Brain perfusion correlates of medial temporal lobe atrophy and white matter hyperintensities in mild cognitive impairment

Abstract Objective To assess the association of Medial Temporal lobe Atrophy (MTA) and White Matter Hyperintensities (WMHs) with gray matter perfusion in Mild Cognitive Impairment (MCI). Methods 56 MCI patients (age = 69.3 ± 7.0, 32 females) underwent brain MR scan and ^99mTc ECD SPECT. We evaluated MTA according to Scheltens' fivepoint scale on T1 MR images, and assessed WMHs using the rating scale for age-related white matter changes on T2-weighted and FLAIR MR images. We divided MCI into age-matched subgroups with high and low MTA and high and low WMHs load. We processed SPECT images with SPM2 following an optimized protocol and performed a voxel-based statistical analysis comparing high vs. low MTA and high vs. low WMHs, setting p-value at 0.001 uncorrected, thresholding cluster extent at 100 voxels, using proportional scaling and entering age and WMHs or MTA respectively as nuisance covariates. Results MCI with high compared with low MTA showed hypoperfusion in the left hippocampus and in the left parahippocampal gyrus. MCI with high compared with low WMHs showed a hypoperfusion area in the left insular region and superior temporal gyrus. Conclusions MTA in MCI is associated with hippocampal gray matter hypoperfusion while WMHs is associated with gray matter hypoperfusion in areas of the insula and temporal neocortex. These results confirm that MTA is associated with local functional changes and suggest that WMHs may be associated with remote brain cortical dysfunction.     

Risk factors for mild cognitive impairment in the Cardiovascular Health Study Cognition Study: part 2

OBJECTIVE: To examine the risk factors for mild cognitive impairment (MCI) in a longitudinal population study-the Cardiovascular Health Study Cognition Study. DESIGN: We examined the factors that in the period 1991 through 1994 predicted the development of MCI in all participants of the Cardiovascular Health Study Cognition Study. Further examination was conducted in the Pittsburgh, Pa, cohort (n = 927), where participants with MCI were classified as having either the MCI amnestic-type or the MCI multiple cognitive deficits-type. SETTING: Multicenter population study. PATIENTS: This study includes all participants of the Cardiovascular Health Study Cognition Study (n = 3608) who had a magnetic resonance imaging (MRI) scan of the brain between 1991 and 1994, and detailed neuropsychological, neurological, and medical evaluations to identify the presence of MCI or dementia in the period 1998 to 1999. The mean time between the closest clinical examination to the MRI and the diagnostic evaluation for cognitive disorders was 5.8 years for the Cardiovascular Health Study Cognition Study cohort and 6.0 years for the Pittsburgh cohort. MAIN OUTCOME MEASURES: Risk factors for MCI at the time of the MRI were identified using logistic regression, controlling for age, race, educational level, baseline Modified Mini-Mental State Examination and Digit Symbol Test scores, measurements of depression, MRI findings (atrophy, ventricular volume, white matter lesions, and infarcts), the presence of the apolipoprotein E (APOE) epsilon4 allele, hypertension, diabetes mellitus, and heart disease. RESULTS: Mild cognitive impairment (n = 577) was associated with race (African American), low educational level, low Modified Mini-Mental State Examination and Digit Symbol Test scores, cortical atrophy, MRI-identified infarcts, and measurements of depression. The MCI amnestic-type was associated with MRI-identified infarcts, the presence of the APOE epsilon4 allele, and low Modified Mini-Mental State Examination scores. The MCI multiple cognitive deficits-type was associated with low Modified Mini-Mental State Examination and Digit Symbol Test scores. CONCLUSIONS: The development of MCI is associated with measurements of cognition and depression, racial and constitutional factors, and cerebrovascular disease. Early cognitive deficits seem to be a common denominator for the 2 forms of MCI; the presence of cerebrovascular disease and the APOE epsilon4 allele is associated with the amnestic type of MCI.     

