[show abstract][hide abstract] ABSTRACT: Comprehensive reviews of neurocognitive outcomes following mild, uncomplicated traumatic brain injury (TBI) in children have shown minimal effects on neurocognition, especially in methodologically rigorous studies. In this study, we report longitudinal (1, 6, and 12 months post injury) results in four domains of neurocognitive functioning in a large sample of children with mild TBI (n = 124, ages 8-17 at injury) relative to two demographically matched control groups (other injury: n = 94 and non-injury: n = 106). After accounting for age and parental education, significant main effects of group were observed on 7 of the 10 neurocognitive tests. However, these differences were not unique to the TBI sample but were found between both the TBI and other injury groups relative to the non-injured group, suggesting a general injury effect. Effects were primarily within the domains measuring memory, psychomotor processing speed, and language. This is the largest longitudinal study to date of neurocognitive outcomes at discrete time points in pediatric mild TBI. When controlling for pre-injury factors, there is no evidence of long-term neurocognitive impairment in this group relative to another injury control group. The importance of longitudinal analyses and use of appropriate control groups are discussed in the context of evaluating the effects of mild TBI on cognition.
Journal of the International Neuropsychological Society 08/2011; 17(5):886-95. · 2.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: The concept of "reserve" has traditionally been defined on the basis of a single indicator (e.g., education or intracranial volume) that purports to moderate or buffer the effects of brain damage on different clinical outcomes. While studies have shown modest effects for some indicators, it has left the concept of "reserve" wanting as an explanatory construct. More recently efforts have been made to identify groups of indicators hypothesized to represent a construct for brain or cognitive reserve. These efforts have also proved wanting because of the lack of evidence to justify such a priori groupings of variables into a brain or cognitive reserve construct. This theoretical paper addresses the issue of construct validity (convergent and discriminant) for both brain and cognitive reserve as single or multiple reserve factors. Conceptual models are proposed that are (a) derived from the current extant reserve literature and (b) empirically testable in order to facilitate establishment of construct validity for the commonly used, and perhaps misused, brain and cognitive reserve concepts.
Journal of Clinical and Experimental Neuropsychology 01/2011; 33(1):121-30. · 1.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: The present case study examines, through longitudinal neuropsychological assessment over a time span of 3 years, the course of pathological left-handedness (PLH; Orsini & Satz, 1986; Satz, Soper, & Orsini, 1988; Satz, Orsini, Saslow, & Henry, 1985; Satz, 1973; Soper & Satz, 1984) in a 6-year, 2-month-old female. The case illustrates for the first time, in a data-based and time-delineated fashion, the pattern of changes that have been previously attributed to this syndrome (Satz et al., 1985) including trophic alterations, abrupt shift in manual dominance, and probable interhemispheric reorganization detrimental to visual-spatial functions (crowding hypothesis). Theoretical and applied implications associated with the present findings are also addressed.
Child Neuropsychology 08/2010; August 1998(Vol. 4):98-109. · 2.24 Impact Factor
[show abstract][hide abstract] ABSTRACT: Neurodevelopmental and neurobehavioral manifestations in infancy and childhood, resulting from Human Immunodeficiency Virus-Type
1 (HIV-1) infection, continue to warrant special and distinct consideration in this handbook.
[show abstract][hide abstract] ABSTRACT: This investigation examined the test-retest reliability and the factorial validity of the Children's Color Trails Test 1 & 2 (CCTT) using two distinct and independent studies and their respective research samples. The reliability of the CCTT was evaluated in a study with 6-12-year-old children (n = 54) strictly selected and diagnosed with attention-deficit/hyperactivity disorder from an interventional protocol using test-retest coefficients at 8- and 16-week time intervals. Factorial validity was investigated using groups of children with traumatic brain injury (TBI) (n = 137), children with other types of trauma than brain or head injury (Other Injury) (n = 132), and healthy controls (n = 114) from a protocol assessing the neuropsychological sequelae of traumatic brain injury. The results revealed completion time test-retest reliability in the moderate range, which may be considered modest (r(tt) =.46-.68) in this sample of children with ADHD. Interference reliability coefficients were greater and in the moderate-high range (r(tt) =.75-.78). Factorial analytic results revealed a three-factor structure solution for all three groups (TBI, Other Injury, and controls). As a result of CCTT's factorial loadings, Factor 1 was labeled speed of perceptual tracking and susceptibility to interference, Factor 2 was labeled inattention and impulsivity, and Factor 3 was labeled simple inattention. Relative limitations and strengths associated with this investigation including practice effects associated with repeated CCTT administrations also were addressed within the context of the extant findings and existing trail-making test literature.
