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Mark Barber

Publications and source records attributed to Mark Barber.

8 recordsLinked to original sources
PubMed2006

D-dimer predicts early clinical progression in ischemic stroke: confirmation using routine clinical assays.

BACKGROUND AND PURPOSE: Plasma d-dimer levels, measured using a research laboratory assay, independently predict progressing ischemic stroke. We wished to confirm these findings using commercially available assays and to provide data to allow the design of intervention studies. METHODS: We studied 219 consecutive acute ischemic stroke admissions of whom 54 (25%) met criteria for progressing stroke. RESULTS: There were strong correlations between d-dimer results as measured by the Biopool AB, MDA and VIDAS assays; correlation coefficients r=0.91 to 0.94; all P<0.001. In binary logistic regression analyses, d-dimer, as measured by the 3 different assays, was an independent predictor of progressing stroke (odds ratios, 1.87 to 2.45; all P<0.001). This confirms the results of our original analysis (Biopool AB) using 2 commercial d-dimer assays, demonstrating the potential usefulness of d-dimer in providing early prognostic information after ischemic stroke in different clinical settings. We also provide information on the performance of the 3 assays in predicting progressing stroke at a variety of cutoff values. CONCLUSIONS: Ischemic stroke patients at high risk of early progression can be identified using commercial d-dimer measurements. This could allow selection of high-risk patients for inclusion in randomized trials of early antithrombotic treatments.

Brain Ischemia↗
PubMed2004

Hemostatic function and progressing ischemic stroke: D-dimer predicts early clinical progression.

BACKGROUND AND PURPOSE: Early clinical progression of ischemic stroke is common and is associated with increased risk of death and dependency. We hypothesized that activation of the coagulation system is an important contributor in some cases of deterioration. We aimed to characterize alterations in circulating hemostatic markers in patients with progressing stroke. METHODS: Consecutive acute ischemic stroke admissions were recruited. Progressing stroke was defined by deterioration in components of the Scandinavian Stroke Scale. Hemostatic markers (coagulation factors VIIc, VIIIc, and IXc, prothrombin fragments 1+2 [F1+2], thrombin-antithrombin complexes [TAT], D-dimer, fibrinogen, von Willebrand factor [vWF] and tissue plasminogen activator) were measured within 24 hours of symptom recognition. RESULTS: Fifty-four (25%) of the 219 patients met criteria for progressing stroke. F1+2 (median 1.28 versus 1.06 nmol/L, P=0.01), TAT (5.28 versus 4.07 microg/L, P<0.01), D-dimer (443 versus 194 ng/mL, P<0.001) and vWF (216 versus 198 IU/dL, P<0.05) levels were higher in these patients than in stable/improving patients. In logistic regression analysis, with all important clinical and laboratory variables included, only natural log D-dimer (odds ratio [OR]: 1.87; 95% confidence interval [CI]: 1.38 to 2.54; P=0.0001) and mean arterial blood pressure (OR: 1.26 per 10 mm Hg change; 95% CI: 1.05 to 1.51; P=0.01) remained independent predictors of progressing stroke. CONCLUSIONS: There is evidence of excess thrombin generation and fibrin turnover in patients with progressing ischemic stroke. Measurement of D-dimer levels can identify patients at high risk for stroke progression. Further research is required to determine whether such patients benefit from acute interventions aimed at modifying hemostatic function.

Aged↗
PubMed2004

Validity of the Telephone Interview for Cognitive Status (TICS) in post-stroke subjects.

