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Effect of cause of injury on lesion location, injury severity and outcome following traumatic brain injury
32
Abstracts from the 18th Annual Meeting
Even fewer studies have investigated the long-term effects of decompression sickness (Curley, Schwartz, & Zwingelberg, 1988; Levin, Goldstein, Norcross, Amparo, Guinto, & Mader, 1989; Peters, Levin, & Kelly, 1977) and only one investigation was found which reported possible chronic effects of decompression sickness, and this was limited to only 26 days post injury in one case and 14 days post injury in the other (Levin, Goldstein, Norcross et al., 1989). The current investigation examined neuropsychological test data 3 months post injury in one clinical case in order to document long-term neurobehavioral changes in an individual with decompression sickness and to record neuropsychological changes associated with breathing surface-supplied air. Findings suggest neuropsychological impairment as a result of decompression sickness can continue over 3 months post injury. Specifically, the individual in the current case study had difficulty with performance IQ, memory, motor speech/strength/dexterity, maintaining a cognitive set, visual-spatial construction and spatial perception/reasoning. When these results are added to those obtained by Levin, Goldstein, Norcross and colleagues (1989) and Peters, Levin, and Kelly (1977), they indicate that memory and motor performance are likely the most common neurobehavioral deficits after decompression sickness, and that these sequelae can continue well beyond the initial cerebral insult. Furthermore, they are similar to performance decrements found in individuals during dives of up to 686 meters (Logue, Schmitt, Rogers, & Strong, 1986; Vaernes, Aarli, Klove, & Tonjum).
Henley, T. G., Ardila, A., & Puentes, G. Short-term Recovery Following Mild to Moderate TBL The purpose of this study was to further investigate short term spontaneous recovery following TBI. The goal was to determine which cognitive functions are more resilient after brain injury and if functions differ in terms of time of recovery. The participants were 25 patients admitted to a metropolitan teaching hospital neurorehabilitation unit with the diagnosis of mild to moderate TBI (Mean Age: 27.92, Mean Education Level: 12.28). Each participant was administered a battery of 11 neuropsychological tests while on the rehabilitation unit and at a 3-month follow up appointment. It was found that test performance ranged from average to severely impaired on first administration. The mean score for each test improved on second administration and a majority of the tests fell in the average to mildly impaired range, t-tests for paired samples revealed that four functions yielded significant improvement between administrations: Block Design (t = 3.84; p < .001), Hooper, (t = 3.79; p < .001), Digit Span (t = 3.52; p < .002), and COWAT, (t = 3.17; p < .004). The 7 remaining cognitive functions did not demonstrate significant improvement. The current findings support the notion that individuals do in fact demonstrate spontaneous recovery in all areas, however, functions vary with regard to rate and quantity of recovery over a 3-month period.
Hillary, Fo, Schatz, P., Moelter, S., & Chute, D. L. Effect of Cause of Injury on Lesion Location, Injury Severity and Outcome Following Traumatic Brain Injury. Previous research occasioned us to hypothesize that the mechanics of traumatic brain injury produce different anatomical locations and severity's of brain injuries. Location of lesion, injury severity, and outcome following traumatic brain injury were analyzed for 236 of a pool of 500 individuals who were applicants to the Pennsylvania Head Injury Program. Subjects were selected as belonging to one of four major groups based on the circumstance around which they sustained their TBI: motor vehicle occupants wearing seat belts (n = 31), unbelted motor vehicle occupants (n = 130), victims of assault (n =
Abstracts from the 18th Annual Meeting
33
33), and individuals who suffered TBI from a fall (n = 42). The different physical forces exerted at the time of injury for each of these four groups led us to hypothesize that individuals would sustain anatomically different injuries. Analyses of emergency room, radiology, and acute care hospital records revealed a significant effect of cause of injury on lesion location. Belted motor vehicle occupants sustained significantly more subcortical injuries (p < .02), unbelted motor vehicle occupants sustained significantly more posterior cortical lesions (p < .0001), and subjects in the fall and assault groups sustained significantly more epidural and subdural hematomas (p < .0002). Location of anatomical lesion had a significant effect on severity of injury. Upon admission to the emergency room, motor vehicle occupants were assigned significantly more impaired Glasgow Coma Scale scores (p < .002) and experienced significantly longer loss of consciousness (p < .05) than subjects in the assault and fall groups. No significant group differences were noted on functional outcome measures when rated at an average of 3.6 years post injury. Despite receiving less impaired ratings of severity of injury than motor vehicle occupants, subjects in the fall and assault groups did not ultimately achieve a higher level of functional ability. Socioeconomic and personality variables are believed to contribute to this deleterious effect on functional outcome. The fall and assault groups are distinguished from the motor vehicle occupant groups by having significantly lower levels of education (p < .005), significantly higher incidence of alcohol use at the time of injury (p < .001), and they were significantly more likely to be single and male. These data show that the location and severity of lesion are different as a likely result of the mechanics of brain injury, with no resultant effect on functional outcome. We speculate, however, that socioeconomic and personality variables may contribute to poorer functional outcomes.
