Symptom exaggeration and symptom validity testing in persons with medically unexplained neurologic presentations

Abstract

Neurologists often evaluate patients whose symptoms cannot be readily explained even after thorough clinical and diagnostic testing. Such medically unexplained symptoms are common, occurring at a rate of 10%-30% among several specialties. These patients are frequently diagnosed as having somatoform, functional, factitious, or conversion disorders. Features of these disorders may include symptom exaggeration and inadequate effort. Symptom validity tests (SVTs) used by psychologists when assessing the validity of symptoms and impairments are structured, validated, and objectively scored. They could detect poor effort, underperformance, and exaggeration. In settings with appropriate prior probabilities, detection rates for symptom exaggeration have diagnostic utility. SVTs may help in moderating expensive diagnostic testing and redirecting treatment plans. This article familiarizes practicing neurologists with their merits, shortcomings, utility, and applicability in practice.

The Rey 15-item test Figure. An early test for memory malingering (Rey, 1958). After a 10-second presentation of this card, the patient is asked to draw as many items as possible from memory. Although seemingly difficult because it contains 15 items, the task is actually simple because the logical progression of stimuli makes them very easy to remember. The total number of items recalled, with a cutoff of ⩽7, shows high specificity but low sensitivity for symptom exaggeration. Although more sophisticated symptom validity tools have replaced this test, we show this figure as a prototype of visual memory testing.