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IQ after TBI: Smarter patients or inflated scores?
Abstracts from the 19th Annual Meeting
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( G O A T = 75). The Haistead-Reitan Category Test, Trail Making Test, WAIS-III Block Design Subtest and the Folstein Mini-Mental State Exam (MMSE) were administered. Significant correlations were found for the above four measures, as well as for the length of hospitalization and the G O A T (at a mean of 2 weeks postadmission) with the GCS. When patients with mild GCS scores (12-15) were compared to those with moderately impaired GCS scores (9-11), significant differences were found between these groups as follows: (a) patients in the mild group had shorter length of hospitalization; (b) patients in the moderate GCS group had lower scores on the GOAT; (c) patients in the moderate GCS group had greater general impairment on the MMSE. These findings support the ability of GCS scores to define severity of TBI, and to predict early neuropsychological outcome on measures of various neuropsychological functions.
Martin, T., Donders, J., & Thompson, E. IQ After TBI: Smarter Patients or Inflated Scores? The General Ability Measure for Adults (GAMA) and the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) were administered to 46 patients with traumatic brain injury (TBI), selected from a 1-year series of consecutive rehabilitation referrals. Individuals with prior neurological, psychiatric, or substance abuse histories were excluded. In the complete sample, G A M A IQ demonstrated a substantial correlation with WAISIII FSIQ (r = .78, p < .0001). However the G A M A tended to overestimate performance on the WAIS-III, with a standard error of estimation of 5.49 points. In terms of criterion validity, the findings were mixed, at best. Of the combination of G A M A IQ and the four WAIS-III factor index scores, only Processing Speed (PS) demonstrated consistent sensitivity to injury severity. The latter was evidenced by a statistically significant difference in PS between patients with mild TBI (GCS > 12 and negative CT) and patients with more severe injuries, F(1, 44) = 10.16, p < .01, and by a moderate correlation between PS and length of coma (r = -.36, p < .05). The current results are consistent with previous findings that suggested that the G A M A might overestimate cognitive performance level in patients with TBI. They also suggest that some of the WAIS-III indexes may not be sufficiently sensitive to injury severity. In particular, the lack of criterion validity of the Perceptual Organization index is concerning, given that Performance measures from the WAIS-R have been shown previously to be relatively more useful in this regard. The decreased emphasis on speeded performance on the WAIS-III, particularly with the introduction of the untimed subtest Matrix Reasoning (which yielded the highest scaled score in our moderate/severe group) may be the reason for this phenomenon. Practitioners should be aware of the fact that some recently developed tests of psychometric intelligence may yield inflated scores in patients with moderate to severe TBI.
Lopez, A., Durant-Wilson, D. M., & Hartlage, L. C. Age-Related Patterns of Behavioral Changes Following TBI. Although age-related differences in patterns of neurocognitive impairment following TBI have been well-documented, there has been sparse study of possible age-related differences in patterns of emotional or behavioral sequelae of TBI. This project studied changes from pre-injury baseline among patients in three age groups: <26 years (n = 24); 26-44 years (n = 48); >44 years (n = 24). All patients were seen for examination of neuropsychological status following TBI. Neuropsychological impairment severity ranged from mild to severe. Due to uneven numbers, behavior change patterns were converted to percentages in each age range showing change from baseline on a 68-item Behavior Change Inventory.
787
( G O A T = 75). The Haistead-Reitan Category Test, Trail Making Test, WAIS-III Block Design Subtest and the Folstein Mini-Mental State Exam (MMSE) were administered. Significant correlations were found for the above four measures, as well as for the length of hospitalization and the G O A T (at a mean of 2 weeks postadmission) with the GCS. When patients with mild GCS scores (12-15) were compared to those with moderately impaired GCS scores (9-11), significant differences were found between these groups as follows: (a) patients in the mild group had shorter length of hospitalization; (b) patients in the moderate GCS group had lower scores on the GOAT; (c) patients in the moderate GCS group had greater general impairment on the MMSE. These findings support the ability of GCS scores to define severity of TBI, and to predict early neuropsychological outcome on measures of various neuropsychological functions.
Martin, T., Donders, J., & Thompson, E. IQ After TBI: Smarter Patients or Inflated Scores? The General Ability Measure for Adults (GAMA) and the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) were administered to 46 patients with traumatic brain injury (TBI), selected from a 1-year series of consecutive rehabilitation referrals. Individuals with prior neurological, psychiatric, or substance abuse histories were excluded. In the complete sample, G A M A IQ demonstrated a substantial correlation with WAISIII FSIQ (r = .78, p < .0001). However the G A M A tended to overestimate performance on the WAIS-III, with a standard error of estimation of 5.49 points. In terms of criterion validity, the findings were mixed, at best. Of the combination of G A M A IQ and the four WAIS-III factor index scores, only Processing Speed (PS) demonstrated consistent sensitivity to injury severity. The latter was evidenced by a statistically significant difference in PS between patients with mild TBI (GCS > 12 and negative CT) and patients with more severe injuries, F(1, 44) = 10.16, p < .01, and by a moderate correlation between PS and length of coma (r = -.36, p < .05). The current results are consistent with previous findings that suggested that the G A M A might overestimate cognitive performance level in patients with TBI. They also suggest that some of the WAIS-III indexes may not be sufficiently sensitive to injury severity. In particular, the lack of criterion validity of the Perceptual Organization index is concerning, given that Performance measures from the WAIS-R have been shown previously to be relatively more useful in this regard. The decreased emphasis on speeded performance on the WAIS-III, particularly with the introduction of the untimed subtest Matrix Reasoning (which yielded the highest scaled score in our moderate/severe group) may be the reason for this phenomenon. Practitioners should be aware of the fact that some recently developed tests of psychometric intelligence may yield inflated scores in patients with moderate to severe TBI.
Lopez, A., Durant-Wilson, D. M., & Hartlage, L. C. Age-Related Patterns of Behavioral Changes Following TBI. Although age-related differences in patterns of neurocognitive impairment following TBI have been well-documented, there has been sparse study of possible age-related differences in patterns of emotional or behavioral sequelae of TBI. This project studied changes from pre-injury baseline among patients in three age groups: <26 years (n = 24); 26-44 years (n = 48); >44 years (n = 24). All patients were seen for examination of neuropsychological status following TBI. Neuropsychological impairment severity ranged from mild to severe. Due to uneven numbers, behavior change patterns were converted to percentages in each age range showing change from baseline on a 68-item Behavior Change Inventory.