Cerebrovascular diseases
-
Cerebrovascular diseases · Jan 2005
Ethical issues of informed consent in acute stroke. Analysis of the modalities of consent in 56 patients enrolled in urgent therapeutic trials.
Many patients may be mentally incompetent or physically unable to give informed consent at the acute stage of stroke. Accordingly, we aimed to investigate the modalities of informed consent in urgent therapeutic stroke trials, the awareness of patients and relatives regarding stroke clinical trials and the impact of decision making on patients and relatives. ⋯ Our study emphasizes the specific ethical difficulties of informed consent in the setting of acute stroke research. Only a minority of patients are able to give consent at the acute stage. Increasing age and neurological deficit are independent predictors of inability to give consent. Thus, the responsibility for consent usually relies on relatives with potential inaccuracy of decision concerning the patient's wish or even conflict of interest. Further evaluation of the psychological impact of decision on relatives is needed in this setting of acute stroke.
-
Cerebrovascular diseases · Jan 2005
Cognitive correlates of cerebral white matter lesions and water diffusion tensor parameters in community-dwelling older people.
The biological basis of cognitive ageing is unknown. One underlying process might be disruption of white matter tracts connecting cortical regions. White matter lesions (WML) seen on structural MRI may disrupt cortical connections, but diffusion tensor MRI (DT-MRI) parameters - mean diffusivity (
) and fractional anisotropy (FA) - may reflect more subtle changes in white matter integrity. Here the relationships between WML load, DT-MRI parameters and cognition in a large cohort of elderly subjects with a very narrow age range were investigated. ⋯ DT-MRI parameters, in particular , are sensitive to early ultrastructural changes underlying cognitive ageing. Executive function may be the cognitive domain most sensitive to age-related decline in white matter tract integrity. -
Cerebrovascular diseases · Jan 2005
Stroke units, tissue plasminogen activator, aspirin and neuroprotection: which stroke intervention could provide the greatest community benefit?
Although a number of acute stroke interventions are of proven efficacy, there is uncertainty about their community benefits. We aimed to assess this within a defined population. ⋯ Although tPA is the most potent intervention, management in stroke units has the greatest population benefit and should be a priority.
-
Cerebrovascular diseases · Jan 2005
Clinical TrialSuperficial temporal artery duplex ultrasonography for improved cerebral hemodynamics after extracranial-intracranial bypass surgery.
To investigate the utility of superficial temporal artery (STA) duplex ultrasonography (STDU) for evaluating the improvement of the cerebral hemodynamics after extracranial-intracranial (EC-IC) bypass. ⋯ STDU was available for evaluating postsurgical patency of the bypass flow and the rCBF of the ipsilateral MCA territory. The mean blood flow velocity of the operated STA is a highly sensitive parameter for predicting rCBF in the ipsilateral MCA territory after EC-IC bypass.
-
Cerebrovascular diseases · Jan 2005
ReviewSelecting patients for early stroke treatment with penumbra images.
Review of results of experimental and clinical studies indicates that the area of physiologically impaired, but potentially salvageable, tissue surrounding the central core of focal cerebral ischemia that develops shortly after onset of vessel occlusion is complex and dynamic with severity and duration thresholds for hypoxic stress and injury that are specific to tissue site, cell type, molecular pathway or gene expression investigated, and efficiency of collateral or residual flow and reperfusion. Identification of this ischemic penumbra in the acute stroke clinical setting is an important goal for stroke researchers and clinicians. Recent advances in neuroimaging allowed a better understanding of this physiopathological process. ⋯ A number of multicenter clinical trials are now under way to test these models and confirm the utility of penumbra imaging for treatment decisions. Present knowledge about visualization of the salvageable penumbra suggests a promising future in which penumbra imaging studies are performed routinely in the acute stroke setting and the data provided by these studies assist in individualizing therapeutic decisions and identifying effective therapies that can be delivered at late time points. So, the main target of management is 'penumbra', or salvageable tissue, which is primarily dependent upon the expediency of the whole process, better expressed by the phrase 'Penumbra (and not Time) is Brain'.