Search results for "Cerebral Arteries"
showing 10 items of 67 documents
Transcranial Doppler diagnosis of cerebral vasospasm following subarachnoid haemorrhage: correlation and analysis of results in relation to the age o…
1994
A retrospective analysis was undertaken to determine whether cerebral vasospasm following subarachnoid haemorrhage (SAH) correlates with the age of patients. For at least 3 weeks after bleeding 80 subjects underwent very close follow-up with clinical examination and transcranial Doppler records of the blood velocities within the basal cerebral arteries. Firstly a correlation between measured maximal mean blood flow velocities and age was made. Secondly, according to their age and the maximum of recorded mean velocities (v), the patients were divided into groups as follows: age 55 years or less, age more than 55 years; and maximum velocity v190 cm/s, 90 cm/sv2120 cm/s, 120 cm/sv3160 cm/s, v4…
Endothelium-independent contractions of human cerebral arteries in response to vasopressin.
1990
We studied the effects of vasopressin in isolated segments from branches (500-700 micrograms in external diameter) of human middle cerebral arteries obtained during autopsy of 15 patients who had died 3-8 hours before. Paired segments, one normal and the other de-endothelized by gentle rubbing, were mounted for isometric recording of tension in organ baths. In 11 normal segments, vasopressin produced concentration-dependent contractions with an EC50 of 7.0 X 10(-10) M. Removal of the endothelium from 12 segments did not significantly affect vasopressin-induced contractions. Vasopressin produced further contractions in arterial segments with (n = 4) or without (n = 5) endothelium precontract…
Role of endothelium and calcium channels in endothelin-induced contraction of human cerebral arteries
1990
Endothelin constricted human isolated cerebral arteries in a concentration-dependent manner. The maximal tension developed, as well as EC50 values were similar in arteries with and without endothelium. Removal of extracellular calcium or addition of the calcium antagonist nicardipine (10(-6)M), attenuated but did not abolish responses to endothelin. These experiments show that the endothelin-induced contraction in human cerebral arteries is not linked to the presence of intact endothelial cells. The data also show that the contractile effects of endothelin cannot be explained solely by an action on voltage-dependent calcium channels.
A multidisciplinary approach to assess recovery of consciousness in a patient with moyamoya disease
2019
Abstract Introduction Moyamoya disease (MMD) meaning “hazy puff of smoke” in Japanese is a rare chronic cerebrovascular syndrome characterized by progressive stenosis and occlusion of the internal carotid arteries (ICAs) anterior cerebral arteries (ACAs), and middle cerebral arteries (MCAs). Methods Our moyamoya patient with severely impaired cognitive and motor functions underwent a specific motor and neuropsychological rehabilitative treatments to assess the recovery of consciousness. Results Results obtained showed an improvement of clinical and neuropsychological examination. These findings highlighted the importance of an intensive rehabilitation techniques used in the care of disorder…
Intra- and extracerebral blood flow changes and flushing after intravenous injection of human corticotropin-releasing hormone
1994
To study facial flush after systemic administration of human corticotropin-releasing hormone (hCRH) we injected 100 micrograms hCRH intravenously to ten healthy young men. The increase in facial temperature was measured by infrared camera. A significant increase in facial temperature of 1.39 degrees C +/- 0.3 was found within 7 min in all patients, which lasted up to 60 min, although facial flushing was visible in only 50% (5/10) of the probands. In a second experiment 100 micrograms hCRH was then administered to seven other healthy young men. Intra- and extracerebral blood flow velocity changes in the medial cerebral artery (MCA) and external carotid artery (ECA) were measured after hCRH a…
Water Jet Dissection in Neurosurgery: An Update After 208 Procedures With Special Reference to Surgical Technique and Complications
2010
Background Water jet dissection represents a promising technique for precise brain tissue dissection with preservation of blood vessels. In the past, the water jet dissector has been used for various pathologies. A detailed report of the surgical technique is lacking. Objective The authors present their results after 208 procedures with a special focus on surgical technique, intraoperative suitability, advantages, and disadvantages. Methods Between March 1997 and April 2009, 208 patients with various intracranial neurosurgical pathologies were operated on with the water jet dissector. Handling of the device and its usefulness and extent of application were assessed. The pressures encountere…
Surgically verified variations in the A1 segment of the anterior cerebral artery
1991
✓ Two patients with rare variations of the A1 segment of the anterior cerebral artery are presented. One patient had a perforation of the optic tract by an abnormal course of the A1 segment, and the other harbored an aneurysm of the A1 segment running below the optic nerve. The authors present a summary of A1 segment variations described in the literature.
Evaluation of collateral flow capacity in patients with vascular or tumorous lesions of the skull base by Doppler sonography
1991
In 12 patients with vascular or tumorous lesions of the skull base, the collateral flow capacity was examined by transcranial Doppler sonography and carotid compression studies. In four patients no cross flow mechanism was found, in two patients the test remained unclear, and in six patients the examination suggested a good collateral flow capacity. However, for this application of Doppler sonography no borderlines have yet been defined and thus interpretation is difficult. Intraoperative Doppler sonography was used in five patients and proved to be helpful for localisation of the internal carotid artery within skull base tumors.
CT-guided stereotactic biopsy aided by Doppler ultrasonic vascular monitoring
1992
The use of a 20 MHz pulsed Doppler technique during stereotactic brain tumour biopsies is described. By means of a miniaturized ultrasonic probe the tissue planned for biopsy was investigated for vessel signals. Out of 41 patients, with this technique a flow-pulse curve in front of the biopsy cannula was registered in 14 cases. In 9 cases one pulse curve was determined and in 5 cases two or more flow curves were found, indicating the presence of arterial vessels. The depth of the vessels signal could be localized and this area avoided for biopsy sampling. In a series of 41 stereotactic biopsies carried out in this way there was no intra-operative haemorrhage or postoperative haematoma.
Endovascular therapy for vasospasm after aneurysmatic subarachnoid hemorrhage
2016
Balloon angioplasty and/or selective intra-arterial vasodilator therapies are treatment options in patients with vasospasm after subarachnoid hemorrhage (SAH). We analyzed the effect of balloon angioplasty and/or selective intra-arterial vasodilator therapy in our patients.Twenty-six patients (vasodilation group, VDT) were treated with intra-arterial nimodipine. The balloon angioplasty with nimodiopine-group (BAP-N group) comprised 21 patients. The primary endpoint of this study was successful angiographic vessel dilation in vasospastic vessels after balloon angioplasty, together with nimodipine (BAP-N group), compared to intra-arterial vasodilator therapy (VDT group) with nimodipine alone.…