Biomedical subjects

David J Moser

Publications and source records attributed to David J Moser.

At least 37 records · Page 2Linked to original sources

PubMed2004

Computer-mediated measurement and subjective ratings of white matter hyperintensities in vascular dementia: relationships to neuropsychological performance.

White matter hyperintensities (WMHs) are frequently found on MRI studies of vascular dementia (VaD) patients. As several studies have demonstrated that WMHs are often associated with severity of illness, cognitive impairment, and functional decline, the accurate and reliable measurement of WMHs on MRI is an important, yet often overlooked, prerequisite for accurate interpretation of neuroimaging studies. Using a sample of 39 VaD patients, we evaluated the reliability and validity of a visual ordinal rating scale and a computer-mediated thresholding technique to evaluate WMHs. Results indicated the computer-mediated technique had slightly stronger inter-rater reliability than the visual ordinal rating scale. Furthermore, the computer-mediated thresholding technique was correlated with measures of neuropsychological functioning believed to be compromised in VaD (i.e., psychomotor speed, executive functioning) while the visual rating scale was not. Results suggest that this computer-mediated thresholding technique is superior to visual ratings of WMHs.

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PubMed2004

Executive impairments predict functional declines in vascular dementia.

The purpose of this study was to examine the course and predictors of functional decline among patients with vascular dementia (VaD). Twenty-eight VaD patients completed three tests of executive functions and underwent MRI scanning to generate quantitative ratings of subcortical neuropathology at a baseline evaluation. The caregiver-rated Lawton and Brody Activities of Daily Living Questionnaire was used to estimate instrumental activities of daily living (IADLs) at the baseline evaluation and at a 1 year follow-up. We hypothesized that: (a) IADLs would decline significantly over the course of 1 year, and (b) baseline performance on executive tasks and subcortical neuropathology would predict IADL impairment at 1 year follow-up, even after accounting for global cognitive dysfunction. A paired samples t-test demonstrated that IADLs declined significantly over the course of 1 year, and regression analyses revealed that baseline performance on executive tasks was a significant predictor of IADLs at the 1 year follow-up, even after accounting for global cognitive dysfunction. Contrary to our expectation, subcortical neuropathology did not explain unique variance in IADLs after accounting for executive dysfunction. These findings demonstrate that baseline executive dysfunction is a significant and powerful predictor of future functional decline in individuals with VaD.

Activities of Daily Living↗

PubMed2003

Neuropsychological functioning pretreatment and posttreatment in an inpatient eating disorders program.

OBJECTIVE: This study was conducted to determine whether neuropsychological dysfunction associated with anorexia nervosa resolves with inpatient treatment. METHOD: Subjects were 28 women being treated for anorexia nervosa. Main study variables included body mass index (BMI), Beck Depression Inventory-II, and neuropsychological test scores. Subjects were tested at admission and discharge. RESULTS: Neuropsychological functioning improved across the course of treatment, with significant changes on tests of memory and psychomotor speed. This improvement was not significantly associated with change in BMI or with the other variables that were studied. DISCUSSION: Patients with anorexia nervosa exhibit subtle neuropsychological dysfunction, which resolves at least partially during treatment. This improvement does not appear to be associated with an increase in BMI. However, it is possible that BMI is not a sufficiently sensitive indicator of nutritional status or that longer-term follow-up is necessary to reveal the nutrition-cognition relationship that we were seeking.

Adult↗

PubMed2003

Cognitive impairment in anorexia nervosa is not due to depressed mood.

OBJECTIVE: Previous research has revealed cognitive deficits in patients with anorexia nervosa. It is unclear whether these deficits are linked to co-morbid depression in this population. We examined the relationship between depressive symptoms and cognitive functioning. METHOD: A large sample of subjects (N = 98) was examined using a common measure of cognitive ability and two measures of depression. RESULTS: We confirmed that there is no relationship between depression and cognitive ability in this group. DISCUSSION: This suggests that alternative explanations be explored for cognitive deficits in patients with anorexia nervosa.

