Biomedical subjects

Sarah Tomaszewski Farias

Publications and source records attributed to Sarah Tomaszewski Farias.

8 recordsLinked to original sources

PubMed2006

The intersubject and intrasubject reproducibility of FMRI activation during three encoding tasks: implications for clinical applications.

The goal of the present study was to evaluate the inter- and intrasubject reproducibility of FMRI activation for three memory encoding tasks previously used in the context of presurgical functional mapping. The primary region of interest (ROI) was the medial temporal lobe (MTL). Comparative ROIs included the inferior frontal and fusiform gyri which are less affected by susceptibility-induced signal losses than the MTL regions. Eighteen subjects were scanned using three memory encoding paradigms: word-pair, pattern, and scene encoding. Nine subjects underwent repeat scanning. Intersubject reproducibility of FMRI activation was evaluated by examining the percent of subjects who showed activation within a given ROI and the range to which individual laterality indices (LIs) varied from the mean. Intrasubject test-retest reproducibility was evaluated by examining the LI test-retest correlation, the average difference between LIs from two separate imaging sessions, and concordance ratios of activation volumes (R(volume) and R(overlap)). For scene encoding the reproducibility of activation volume and LIs within the MTL were as good as or better than the reproducibility within the fusiform and inferior frontal ROIs. For pattern encoding and word-pair encoding, the reproducibility of activation volume and LIs within the MTL tended to be worse compared to the fusiform and inferior frontal ROIs. The differences in FMRI reproducibility appeared more dependent on the task than the susceptibility effects. The results of this study suggest that FMRI-based assessment of the neural substrates of memory using a scene encoding task may be a useful clinical tool.

Acoustic Stimulation↗

PubMed2005

Degree of discrepancy between self and other-reported everyday functioning by cognitive status: dementia, mild cognitive impairment, and healthy elders.

BACKGROUND: Previous studies show individuals with dementia overestimate their cognitive and functional abilities compared to reports from caregivers. Few studies have examined whether individuals with Mild Cognitive Impairment (MCI) also tend to underestimate their deficits. In this study we examined whether degree of discrepancy between patient and informant-reported everyday functioning was associated with cognitive status. METHODS: The sample consisted of 111 ethnically diverse community-dwelling older adults (46 Caucasians and 65 Hispanic individuals), which was divided into four diagnostic categories: cognitively normal, MCI-memory impaired, MCI-nonmemory impaired, and demented. Everyday functional abilities were measured using both a self-report and informant-report version of the Daily Function Questionnaire (DFQ). A Difference Score was calculated by subtracting patients' DFQ score from their informants' score. RESULTS: DFQ Difference Scores were significantly higher in the demented group compared to normals and both of the MCI groups. However, the Difference Scores for the MCI groups were not significantly different than the normals. Further, while patient reported everyday functioning did not differ among the four diagnostic groups, informant reported functional status was significantly different across all diagnostic groups except MCI-nonmemory impaired vs normals. Performance on objective memory testing was associated with informant-rated but not patient-rated functional status. Demographic characteristics of the patients and informants, including ethnicity, had no association with the degree of discrepancy between raters. CONCLUSIONS: Although there may be some mild functional changes associated particularly with the MCI-memory impaired subtype, individuals with MCI do not appear to under-report their functional status as can often been seen in persons with dementia.

Activities of Daily Living↗

PubMed2005

Criterion-referenced validity of a neuropsychological test battery: equivalent performance in elderly Hispanics and non-Hispanic Whites.

This study examined the validity of the Spanish and English Neuropsychological Assessment Scales (SENAS) in comparison with clinical diagnosis of normal cognition versus cognitive impairment, not demented (CIND) versus demented in elderly Hispanics and Whites. Relationships between SENAS scales and diagnosis were essentially the same in Hispanics and Whites. Verbal memory measures were most strongly related, with more than 35% of the variance in these measures accounted for by diagnosis independent of effects of education, age, gender, and language. Diagnosis accounted for more than 10% of the variance (19% on average) in 11 of the 17 measures examined in this study. Logistic regressions showed that verbal memory was important both for distinguishing normal from CIND and CIND from demented. Object naming improved discrimination of CIND from demented beyond that of verbal memory alone. These results provide evidence of equivalent validity across Hispanics and Whites.

Aged↗

PubMed2004

Improvement in seizure control and quality of life in medically refractory epilepsy patients converted from polypharmacy to monotherapy.

