Biomedical subjects

Peter J Hand

Publications and source records attributed to Peter J Hand.

3 recordsLinked to original sources

PubMed2006

Persistent infarct hyperintensity on diffusion-weighted imaging late after stroke indicates heterogeneous, delayed, infarct evolution.

BACKGROUND AND PURPOSE: Some infarcts have persistently hyperintense areas on diffusion-weighted MRI (DWI) even at 1 month after stroke, whereas others have become isointense to normal brain. We hypothesized that late DWI hyperintensity reflected different infarct evolution compared with areas that were isointense by 1 month. METHODS: We recruited patients prospectively with ischemic stroke, performed DWI and perfusion-weighted MRI (PWI) on admission, at 5 days, 14 days, and 1 month after stroke, and assessed functional outcome at 3 months (Rankin Scale). Patient characteristics and DWI/PWI values were compared for patients with or without "still hyperintense" infarct areas on 1-month DWI. RESULTS: Among 42 patients, 27 (64%) had "still hyperintense" infarct regions at 1 month, mostly in white matter. Patients with "still hyperintense" regions at 1 month had lower baseline apparent diffusion coefficient ratio (ADCr; mean+/-SD 0.76+/-0.12 versus 0.85+/-0.12; hyperintense versus isointense; P<0.05), prolonged reduction of ADCr (repeated-measures ANOVA; P<0.01), no difference in baseline perfusion but delayed normalization of mean transit time (P<0.05) and cerebral blood flow ratios (repeated measures ANOVA; P<0.05), initially more severe stroke, and worse 3-month outcome than patients whose lesions were isointense by 1 month. CONCLUSIONS: The late DWI lesion hyperintensity emphasizes the heterogeneity in temporal evolution of stroke injury and suggests ongoing "ischemia." Lower baseline ADCr precedes delayed perfusion normalization, suggesting that worse cell swelling impedes reperfusion. Further study is required to determine underlying mechanisms and any potential for subacute intervention to improve recovery.

Adult↗

PubMed2006

Distinguishing between stroke and mimic at the bedside: the brain attack study.

BACKGROUND AND PURPOSE: The bedside clinical assessment of the patient with suspected stroke has not been well studied. Improving clinical skills may accelerate patient progress through the emergency department. We aimed to determine the frequency and nature of stroke mimics and to identify the key clinical features that distinguish between stroke and mimic at the bedside. METHODS: Consecutive presentations to an urban teaching hospital with suspected stroke were recruited. A standard bedside clinical assessment was performed. The final diagnosis was determined by an expert panel, which had access to clinical features, brain imaging, and other tests. Univariate and multivariate analyses determined the bedside features that distinguished stroke from mimic. RESULTS: There were 350 presentations by 336 patients. The final diagnosis was stroke in 241 of 350 (69%) and mimic in 109 (31%). The mimics included 44 events labeled "possible stroke or TIA." Eight items independently predicted the diagnosis in patients presenting with brain attack: cognitive impairment and abnormal signs in other systems suggested a mimic, an exact time of onset, definite focal symptoms, abnormal vascular findings, presence of neurological signs, being able to lateralize the signs to the left or right side of the brain, and being able to determine a clinical stroke subclassification suggested a stroke. CONCLUSIONS: The bedside clinical assessment can be streamlined substantially. This has important implications for teaching less experienced clinicians how to assess the patient with suspected stroke.

Adolescent↗

PubMed2006

Interobserver agreement for the bedside clinical assessment of suspected stroke.

BACKGROUND AND PURPOSE: Stroke remains primarily a clinical diagnosis, with information obtained from history and examination determining further management. We aimed to measure inter-rater reliability for the clinical assessment of stroke, with emphasis on items of history, timing of symptom onset, and diagnosis of stroke or mimic. We explored reasons for poor reliability. METHODS: The study was based in an urban hospital with an acute stroke unit. Pairs of observers independently assessed suspected stroke patients. Findings from history, neurological examination, and the diagnosis of stroke or mimic, were recorded on a standard form. Reliability was measured by the kappa statistic. We assessed the impact of observer experience and confidence, time of assessment, and patient-related factors of age, confusion, and aphasia on inter-rater reliability. RESULTS: Ninety-eight patients were recruited. Most items of the history and the diagnosis of stroke were found to have moderate to good inter-rater reliability. There was agreement for the hour and minute of symptom onset in only 45% of cases. Observer experience and confidence improved reliability; patient-related factors of confusion and aphasia made the assessment more difficult. There was a trend for worse inter-rater reliability among patients assessed very early and very late after symptom onset. CONCLUSIONS: Clinicians should be aware that inter-rater reliability of the clinical assessment is affected by a variety of factors and is improved by experience and confidence. Our findings have implications for training of doctors who assess patients with suspected stroke and identifies the more reliable components of the clinical assessment.

Aged↗