Biomedical subjects

Sharon G Lynch

Publications and source records attributed to Sharon G Lynch.

6 recordsLinked to original sources

PubMed2006

The relationship between perceived and objective cognitive functioning in multiple sclerosis.

The relationship between perceived cognitive functioning and objective cognitive functioning was studied in 221 patients with multiple sclerosis. Perceptions of global cognitive functioning as well as perceptions of performance on specific cognitive tests were assessed. Patients' perceptions of global cognitive functioning in their daily lives were unrelated to their objective performance on the full cognitive test battery. However, patients' perceptions of their performance on specific tasks correlated with their objective performance on those tasks, even though they underestimated their performance on these tasks. The present study also evaluated predictors of patients' perceived cognitive functioning. Depression, anxiety, fatigue, and level of disability predicted perceptions of global cognitive functioning, whereas objective cognitive performance did not. These results add to our understanding of patients' expressed concerns regarding their cognitive functioning in the wake of multiple sclerosis, suggesting that such concerns should be interpreted with caution by clinicians.

Adult↗

PubMed2005

Cognitive impairment in three subtypes of multiple sclerosis.

Patients with relapsing, primary progressive, and secondary progressive MS were administered the Tower of London and the Stroop Color-Word Interference Test, yielding several measures of executive function and speeded information processing. MS patients' performance was compared with healthy controls and with a clinical control group consisting of patients with rheumatoid arthritis. The MS patients performed the tests more slowly, but did not differ from either group of controls on measures of executive function. Slowing in the speed of information processing was characteristic of MS patients across two basic tasks differing in terms of controlled versus automatic processing and in terms of whether or not rapid responding was an explicit feature of successful performance. Although evident in all subtypes, this slowing was more pronounced in secondary progressive patients and somewhat less pronounced in primary progressive patients. Furthermore, the slowing was unrelated to patients' disability status or level of depression.

Adult↗

PubMed2005

The association between cognitive impairment and physical disability in multiple sclerosis.

BACKGROUND: The association between cognitive impairment and physical disability was examined in a larger, more representative sample of patients with multiple sclerosis (MS) than in previous studies. METHOD: Two hundred and fifty-three patients attending an MS clinic were assessed with respect to physical disability using the Expanded Disability Status Scale and cognitive impairment using a battery of neuropsychological tests. RESULTS: Physical disability correlated with duration of disease; cognitive impairment did not. Virtually all measures derived from the cognitive battery were significantly correlated with physical disability. Three measures of speeded information processing and one involving delayed recall of verbal material were unique predictors of disability status. The relationship between cognitive impairment and physical disability was equivalent for patients with shorter (< 3 years) versus longer (> 10 years) disease duration. Cognitive impairment correlated with the rate of disability progression as reflected by the progression index. CONCLUSION: Cognitive impairment is more closely associated with physical disability than most previous studies indicate. This relationship appears to be stable throughout the duration of MS, although this conclusion is qualified by the cross-sectional design of the study. Further attention should be paid to cognitive impairment as a possible predictor of the rate of patients' physical decline.

Adult↗

PubMed2004

Cognitive impairment in relapsing and primary progressive multiple sclerosis: mostly a matter of speed.

Based on the assumption that cognitive impairment in MS is consistent with subcortical dementia, a battery of neuropsychological tests was assembled that included measures of executive function (Tower of London and Wisconsin Card Sorting Test), verbal learning and memory (a paired associates learning test), and speeded information processing (Stroop Color Word Interference Test). The battery was administered to patients with relapsing and primary progressive MS and to healthy controls. Differences between patients and controls occurred on several of the measures. However, when differences with respect to fatigue and depression were statistically controlled, the only differences that remained significant involved measures relating to the speed of information processing. Patients performed more slowly than controls, with the disparity being greater for relapsing patients than for those with primary progressive disease. The slowing was evident on measures of automatic as well as controlled processing and regardless of whether speed was an explicit feature of successful performance or recorded unobstrusively while the patient concentrated on planning a correct solution to a problem. Parallels were noted between cognitive slowing associated with MS and that of normal aging.

Adult↗

PubMed2003

The cognitive performance of patients with multiple sclerosis during periods of high and low fatigue.

The objective of this study was to examine whether multiple sclerosis (MS)-related fatigue affects patients' cognitive performance. Thirty patients who had substantial fatigue in conjunction with MS and who reported marked diurnal variability in the severity of their fatigue were tested on two occasions: during a period of high fatigue and during a period of relatively low fatigue. The order of these sessions was counterbalanced across patients. During both sessions, patients completed a questionnaire concerning their present state of fatigue and a battery of neuropsychological tests of planning, selective attention, and paired associate learning. Although patients confirmed greater fatigue during the period of high fatigue and felt they had performed more poorly during this period, there were no differences in cognitive performance that could be attributed to fatigue. Instead, all subjects showed improvement from the first to the second session regardless of whether the latter entailed a period of high or low fatigue. In contrast to studies reporting fatigue-related declines in MS patients' cognitive performance, no differences in performance were found when MS patients were tested during periods of high versus low fatigue. These contrasting results, stemming from differences in experimental design, are discussed in terms of their implications for assessing cognitive function in patients with MS.

Adult↗

PubMed2002

Activation of histamine H2 receptors ameliorates experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE), a model of multiple sclerosis, is an autoimmune, demyelinating disease of the CNS. Pro-inflammatory cytokines (e.g. tumour necrosis factor-alpha (TNF-alpha) and interleukin (IL)-12) and reactive oxygen species are implicated in promoting EAE. Since histamine H(2) receptor activation suppresses production of O(2)*-, TNF-alpha, and IL-12 by inflammatory cells, we tested the hypothesis that dimaprit, an H(2) agonist, would reduce the clinical severity and pathology of EAE. Dimaprit treatment significantly reduced clinical signs compared to vehicle in both C57BL/6 and iNOS deficient EAE mice. Furthermore, dimaprit significantly reduced CNS staining for lectin-positive macrophages and decreased extravasated albumin staining, an indicator of blood-brain barrier leakage. These data provide a rationale for exploring H2 receptor activation for therapeutic value in multiple sclerosis.

Animals↗