In a retrospective chart review, we identified 35 patients with medically refractory epilepsy (MRE) who had been converted from polypharmacy to monotherapy and maintained on monotherapy for at least 12 months. None of the 35 patients had worsening of their seizure frequency after the conversion to monotherapy. Fourteen of the 35 patients (40%) became seizure-free. Nine of 35 patients (26%) had a 50% reduction in seizure frequency. Five of 35 patients (14%) had a 75% reduction in seizure frequency. Twenty-eight (80%) of 35 patients participated in a quality-of-life questionnaire. Quality of life was rated as better on monotherapy as compared with polypharmacy in a number of domains: memory loss, concern over medication long-term effects, difficulty in taking the medications, trouble with leisure time activities, and overall state of health. This improvement reached statistical significance. Conversion to monotherapy in patients with MRE may be successful in achieving a reduction in seizure frequency and an improvement in quality-of-life parameters. A prospective, randomized trial is necessary to validate these findings.

Adult↗

PubMed2004

Everyday functioning in relation to cognitive functioning and neuroimaging in community-dwelling Hispanic and non-Hispanic older adults.

The purpose of this study was to examine how a specific informant-based measure of everyday functioning, the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE; Jorm & Korten, 1988) relates to cognition and structural neuroimaging in a large multicultural, multilingual sample of Caucasians and Hispanics. Cognitive variables included selected subtests from the Spanish and English Neuropsychological Assessment Scales (SENAS; Mungas et al., 2000): Verbal Memory, Object Naming, Verbal Attention Span, Verbal Conceptual Thinking, and Pattern Recognition. The association between the IQCODE and selected neuroimaging variables, hippocampal volume and white matter hyperintensity, was evaluated in a subsample of English- and Spanish-speaking Hispanic individuals. The cognitive variables showed strong bivariate relationships with the IQCODE, although only Verbal Memory and Object Naming independently predicted level of functional ability. Verbal Memory was the strongest predictor of functional status, accounting for 23% of the variance in the IQCODE. White matter hyperintensity was also independently related to the IQCODE, accounting for 18% of the variance. Hippocampal volume was related to the IQCODE in a simple bivariate analysis, but was not an independent predictor of reported functional status after controlling for age. The relationships between cognitive variables and functional status, as well as between the imaging variables and the IQCODE, did not differ across language-ethnic groups.

Activities of Daily Living↗

PubMed2003

Psychogenic nonepileptic seizures: acute change in event frequency after presentation of the diagnosis.

Seizure frequency during inpatient video EEG monitoring was examined before and after the diagnosis of psychogenic nonepileptic seizures (PNES) was presented to patients (N=22). A control group of 10 patients with epileptic seizures (ES) were also followed from pre- to postdiagnosis. The number of PNES or ES within the 24-hour period prior to diagnosis was compared with the number of events that occurred within the 24-hour period after presentation of the diagnosis. Findings indicate that patients with PNES had a significant decrease in the frequency of events after diagnosis, while those with ES showed no change in event frequency after diagnosis. Eighteen of twenty-two patients with PNES had no further events during an acute follow-up period. Results suggest that providing patients with a diagnosis of PNES appears to reduce the acute frequency of PNES and may be an important first step in the long-term remediation of PNES. Long-term follow-up is needed to determine if such feedback alters the course of the disorder.

Acute Disease↗

PubMed2003

Pyridoxine-dependent seizures and cognition in adulthood.

A case report of neonatal onset pyridoxine-dependent seizures in a male patient with early diagnosis and treatment is presented. The patient's epilepsy was recognized and treated with pyridoxine (vitamin B6) within 8 hours of birth. Treatment has been nearly continuous since that time. This paper reports the results of a full neuropsychological evaluation at age 37 years and MRI completed at age 31 years. Consistent with other case reports in the literature, there was a significant Performance IQ (PIQ) advantage with decreased Verbal IQ (VIQ) and expressive language skills (Full-Scale IQ 71, VIQ 64, PIQ 85). MRI demonstrated characteristic thinning of the posterior corpus callosum. This report provides an example of early treatment that nonetheless results in a mild mental retardation. The similarity of the structural changes on MRI and the cognitive profile of this patient to those of others reported in the literature suggest that the underlying mechanism for both may be the same.

Adult↗

PubMed2003

The relationship between neuropsychological performance and daily functioning in individuals with Alzheimer's disease: ecological validity of neuropsychological tests.

The current study examined the relationship between neuropsychological test performance and functional status in 42 individuals diagnosed with Alzheimer's disease. A comprehensive battery of cognitive tests was employed in order to assess a wide range of neuropsychological abilities. Functional status was measured through the use of both a performance-based scale of activities of daily living (an expanded version of the Direct Assessment of Functional Status; DAFS, Loewenstein et al., 1989), and by a caregiver/informant-based rating scale (Instrumental Activities of Daily Living; IADL, Lawton & Brody, 1969). Findings suggest that neuropsychological functioning is moderately predictive of functional status. Using multiple regression analyses, neuropsychological variables accounted for 25% of the variance in the IADL and 50% of the variance in the DAFS. Individual domains of both functional measures were also significantly predicted by the neuropsychological variables. The findings provide evidence of a relationship between neuropsychological test performance and ADLs in an Alzheimer disease patient population.

Activities of Daily Living↗