Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Maintenance of cerebral perfusion pressure is a prerequisite for the prevention of cerebral ischemia. Physiological fluctuations in systemic perfusion pressure are compensated by cerebrovascular autoregulation. Cerebral hypoperfusion could result from (1) systemic hemodynamic failure (eg, distal to severe arterial stenosis), overcharging the vasoregulatory capacity; (2) dysfunction and exhaustion of cerebrovascular autoregulation; or (3) both. Ultrasound offers an excellent temporal resolution, is noninvasive, and is easily applicable for follow-up investigations. Despite its poor spatial resolution, transcranial Doppler sonography has been used for determination of cerebral perfusion reserve studies measuring cerebral blood flow velocity (CBFV) during hypercapnia or application of vasoactive agents (eg, acetazolamide). This approach evaluates vasomotor regulation in patients with hemodynamic compromise distal to severe stenosis or occlusion of the brain supplying arteries. Monitoring CBFV during tilt table examinations directly measures cerebral autoregulation. In patients with systemic orthostatic hypotension, maintainance or failure of cerebrovascular compensation and, even more importantly, cerebrovascular dysautoregulation, despite normal systemic blood pressure regulation, may be demonstrated. Vasoneuronal coupling is reflected by CBFV variations during appropriate neuronal stimulation. Neuronal dysfunction is associated with CBFV abnormalities as exemplified by preconditions of focal cerebral dysfunction in the posterior cerebral artery (PCA) in migraineurs with aura, where massive alteration of vasoneuronal coupling and ischemia is threatening during spreading depression. A highly significant asymmetric gain of vasoneuronal coupling in the interictal state may act as a trigger mechanism in these patients. Testing for vasoneuronal coupling within the middle cerebral artery (MCA) territory is more difficult due to the poor spatial resolution with various neuronal stimuli (eg, motorsensory or cognitive paradigms), only eliciting local neuronal areas underrepresented in the MCA CBFV global changes. However, motor stimulation evoked CBFV may be used to indicate dysintegration of vasoneuronal coupling in the course of acute cerebral ischemia with sensorimotor hemiparesis and, moreover, seems to be of prognostic value regarding the motor deficit.
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PMID:Cerebrovascular regulation and vasoneuronal coupling. 769

This initial study examines cognitive function in individuals with asymptomatic orthostatic hypotension. Cerebral hypoperfusion accompanying repeated episodes of orthostatic hypotension may eventually produce some cerebral structural deterioration which, depending on foci, could compromise cognitive function. Subjects (aged 55 to 74 years) were relatively healthy women and men, the majority of whom were being treated for non-insulin-dependent diabetes mellitus. Blood pressure (BP) and pulse were measured under supine and upright posture. The difference between BP and pulse under supine and standing conditions indexed orthostatic hypotension. About 1 hr after evaluation of orthostatic hypotension, cognitive testing was performed with individuals comfortably seated. Results showed that, irrespective of possible confounders, including depression, decreased systolic BP in response to upright posture predicted slower reaction times and compromised serial list learning, although sparing immediate and working memory. Orthostatic hypotension, measurable in more than 4% of the elderly, is a hitherto unexplored source of cognitive decline.
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PMID:Do you mind standing?: cognitive changes in orthostasis. 896 6

Decreased cerebral blood flow is documented in depression. In this study, 15 patients were studied with 99mTc-HMPAO SPECT before and after a course of electroconvulsive therapy (ECT). Improvement in frontal and temporal hypoperfusion was seen only in those patients who responded to ECT. Cerebral hypoperfusion may be a state-dependent marker in depressive illness.
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PMID:Effects of electroconvulsive therapy on regional cerebral blood flow measured by 99mtechnetium HMPAO SPECT. 1255 21

With the increase in the aging population, it is important to understand the individual diseases and their interactions which are prevalent and have a great impact on the health status of the elderly. Hypertension is one of the most common diseases in older age and may impact the health status because it is the main risk factor for cardiovascular and cerebrovascular diseases such as heart failure and stroke. Recently, much evidence has been accumulated showing that hypertension plays an important role in the development and progression of cognitive impairment and dementia. Cerebral hypoperfusion secondary to severe atherosclerosis resulting from long-standing hypertension may be a major biological pathway linking high blood pressure (BP) to cognitive decline and dementia. Furthermore, increased BP variability has also been reported to be significantly associated with white matter hyperintensities and brain atrophy, which are predisposing conditions of dementia, depression, and falls in the elderly even after adjusting for BP levels and other confounding variables. Several mechanisms have been shown to be involved in the association between BP variability and cognitive impairment in elderly individuals. In addition to an increased cerebral blood flow fluctuation, neurohumoral activation, endothelial dysfunction, inflammation, and oxidative stress have been suggested to be the underlying mechanisms. However, clinical trials provide limited evidence for a protective effect of antihypertensive therapy against dementia and stroke-related cognitive decline. In this article, we aimed to review the existing evidence of the connection between BP variability and cognitive impairment in elderly people.
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PMID:Blood Pressure Variability and Cognitive Function in the Elderly. 2658 26