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Biomedical subjects

C Warlow

Publications and source records attributed to C Warlow.

15 recordsLinked to original sources
PubMed1992

Atrial fibrillation and stroke: prevalence in different types of stroke and influence on early and long term prognosis (Oxfordshire community stroke project)

OBJECTIVE: To determine in patients with first ever stroke whether atrial fibrillation influences clinical features, the need to perform computed tomography, and prognosis. DESIGN: Observational cohort study with maximum follow up of 6.5 years. SETTING: Primary care, based on 10 general practices in urban and rural Oxfordshire. SUBJECTS: Consecutive series of 675 patients with first ever stroke registered in the Oxfordshire community stroke project. MAIN OUTCOME MEASURES: Prevalence of atrial fibrillation by type of stroke; effect of atrial fibrillation on case fatality rate and risk of recurrent stroke, vascular death, and death from all causes. RESULTS: Prevalence of atrial fibrillation was 17% (95% confidence interval 14% to 20%) for all stroke types (115/675), 18% (15% to 21%) for cerebral infarction (97/545), 11% (4% to 11%) for primary intercerebral haemorrhage (7/66), and 0% (0 to 11%) for subarachnoid haemorrhage (0/33). For patients with cerebral infarction the 30 day case fatality rate was significantly higher with atrial fibrillation (23%) than with sinus rhythm (8%); the risk of early recurrent stroke (within 30 days) was 1% with atrial fibrillation and 4% with sinus rhythm. In patients who survived at least 30 days the average annual risk of recurrent stroke was 8.2% (5.9% to 10.9%) with sinus rhythm and 11% (6.0% to 17.3%) with atrial fibrillation. CONCLUSIONS: After a first stroke atrial fibrillation was not associated with a definite excess risk of recurrent stroke, either within 30 days or within the first few years. Survivors with and without atrial fibrillation had a clinically important absolute risk of further serious vascular events.

Aged↗
PubMed1992

Diurnal variation in incidence of stroke: Oxfordshire community stroke project.

OBJECTIVE: To determine whether diurnal variation occurs in the onset of stroke. DESIGN: Community based study over four years. SETTING: Oxfordshire, United Kingdom. SUBJECTS: 105,000 people, of whom 675 had a first ever stroke. 545 had a cerebral infarction, 66 had primary intracerebral haemorrhage, 33 had subarachnoid haemorrhage, and in 31 the type of stroke was not known. MAIN OUTCOME MEASURES: Time of stroke and degree of activity at onset. RESULTS: In the 578 patients for whom it was known whether onset occurred while asleep or awake, the proportion with onset during sleep was 25% (135/545) for cerebral infarction, 17% (11/66) for primary intracerebral haemorrhage, and 0% (0/33) for subarachnoid haemorrhage. This difference persisted if patients in whom it was not known whether they were asleep or awake at onset were classed as asleep. For all stroke types together there was a significant (chi 2 = 218.7, p less than 0.001) diurnal variation with a morning peak between 0800 and 1000, which persisted even after allowing for strokes first noted on waking by redistributing the hour of onset through the preceding eight hours (chi 2 = 47, p less than 0.001). A significant diurnal variation was also found in the onset of cerebral infarction (peak 0800-1000, chi 2 = 208.4, p less than 0.001). Fewer patients had other forms of stroke and the diurnal variations for primary intracerebral haemorrhage (peak 1000-1200) and subarachnoid haemorrhage (peaks 0800-1000 and 1800-2000) were not significant. There seemed to be a second smaller peak for all types of stroke. CONCLUSIONS: All types of stroke are most likely to occur after waking in the morning. The cause of the circadian variation requires further study.

Cerebral Hemorrhage↗
PubMed1992

Migraine aura without headache: transient ischaemic attack or not?

Patients with "migraine aura without headache" can be separated from those with transient ischaemic attacks (TIA) on the basis of the onset of symptoms, which is generally gradual and which spread or intensify over minutes or hours, and from the typical migrainous nature of their visual symptoms. Fifty cases were prospectively identified and these were compared with 50 age matched patients with a TIA. Surprisingly, there were no significant differences in the prevalence of vascular risk factors and diseases in the two groups although those with TIAs tended to have more. Only one patient with "migraine aura without headache" suffered a subsequent vascular event (a myocardial infarction). Three patients with TIAs had strokes and two others died from vascular disease. Although the results are not conclusive, they do suggest that patients with the clinical characteristics of "migraine aura without headache" have a low risk of subsequent vascular events, lower than those with TIAs, despite perhaps having similar prevalence of vascular risk factors. Although their risk factors should be treated, patients with "migraine aura without headache" should be reassured and not subjected to inappropriate and potentially hazardous investigations and treatment.

Adult↗
PubMed1991

Classification and natural history of clinically identifiable subtypes of cerebral infarction.