Adolescent↗

PubMed2003

Clinical correlates of cognitive decline in vascular dementia.

OBJECTIVE: To determine whether demographic data, dementia severity, functional status, whole brain volume (WBV), or subcortical hyperintensity volume (SH) predict subsequent cognitive decline in vascular dementia (VaD). BACKGROUND: The identification of variables that accurately predict progressive cognitive decline in dementia has important clinical implications. METHODS: A cohort of 30 patients with VaD completed neurologic and neuropsychologic examinations and magnetic resonance imaging of the brain at baseline and again after 12 months. All participants met clinical and research criteria for VaD according to standard guidelines. Change scores were computed for measures of verbal fluency, verbal learning, and visual learning. Potential correlates of cognitive change included age, education, score on the Hachinski scale, WBV, SH, and functional ability. RESULTS: As a group, lower WBV and lower Hachinski score correlated with decline in verbal fluency and visual learning, whereas lower Hachinski score correlated with decline in verbal learning. However, when subdivided by disease type, this pattern held only for individuals with evidence of a cortical stroke at baseline. No clinical variables correlated with cognitive decline among individuals without a cortical infarction. CONCLUSIONS: Assessment of cognitive decline in VaD should be guided by dementia subtype, with particular attention directed at severity of cerebral atrophy rather than classic symptoms of infarction.

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PubMed2003

Sensitivity of the dementia rating scale in vascular dementia: comparison between two sets of criteria to define cognitive impairment.

BACKGROUND: The Dementia Rating Scale (DRS) is a common measure of cognitive function, but its sensitivity to identify deficits across cognitive domains in vascular dementia (VaD) remains unclear. METHODS: We compared the sensitivity and specificity of two recommended cutoff scores of the DRS. Thirty-eight patients diagnosed with VaD participated in the current study. RESULTS: The original recommendations resulted in poor sensitivity for the DRS total score and attention, construction, and memory subscales. The more recent recommendations greatly improved the sensitivity of the subscales and the total DRS score, but resulted in decreased specificity. Correlations between the specific DRS subscales and criterion measures of cognitive function revealed good convergent and divergent validity for most subscales. CONCLUSIONS: The DRS is a valid measure of cognitive dysfunction in VaD, but clinicians should consider using the more recent recommendations developed for AD to determine impaired performances in VaD.

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PubMed2003

Long-term citicoline (cytidine diphosphate choline) use in patients with vascular dementia: neuroimaging and neuropsychological outcomes.

BACKGROUND: Cytidine diphosphate choline (citicoline) has been previously shown to have efficacy in reducing the functional impairments associated with acute stroke. Citicoline is thought to have neuroprotective benefits and has been used for the treatment of chronic cerebrovascular disorders, though its effectiveness has not been fully tested. This randomized, double-blind clinical trial was conducted to determine whether daily citicoline treatment improves neurocognitive and neuroimaging outcome over 12 months among patients diagnosed with vascular dementia (VaD). METHODS: 30 patients diagnosed with VaD, based upon NINDS-AIREN and DSM-IV criteria, were randomized and treated with either 500 mg of citicoline or placebo twice per day. Patients were assessed at baseline, and at 6, and 12 months on a battery of neurocognitive tests. Neuroimaging measures of total brain volume and subcortical/periventricular hyperintensity (SH) volume on magnetic resonance imaging (MRI) were collected at baseline and the 12-month follow-up. RESULTS: The citicoline and placebo treatment groups did not differ in their neuropsychological performance at baseline and the 12-month follow-up. Significant declines in neuropsychological performance were noted, as well as significantly increased SH and reduced total brain volumes on MRI for both groups at the 12-month follow-up. CONCLUSIONS: The efficacy of long-term citicoline treatment for cognitive impairment and neuropathological decline in those patients already meeting criteria for VaD does not appear to be substantiated by the current study.

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PubMed2003

Untreated initial psychosis: relation to cognitive deficits and brain morphology in first-episode schizophrenia.