The Clinical Neuropsychologist 10/2008; 23(4):645-60. · 1.68 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cognitive and emotional correlates of toxic mold exposure and potential dose-response effects for both outcomes were investigated. Self-reported length of exposure, time since last exposure, and serum immunoglobulin (IgG) levels were assessed. Despite CNS complaints often seen with mold exposed individuals, overall results did not uncover concomitant cognitive deficits suggested in previous studies or a significant reduction in intellectual functioning. Fewer subjects were excluded as result of failing effort/motivation assessment than expected. Correlations of IgG and cognitive function are discussed. A dose-effect for self-reported length of exposure and cognitive outcome was not seen. The sample's overall Minnesota Multiphasic Personality Inventory II (MMPI-2) profile indicated elevations on scales 1, 2, 3, 7 and 8. MMPI-2 clinical scales 1 and 3 were significantly correlated with length of exposure. The MMPI-2 may be sensitive to increasing physical and emotional sequelae as length of exposure increases. A potential subgroup of cognitively impaired outliers within mold exposure litigants is explored. Limitations of self-reported and objective measurements for mold exposure and exploratory statistical methodology are discussed.
Archives of Clinical Neuropsychology 06/2007; 22(4):533-43. · 2.00 Impact Factor
[show abstract][hide abstract] ABSTRACT: The effect of age on cognition was examined with a variety of neuropsychological tests in 220 aircraft pilots. The assessment included tests of psychomotor speed, information processing speed, attention and executive ability, verbal learning and memory, and visual learning and memory. Pilot age was between 28 and 62 with a mean ageof48years. Test performance was regressed on pilot age to determine the function (linear or nonlinear) of age-related differences in cognition. Individual performance was also examined by assessing outlier test scores (> 2 SD) relative to the overall group mean. Age was significantly associated with test performance across several domains; when significant, a linear function best described the association. Pilot age was not associated with immediate verbal recall or recognition or with immediate visual recall. Almost all performance outliers occurred in pilots over 40 years old. Implications of a gradual decline in pilot cognition are discussed as well as the consideration of a subgroup of relatively poor cognitive performing pilots and the potential importance of assessing individual differences.
International Journal of Aviation Psychology 01/2007; 17(1):77-90. · 0.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: Following traumatic brain injury (TBI), patients often report memory difficulties, as well as reduced information processing speed. However, it remains unclear the extent to which these deficits contribute to functional impairment. In the present study, we compared the relative contribution of verbal memory and information processing speed to functional impairment at 12-month post-injury, in 87 patients with moderate-to-severe TBI. Employing structural equation modeling, we found that information processing speed, but not verbal memory functions, significantly mediated the relationship between TBI severity and post-TBI adaptive functioning. These findings suggest that despite the pervasive memory complaints among patients with TBI, it is the impact of neurotrauma on frontal systems that appears to be primarily responsible for patients' difficulties in social and occupational functioning.
Journal of Clinical and Experimental Neuropsychology 06/2006; 28(4):581-91. · 1.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: Literature exists to suggest that the severity of traumatic brain injury (TBI) is positively associated with the severity of functional impairment. However, potential mediators of this relationship have not been studied systematically. In the present study, we evaluated a model hypothesized to explain the relationship between TBI severity and functional impairment in 87 patients with moderate-to-severe TBI, studied longitudinally. Using structural equation modeling, we found that only neuropsychological status (but not emotional or behavioral difficulties) consistently mediated the relationship between TBI severity and functional outcome at 12-months post-injury. These findings suggest that, of the factors examined here, neurocognitive compromise plays the most prominent role in mediating post-TBI adaptive functioning in moderate-to-severe TBI, which has important implications for post-injury interventions.