Kervick, R., Askinazi, L., & Williams, J. M. The Neuropsychological Outcome of Mild Brain Injury: A Narrative and Meta-Analytic Review. Mild Traumatic Brain Injury (MTBI) has become an important diagnostic construct in the forensic applications of clinical neuropsychology. MTBI cases are the most often controversial and litigated cases. Although neuropsychologists commonly make inferences concerning the validity of impairment in cases of MTBI, there have been few attempts to provide aggregate knowledge of outcome and none that have taken a meta-analytic approach. The present study reviewed the cognitive outcome of MTBI using meta-analysis. Twenty-eight studies were included in the review. Effect sizes were directly calculated for studies that contained control groups. For studies that did not contain a control group, effect sizes were estimated by comparing the MTBI group test scores to normative standards derived for the dependent measures. Most of the studies of MTBI used conventional, well-normed tests, such as the Wechsler Adult Intelligence Scale (WAIS), and as a consequence, very few studies were excluded from the analysis because an effect size could not be computed. The study was also able to include relatively new normative systems for some tests, such as the Paced Auditory Serial Addition Test (PASAT), that were not available at the time the original study using the P A S A T was conducted. Results indicated that the effect sizes were generally small for measures of intelligence and memory (d = .1 to .3). Slight increases in effect size were observed for a variety of tests that assess psychomotor speed and attention. This suggests that MTBI typically results in very small changes of cognition. These levels are well within the range of influence of extraneous factors, such as psychological depression and malingering. This also suggests that patients who demonstrate extremely poor performance following MTBI are atypical. If there is no indication the patient sustained a more severe injury, such low performance levels may represent premorbid status or the influence of some extraneous factor.
Abstracts from the 18th Annual Meeting
Even fewer studies have investigated the long-term effects of decompression sickness (Curley, Schwartz, & Zwingelberg, 1988; Levin, Goldstein, Norcross, Amparo, Guinto, & Mader, 1989; Peters, Levin, & Kelly, 1977) and only one investigation was found which reported possible chronic effects of decompression sickness, and this was limited to only 26 days post injury in one case and 14 days post injury in the other (Levin, Goldstein, Norcross et al., 1989). The current investigation examined neuropsychological test data 3 months post injury in one clinical case in order to document long-term neurobehavioral changes in an individual with decompression sickness and to record neuropsychological changes associated with breathing surface-supplied air. Findings suggest neuropsychological impairment as a result of decompression sickness can continue over 3 months post injury. Specifically, the individual in the current case study had difficulty with performance IQ, memory, motor speech/strength/dexterity, maintaining a cognitive set, visual-spatial construction and spatial perception/reasoning. When these results are added to those obtained by Levin, Goldstein, Norcross and colleagues (1989) and Peters, Levin, and Kelly (1977), they indicate that memory and motor performance are likely the most common neurobehavioral deficits after decompression sickness, and that these sequelae can continue well beyond the initial cerebral insult. Furthermore, they are similar to performance decrements found in individuals during dives of up to 686 meters (Logue, Schmitt, Rogers, & Strong, 1986; Vaernes, Aarli, Klove, & Tonjum).
Henley, T. G., Ardila, A., & Puentes, G. Short-term Recovery Following Mild to Moderate TBL The purpose of this study was to further investigate short term spontaneous recovery following TBI. The goal was to determine which cognitive functions are more resilient after brain injury and if functions differ in terms of time of recovery. The participants were 25 patients admitted to a metropolitan teaching hospital neurorehabilitation unit with the diagnosis of mild to moderate TBI (Mean Age: 27.92, Mean Education Level: 12.28). Each participant was administered a battery of 11 neuropsychological tests while on the rehabilitation unit and at a 3-month follow up appointment. It was found that test performance ranged from average to severely impaired on first administration. The mean score for each test improved on second administration and a majority of the tests fell in the average to mildly impaired range, t-tests for paired samples revealed that four functions yielded significant improvement between administrations: Block Design (t = 3.84; p < .001), Hooper, (t = 3.79; p < .001), Digit Span (t = 3.52; p < .002), and COWAT, (t = 3.17; p < .004). The 7 remaining cognitive functions did not demonstrate significant improvement. The current findings support the notion that individuals do in fact demonstrate spontaneous recovery in all areas, however, functions vary with regard to rate and quantity of recovery over a 3-month period.
