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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using noninvasive (echoventriculometry (Echo-VM), REG and invasive (planimetric PEG, graphic recording of the CSF pressure) methods of examination, the authors determined the size of cerebral ventricles and the status of the cerebral hemo- and CSF dynamics in 606 patients with various chronic diseases of the brain (consequences of craniocerebral injury, epilepsy, discirculatory encephalopathy, etc.). According to PEG and Echo-VM findings, two groups of patients were distinguished. In moderate dilatation of cerebral ventricles the most significant finding was an increase in the pulse pressure of the CSF, whereas its mean pressure was normal or slightly elevated. In patients with pronounced hydrocephaly the pulse and mean pressure of the CSF tended to decrease. The progress of hydrocephaly was parallelled by increasing disorders of the cerebral hemodynamics expressed in hindered venous outflow from the cranial cavity and elevated peripheral vascular resistance. Four CSF-related syndromes have been identified (normotension, total CSF hypertension, intraventricular tension, total CSF hypotension) differing in their diagnostic and prognostic significance and in the pathogenesis of disorders of the hemo- and CSF dynamics.
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PMID:[Status of the ventricular system and dynamics of the cerebrospinal fluid changes in chronic brain diseases]. 325 71

Eight patients with subarachnoid and/or intraventricular haemorrhage underwent continuous extraventricular drainage and cerebrospinal fluid production was estimated by modified open drainage. The patients were in Hunt & Hess grades 2-5 on admission. Drainage was instituted within 24 h after the last bleeding episode in seven patients and the duration of drainage was 3-37 days. The median amount of CSF that was drained in 24 h was 210 ml. CSF production rate was 0.10-0.55 ml/min (median 0.28 ml/min) and there was a great variation within as well as between patients. Thus there was a trend towards a reduction in CSF production compared to reported normal values for CSF production. Three of six surviving patients required a shunt. The possible role of reduction in CSF production rate in the modification of intracranial hypertension and hydrocephalus after subarachnoid haemorrhage is discussed.
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PMID:Cerebrospinal fluid production in subarachnoid haemorrhage. 326 99

The acute administration of ANG II into the brain of experimental animals produces transient pressor effects, a marked increase in drinking, release of the antidiuretic hormone, increase in total peripheral resistance, a diuretic and natriuretic effect and an increase in sympathetic outflow. The chronic administration of ANG II into a cerebrolateral ventricle produces sustained pressor effects only if 0.9% sodium chloride solution is used as the drinking fluid. The hypertension is due to an increase in total peripheral resistance which appears to be due to an increase in intrinsic tone of vascular smooth muscle. In addition there was enhanced responsiveness of the vasculature to norepinephrine and ANG II and a decrease in reflex vasodilatation of the hind limb of ANG II treated dogs. The chronic elevation of ANG II in the CSF plus an increase in NaCl intake produces a low renin, sodium dependent, expanded volume hypertension. Data are presented suggesting that this model of hypertension is induced by the central release of an inhibitor of the Na+,K+-Pump.
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PMID:The central effects of the renin-angiotensin system. 328 Jan 70

Posthemorrhagic ventriculomegaly may be due to perinatal brain damage and consequent cerebral atrophy, or represent progressive hydrocephalus due to impairment of CSF flow and reabsorption. 'Arrested' hydrocephalus occurs when the CSF pathways are adequate and, hence, intracranial hypertension no longer exists. The differential diagnosis is often difficult and insidious progressive hydrocephalus should always be a concern in the high-risk preterm newborn. We report 10 preterm infants who were discharged with the diagnosis of arrested hydrocephalus (7) or cerebral atrophy (3), and who later developed progressive severe hydrocephalus 1.5-15 months after the discharge. Five had been treated with intermittent lumbar punctures, while 4 had not received any treatment prior to nursery discharge. One infant died prior to the shunt procedure. Progressive insidious hydrocephalus should be suspected in preterm infants with intracranial hemorrhage following discharge from the nursery.
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PMID:Insidious hydrocephalus in the preterm newborn following discharge from the nursery. 333 27

One hundred and fifty patients with intracranial aneurysms, operated on consecutively in the early stage in our department, were re-evaluated retrospectively. Seven surgeons operated on 159 aneurysms in 150 patients. Seventy-nine percent of the patients were in grades I-III (scale of Hunt and Hess), 21% in grades IV-V. Seventy-one percent had a severe haemorrhage (classification of Fisher et al.), 21% had an intracerebral haematoma. Intraoperative CSF drainage was an almost indispensable tool while postoperative external drainage did not prove to be helpful in preventing vasospasm and/or hydrocephalus. Induced hypotension was abandoned in favour of temporary clipping. Thirteen percent of the patients suffered a permanent or fatal immediate postoperative deterioration, while 11% developed delayed neurological deficits. Five percent were related to vasospasms alone, they were all transient. Five percent had vasospasm combined with other complications. One of them had permanent and the other one fatal deficits. One percent deteriorated due to embolism or occluded vessels. The results improved with the introduction of the calcium channel blocker nimodipine, induced hypertension and transcranial Doppler sonographic control of the vasospasm. Patients in good preoperative condition had a good early outcome in 69%. The result was fair in 21% and poor in 4%, while 6% of the patients died. In the poor condition group 22% of the patients made a good, 13% a fair, and 59% a poor recovery, 16% of whom died.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Early aneurysm surgery: a 7 year clinical practice report. 335 69