White matter hyperintensities are related to physical disability and poor motor function

OBJECTIVE: To determine the impact of white matter hyperintensities (WMHs) on physical health and cognitive function in 60-64 year old individuals residing in the community. METHODS: A subsample of 478 persons aged 60-64 from a larger community sample underwent brain magnetic resonance imaging (MRI) scans. WMHs on T2 weighted FLAIR (fluid attenuated inversion recovery) MRI scans were assessed using an automated procedure. Subjects were assessed for global cognitive function, episodic memory, working memory (digit span), information processing speed (Symbol Digit Modalities Test; SDMT), fine motor dexterity (Purdue Pegboard), and grip strength, and completed the Physical Component Summary of the Short Form Health Survey (SF-12). Regression analyses were used to examine the effect of WMHs on physical and cognitive function. RESULTS: Deep and periventricular WMHs were present in all subjects, with women having slightly more lesions than men. WMHs were significantly associated with poorer reported physical health on the SF-12 scale, after adjusting for depression, cognitive function, and brain atrophy. WMHs were also related to lower scores on the Purdue Pegboard test, grip strength, choice reaction time, and SDMT, but not on tests of episodic memory, working memory, general intellectual function, and global cognitive function. On regression analyses, the Purdue Pegboard test and grip strength were related to physical disability. CONCLUSION: WMHs are common, albeit mild, in middle adult life. They are associated with physical disability, possibly through reduced speed, fine motor coordination, and muscular strength. They are also related to slowed information processing speed but not other cognitive functions.     

Cystatin C as a marker of cognitive function in elders: findings from the health ABC study

We determined whether serum cystatin C, a novel measure of kidney function that colocalizes with brain beta-amyloid, is associated with cognition among 3,030 elders. Those with high cystatin C (n = 445; 15%) had worse baseline scores on Modified Mini-Mental State Examination or Digit Symbol Substitution Test (p or=1.0 standard deviation) was greatest among those with high cystatin C (Modified Mini-Mental State Examination: 38 vs 25%; adjusted odds ratio, 1.92; 95% confidence interval, 1.37-2.69; Digit Symbol Substitution: 38 vs 26%; odds ratio, 1.54; 95% confidence interval, 1.10-2.15).     

Annual rate and predictors of conversion to dementia in subjects presenting mild cognitive impairment criteria defined according to a population-based study

Elderly subjects diagnosed with mild cognitive impairment (MCI) are becoming the target of intervention trials. The criteria used for MCI are principally issued from prospective clinical studies, although longitudinal population-based studies having identified several cognitive predictors of dementia can be of great contribution in the definition of these criteria. This study was conducted to explore the external validity of MCI criteria issued from a longitudinal population-based study, and subsequently to identify the best predictors of the short-term conversion to Alzheimer's disease 2 years after the MCI diagnosis. Ninety elderly volunteers with memory complaint diagnosed with MCI on the basis of their functional and neuropsychological performances were followed up within 2 years. The potential predictors of the conversion to dementia collected at baseline included age, gender, educational level, size of temporal lobe, apolipoprotein E genotype and a series of neuropsychological measures (Mac Nair Scale, Mini-Mental State Examination, Benton Visual Retention Test, Isaacs Set Test, Digit Symbol Substitution Task, Letter Cancellation Task, digit span tasks and finger-tapping test). Within the 2 years, 29 subjects (32.2%) presented a conversion to dementia. The risk of conversion to dementia was associated with age and size of temporal lobe but not with gender, education, or apolipoprotein E4 genotype. Several neuropsychological measures were associated with the risk of conversion to dementia, but in a logistic regression performed with the significant variables found in the univariate analysis, only the Letter Cancellation Test was shown to be an independent predictor. In conclusion, the quite elevated conversion rates obtained show the usefulness, when defining MCI criteria, of considering not only memory impairment but also impairment in other cognitive areas, as well as mild impairment on higher-order activities of daily living. Among the variables considered, the Letter Cancellation Test proved to be a major predictor of short-term conversion to dementia.     

Mild head injury and speed of information processing: A prospective study of professional rugby league players

Abstract

The sensitivity of several short tests of speed of information processing to the effects of mild head injury in rugby league football was investigated. The measures used were the Symbol Digit Modalities Test, the Digit Symbol Substitution Test, and the Speed of Comprehension Test. Two studies were conducted, the first to examine the effect of practice, the second to determine sensitivity to cognitive impairment immediately following injury. The first study established alternate form equivalence and demonstrated that performance on the Speed of Comprehension and Digit Symbol Substitution tests improved with practice, whereas the Symbol Digit Modalities test remained stable. A second study of 10 players who subsequently sustained mild head injuries showed that measures of speed of information processing were sensitive to impairment in the postacute phase, whereas an untimed task of word recognition (Spot-the-Word) was not. Speed of Comprehension was more sensitive to postinjury impairment than either the Digit Symbol Substitution or Symbol Digit Modalities tests. A repeated baseline assessment before injury using the higher score to reflect a player's potential, allowed measurement of impaired performance on sensitive tests.     