OBJECTIVE: Studies of patients experiencing their first episode of psychosis have demonstrated that they typically remain undiagnosed and untreated for 1-2 years. It has been postulated that prolonged untreated psychosis may have serious effects: poor response to neuroleptic medications, poor clinical outcomes, and direct neurotoxicity. This study investigated the relationships between duration of untreated initial psychosis and neurocognitive functioning and high-resolution imaging brain measurements. METHOD: A total of 156 subjects with DSM-IV schizophrenia, schizophreniform disorder, or schizoaffective disorder were evaluated during their first episode of psychosis. Measurements included nine domains of neurocognitive functioning, volumetric measures of total brain tissue, gray and white matter, and CSF, and measures of brain surface anatomy. RESULTS: The mean duration of untreated initial psychosis was 74.3 weeks. Correlations between neurocognitive functioning, brain volumetric measurements, and surface anatomy measurements with duration of untreated initial psychosis were weak; none reached statistical significance. When the group was divided on the basis of median duration of untreated initial psychosis, there were again no significant differences between the groups with long and short duration of untreated initial psychosis except on two measures (verbal memory and cortical sulcal depth). CONCLUSIONS: The absence of strong correlations suggests that untreated initial psychosis has no direct toxic neural effects. These results suggest that large-scale initiatives designed to prevent neural injury through early intervention in the prepsychotic or early psychosis phase may be based on incorrect assumptions that neurotoxicity or cognitive deterioration may be avoided. Nevertheless, early treatment is justified because it reduces suffering.

Adult↗

PubMed2003

The influence of cognitive impairment and behavioral dysregulation on daily functioning in the nursing home setting.

OBJECTIVE: The influence of psychiatric symptoms and cognitive impairment on daily living skills was explored in a series of nursing home residents. Three categories of symptoms were examined: behavioral disturbances, depression, and delusions. METHOD: Nursing home residents (N=69) underwent comprehensive psychiatric evaluations. Relationships among psychiatric symptoms, cognitive function, and daily living skills were assessed by using regression and correlation analyses. RESULTS: Cognitive decline had the greatest effect on functional impairment in a standard least squares model, followed by behavioral disturbances. Psychiatric symptoms correlated positively with each other and with functional impairment, and correlated inversely with cognitive functioning. CONCLUSIONS: Cognitive decline appears to confer the greatest burden of functional disability in the nursing home setting. After cognitive effects were accounted for, behavioral dysregulation was also associated with functional impairment. In conclusion, interventions to enhance cognition and ameliorate behavioral disturbances are important areas for future studies in long-term care.

Activities of Daily Living↗

PubMed2002

The serial position effect in mild and moderately severe vascular dementia.

The present study examined the serial position effect in 2 subgroups of individuals with vascular dementia (VaD). Nineteen individuals with mild VaD and 17 individuals with moderate VaD were administered the California Verbal Learning Test. Both groups were impaired on a general memory measure, and the moderately impaired group demonstrated significantly poorer recall than the mildly impaired group on the first learning trial and on total learning across trials. In addition, individuals with mild dementia demonstrated an intact primacy and recency effect, whereas individuals with moderate dementia demonstrated neither primacy nor recency effects. The latter findings are consistent with studies examining the serial position effect in other dementia populations, and suggests that the absence of primacy and recency effects in more advanced dementia may occur regardless of dementia type.

Cytidine Diphosphate Choline↗

PubMed2002

The relationship of subcortical MRI hyperintensities and brain volume to cognitive function in vascular dementia.

