Cerebral blood flow in low pressure hydrocephalus.
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Cerebrospinal Fluid Shunts↗
Biomedical subjects
A Brawanski
Publications and source records attributed to A Brawanski.
[Effect of the Ca antagonist nimodipine on global and regional cerebrovascular circulation].
The effects of Nimodipine on the global and regional cerebral blood flow were studied in 42 patients with cerebrovascular disorders. In 25 patients with focal deficits such as transitory ischemic attack (TIA), prolonged reversible ischemic neurological deficit (PRIND), and minor stroke due to arteriosclerosis, and in eleven patients with cerebral vasospasm after subarachnoid hemorrhage, the cerebral blood flow was measured by 133Xenon inhalation technique 60 min after oral administration of 40, 60, or 80 mg Nimodipine. In 6 patients with vasospasm the effects of Nimodipine i.v. were examined. The result in twelve patients with minor stroke who were only given placebo (lactose; "test-retest") was identical regional (rCBF) and global (CBF) cerebral blood flow before and 60 min after; placebo, blood pressure, and arterial pCO2 remained constant as well. After Nimodipine, however, the CBF increases, the increase after vasospasm being significant when taking the pCO2 in the Wilcoxon test into account. The rCBF increases much more in the regions with low perfusion rates than in well-perfused areas. This is also observed in the patients with TIA, PRIND, or minor stroke, most clearly after oral administration of 60 mg, whereas regions with normal perfusion rates show little reaction. The blood pressure was lowered, depending on the initial pressure. There was no evidence of a steal phenomenon.
Adult↗
Increased ICP without ventriculomegaly. Diagnostic and therapeutic problems in a 1-year-old boy.
The case of a 1-year-old boy with pseudotumor cerebri is reported. After the diagnosis had been made, an epidural pressure transducer was implanted. Correlation calculation of the pulse amplitudes and the systolic ICP and Fourier analysis of the ICP modulations were performed. The ICP data reached values up to 50 mmHg and the mathematical calculations provided information on the reduced intracranial compliance. After the implantation of a ventriculoperitoneal shunt, all parameters normalized.
Cerebral Ventriculography↗
Acute effects of nimodipine on the cerebral blood flow and intracranial pressure.
The effects of nimodipine, a calcium antagonist with preferential cerebrovascular activity, on the global and regional cerebral blood flow (CBF and rCBF), the intracranial pressure (ICP), and the cerebral perfusion pressure (CPP), were investigated in an acute study. The rCBF of 54 patients was measured by the Xe133 inhalation method under identical conditions before and 60 min after oral administration of nimodipine. 12 patients with focal cerebral circulation disturbances of arteriosclerotic origin, who had suffered a cerebral accident (TIA, PRIND, minor stroke) no more than 3 weeks previously, were given a placebo (test-retest controls) and 25 patients of the same diagnosis and age group were given 40-80 mg nimodipine orally. 11 patients with acute subarachnoid hemorrhage (SAH) from ruptured anterior communicating artery aneurysms and clinical and angiographic signs of vasospasm (Hunt- and Hess grade 3) were likewise treated with nimodipine by the oral route. 6 patients with cerebral vasospasm received nimodipine in i.v. doses of 0.5-2 mg/h. The cerebral blood flow, assessed on the basis of the initial slope index (ISI), before and after the medication, was compared by statistical methods. 12 patients with head injury were given nimodipine intravenously in a dose of 0.5-2 mg with continuous monitoring of the ICP and the blood pressure. The pressure values were evaluated continuously by computer, with calculation of the perfusion pressure, and tested for statistical significance. Oral nimodipine therapy resulted in a significant (14%) increased of the CBF (taking account of the arterial pCO2), the improvement of blood flow being even more pronounced in the hypoperfused regions.(ABSTRACT TRUNCATED AT 250 WORDS)
Acute Disease↗
Atraumatic rCBF measurement: an aid in the timing of surgery and the management of spasm following SAH.
We tested the ability of a non-invasive regional cerebral blood flow (rCBF) measurement to show vasospasm. The correlations between the flow values, the clinical condition, the CT scan and angiography were also studied. During none of the measurements were there any negative side effects on the patients. A bad clinical condition was usually accompanied by low flow data during the rCBF investigation. In accordance with local clinical signs (e.g., hemiparesis) we observed corresponding local hypoperfusion. These results were also confirmed by several follow-up studies in which good correlations between the rCBF findings, the angiography and the CT scan were found. As the rCBF investigation can be repeated within a very short time, we used this method for the testing of vasoactive drugs. Nimodipine (Bayer) showed promising results which suggest further clinical investigations. The main problem connected with the rCBF measurement is the limited ability of the patient to cooperate. For the detection of vasospasm the low resolution both in localisation and depth of this method is of only minor importance. We partly overcame this disadvantage by developing a special respirator enabling us to investigate artificially ventilated patients. We think that the measurement of rCBF is an important aid for the timing of the operation.
Cerebral Angiography↗
The quality of functional MR images in patients with brain tumors: influences of neurological disorders and tumor location.
The aim of our study was to investigate the influence of neurological disorders, and the influence of tumor and perifocal edema location on functional magnetic resonance imaging (fMRI) quality. fMRI quality tended to be better the closer the tumor and the perifocal edema were located to the pmc. Hemipareses and seizures had no significant influence on fMRI quality. Therefore, hemiparetic patients do not have to be excluded beforehand. The evaluation of time courses is essential before using z-maps to localize eloquent brain regions preoperatively.
Adult↗