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Biomedical subjects

D Dunbabin

Publications and source records attributed to D Dunbabin.

6 recordsLinked to original sources
PubMed2001

Hormonal factors and risk of aneurysmal subarachnoid hemorrhage: an international population-based, case-control study.

BACKGROUND AND PURPOSE: Subarachnoid hemorrhage (SAH) is more common in women than in men, but the role of hormonal factors in its etiology remains uncertain. The aim of this study was to examine the relationship between hormonal factors and risk of SAH in women. METHODS: This was a prospective, multicenter, population-based, case-control study performed in 4 major urban centers in Australia and New Zealand. Two hundred sixty-eight female cases of first-ever aneurysmal SAH occurred during 1995-1998. Controls were 286 frequency-matched women from the general population of each center. Outcome measures included risk of SAH associated with use of oral contraceptive pills (OCPs), hormone replacement therapy (HRT), and various endogenous hormonal factors including menstrual patterns, parity, age at birth of first child, and breast-feeding practices. RESULTS: Cases and controls did not differ with regard to menstrual and reproductive history except in age at birth of first child, where older age was associated with reduced risk of SAH (odds ratio [OR], 0.63; 95% CI, 0.43, 0.91). Relative to never use of HRT, the adjusted OR for ever use of HRT was 0.64 (95% CI, 0.41, 0.98), which did not alter significantly after further adjustment for possible confounding factors. Borderline evidence of an inverse association was detected for past use of HRT (adjusted OR, 0.59; 95% CI, 0.30, 1.13) and current use of HRT (adjusted OR, 0.67; 95% CI, 0.40, 1.13), but there was no evidence of an association for use of OCPs (adjusted OR, 0.97; 95% CI, 0.58, 1.60). CONCLUSIONS: The risks of SAH are lower in women whose first pregnancy is at an older age and women who have ever used HRT but not OCPs. The findings suggest an independent etiologic role for hormonal factors in the pathogenesis of aneurysmal SAH and provide support for a protective role for HRT on risk of SAH in postmenopausal women.

Age Distribution↗
PubMed1999

Reperfusion therapy for stroke.

Stroke is a heterogeneous disease, but about 85% of strokes are as a result of cerebral ischaemia due to arterial occlusion. It seems logical to assume that, as in myocardial infarction, treatment designed to dissolve clots should be helpful. We now have a substantial amount of data on the use of aspirin, heparin and thrombolytic drugs in the treatment of acute ischaemic stroke. Aspirin 300 mg daily has a modest effect in reducing mortality and handicap when used within 48 hours of stroke onset. The beneficial effects of low dose, medium dose subcutaneous unfractionated heparin, and various low molecular weight heparins in reducing early recurrent ischaemic stroke seem to be outweighed by haemorrhagic side effects. Streptokinase used within six hours of stroke onset results in excess mortality with some reduction in handicap in survivors, while in carefully selected patients recombinant tissue plasminogen activator (r-TPA) may be less hazardous. At the moment it is unclear which stroke patients will benefit from the use of r-TPA, and the use of criteria, as outlined by the NINDS group, means that only a very small proportion of stroke victims are suitable for thrombolytic therapy. Further research is necessary, while the concept of a 'Brain Attack' with appropriate urgency being used in the assessment of possible stroke needs development.

Anticoagulants↗
PubMed1999

Effects of spontaneous recanalization on functional and electrophysiological recovery in acute ischemic stroke.

BACKGROUND AND PURPOSE: Transcranial Doppler ultrasound (TCD) studies have shown that spontaneous recanalization results in a better clinical improvement after the onset of stroke. However, its effect on electrophysiological recovery is still unknown. The aim of this study was to determine the effects of spontaneous recanalization on the change in central motor conduction time (CMCT) in acute ischemic stroke. METHODS: Seventeen healthy subjects and 38 consecutive patients with a first acute ischemic stroke involving the middle cerebral artery territory were included. TCD was used to detect spontaneous recanalization. Transcranial magnetic stimulation was used to determine the change in CMCT on days 1 and 14. Improvement of the CMCT at day 14 was indicated if it decreased in comparison with previous data recorded at day 1 or when a nonrecordable motor response at day 1 reappeared at day 14. No CMCT improvement was indicated when there was no recordable motor response at day 1 and day 14 or the CMCT at day 14 worsened, becoming absent or more delayed. The Pearson chi(2) test was used to assess the statistical significance of the results in this study. RESULTS: Spontaneous recanalization was observed in 62% of the patients: 24% before 24 hours and 38% after this period. No recanalization was observed in 14 patients. The CMCT improved in 87% of the patients who had recanalized before 24 hours and 62% in the recanalized after 24 hours group (P=0.005). In contrast, CMCT improved in only 17% of the patients in the non-recanalized group CONCLUSIONS: These data show that spontaneous recanalization results in a better recovery of the central motor pathway leading to a better CMCT improvement in acute ischemic stroke.

Adult↗
PubMed1999

Correlation between functional and electrophysiological recovery in acute ischemic stroke.

BACKGROUND AND PURPOSE: There is still controversy about the prognostic value of motor evoked potentials (MEPs) in the assessment of hemiplegia. The aims of this study are to determine the relationship between functional and electrophysiological recovery and thus the value of MEP as a prognostic indicator of clinical outcome in acute ischemic stroke. METHODS: Seventeen healthy subjects and 38 stroke patients were included in this study. Functional recovery was assessed with the Modified Canadian Neurological Scale (MCNS), the Barthel Activities of Daily Living Index (BI), and the Rankin scale. Transcranial magnetic stimulation was used to determine the change in central motor conduction time (CMCT). Stroke outcome was assessed at the end of 2 weeks. One-way ANOVA with post hoc comparisons using the Scheffé procedure as well as t tests were used to assess the significance of the results in this study. RESULTS: Unpaired t test showed significantly higher mean scores of the MCNS (2P=0.001), BI (2P=0.002), and Rankin scale (P<0.001) at day 14 in the group of patients with recordable MEP at day 1. A better clinical improvement with a higher mean score of the MCNS (2P<0.001), BI (2P<0.001), and the Rankin scale (2P<0.001) was also observed in the patients in whom the CMCT improved. CONCLUSIONS: These data show that there is a close relationship between clinical and electrophysiological improvement and that MEP is a useful prognostic indicator of clinical outcome.

Adult↗
PubMed1992

Cost-effective intervention in stroke.

A rigorous assessment of current practice in all branches of medicine is necessary to ensure that we are minimising the costs and maximising the effectiveness of management and treatment. This is especially important in cerebrovascular disease which imposes a large burden of death; it is the third commonest cause of death after cancer and heart disease in most developed countries, and the commonest cause of long term disability on society. Stroke consumes up to 5% of healthcare expenditure in developed countries, and costs can be expected to remain static or increase with an increase in the proportion of elderly (who are at high risk of stroke) in the community over coming decades. This article reviews the epidemiology of stroke (risk factors, incidence, prevalence and the burden of disability and handicap), the various studies dealing with the community and individual costs of stroke, and the cost-effectiveness of interventions to prevent stroke such as control of hypertension, reduction in cigarette intake, encouragement of a healthy lifestyle, antiplatelet or anticoagulant therapy, and carotid endarterectomy. Acute treatment of stroke remains an area of major potential therapeutic benefit, but no widely applicable therapy currently exists, although many treatments are being investigated. Rehabilitation after stroke is costly, but may result in significant reduction in disability and handicap with reduced need for long term institutional care. The clinical implications of these studies and the potential for future research are also discussed.

Aged↗