Estimating premorbid intelligence in persons with traumatic brain injury: an examination of the Test of Premorbid Functioning.

Knowledge of intelligence is essential for interpreting cognitive performance following traumatic brain injury (TBI). The Test of Premorbid Functioning (ToPF), a word reading test co-normed with the Wechsler Adult Intelligence Scale 4th Edition (WAIS-IV), was examined as a tool for estimating premorbid intelligence in persons with a history of TBI. Fifty-two participants with mild, moderate, or severe TBI were administered the ToPF and WAIS-IV between two weeks and 19 months post-injury. The independent ability of the ToPF/demographic score and the Verbal Comprehension Index (VCI) to predict WAIS-IV Full Scale IQ (FSIQ) was examined, as were discrepancies between ToPF and WAIS-IV scores within and between participants. The ToPF/demographic predicted FSIQ accounted for a significant proportion of variability in actual FSIQ, above and beyond that accounted for by education or time since injury. ToPF and WAIS-IV scores did not differ by injury severity. In our sample, the ToPF/demographic predicted FSIQ underestimated intelligence in a substantial portion of our participants (31%), particularly in those with high average to superior intelligence. Finally, VCI scores were more predictive of actual FSIQ than the ToPF/demographic predicted FSIQ. The ToPF frequently underestimated post-injury intelligence and is therefore not accurately measuring premorbid intelligence in our sample, particularly in those with above average to superior intelligence. Clinicians are encouraged to administer the entire WAIS-IV, or at minimum the VCI subtests, for a more accurate measure of intelligence in those with above average intelligence and history of TBI.

Rey Tangled Line Test: A measure of processing speed in TBI.

OBJECTIVE: Neuropsychological assessment plays a key role in characterizing and detecting cognitive impairment after traumatic brain injury (TBI). The Rey Tangled Line Test (RTLT), an understudied neuropsychological assessment thought to be capable of detecting visual processing deficits, was examined to determine which cognitive abilities may contribute to performance on the test in participants with a history of TBI. METHOD: One-hundred participants with a history of mild to severe TBI were administered a battery of neuropsychological tests assessing attention, executive functioning, memory, visual construction, motor functioning, and processing speed between 30 days and 5 years postinjury. An exploratory principal components analysis (PCA) was performed to determine which cognitive tests the RTLT was most highly associated with. RESULTS: No difference in RTLT latency was present between mild and moderate/severe TBI. The PCA resulted in 5 factors. RTLT latency had a significant primary factor loading on the "processing speed" factor, and a secondary loading on the "motor" factor. Forty-two percent of participants had an impaired latency score. CONCLUSIONS: RTLT latency appears to measure processing speed, and likely aspects of motor functioning, in our sample. The RTLT may be useful as a rapid assessment in individuals with a history of TBI to detect cognitive deficit before initiating further cognitive testing or rehabilitation efforts. (PsycINFO Database Record (c) 2019 APA, all rights reserved).