The Relationship Between Initial Physical Examination Findings and Failure on Objective Validity Testing During Neuropsychological Evaluation After Pediatric Mild Traumatic Brain Injury

Abstract

Background:The symptomatology after mild traumatic brain injury (mTBI) is complex as symptoms are subjective and nonspecific. It is important to differentiate symptoms as neurologically based or caused by noninjury factors. Symptom exaggeration has been found to influence postinjury presentation, and objective validity tests are used to help differentiate these cases. This study examines how concussed patients seen for initial medical workup may present with noncredible effort during follow-up neuropsychological examination and identifies physical findings during evaluation that best predict noncredible performance.Hypothesis:A portion of pediatric patients will demonstrate noncredible effort during neuropsychological testing after mTBI, predicted by failure of certain vestibular and cognitive tests during initial examination.Study Design:Retrospective cohort.Level of Evidence:Level 4.Methods:Participants (n = 80) underwent evaluation by a sports medicine physician ≤3 months from injury, were subsequently seen for a neuropsychological examination, and completed the Medical Symptom Validity Test (MSVT). Variables included results of a mental status examination (orientation), serial 7s examination, Romberg test, and heel-to-toe walking test. The primary outcome variable of interest was pass/fail of the MSVT.Results:Of the participants, 51% were male and 49% were female. Eighteen of 80 (23%) failed the MSVT. Based on univariable logistic regression analysis, the outcomes of the Romberg test (P = 0.0037) and heel-to-toe walking test(P = 0.0066) were identified as significant independent predictors of MSVT failure. In a multivariable model, outcome of Romberg test was the only significant predictor of MSVT failure. The probability of MSVT failure was 66.7% (95% CI, 33.3% to 88.9%) when a subject failed the Romberg test.Conclusion:A meaningful percentage of pediatric subjects present evidence of noncredible performance during neuropsychological examination after mTBI. Initial examination findings in some cases may represent symptom exaggeration.

Clinical predictors of symptom resolution for children and adolescents with sport-related concussion

“…Previous work suggests that approximately 23% of children failed a well-validated performance validity test after a concussion. 42 Taken together with our findings, it is plausible that some individuals truly cannot control their balance when evaluated, resulting in an abnormal performance on the Romberg test, while others may have exaggerated their movements. Regardless, both sets of individuals may require special attention soon after concussion, as they may be at an increased risk for experiencing prolonged symptoms.…”

“…23 However, in our sample, patients were classified as having abnormal test performance when they demonstrated significant loss of balance or increased upper-body movement, which can be a sign of exaggeration or feigning of symptoms. 42 Thus, it is difficult to determine whether patients who demonstrated abnormal performance on the Romberg test had postural instability due to a physiological deficit, noncredible effort, or exaggerated movements during the test. Therefore, there may be multiple reasons underlying the independent association between abnormal Romberg test performance and longer symptom duration in our cohort of youths with concussion.…”

“…20,44 In addition to postural instability assessment, the Romberg test may also serve as a method to determine if patients are exaggerating their postinjury deficits in a manner that reflects balance dysfunction. 42 The idea that some youths may exaggerate or feign symptoms after concussion has been studied in the context of neuropsychological testing and symptom reporting, 1,7,26 but it has not received substantial attention with regard to postural stability tests. Previous work suggests that approximately 23% of children failed a well-validated performance validity test after a concussion.…”