Distinguishing impairments in speed of information processing between traumatic brain injury and chronic pain

Abstract

Speed of information processing deficits are hallmark symptoms of, and a primary consideration, in the differential diagnosis of mild traumatic brain injury (MTBI). Chronic pain is a common comorbid symptom following trauma-induced brain injury and can impact information processing speed thereby creating a potential confound in a differential diagnosis. Examining Chronic Pain, MTBI, Severe Traumatic Brain Injury (STBI), and a Healthy Control group, the Computerized Tests of Information Processing (CTIP) were used to assess processing speed. CTIP results were contrasted with traditional paper and pencil neuropsychological (NP) tests (Digit Span, Digit Symbol, Trails A & B) across groups. The Chronic Pain group performed significantly worse than the MTBI and Control groups on the CTIP with no significant differences between the Chronic Pain and Control group on any traditional NP test. Notably, there were no significant differences in scores on the CTIP or traditional NP tests between the Chronic Pain and the STBI groups. Discriminant analyses indicated the Semantic test was the strongest predictor of group membership among CTIP tasks, correctly predicting 41% of the present sample and estimating 34% correct prediction in a new sample. Digit Span was the strongest predictor when the CTIP and traditional NP tests were examined together with the model correctly predicting 47.5% in the present sample and estimating 35% correct prediction in a new sample. In regression analyses, depressive symptoms predicted Semantic CTIP scores; fatigue, and a measure of the current affective quality of pain, predicted Digit Span scores; and cumulative effects of multiple symptoms predicted most CTIP and traditional NP scores. These results provide additional evidence that individuals with Chronic Pain experience notable impairments in information processing speed with the potential to confound NP test results for potentially brain injured patients. Implications, limitations and future recommendations are discussed.