BACKGROUND: Cognitive impairment and dementia are very common after stroke. Telephone screening has potential advantages for clinical follow-up and population-based research in this group. We wished to test the validity of the Telephone Interview for Cognitive Status (TICS) for cognitive testing in post-stroke subjects. METHODS: Cognitive function in stroke outpatients was assessed using the R-CAMCOG (a modification of the cognitive part of the Cambridge Examination for Mental Disorders of the Elderly, for use in stroke subjects) along with the TICS and a modified version, the TICSm. The tests were administered in random order. A cut-off point of 33 on the R-CAMCOG was used to define post-stroke dementia. RESULTS: Sixty-four patients with a median age of 72 years were assessed. The Pearson correlation coefficients between the R-CAMCOG and the TICS and TICSm were 0.833 and 0.855 (both p <0.001) respectively. Twenty-four (38%) patients met R-CAMCOG criteria for post-stroke dementia. The area under the ROC curve for both the TICS and TICSm was 0.94. Using a cut-off of 28 or less on the TICS produced a sensitivity of 88% and a specificity of 85% for the diagnosis of post-stroke dementia. For the TICSm a cut-off of 20 or lower produced a sensitivity of 92% and a specificity of 80%. CONCLUSIONS: The TICS and TICSm telephone questionnaires are practicable and valid methods of assessing cognitive function in community outpatients following stroke. Scores of < or =28 and < or =20 respectively carry good sensitivity and specificity for the diagnosis of post-stroke dementia.

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PubMed2003

Validity and reliability of estimating the scandinavian stroke scale score from medical records.

BACKGROUND: Reliable estimation of severity of neurological impairments early after stroke is essential for research and audit of acute stroke care. Obtaining this information prospectively requires significant resources. We wished to assess the reliability of estimating the Scandinavian Stroke Scale (SSS) score retrospectively from routine hospital admission records. METHODS: Acute stroke admissions to a large urban hospital were examined and had their SSS scored by an experienced physician within 4 h of the examination performed by the medical admissions team. Two examiners (a trained research nurse and a second physician), blinded to the patients' clinical condition, later independently estimated retrospective SSS scores using information documented in the medical admission notes. RESULTS: Fifty patients were recruited [median age 73 years (interquartile range 61, 79)]. Weighted kappa statistics for agreement between domains of the face-to-face and retrospective SSS were as follows: consciousness 0.73, eye movements 0.60, arm motor power 0.83, hand motor power 0.71, leg motor power 0.81, orientation 0.81, speech 0.80, and facial palsy 0.53. The intraclass correlation coefficient for face-to-face and retrospective SSS composite scores was 0.97 (95% CI 0.96-0.98), p < 0.0001. Interobserver reliability for the different components of the retrospective SSS was excellent (kappa values greater than 0.75) apart from consciousness (0.71) and eye movements (0.58). CONCLUSIONS: The composite SSS score and most of its individual components can be reliably estimated retrospectively from routine hospital admission records. This method is potentially useful both in observational studies and in case-mix adjustment for audit purposes.

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PubMedDate not supplied

Predictors of early neurological deterioration after ischaemic stroke: a case-control study.

BACKGROUND: Early neurological deterioration after ischaemic stroke (stroke in progression) is reported to be common and associated with poor outcome or death. The causes of progressing stroke are, however, uncertain. OBJECTIVE: To determine whether prior drug treatment (with anticoagulant or antiplatelet agents) or early adverse physiological features (pyrexia, hypoxia, dehydration or hyperglycaemia) are associated with progressing ischaemic stroke. METHODS: The study used a case-control design. From a database of 873 consecutive acute stroke admissions, 196 cases of progressing ischaemic stroke (defined by point deterioration in components of the Scandinavian Stroke Scale or death over the first 72 h after hospital admission) were matched to 196 controls on the basis of age and stroke type. Univariate and conditional logistic regression techniques were used to explore predictors of progressing stroke. RESULTS: Cases and controls were well matched for baseline stroke severity. Warfarin use prior to admission was associated with a reduced risk of progressing stroke [odds ratio (OR) 0.10, p = 0.005]. Prior antiplatelet use was not related. A previous history of diabetes (OR 2.11, p = 0.039) and elevated systolic blood pressure on admission (OR 1.01 for each 1 mm Hg rise, p = 0.017) predicted progressing stroke. Although there were no differences in time to presentation or to brain imaging, a visible causative lesion on CT scanning was more common in the progressing stroke group (OR 2.30, p = 0.022). We found no evidence that adverse physiological features were associated with progressing stroke. Outcomes were worse in the progressing stroke group with 70% being dead or dependent by 30 days compared to 55% in the control group (p = 0.002). CONCLUSION: Prior warfarin use may be protective against progressing ischaemic stroke. A previous history of diabetes along with elevated admission systolic blood pressure predict deterioration. We found no evidence for an association between adverse physiological features and progressing stroke.

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