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.