Journal of Clinical and Experimental Neuropsychology 06/2006; 28(4):567-80. · 1.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: Both depression and neurocognitive compromise are commonly observed among persons infected with the Human Immunodeficiency Virus (HIV). To date, the majority of studies have failed to find a consistent relationship between mood and cognition among HIV-seropositive (HIV+) individuals, suggesting that these constructs are independent of one another. However, depression is a multi-dimensional syndrome and its measurement often utilizes multi-factorial instruments containing cognitive, affective, somatic, and motivational components. The degree to which various symptoms or dimensions of depression might be related to neuropsychological performance in HIV-1 infection is not typically explored and was a main objective of the current study. A sample of 247 HIV+ persons completed both a comprehensive neurocognitive battery and the Beck Depression Inventory (BDI) as part of a standard clinical evaluation at a major community hospital. To examine the dimensionality of the BDI, a principal components analysis was conducted which suggested a three-factor solution comprised of factors representing Self-Reproach (SR), Mood-Motivation Disturbance (MM), and Somatic Disturbance (SOM). The relationship between each of these three factors and neurocognitive performance was examined using both regression and analysis of variance techniques. These analyses showed the MM factor, more so than either the SR or SOM factors, to be associated with several aspects of neurocognitive performance, including verbal memory, executive functioning, and motor speed. These findings suggest that certain items on depression rating scales may be more indicative of central nervous system (CNS) involvement than others. The association between disturbance in mood and motivation and neurocognitive compromise may suggest that each are sequelae of disease specific mechanisms.
Journal of Clinical and Experimental Neuropsychology 05/2006; 28(3):420-37. · 1.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: The study explored encoding, storage, and retrieval components of memory functioning in four groups of subjects: (1) normal elderly; (2) elderly subjects in the early prestages of DAT; (3) elderly subjects with a more advanced DAT; (4) younger subjects in the early prestages of AIDS dementia. Each group consisted of 26 subjects, who were administered the Rey Auditory-Verbal Learning Test. The results suggest impaired encoding and retrieval in the DAT groups. The AIDS group demonstrated deficient storage and retrieval. Their pattern of memory deficits was similar to that seen in normal aging. The results speak in favor of the hypothesis of subcortical nature of neurological changes in normal aging.
[show abstract][hide abstract] ABSTRACT: Despite the use of laboratory markers in estimating HIV prognosis, significant variation in the natural history of HIV-1 infection remains unexplained. Recent studies suggest psychosocial risk factors have important prognostic significance in HIV disease. The objective of the present study was to examine the prognostic influence of age, general intellectual functioning, and emotional distress across the spectrum of HIV disease progression. The study sample was drawn from the Multicenter AIDS Cohort Study (MACS), a 13-year, prospective study of HIV-seropositive men recruited from four study centers across the country. The participants were 1,231 HIV-seropositive MACS participants, followed from baseline (median 8/15/87) to the end of the observation period (12/15/98). HIV disease progression was evaluated with respect to three outcome measures: (1) number of years from baseline testing to the first AIDS defining illness (progression to AIDS), (2) years from baseline to HIV-dementia (progression to dementia), and (3) years from baseline to death (survival). The influence of psychosocial risk factors on outcome measures was evaluated using survival analyses. General intellectual functioning, age, and somatic symptoms of depression, were found to be significant predictors of HIV disease progression and survival. Older age at baseline was associated with a more rapid progression to dementia and death. Lower Shipley IQ estimates were associated with a more rapid disease progression (AIDS and dementia) and shortened survival. Somatic symptoms of depression were associated with shortened survival. In addition, age, IQ, and somatic symptoms of depression, had an additive effect with an increase in the number of risk factors associated with accelerated disease progression and shortened time to death. These findings remained consistent, despite controlling for baseline CD4 and HIV medication use. Psychosocial cofactors are important in understanding HIV disease progression. Methods for estimating HIV prognosis may become more reliable if psychosocial factors are considered. Future research will clarify if psychosocial risk factors reflect central nervous system integrity, brain reserve capacity or mediate morbidity and mortality through social economic status, access to health care and other social correlates.
Journal of Clinical and Experimental Neuropsychology 09/2003; 25(5):654-70. · 1.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: We hope that this chapter has conveyed the fact that many of the psychiatric symptoms, signs, and syndromes described in earlier
chapters of this text commonly appear following CNS disturbance. Likewise, many of the most prevalent neurological disorders
have important psychiatric sequelae. Freud, in his Project for a scientific pychology, speculated that in the future we would find that “behind every crooked thought lies a crooked neuron,” recognizing the intimate
relationship between psychological phenomenon and neurophysiology. Fortunately, the Cartesian dualism, which has artificially
dichotomized disorders of the mind and disorders of the brain, has faded considerably during the last decade. With the continued
advances in neuropsychology and kindred disciplines, especially neuroimaging, Freud’s prediction again appears prescient.
