字记忆测验是鉴别伪装智力低下的有效评定工具。     

伪聋及夸大性耳聋患者听力检查的护理

目的 针对伪聋及夸大性耳聋患者心理特点进行护理，最终对其听力作出正确评估。方法 对初次检查结果可疑者，分析其行为动机，进行正确有效的思想疏导工作，使患者以积极的态度接受检查。结果 经说服教育和心理护理。所有病例均获得满意检查结果。确定初诊为伪聋者58例，夸大性耳聋者67例。动机包括为获取经济赔偿或诉讼优势；工伤评残或老兵退役评残；逃避工作或训练；医疗纠纷等。结论 伪聋和夸大性耳聋有其复杂的主观动机，通过正确引导和心理护理，最终均能获得真实听力结果。     

Fraudulently Claiming Following a Road Traffic Accident: A Pilot Study of UK Residents’ Attitudes

The United Kingdom Government recently expressed concern about the financial repercussions that feigned whiplash claims following road traffic accidents (RTAs) are having on the insurance industry and the United Kingdom economy. Indeed, this is a problem that is a likely result of a significant percentage of otherwise law-abiding citizens, who interpret this behaviour to be victimless. Nevertheless, feigning illness for some external incentive is not new, and psychiatry has long battled with the problem of ‘malingering’. Previous research has indicated that a substantial prevalence of malingering exists across a variety of contexts; however, establishing the ground truth of those who malinger for financial compensation is problematic. This article presents an alternative approach that provides a brief insight into the problem of malingering following a RTA. A total of 197 United Kingdom residents completed a hypothetical questionnaire that examined their likelihood of malingering with respect to depression, posttraumatic stress disorder (PTSD), or whiplash following a RTA. The results suggest that a substantial percentage of those in the present sample indicated they would be likely to malinger using either a partial malingering or a false imputation strategy. Malingering following a RTA in the United Kingdom appears to be regarded with little severity, and the present paper discusses the wider implications of the findings.     

血清皮质醇、醛固酮水平在男性伪装精神病司法鉴定中的变化特点

目的:探讨血清皮质醇(COR)、醛固酮(ALD)水平在暴力违法精神疾病司法鉴定中对伪装精神病(诈病)的诊断与鉴别作用。方法:将男性暴力违法(被控故意杀人和伤害)者作为研究对象,分别比较完全责任能力伪装精神疾病组(简称诈病组)、无精神病无诈病表现完全责任能力组(简称完全组)、精神分裂症限定责任能力组(简称限定组)、精神分裂症无责任能力组作为对照组(简称对照组)血清COR、ALD水平。结果:(1)鉴定前后COR、ALD水平自身对照比较:诈病组COR、ALD水平差异均有极显著性(P<0.001);完全组COR有差异(P<0.05),ALD降低但无统计学意义(P>0.05);限定组COR有差异(P<0.05),ALD差异有显著性(P<0.01);对照组COR、ALD均降低,但无统计学差异(P>0.05)。(2)诈病组血清COR、ALD水平下降率高于其他组,差异均有显著性(P<0.001)。(3)鉴定前诈病组COR、ALD水平与其他组比较差异均有极显著性(P<0.001);完全组与限定组比较COR无差异(P>0.05),ALD有差异(P<0.05);完全组与对照组比较COR无差异(P>0.05),ALD差异有极显著性(P<0.001);限定组与对照组比较COR无差异(P>0.05),ALD差异有显著性(P<0.01)。(4)鉴定后诈病组与完全组比较:COR高于完全组差异有极显著性(P<0.001);ALD高于完全组,但差异无显著性(P>0.05)。诈病组与限定组比较:COR高于限定组差异有显著性(P<0.01);ALD高于限定组差异有极显著性(P<0.001)。诈病组与对照组比较:COR高于对照组,差异有显著性(P<0.05);ALD高于对照组,差异有极显著性(P<0.001)。结论:血清COR、ALD水平在应激层面对伪装精神疾病的诊断与鉴别以及对不同责任能力的判定具有一定的客观参考价值。     

A decision-analysis model to diagnose feigned hand weakness

Malingering is a condition in which patients exaggerate incapacity. Feigned hand weakness is one form of malingering, and it is often seen after work-related hand injuries. Malingering is prevalent in the workers' compensation system, which devotes a large proportion of valuable resources to unwarranted claims. Feigned hand weakness must be detected early because it is relatively prevalent and expensive to society. Clinical evaluation is the first step in detecting feigned hand weakness, but it is not very specific. Therefore, every suspected positive clinical result must be followed up with a more advanced test that has better specificity. Three advanced tests are (1) five-rung grip test, (2) rapid grip tests (rapid exchange grip and rapid simultaneous grip), and (3) computerized measure of grip. Among these, computerized measure of grip is the most specific; therefore, it is the best second-line test.