Homocysteine,white matter hyperintensities,and cognition in healthy elderly people

Hyperhomocysteinemia is associated with an increased risk of vascular disease, and recent results suggest that it also could increase the risk of dementia. We examined the relationship between homocysteine and cognitive decline in 1,241 subjects aged 61 to 73 years, followed up over 4 years. Plasma homocysteine levels were determined in all participants as well as cardiovascular risk factors, apolipoprotein E genotype, plasma levels of folate, and vitamin B12. Cognitive performances were assessed repeatedly by using Mini-Mental State Examination, Trail Making Test, Digit Symbol Substitution Test, and Finger Tapping Test. At 2-year follow-up, 841 subjects underwent cerebral magnetic resonance imaging, and white matter hyperintensities were rated visually. Analyses were adjusted for all cardiovascular risk factors. Cross-sectional analyses showed that higher concentrations of homocysteine were significantly related to poorer performances at all neuropsychological tests. Longitudinal analyses confirmed this finding. The odds of cognitive decline was 2.8-fold (p < 0.05) higher in subjects with homocysteine levels above 15 micromol/L compared with those with homocysteine levels below 10 micromol/L. In participants who underwent magnetic resonance imaging, the relationship between homocysteine and cognition was unchanged after taking into account white matter hyperintensities suggesting that white matter hyperintensities do not mediate the association between homocysteine and cognition.     

Heritability of cognitive performance in aging twins. The National Heart, Lung, and Blood Institute Twin Study

The genetic contribution to performance on scales designed to measure mild to moderate decrements in cognitive functioning in a population at risk is unknown. In the present analysis, 134 monozygotic and 133 dizygotic male twin pairs (mean age, 63 years) were given three cognitive tests: the Mini-Mental State examination, the Iowa Screening Battery for Mental Decline, and, for comparison, the Digit Symbol Substitution Test from the Wechsler Adult Intelligence Scale. The primary objective of the analysis was to test for a significant heritable component to performance on these measures. A secondary objective was to determine the extent to which shared variance with significant confounders such as education, age, and depression affects the outcome of the heritability analysis. Results indicate that performance on tests intended to measure cognitive decline in the elderly does have a significant genetic component and that these estimates tend to increase after adjustment for covariates. Heritability estimates adjusted for covariates were 30% for the Iowa Screening score, 60% for the Mini-Mental State score, and 67% for the Digit Symbol Substitution score.     

White-matter changes in early and late stages of mild cognitive impairment

Mild Cognitive Impairment (MCI) is characterized by cognitive deficits that exceed age-related decline, but not interfering with daily living activities. Amnestic type of the disorder (aMCI) is known to have a high risk to progress to Alzheimer’s Disease (AD), the most common type of dementia. Identification of very early structural changes in the brain related to the cognitive decline in MCI patients would further contribute to the understanding of the dementias. In the current study, we target to investigate whether the white-matter changes are related to structural changes, as well as the cognitive performance of MCI patients. Forty-nine MCI patients were classified as Early MCI (E-MCI, n = 24) and Late MCI (L-MCI, n = 25) due to their performance on The Free and Cued Selective Reminding Test (FCSRT). Age-Related White-Matter Changes (ARWMC) scale was used to evaluate the white-matter changes in the brain. Volumes of specific brain regions were calculated with the FreeSurfer program. Both group and correlation analyses were conducted to show if there was any association between white-matter hyperintensities (WMHs) and structural changes and cognitive performance. Our results indicate that, L-MCI patients had significantly more WMHs not in all but only in the frontal regions compared to E-MCI patients. Besides, ARWMC scores were not correlated with total hippocampal and white-matter volumes. It can be concluded that WMHs play an important role in MCI and cognitive functions are affected by white-matter changes of MCI patients, especially in the frontal regions.     

Association of nonsteroidal anti-inflammatory drugs and aspirin with cognitive performance in middle-aged adults.

OBJECTIVES: To assess the cross-sectional association of regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) or aspirin with cognitive function in 13,153 individuals, aged 48-67 years, participating in the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: Regular use of NSAIDs or aspirin was analyzed in relation to the results of three cognitive tests, the Delayed Word Recall Test, the WAIS-R Digit Symbol Subtest, and the Word Fluency Test. RESULTS: After adjustment for covariates previously found to be associated with cognition in this sample, we found a weak negative association between current use of aspirin and poor Word Recall [OR = 0.84 (95% confidence interval: 0.68-1.04)] and poor Word Fluency [OR = 0.85 (0.70-1.03)]. We found no association between current use of aspirin and Digit Symbol score, nor did we find current NSAID use to be significantly associated with any of the cognitive tests. CONCLUSIONS: This study suggests a modest association, at best, between NSAIDs or aspirin and better cognitive function.     

