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Biomedical subjects

Martin M Brown

Publications and source records attributed to Martin M Brown.

24 records · Page 2Linked to original sources
PubMed2003

Markers of endothelial dysfunction in lacunar infarction and ischaemic leukoaraiosis.

Patients with cerebral small vessel disease (SVD) can present as isolated lacunar infarction or with diffuse white matter changes, with the imaging appearance of leukoaraiosis. Endothelial dysfunction, which can lead to breakdown of the blood-brain barrier, impaired cerebral autoregulation and prothrombotic changes, is believed to be important in mediating disease. Circulating levels of intercellular adhesion molecule 1 (ICAM1), thrombomodulin (TM), tissue factor (TF) and tissue factor pathway inhibitor (TFPI) are markers of endothelial activation and damage, and may provide insights into disease pathogenesis or differences between phenotypes. We therefore measured these markers in a prospective series of patients with lacunar stroke. One hundred and ten white Caucasian patients with previous lacunar stroke and 50 community control subjects were studied. Markers of endothelial function were measured on venous blood samples. Patients were classified on brain imaging into two groups: isolated lacunar infarction (n = 47) and ischaemic leukoaraiosis, defined as a clinical lacunar stroke and leukoaraiosis on brain imaging (n = 63). The number of lacunes and severity of leukoaraiosis were also scored on MRI. ICAM1, TM and TFPI were elevated in cerebral SVD subjects compared with controls (P <or= 0.006). The ischaemic leukoaraiosis group had a different endothelial marker profile, with lower levels of TFPI (P = 0.01) and a higher TF/TFPI ratio (P = 0.01) compared with the isolated lacunar infarction group. TM levels were associated with the number of lacunes (P = 0.008) and the leukoaraiosis score (P = 0.03), but TF levels and the TF/TFPI ratio were associated only with the extent of leukoaraiosis (P <or= 0.02). These results suggest that there is evidence of chronic endothelial dysfunction in cerebral SVD, and endothelial prothrombotic changes may be important in mediating the ischaemic leukoaraiosis phenotype. Therapies which help to stabilize the endothelium may have a role in this group of patients.

Aged↗
PubMed2002

A multicentre observational study of presentation and early assessment of acute stroke.

OBJECTIVE: To investigate delays in the presentation to hospital and evaluation of patients with suspected stroke. DESIGN: Multicentre prospective observational study. SETTING: 22 hospitals in the United Kingdom and Dublin. PARTICIPANTS: 739 patients with suspected stroke presenting to hospital. MAIN OUTCOME MEASURES: Time from onset of stroke symptoms to arrival at hospital, and time from arrival to evaluation by a senior doctor. RESULTS: The median age of patients was 75 years, and 400 were women. The median delay between onset of symptoms and arrival at hospital was 6 hours (interquartile range 1 hour 48 minutes to 19 hours 12 minutes). 37% of patients arrived within 3 hours, 50% within 6 hours. The median delay for patients using the emergency service was 2 hours 3 minutes (47 minutes to 7 hours 12 minutes) compared with 7 hours 12 minutes (2 hours 5 minutes to 20 hours 37 minutes) for referrals from general practitioners (P<0.0001). Use of emergency services reduced delays to hospital (odds ratio 0.45, 95% confidence interval 0.23 to 0.61). The median time to evaluation by a senior doctor was 1 hour 9 minutes (interquartile range 33 minutes to 1 hour 50 minutes) but was undertaken in only 477 (65%) patients within 3 hours of arrival. This was not influenced by age, sex, time of presentation, mode of referral, hospital type, or the presence of a stroke unit. Computed tomography was requested within 3 hours of arrival in 166 (22%) patients but undertaken in only 60 (8%). CONCLUSION: Delays in patients arriving at hospital with suspected stroke can be reduced by the increased use of emergency services. Over a third of patients arrive at hospital within three hours of stroke; their management can be improved by expediting medical evaluation and performing computed tomography early.

Acute Disease↗
PubMedDate not supplied

Brain attack: a new approach to stroke.

'Brain' attack' is a new term to describe the acute presentation of stroke which emphasises the need for urgent action. The article describes the basis for this new approach to acute stroke treatment. Rational treatment requires individual causes of stroke to be identified early and treatment targeted at the mechanism. Acute stroke treatment aims to preserve the ischaemic penumbra, protect neurons against further ischaemia and enhance brain plasticity to maximise recovery. There is a strong evidence base supporting the routine use of aspirin, but not heparin, in acute ischaemic stroke. There is also convincing evidence supporting intravenous thrombolysis using recombinant tissue plasminogen activator in selected patients within 3 hours of stroke onset. Surprisingly, as many as 33% of suspected-stroke patients arrive in Accident & Emergency departments in the UK within 3 hours of onset. New techniques in MR imaging, particularly diffusion weighted imaging, are transforming the approach to diagnosis of acute stroke. Although neuroprotective drugs have proved disappointing, active neuroprotection in acute stroke should include control of blood pressure within certain limits, antipyretic therapy, maintenance of blood glucose, and early feeding and fluid replacement. Surgical hemicraniectomy should be considered in patients with malignant cerebral oedema. There is good evidence that the best way to enhance recovery from stroke is to admit the patient to a stroke unit. To enable patients to benefit from the early active approach outlined in the article, the following are needed: the development of acute stroke units; imaging protocols; and education of patients, general practitioners and the ambulance services. Stroke care has become a specialised field, requiring input from stroke physicians, as well as the multidisciplinary rehabilitation team. The British Association of Stroke Physicians (BASP) has therefore developed a curriculum which is designed to lead to the development of a new sub-specialty of stroke medicine.

Animals↗