Reduced risk of ICA ligation after balloon occlusion test

Correlation of cerebral blood flow and MCA flow velocity measured in healthy volunteers during acetazolamide and CO2 stimulation

Abstract The assessment of the cerebrovascular reserve capacity (RC) has become a widely used tool in the management of cerebrovascular disease. Discrepancies become obvious, however, if results obtained with different methods are compared. Aim of the present study, therefore, was to compare blood velocity and cerebral perfusion data in the same group of healthy test persons. In 32 volunteers regional cerebral blood flow (rCBF) was measured with the 133 Xe-inhalation method. F1 as grey matter flow and the initial slope index (ISI) were computed. Simultaneously flow velocity in the middle cerebral artery (V MCA ) was assessed by transcranial Doppler sonography (TCD). Measurements were perfor…

Transcranial Doppler diagnosis of cerebral vasospasm following subarachnoid haemorrhage: correlation and analysis of results in relation to the age of patients.

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…

Cerebral blood flow autoregulation during hypobaric hypotension assessed by laser Doppler scanning.

Hypobaric hypotension was used to reduce systemic blood pressure in rats below the lower threshold of CBF autoregulation to evaluate a new laser Doppler (LD) “scanning” technique. Spontaneously breathing male Wistar Kyoto rats (n = 8) were anesthetized with chloral hydrate and the head fixed in a stereotaxic head holder. A cranial window with intact dura mater was introduced to assess local CBF (lCBF) by LD. One stationary probe served to detect rapid flow changes, whereas the second probe was used to sample lCBF recordings from many cortical locations by means of a stepping motor-controlled micromanipulator to obtain lCBF frequency histograms. Advantages are an improved spatial resolution…

nrCBF and EEG Monitoring During Probatory Balloon Occlusion of the Internal Carotid Artery

Surgical treatment of tumors in the neck and throat rounding the carotid artery or of giant aneurysms originating from this vessel often makes ligation or resection of the internal carotid artery necessary. This procedure carries a 15%–30% morbidity from cerebral ischemia according to the literature (2, 7).

Tissue elastance and fluid conduction in normotensive and hypertensive intracerebral mass haematomas.

This is an investigation into the prognostic factors of 117 patients with spontaneous normo- and hypertensive intracerebral haematomas, supported by animal experiments. Preserved tissue elastance and fluid conduction enables the drainage of intrinsic haematoma serum into the CSF spaces in normotensive patients, who showed an increased extension of a perifocal hypodensity in the CT. Arterial hypertension decreased the possibility of fluid resolution. Our experimental studies showed that in hypertensive cases the serum remained trapped in the haematoma, which explains the small hypodense area around the haematoma in most of the hypertensive cases. If as an exception in hypertensives of perifo…

Pre- and intraoperative methods of controlling cerebral circulation in giant aneurysm surgery.

The surgical treatment of giant aneurysms usually requires temporary clipping of the aneurysmatic vessel. In planning the surgical approach and in applying temporary clips, the surgeon must consider collateral circulations. The functional integrity of the collateral vessels frequently decides the patient's outcome. In 8 patients with internal carotid artery giant aneurysm, measurements of blood flow velocities in the ipsilateral middle cerebral artery were performed preoperatively with transcranial Doppler ultrasound (TCD) during manual occlusion of the carotid artery at the neck. Three different perfusion patterns were established, and each collateral capacity was rated as insufficient, te…

Risk and Benefit of STA/MCA Anastomoses

The advantage of EC/IC operation has not yet been proved unequivocally enough. We therefore attempted to analyze our cases in order to establish the possible benefit and risk of the operation. We compared the outcome of the operated and nonoperated patients with reference to the literature.

Aneurysm surgery of patients in poor grade condition. Indications and experience

Out of a total of 196 patients admitted with aneurysmal subarachnoid haemorrhage (SAH) to the neurological department in Mainz over a 42 month period, 48 patients (24.5%) were considered as grade IV or V on admission. Aneurysm surgery within 48 hours after SAH was performed in 56.3% of these patients, 2% were operated between day 3 and 7 and 16.6% were operated after day 7. 25% did not undergo operation because of severe neurological deficit and brain damage. The overall outcome according to the Glasgow outcome scale in the surgically treated group was full recovery in 11.1%, moderate disability in 16.7%, severe disability in 47.2%, vegetative state in 2.8% and death in 22.2%. All patients …

Significance of resting and stimulated cerebral blood flow for predicting the risk of hemodynamic cerebral ischemia in a model of chronic hemodynamic insufficiency.

OBJECTIVE: It has been postulated that patients with a compromised cerebrovascular reserve capacity (RC), defined as cerebral blood flow (CBF) response to acetazolamide (ACZ) (by percent), are at higher risk for ischemic stroke. The value of CBF and RC for predicting the risk of hemodynamically induced impairment of cerebral function is examined. METHODS: Both common carotid arteries were occluded in 22 Wistar-Kyoto rats. Thirty-one days later, mean arterial blood pressure was reduced to 40 mm Hg for 30 minutes. Laser Doppler scanning of CBF at resting conditions and after intraperitoneal administration of ACZ (0.1 mg/g body weight) was performed 30 minutes and 28 days after occlusion as we…

Cerebral blood flow in autogenic training and hypnosis.

In 12 healthy volunteers with at least an experience of six months in autogenic training (AT), the cerebral blood flow (CBF) was measured at rest, in AT and in hypnosis (H). The results were correlated with individual test profiles. The cortical flow pattern at rest of our AT trained volunteers did not show the hyperfrontality which is described in the literature. This may be interpreted as an effect of better and habitualized relaxation in long trained AT practitioners. This flow pattern corresponds to the low grades of neuroticism and aggressivity found in the tests. Furthermore an activation in central cortical areas and a deactivation in regions which are associated with acoustic and au…

Evaluation of collateral flow capacity in patients with vascular or tumorous lesions of the skull base by Doppler sonography

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.

nrCBF for Timing of Angiography and Operation in Subarachnoid Hemorrhage

Early operation on cerebral aneurysms is demanded not least because of the threat of spasm of the cerebral vessels. As is generally recognized, this is to be expected in a very high percentage within a few days after the first aneurysm hemorrhage and frequently cannot be diagnosed clinically (4, 5). Many neurosurgeons have rated the risk of operating in the presence of vasospasm so high that, like C.G. DRAKE in 1975 (2), they demanded control angiography with its own risk, especially in existing vasospasm in early angiography and the aneurysm operation itself could not take place rapidly.

Cerebral blood flow, computerized tomography and angiography in 562 cases of cerebrovascular insufficiency

The measurement of cerebral blood flow (CBF) in addition to cerebral computerized tomography (CT) and angiography is most reliable in cases of transient ischemic attacks (TIA) and prolonged reversible ischemic neurologic deficits (PRIND). Alterations of CBF can be detected in symptom-free intervals. The cerebrovascular reactivity to CO2 stimulus is regarded as an especially suitable tool to prove the cerebrovascular reserve. If it is diminished, cerebral angiography should be carried out since it will often show major obstructive lesions. Angiography shows no sure correlation between CBF and collateral circulation. Strong opthalmic pathways in unilateral occlusion of the internal carotid ar…