Factor structure of the modified Rivermead Post-concussion Symptoms Questionnaire (mRPQ): an exploratory analysis with healthy adult simulators.

Consistent with prior RPQ research, a unidimensional or bifactor structure was measurable from standard RPQ symptoms. Whilst this study did not find support for domain-level symptom scores for either typical or atypical symptoms, the findings support the use of an overall atypical symptoms score.