Role of the hypothalamic digitalis-like substance (EDLS) on the hypertension associated with an excess intake of sodium and the releasing mechanism were investigated. The blood pressure in rats fed with a sodium diet increased significantly after 4 weeks of the treatment compared to the control rats fed with a regular diet, which was accompanied by increased urinary output of the EDLS. Electrical lesions of the AV3V area in the hypothalamus significantly decreased both the urinary EDLS level and the blood pressure elevated by the sodium-loading. With the immunohistochemistry using digoxin antibody, the immunoreactives were localized in the neurons of paraventricular and supraoptic nuclei and some other hypothalamic areas, and were also seen in the nerve fibers distributed in the basal hypothalamus, infundibulum, and pituitary posterior lobe. Assuming that the CSF sodium is responsible for the release of EDLS, hypertonic NaCl (2.5 M) was infused into the lateral ventricle for 30 minutes. Blood pressure increased gradually, attaining peak rises about 30 minutes later. The plasma content of the EDLS was significantly greater in the hypertonic NaCl group than the control group treated with either the artificial CSF or 2.5 M of urea solution. On the other hand, the hypothalamic content decreased with the infusion of the hypertonic saline. Furthermore, the continuous intracerebroventricular infusions of the hypertonic NaCl with osmotic minipumps in conscious rats significantly increased the arterial pressure after 6 days. Thereby, the plasma level of the EDLS was significantly greater than the control rats that received only the artificial CSF.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hypothalamic digitalis-like substance is released with sodium-loading in rats. 340 53

In 1975, Flitter et al. proposed a Doppler technique for evaluating CSF shunt patency. Owing to the presence of many false positives, a new method of investigation is proposed in order to achieve more reliable results by using the Doppler technique after air has been injected into the shunt reservoir. Ninety patients with a CSF shunt were examined. Fifty cases were studied both immediately after surgery (7-10 days) and at a later date (more than 2 months from surgery) in order to obtain a control group. In a further 38 cases with signs of intracranial hypertension, it was possible, by means of the air test, to distinguish surgical and non-surgical cases. In 2 cases with clinical signs of hypotension, it was possible, by means of the test, to demonstrate the hyperfunctioning of the shunt. The "Flitter test" proved to be useful in the early post-operative period only.
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PMID:Evaluation of CSF shunt patency by continuous wave Doppler ultrasound technique. 345 66

The effect of a supratentorial expanding mass lesion and of uniform increase of ICP on regional cerebral blood flow was examined in 31 cats. The blood flow was measured using the radioactive microsphere technique and continuous ICP increase was produced by inflating an extradural balloon or by infusion of mock CSF into subarachnoid lumbar space. Four additional animals in whom no ICP rise was produced were used as controls; several blood flow measurements were performed at different ICP levels and after sudden ICP release. The analysis of the data obtained revealed that intracranial hypertension caused inhomogenous pattern of blood flow change with compartmentalization of flow between supra- and infratentorial structures connected with cisternal herniation. The flow decrease may correspond to the craniocaudal pressure gradients in the brain stem. Irrespective of the method used to produce intracranial hypertension the blood flow in the lower brain stem was less susceptible to diminished perfusion pressure. Sparing of cerebral blood flow in the lower brain stem during progressive brain compression can be explained by compartmentalization. The ranking of regions at cerebral perfusion pressure below 60 mm Hg was similar for the lower brain stem regions independently of the method which was used to increase the ICP. This suggests that when CBF becomes reduced due to increase of ICP the perfusion favours the areas where neurons related to control of circulation are located. Diffuse increase of ICP produced no interhemispheric differences in the blood flow. These differences were detected when balloon compression was used. Asymmetry of perfusion in the brain stem structures was not observed. During continuously increasing ICP an increase of blood pressure taking place before pupillary dilatation occurred was not caused by medullary ischaemia. If the pressure continued to increase the vasopressor response occurring after pupillary dilatation took place did not improve the cerebral blood flow. Increase of cerebral perfusion followed a sudden release of ICP. In an experimental animal subjected to unilateral compressive lesion producing tentorial herniation, hyperperfusion involved especially the thalamus and the midbrain with relative flow decrease in the lower brain stem.
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PMID:Blood flow in brain structures during increased ICP. 348 Nov 99

Contraindications to performing a lumbar puncture include local infection, intracranial hypertension and complete spinal block. Routine parameters include pressure, appearance, glucose, protein and cytology. Specific studies such as antigen-antibody tests may identify infectious agents. The color of the CSF may indicate infection, previous hemorrhage or, rarely, metastatic melanoma. The IgG-albumin index is useful when there is inflammation, as in multiple sclerosis.
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PMID:CSF evaluation in neurologic disease. 350 98

The author discusses the epidemiology, the diagnosis, the clinical and morphological aspects of cerebral vasospasm from his personal experience and a study of the literature. Prediction and diagnosis of vasospasm is possible by evaluation of the amount of blood on CT scan, measuring fibrin breakdown products in the CSF and the findings of early EEG and Transcranial Doppler Sonography. CBF measurement is helpful in following the process of ischemia and deciding the right moment for operation. Early surgery on cerebral aneurysms is advocated in order to prevent rebleeding and for early removal of blood clot from the basal cisterns. If vasospasm and ischemia do develop, energetic treatment with hypervolemia and induced hypertension can be started without fear of rebleeding. Prophylactic intravenous administration of Nimodipine is thought to be of real value. Since the introduction of early surgery by the author 80 patients have been operated within 3 days after S.A.H. The mortality was 11% and the morbidity 7.5%. Management mortality and morbidity for the total group of 209 patients with S.A.H. treated either medically or surgically were 23.5% and 6% respectively. If one excludes the 18 patients that died within 24 hours the mortality was 15.6%.
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PMID:[Vascular spasm and cerebral ischemia after meningeal hemorrhage caused by rupture of an aneurysm]. 351 64


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