Hillary, Fo, Schatz, P., Moelter, S., & Chute, D. L. Effect of Cause of Injury on Lesion Location, Injury Severity and Outcome Following Traumatic Brain Injury. Previous research occasioned us to hypothesize that the mechanics of traumatic brain injury produce different anatomical locations and severity's of brain injuries. Location of lesion, injury severity, and outcome following traumatic brain injury were analyzed for 236 of a pool of 500 individuals who were applicants to the Pennsylvania Head Injury Program. Subjects were selected as belonging to one of four major groups based on the circumstance around which they sustained their TBI: motor vehicle occupants wearing seat belts (n = 31), unbelted motor vehicle occupants (n = 130), victims of assault (n =
Abstracts from the 18th Annual Meeting
33
33), and individuals who suffered TBI from a fall (n = 42). The different physical forces exerted at the time of injury for each of these four groups led us to hypothesize that individuals would sustain anatomically different injuries. Analyses of emergency room, radiology, and acute care hospital records revealed a significant effect of cause of injury on lesion location. Belted motor vehicle occupants sustained significantly more subcortical injuries (p < .02), unbelted motor vehicle occupants sustained significantly more posterior cortical lesions (p < .0001), and subjects in the fall and assault groups sustained significantly more epidural and subdural hematomas (p < .0002). Location of anatomical lesion had a significant effect on severity of injury. Upon admission to the emergency room, motor vehicle occupants were assigned significantly more impaired Glasgow Coma Scale scores (p < .002) and experienced significantly longer loss of consciousness (p < .05) than subjects in the assault and fall groups. No significant group differences were noted on functional outcome measures when rated at an average of 3.6 years post injury. Despite receiving less impaired ratings of severity of injury than motor vehicle occupants, subjects in the fall and assault groups did not ultimately achieve a higher level of functional ability. Socioeconomic and personality variables are believed to contribute to this deleterious effect on functional outcome. The fall and assault groups are distinguished from the motor vehicle occupant groups by having significantly lower levels of education (p < .005), significantly higher incidence of alcohol use at the time of injury (p < .001), and they were significantly more likely to be single and male. These data show that the location and severity of lesion are different as a likely result of the mechanics of brain injury, with no resultant effect on functional outcome. We speculate, however, that socioeconomic and personality variables may contribute to poorer functional outcomes.
Kervick, R., Askinazi, L., & Williams, J. M. The Neuropsychological Outcome of Mild Brain Injury: A Narrative and Meta-Analytic Review. Mild Traumatic Brain Injury (MTBI) has become an important diagnostic construct in the forensic applications of clinical neuropsychology. MTBI cases are the most often controversial and litigated cases. Although neuropsychologists commonly make inferences concerning the validity of impairment in cases of MTBI, there have been few attempts to provide aggregate knowledge of outcome and none that have taken a meta-analytic approach. The present study reviewed the cognitive outcome of MTBI using meta-analysis. Twenty-eight studies were included in the review. Effect sizes were directly calculated for studies that contained control groups. For studies that did not contain a control group, effect sizes were estimated by comparing the MTBI group test scores to normative standards derived for the dependent measures. Most of the studies of MTBI used conventional, well-normed tests, such as the Wechsler Adult Intelligence Scale (WAIS), and as a consequence, very few studies were excluded from the analysis because an effect size could not be computed. The study was also able to include relatively new normative systems for some tests, such as the Paced Auditory Serial Addition Test (PASAT), that were not available at the time the original study using the P A S A T was conducted. Results indicated that the effect sizes were generally small for measures of intelligence and memory (d = .1 to .3). Slight increases in effect size were observed for a variety of tests that assess psychomotor speed and attention. This suggests that MTBI typically results in very small changes of cognition. These levels are well within the range of influence of extraneous factors, such as psychological depression and malingering. This also suggests that patients who demonstrate extremely poor performance following MTBI are atypical. If there is no indication the patient sustained a more severe injury, such low performance levels may represent premorbid status or the influence of some extraneous factor.