Differentiation of cognitive and motor aspects in a digit symbol substitution test in Anorexia nervosa patients, before and after weight restoration

BACKGROUND: In a previous study, using computerized analysis of fine motor behaviour, seriously underweight anorexia nervosa patients in the early phase of treatment were found to have shorter reaction times, but not movement times, in experimental drawing and copying tasks. These differences persisted with weight restoration. SAMPLING AND METHODS: Using computerized analysis of writing and drawing behaviour during the performance of a Digit Symbol Substitution Test, 15 anorexia nervosa patients were compared with 15 normal controls, matched for age, sex and educational level. Patients were retested after weight restoration, as were controls after a similar interval. RESULTS: Patients turned out to be superior in the cognitive, but not in the motor aspects of the Digit Symbol Substitution Test. These differences persisted after weight restoration. A practice effect, due to repeated testing, was found in both groups, which turned out to be cognitive in nature. CONCLUSIONS: The findings show that this new technique can add to the interpretation of classic neuropsychological tests. The results are compatible with previous findings of intact or even superior functioning in anorexia nervosa patients on neuropsychological tasks requiring considerable cognitive effort.     

Intensity of recreational physical activity throughout life and later life cognitive functioning in women

Long-term physical activity may affect risk of cognitive impairment but few studies have examined later life cognition in relation to intensity of life-long physical activity. We examined the associations between the intensity of long-term recreational physical activity and neuropsychological functioning in 90 healthy postmenopausal women on tests found to be useful in the early identification of dementia. Information was collected about their participation in strenuous and moderate activities between high school and menopause. Summary measures of long-term strenuous and moderate activity were constructed for each participant. All analyses were adjusted for relevant covariates. The six linear regression analyses showed significant positive associations between moderate activity and Wechsler Adult Intelligence Scale Revised (WAIS-R), Digit Span backward, WAIS-R Digit Symbol, and Trail Making Test Part B. Significant negative relationships were found between strenuous activity and Rey Auditory Verbal Learning Test delayed verbal recall, Complex Figure Test delayed visual memory, WAIS-R Digit Span backward, category fluency, and WAIS-R Digit Symbol. The associations found in the present study suggest that while moderate activity may be protective, long-term strenuous activity before menopause may lower cognitive performance later in life. These results support further investigation of the effects of life-long exercise intensity on cognition in later life.     

Neuropsychological prediction of conversion to Alzheimer disease in patients with mild cognitive impairment

CONTEXT: The likelihood of conversion to Alzheimer disease (AD) in mild cognitive impairment (MCI) and the "optimal" early markers of conversion need to be established. OBJECTIVES: To evaluate conversion rates to AD in subtypes of MCI and to identify neuropsychological measures most predictive of the time to conversion. DESIGN: Patients were followed up semiannually and controls annually. Subtypes of MCI were determined by using demographically adjusted regression norms on neuropsychological tests. Survival analysis was used to identify the most predictive neuropsychological measures. SETTING: Memory disorders clinic. PARTICIPANTS: One hundred forty-eight patients reporting memory problems and 63 group-matched controls. MAIN OUTCOME MEASURE: A consensus diagnosis of probable AD. RESULTS: At baseline, 108 patients met criteria for amnestic MCI: 87 had memory plus other cognitive domain deficits and 21 had pure memory deficits. The mean duration of follow-up for the 148 patients was 46.6 +/- 24.6 months. In 3 years, 32 (50.0%) of 64 amnestic-"plus" and 2 (10.0%) of 20 "pure" amnestic patients converted to AD (P = .001). In 148 patients, of 5 a priori predictors, the percent savings from immediate to delayed recall on the Selective Reminding Test and the Wechsler Adult Intelligence Scale-Revised Digit Symbol Test were the strongest predictors of time to conversion. From the entire neuropsychological test battery, a stepwise selection procedure retained 2 measures in the final model: total immediate recall on the Selective Reminding Test (odds ratio per 1-point decrease, 1.10; 95% confidence interval, 1.05-1.14; P < .0001) and Digit Symbol Test coding (odds ratio, 1.06; 95% confidence interval, 1.01-1.11; P = .01). The combined predictive accuracy of these 2 measures for conversion by 3 years was 86%. CONCLUSIONS: Mild cognitively impaired patients with memory plus other cognitive domain deficits, rather than those with pure amnestic MCI, constituted the high-risk group. Deficits in verbal memory and psychomotor speed/executive function abilities strongly predicted conversion to AD.     