[show abstract][hide abstract] ABSTRACT: Utilizing [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET), we assessed the temporal pattern and the correlation of functional and metabolic recovery following human traumatic brain injury.
Fifty-four patients with injury severity ranging from mild to severe were studied. Thirteen of these patients underwent both an acute and delayed FDG-PET study.
Analysis of the pooled global cerebral metabolic rate of glucose (CMRglc) values revealed that the intermediate metabolic reduction phase begins to resolve approximately one month following injury, regardless of injury severity. The correlation, in the 13 patients studied twice, between the extent of change in neurologic disability, assessed by the Disability Rating Scale (DRS), and the change in CMRglc from the early to late period was modest (r = -0.42). Potential explanations for this rather poor correlation are discussed. A review of the pertinent literature regarding the use of PET and related imaging modalities, including single photon emission tomography (SPECT) for the assessment of patients following traumatic brain injury is given.
The dynamic profile of CMRglc that changes following traumatic brain injury is seemingly stereotypic across a broad range and severity of injury types. Quantitative FDG-PET cannot be used as a surrogate technique for estimating degree of global functional recovery following traumatic brain injury.
Journal of Head Trauma Rehabilitation 05/2001; 16(2):135-48. · 4.44 Impact Factor
[show abstract][hide abstract] ABSTRACT: HIV-1 infected persons who are pursuing disability benefits are increasingly seeking neuropsychological assessment for purposes of corroborating functional impairment. Thus, research on the utility of measures of symptom validity among these patients is needed. Recently, Mittenberg, Azrin, Millsaps, and Heilbronner (1993) proposed a malingering index score for the WechslerMemoryScale-Revised that is derived by subtracting the Attention/Concentration Index (ACI) score from the General Memory Index Score (GMI). This study is a cross-validation of the specificity of the GMI-ACI Malingering Index in a sample of 55 non-compensation-seeking HIV-positive (HIV+) patients. An overall false-positive rate of 7% was observed for the GMI-ACI Malingering Index. However, further analyses showed that GMI-ACI Malingering Index scores were correlated with GMI scores such that false-positive errors were substantially higher (18%) among patients who obtained above-average GMI scores. These findings suggest a cautious approach to application of the GMI-ACI Malingering Index, particularly among patients who obtain above-average GMI scores.
[show abstract][hide abstract] ABSTRACT: This study examined the treatment outcome of high-dose (1500 mg/day) zidovudine (AZT) on neuropsychological (NP) functioning (Trailmaking Test A & B, WAIS-R Digit Symbol, and Rey Auditory Verbal Learning Test) across a 12-month period in mildly symptomatic HIV-1 seropositive men (n = 46 at entry) enrolled in a randomized, double-blind, placebo-controlled trial (VA Cooperative Studies Program #298). Neither short-term (0-6 months) nor long-term (0-12 months) AZT administration revealed enhancement in NP performance. The results suggest that, although AZT may afford patients prophylactic benefits, protracted high-dose AZT treatment does not improve NP functioning in mildly symptomatic HIV-positive individuals.
Journal of the International Neuropsychological Society 01/2001; 7(1):27-32. · 2.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: The purpose of this study was to examine the independent and interactive effects of HIV-1 serostatus and cocaine on neuropsychological (NP) performance in a sample of 237 gay and bisexual urban-dwelling African American men. Consistent with current evidence, it was expected that the greatest neuropsychological performance deficits would be evident (1) in the symptomatic seropositives (SSPs), especially in domains affected by HIV (i.e., memory and psychomotor speed), and on tests that are sensitive to subtle slowing; (2) in those who are recent and frequent cocaine abusers; and (3) in those who are both HIV seropositive and cocaine abusers. Multivariate analyses controlling for age and alcohol use confirmed expectations, with symptomatic seropositives (SSPs) evidencing significantly poorer psychomotor speed than the seronegatives (SNs), and slower reaction time and poorer nonverbal memory than the asymptomatic seropositives (ASPs). Moderate to heavy recent cocaine use was associated with slower psychomotor speed. However, contrary to expectations, no interaction of serostatus and cocaine was noted for any NP domain, and the expected serostatus and cocaine effects on verbal memory and frontal systems were not obtained. Level of alcohol consumption exacerbated the detrimental effects of HIV-1 on a computerized reaction time test which is especially sensitive to subtle slowing. This study provides one of the first descriptions of the neuropsychological effects of HIV-AIDS in a non-injection drug-using community sample of gay and bisexual African American men.