We describe the incidence and natural history of four clinically identifiable subgroups of cerebral infarction in a community-based study of 675 patients with first-ever stroke. Of 543 patients with a cerebral infarct, 92 (17%) had large anterior circulation infarcts with both cortical and subcortical involvement (total anterior circulation infarcts, TACI); 185 (34%) had more restricted and predominantly cortical infarcts (partial anterior circulation infarcts, PACI); 129 (24%) had infarcts clearly associated with the vertebrobasilar arterial territory (posterior circulation infarcts, POCI); and 137 (25%) had infarcts confined to the territory of the deep perforating arteries (lacunar infarcts, LACI). There were striking differences in natural history between the groups. The TACI group had a negligible chance of good functional outcome and mortality was high. More than twice as many deaths were due to the complications of immobility than to direct neurological sequelae of the infarct. Patients in the PACI group were much more likely to have an early recurrent stroke than were patients in other groups. Those in the POCI group were at greater risk of a recurrent stroke later in the first year after the index event but had the best chance of a good functional outcome. Despite the small anatomical size of the infarcts in the LACI group, many patients remained substantially handicapped. The findings have important implications for the planning of stroke treatment trials and suggest that various therapies could be directed specifically at the subgroups.

Age Factors↗
PubMed1991

The United Kingdom transient ischaemic attack (UK-TIA) aspirin trial: final results.

From 1979-85, 2435 patients with a transient ischaemic attack or minor ischaemic stroke were randomly allocated to receive long term "blind" treatment with aspirin 600 mg twice daily (n = 815), aspirin 300 mg once daily (n = 806) or placebo (n = 814). No patient was lost to follow up. The "intention to treat" comparison included all the serious vascular events and deaths which occurred before the end of the follow up period on 30 September 1986. There was no difference in efficacy between the 300 mg and 1200 mg daily doses of aspirin, but the lower dose was undoubtedly less gastrotoxic. Also, there was no definite difference in the response of males and females to aspirin. The odds of suffering a major stroke, myocardial infarction or vascular death were 15% less in the combined aspirin groups compared with the placebo group (95% confidence interval 29% reduction to 3% increase in odds) which is compatible with the continuing overview of all the similar trials of antiplatelet drugs where the relative reduction in odds was 25%. There was no statistically significant reduction in the likelihood of either disabling major stroke and vascular death or vascular death occurring.

Aged↗
PubMed1978

Peripheral neuropathy and solitary plasmacytoma.

Three patients with peripheral neuropathy and a solitary plasmacytoma are presented, and the literature is reviewed. It is suggested that middle-aged men with an obscure progressive sensorimotor neuropathy, a raised CSF protein, and otherwise negative investigations should have a full skeletal survey since irradiation of a plasmacytoma may lead to a considerable improvement in the associated neurological disability.

Adult↗
PubMed1976

Deep venous thrombosis of the legs after strokes. Part I--incidence and predisposing factors.

Forty out of 76 patients (53%) who had suffered a cerebrovascular accident developed deep venous thrombosis of the paralysed leg, as detected with the 125I-fibrinogen technique. A further five also had thrombosis in the non-paralysed leg. A study of many predisposing risk factors provided no help either in elucidating the cause of venous thromboembolism or in identifying patients at risk of DVT as a complication of cerebrovascular accidents.

Age Factors↗
PubMed1976

Deep venous thrombosis of the legs after strokes: Part 2-Natural history.

Seven out of 76 patients who had sustained a cerebrovascular accident suffered a pulmonary embolism as diagnosed at necropsy or by unequivocal antemortem criteria. A further five patients had probable embolisation diagnosed only by clinical and chest x-ray criteria. Eleven of these 12 patients had DVT as diagnosed by the 125I-fibrinogen technique. Though 125I-fibrinogen technique has its limitations, thrombosis seemed to be able to develop at several independent sites in the venous system of the leg.

Aged↗
PubMed1976

Platelet function after the administration of chlorpromazine to human subjects.

Chlorpromazine is known to inhibit platelet function in vitro. The intramuscular injection of 50 mg to human volunteers caused only minor changes in platelet function. There was a small, but significant, reduction in the platelet count, the second phase of the double-wave of adenosine diphosphate-induced aggregation and the rate of 5-hydroxytryptamine-induced aggregation. Patients on high doses of chlorpromazine had no demonstrable abnormality of platelet function. This suggests that chlorpromazine, despite its inhibitory effect on platelet function in vitro, is unlikely to interfere with either haemostasis or thrombogenesis after its administration to man.

Blood Cell Count↗
PubMed1975

Fibrinolytic capacity of arm and leg veins after femoral shaft fracture and acute myocardial infarction.

The local fibrinolytic activity generated in the leg and arm veins during venous occlusion (fibrinolytic capacity) and the systemic fibrinolytic activity were measured at intervals in 11 patients after fracture of the femoral shaft and in 11 patients after acute myocardial infarction. In both groups the fibrinolytic capacity of the leg veins and the systemic fibrinolytic activity were significantly reduced two days after the onset of tissue injury. The fibrinolytic capacity of the arm veins was not altered. These results provide a possible explanation for the predilection of venous thrombosis for the leg veins after accidental trauma and acute myocardial infarction.

Adolescent↗