Subjective memory complaints in an elderly sample: a cross-sectional study

BACKGROUND: Community based studies show that neurological or psychiatric symptoms are very frequent among the elderly population, with poor memory complaints being the most common. However, the relationship between poor memory complaints and objective memory performance is unclear. We designed this study to evaluate whether subjective memory complaints (SMC) are associated with objective cognitive performance or depression amongst the elderly Brazilian generation. METHODS: A cross-sectional study was carried out in 114 patients who were 50+, with or without SMC having no obvious cognitive impairment at its baseline (this was screened by the Mini-Mental State Examination with cut-off values adapted according to the subjects' educational background). Subjects were assessed regarding memory difficulty complaints, demographic data and underwent a neuropsychological assessment made up of nine cognitive tests (Rey Auditory Verbal Learning Test, Visual Reproduction Test, Logic Memory--History A, Free and Cued Selective Reminding Test, Stroop Test, Digit Span, Digit Symbol, Trail Making Test, fluency tests: naming animals and fruits) and the Geriatric Depression Scale. RESULTS: Twenty-one percent of the subjects had subjective memory complaints. The scores in the cognitive assessment of subjects with SMC did not differ from the scores of subjects without SMC. However, patients with subjective memory complaints had lower scores in the fluency test--category animals and the Geriatric Depression Scale. CONCLUSIONS: These results support the finding from other cross-sectional studies showing that subjective memory complaints are associated with depressive symptoms rather than objective cognitive performance.     

Assessment of cognitive function in asymptomatic HIV-positive subjects

This retrospective study aims to assess cognitive involvement in pre-AIDS, not drug abuser subjects and to determine whether CD4 status or disease stage best correlates with cognitive changes that may portend development of ADC. 328 cases were analyzed. No differences in psychometric performance in relation to CDC stage were found. Instead, patients with CD4 < 200/microl performed worse overall, with a statistically significant difference for Digit Symbol, Corsi Test, Block Design and HIVDA Scale. Even if cognitive decline is not evident in the early phase of HIV infection, CD4 count seems the more sensitive early indicator of cognitive changes adequately pointed out by the HIVDA Scale, which could be considered a useful screening tool for cognitive deficit.     

抑郁对帕金森病患者执行功能的影响

目的 探讨抑郁对帕金森病(PD)患者执行功能的影响。方法 对41例PD患者及20例对照组进行整体认知功能、执行功能及抑郁状况的评定。整体认知功能评定使用简易智力状态量表(MMSE); 执行功能评定包括言语流畅性测验(VFT),连线测验(TMT),Stroop字色干扰测验(SCWT),画钟测验(CDT),数字符号替换测试(DSST)及数字广度测试(DST)等; 使用贝克抑郁自评量表(BDI)评估抑郁状态。结果 抑郁组SFT, PFT, DST, DSST, CDT, TMA,TMB, Stroop-B, Stroop-C,SIE评分均差于对照组(P<0.05); 非抑郁组PFT, DST, DSST,TMA,TMB, Stroop-C,SIE评分差于对照组(P<0.05); 与非抑郁组比较,抑郁组SFT, PFT, DST, DSST, TMA, TMB, Stroop-B, Stroop-C, SIE评分较差(P<0.05)。结论 PD患者存在明显的执行功能障碍,抑郁可以明显加重PD患者的执行功能障碍。     

Parsing the components of the psychomotor syndrome in schizophrenia

Docx L, Morrens M, Bervoets C, Hulstijn W, Fransen E, De Hert M, Baeken C, Audenaert K, Sabbe B. Parsing the components of the psychomotor syndrome in schizophrenia. Objective: Catatonia, extrapyramidal signs, psychomotor slowing, and (motoric) neurological soft signs are well-known psychomotor symptoms in schizophrenia. This study aims at investigating the interrelations between these symptoms. In addition, associations between psychomotor symptoms, clinical symptoms, and cognitive functioning will be studied. Method: An extensive test battery containing psychomotor (Bush Francis Catatonia Rating Scale; St Hans Rating Scale; Salpêtrière Retardation Rating Scale; Neurological Evaluation Scale) and clinical (Positive and Negative Syndrome Scale; Calgary Depression Scale) rating scales as well as instrumental psychomotor tests (Line Copying Task; Finger Tapping Task) and cognitive tasks (Symbol Digit Substitution Test; Stroop Colour Word Test; Continuous Performance Test; Letter Number Sequencing) was administered to a sample of 124 patients with schizophrenia or schizoaffective disorder. Results: Correlational analyses showed that two clusters emerge from our data: first, a psychomotor poverty cluster referring to the interrelations between catatonia, parkinsonism, psychomotor slowing, and negative symptoms; second, a cluster containing motoric neurological soft signs, which were found to be correlated with cognitive functioning. Conclusion: Psychomotor abnormalities are highly prevalent phenomena in schizophrenia that have to be considered as a heterogeneous construct. However, longitudinal and neurobiological research is needed to further explore the precise nature of the interrelations found in this study.     