Journal of the International Neuropsychological Society 04/2000; 6(3):322-35. · 2.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: The purpose of this study was to examine the independent
and interactive effects of HIV-1 serostatus and cocaine
on neuropsychological (NP) performance in a sample of 237
gay and bisexual urban-dwelling African American men. Consistent
with current evidence, it was expected that the greatest
neuropsychological performance deficits would be evident
(1) in the symptomatic seropositives (SSPs), especially
in domains affected by HIV (i.e., memory and psychomotor
speed), and on tests that are sensitive to subtle slowing;
(2) in those who are recent and frequent cocaine abusers;
and (3) in those who are both HIV seropositive and cocaine
abusers. Multivariate analyses controlling for age and
alcohol use confirmed expectations, with symptomatic seropositives
(SSPs) evidencing significantly poorer psychomotor speed
than the seronegatives (SNs), and slower reaction time
and poorer nonverbal memory than the asymptomatic seropositives
(ASPs). Moderate to heavy recent cocaine use was associated
with slower psychomotor speed. However, contrary to expectations,
no interaction of serostatus and cocaine was noted for
any NP domain, and the expected serostatus and cocaine
effects on verbal memory and frontal systems were not obtained.
Level of alcohol consumption exacerbated the detrimental
effects of HIV-1 on a computerized reaction time test which
is especially sensitive to subtle slowing. This study provides
one of the first descriptions of the neuropsychological
effects of HIV–AIDS in a noninjection drug-using
community sample of gay and bisexual African American men.
(JINS, 2000, 6, 322–335.)
Journal of the International Neuropsychological Society 02/2000; 6(03):322 - 335. · 2.70 Impact Factor
[show abstract][hide abstract] ABSTRACT: Neuropsychological manifestations associated with human immunodeficiency virus (HIV-1) infection and relevant cultural factors
warrant special consideration in a handbook of this nature. This unique merit stems partially from the increasing incidence
and cumulative prevalence of this infectious disease affecting ethnic-minority populations in the United States and abroad
(Centers for Disease Control and Prevention, 1996; Mann, Tarantola, & Netter, 1992; World Health Organization, 1996), and partially from the deleterious effects of HIV upon the central nervous system (CNS) of adults (Grant et al., 1987; McArthur, 1994; Navia, Jordan, & Price, 1986; Snider et al., 1983) and children (Belman, 1990; Epstein et al, 1986; Falloon, Eddy, Wiener, & Pizzo, 1989; Pizzo & Wilfert, 1994), and their neuropsychological and neurobehavioral sequelae (Bayés, 1995; Brouwers, Belman, & Epstein, 1991, Brouwers, Moss, Wolters, Eddy, & Pizzo, 1989; Chase et al., in press; Llorente, LoPresti, Levy, & Fernandez, 2000; Llorente, LoPresti, & Satz, 1997; Llorente et al., 1998; Miller et al., 1990; Navia et al., 1986; Tross et al., 1988; van Gorp, Miller, Satz, & Visscher, 1989).
[show abstract][hide abstract] ABSTRACT: This article examines patterns of legal American immigration (migrations to the United States from abroad) and their direct impact on the acquisition of neuropsychological (NP) normative data for Hispanics. The nonrandom and selective nature of these migrations, and their accompanying demographic attributes, are shown to significantly influence the acquisition process. Specifically, the direct impact of several potential sources of bias while procuring NP norms is explored. Total number of immigrants (absolute immigration), occupational allegiance (and possibly education), and intended area of initial residence seem to play influential roles as a result of their direct impact on demographic characteristics known to have significant effects on neuropsychological performance. Possible solutions capable of enhancing the acquisition process are also addressed.
Archives of Clinical Neuropsychology 11/1999; 14(7):603-14. · 2.00 Impact Factor