The relationship between MRI findings (i.e., subcortical hyperintensities; SH, whole brain volume) and the cognitive dysfunction of vascular dementia (VaD) was examined. Participants included 24 persons that met NINDS-AIREN criteria for VaD (MMSE = 19.9 +/- 4.2) and underwent comprehensive neuropsychological assessment and MRI brain imaging. The volume of subcortical hyperintensities (SH) was strongly associated with executive-psychomotor performance, but not with performance across other cognitive domains or global cognitive functional level. Conversely, WBV was strongly associated with global cognitive functioning and performance across most cognitive domains (memory, language, visual integration), but not with executive-psychomotor functioning. The failure of SH to account for either the global dementia evident in these VaD patients or impairments across most cognitive domains suggests that deep subcortical white matter disease may only indirectly contribute to the global cognitive dysfunction of VaD. That WBV emerged as a stronger correlate of dementia raises further questions regarding the cerebral mechanisms that contribute to the development of VaD.

Aged↗

PubMed2002

Neuropsychological characteristics of patients in a hospital-based eating disorder program.

The existence of cognitive deficits associated with eating disorders has been debated for some time. The present study investigated cognitive impairments in a large sample of patients with anorexia nervosa from an inpatient treatment program. Fifty-nine women with anorexia nervosa were given a battery of neuropsychological tests assessing multiple cognitive domains. Over half of the patients had mild cognitive impairments in two or more neuropsychological tasks and approximately one-third failed two or more tasks. Depression level and body mass were not associated with cognitive impairment. Whether effective restoration of weight and resolution of core psychopathology contribute to reversal of cognitive deficits requires further research.

Adolescent↗

PubMed2002

The influence of cognitive impairment and psychiatric symptoms on daily functioning in nursing facilities: a longitudinal study.

The influence of psychiatric symptoms and cognitive status on daily living skills was explored among persons with dementia residing in skilled nursing facilities. Psychiatric symptoms were examined in three domains: 1) depression, 2) psychosis, and 3) behavioral disturbances. Twenty-eight subjects were followed for a 1-year duration in rural nursing facilities. The relationship between psychiatric symptoms, cognition, and daily living skills was assessed using correlation and regression analyses. Over a one-year period, cognitive and functional impairment progressed significantly. In contrast, psychiatric symptoms across all three domains did not necessarily persist or increase. Deterioration in cognitive function was significantly correlated with reduced functional status both cross-sectionally and longitudinally. Among psychiatric symptoms, only behavioral disturbances were significantly associated with functional impairment cross-sectionally. Cognitive decline and loss of social functioning may constitute the greatest source of disability among persons in nursing facilities. Furthermore, both impairments increase over time in contrast to psychiatric symptoms, which appear to have a more variable course. These findings may have implications for treatment interventions that seek to enhance functioning in the skilled nursing setting.

Activities of Daily Living↗

PubMed2002

Acute neuropsychological functioning following cardiosurgical interventions associated with the production of intraoperative cerebral microemboli.

Coronary artery bypass graft (CABG) and valve replacement (VR) surgical patients underwent neuropsychological assessment 1-2 days prior to surgery; 7-10 days postsurgery; and 1 month following hospital discharge. A group of matched healthy controls was tested at identical intervals. Cerebral microemboli in both middle cerebral arteries were quantified during surgery using Doppler sonography. Neuropsychological testing results revealed that the CABG and VR groups did not differ from one another at any assessment point. However, surgical patients performed more poorly than healthy controls across all assessments. Surgical patients, as a group, demonstrated a mild decline in attentional functioning and learning efficiency at the 7-10 day follow-up, but these difficulties essentially returned to baseline by the 1-month follow-up. Intraoperative microemboli counts were not significantly associated with postsurgical neuropsychological functioning in either the CABG or VR group.

Case-Control Studies↗

PubMed2002

Capacity to provide informed consent for participation in schizophrenia and HIV research.