The Faces Symbol Test, a newly developed screening instrument to assess cognitive decline related to multiple sclerosis: first results of the Berlin Multi-Centre FST Validation Study

Reliable, language-independent, short screening instruments to test for cognitive function in patients with multiple sclerosis (MS) remain rare, despite the high number of patients affected by cognitive decline. We developed a new, short screening instrument, the Faces Symbol Test (FST), and compared its diagnostic test characteristics with a composite of the Digit Symbol Substitution Test (DSST) and the Paced Auditory Serial Addition Test (PASAT), in 108 MS patients and 33 healthy controls. An Informant-Report Questionnaire, a Self-Report Questionnaire, and a neurologist's estimation of the Every Day Life Cognitive Status were also applied to the MS patients. The statistical analyses comprised of a receiver operating characteristic analysis for test accuracy and for confounding variables. The PASAT and DSST composite score estimated that 36.5% of the MS patients had cognitive impairment. The FST estimated that 40.7% of the MS patients were cognitively impaired (sensitivity 84%; specificity 85%). The FST, DSST and PASAT results were significantly correlated with the patients' physical impairment, as measured by the Expanded Disability Status Scale (EDSS). The results suggest that the FST might be a culture-free, sensitive, and practical short screening instrument for the detection of cognitive decline in patients with MS, including those in the early stages.     

Estrogen, cognitive function and negative symptoms in female schizophrenia

The aim of this study was to evaluate the relationship of serum reproductive hormone levels with cognitive function and negative symptoms in schizophrenic women during the follicular phase of the menstrual cycle. Thirty-five women with chronic schizophrenia who had minimal positive symptoms participated in this study. We evaluated the correlation of serum reproductive hormone levels with the Scale for the Assessment of Negative Symptoms (SANS) and cognitive function tests such as the Immediate Visual Recognition Scale, Oral Fluency Test, List Recall Scale with List Acquisition Scale, Trail Making Tests A and B, and Digit Symbol Test. The patients were divided into two subgroups (low estradiol group and normal estradiol group) using the normal serum reference range for estradiol. Significant correlation between SANS subcategories, such as Alogia and Attention Impairment, and estradiol were found. Moreover, significant relationships between the estradiol level and the Oral Fluency Test, List Recall Scale with List Acquisition Scale, Trail Making Test B and Digit Symbol Test were observed. In the low estradiol group, the SANS scores, except for Anhedonia-Asociality and Avolition-Apathy, were significantly higher than those in the normal estradiol group. Patients in the low estradiol group had a significantly lower performance in the cognitive function tests, except Visual Recognition Scale, when compared to patients in the normal estradiol group. These results suggest that for schizophrenic women of reproductive age, lower levels of estrogen are associated with more severe negative symptomatology as well as reduced performance in cognitive function, especially verbal performance and executive functioning.     

Test-retest reliability and practice effects of a rapid screen of mild traumatic brain injury

Test-retest reliabilities and practice effects of measures from the Rapid Screen of Concussion (RSC), in addition to the Digit Symbol Substitution Test (Digit Symbol), were examined. Twenty five male participants were tested three times; each testing session scheduled a week apart. The test-retest reliability estimates for most measures were reasonably good, ranging from .79 to .97. An exception was the delayed word recall test, which has had a reliability estimate of .66 for the first retest, and .59 for the second retest. Practice effects were evident from Times 1 to 2 on the sentence comprehension and delayed recall subtests of the RSC, Digit Symbol and a composite score. There was also a practice effect of the same magnitude found from Time 2 to Time 3 on Digit Symbol, delayed recall and the composite score. Statistics on measures for both the first and second retest intervals, with associated practice effects, are presented to enable the calculation of reliable change indices (RCI). The RCI may be used to assess any improvement in cognitive functioning after mild Traumatic Brain Injury.