OBJECTIVE: The degree to which people with psychiatric symptoms and cognitive dysfunction can provide informed consent to participate in research is a controversial issue. This study was designed to examine the capacity of subjects with schizophrenia and subjects with HIV to provide informed consent for research participation and to determine the relationships among cognitive dysfunction, psychiatric symptoms, and decisional capacity. METHOD: Twenty-five men and women with a DSM-IV diagnosis of schizophrenia and 25 men and women with HIV were recruited. The groups were compared in terms of neuropsychological functioning, psychiatric symptoms, and ability to provide informed consent to a hypothetical drug trial. RESULTS: Eighty percent of the subjects with schizophrenia and 96% of the HIV-positive subjects demonstrated adequate capacity to consent to the hypothetical drug trial, but subjects in the schizophrenia group had significantly lower scores on two of the four aspects of decisional capacity. For the subjects with schizophrenia, neuropsychological functioning and psychiatric symptoms (e.g., apathy and avolition), but not psychotic symptoms (e.g., hallucinations and delusions), were significantly associated with decisional capacity. CONCLUSIONS: The majority of subjects who are recruited and willing to participate in schizophrenia or HIV research will have adequate capacity to provide consent. Cognitive dysfunction and the symptoms shown to be associated with impaired decisional capacity are not unique to schizophrenia and may occur with many other forms of illness. These findings underscore the importance of considering how decisional capacity will be assessed in all types of research, regardless of the specific condition being studied.

Adolescent↗

PubMed2002

Behavioral problems as predictors of functional abilities of vascular dementia patients.

The relationship of behavioral disturbance and dementia severity to activities of daily living (ADLs) in vascular dementia (VaD) was examined in baseline data for 29 VaD patients. A series of stepwise regression analyses was conducted to examine the extent to which dementia severity, apathy, disinhibition, and executive dysfunction predict ADLs (total, basic, and instrumental). For total ADLs, apathy accounted for 36% of the variance and dementia severity accounted for an additional 15%. For basic ADLs, apathy accounted for 27% of the variance. Dementia severity, executive dysfunction, and disinhibition were not significantly associated with basic ADLs. For instrumental ADLs, dementia severity accounted for 37% of the variance and apathy accounted for an additional 14%. These findings highlight the importance of apathy as an independent factor associated with functional independence beyond general cognitive abilities.

Activities of Daily Living↗

PubMed2002

The global deterioration scale: relationships to neuropsychological performance and activities of daily living in patients with vascular dementia.

In the present study, we examined the relationships between ratings on the Global Deterioration Scale (GDS) and activities of daily living and cognitive function in 39 individuals with vascular dementia (VaD). The results of the study revealed significant correlations between GDS rating and performance on cognitive tests, including memory and overall cognitive ability. In addition, the GDS was significantly related to ratings of instrumental activities of daily living. Comparisons between patients with VaD with GDS scores between 4 and 6 (n = 21) and patients with scores between 2 and 3 (n = 18) revealed greater cognitive and functional deficits in the group with higher GDS scores. Further, the GDS score accurately classified 87% of the patients with VaD. These findings provide support for the validity of the GDS in general staging of dementia severity of VaD.

Activities of Daily Living↗

PubMedDate not supplied

Global cerebral blood flow in relation to cognitive performance and reserve in subjects with mild memory deficits.

PURPOSE: This study was undertaken to explore the mechanisms underlying cognitive reserve in subjects with mild memory deficits by using positron emission tomography (PET). METHODS: Global cerebral blood flow (gCBF) and cerebrovascular reserve (CVR) measurements were performed in 15 elders (5 men, 10 women, 62-84, 71.8 +/- 6.2 years) meeting criteria for mild cognitive impairment (MCI). PET consisted of quantitative [(15)O]water determinations of CBF, two at baseline and one postadministration of acetazolamide (ACZ). RESULTS: Mean gCBF were 44.9 +/- 5.5 during counting, 44.5 +/- 6.7 for the memory task, and 60.2 +/- 4.8 ml/min/100 g for post-ACZ (CVR of 33.9 +/- 13.2%). Task-related gCBF change was significantly related to memory score, performance on the Trail Making Test B (Trails-B), premorbid IQ, and education, and differed significantly between the learning-based groups. CONCLUSIONS: Cognitive reserve appears analogous to cardiac reserve. The ability to alter gCBF paralleled performance on general cognitive measures, was enhanced in higher levels of cognitive reserve, and was impaired in individuals who no longer appear to benefit from repeated exposure to testing.

Acetazolamide↗