E Enevoldsen's research while affiliated with Odense University Hospital and other places

Publications (39)

Article
The pulsatility index (PI) registered by the transcranial doppler (TCD) was examined in relation to arterial pCO2 (paCO2) and epidural pressure (ICP). In 10 normal subjects PI was studied during variations in paCO2. In 10 neurosurgical patients with head injuries concomitant measurements of PI and ICP were obtained. The results showed a negative ex...
Article
The amount of effused blood following a subarachnoid haemorrhage (SAH) was estimated in 48 patients by cerebral computerized tomographic scanning. The cerebral oxygen consumption (CMRO2) was calculated as arteriovenous difference for oxygen multiplied by mean cerebral blood flow measured by the 133-Xe inhalation technique. A significant negative co...
Article
A spasm index, defined as transcranial Doppler detected flow velocity in the middle cerebral artery divided by regional cortical cerebral blood flow (CBF), was used on 24 patients with subarachnoid haemorrhage (SAH). The aim was to estimate degree and time course of vasospasm, even in cases with great day-to-day variation in CBF, and correlate to C...
Article
Forty-eight patients with subarachnoid haemorrhage were studied with repeated rCBF and CMRO2 measurements. Cortical rCBF was measured using xenon-inhalation technique. CMRO2 was calculated as AVDO2 x CBF. When first studied the 29 conscious patients showed relative hyperaemia with CBF at 50 ml and reduced CMRO2 at 2.17 ml. In the following week CBF...
Article
The relation between angiographically determined cerebral vasospasm following a subarachnoid hemorrhage and regional cerebral blood flow (CBF) was studied in 63 investigations of 45 patients. The CBF was measured using the intra-arterial 133-Xe clearance technique within one hour of angiography. A positive correlation between regional CBF and diame...
Article
We used the end-tidal concentration of xenon-133 (air curve) to estimate the profile of its arterial concentration in calculating cerebral blood flow. We examined the effects of pulmonary disease and artificial ventilation on the air curve and the calculated cerebral blood flow. We studied the relation between arterial and end-tidal xenon activitie...
Article
Thirty-three patients with reversible ischemic deficits or completed minor strokes had their cerebral function measured neuropsychologically a few days before and 3 months after extra-intra cranial bypass surgery. Three months post-operatively bypass patency was demonstrated by angiography. Ten patients were operated on the right side and 23 on the...
Article
Thirty-three patients with reversible ischemic deficits or completed minor strokes had their cerebral function measured neuropsychologically a few days before and 3 months after extra-intra cranial bypass surgery. Three months post-operatively bypass patency was demonstrated by angiography. Ten patients were operated on the right side and 23 on the...
Article
In the last few years the possibility of measuring CBF by means of intravenous isotop injection technique and portable monitor has made the use of measuring CBF in the clinical setting of the brain injured patient of current interest. However, knowledge about the hemodynamics of the head trauma is inevitable for the interpretation of the CBF result...
Article
ABSTRACT – A neuropsychological study of 12 patients with transient ischemic attacks from the carotid artery territory was carried out about 2 months following their latest attack, about a week before STA/MCA bypass operation, and again 3 months postoperatively. The results suggest that the TIA patients as a group were slightly intellectually impai...
Article
The cerebral vasomotor reactivity to arterial hypotension and hypocapnia was studied in 34 patients between the 3rd and 13th day after rupture of an intracranial saccular aneurysm. Using the intra-arterial xenon-133 injection method, regional cerebral blood flow (rCBF) and cerebral metabolic rate of oxygen (CMRO 2 ) were measured. The intraventricu...
Article
Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (CMRO2), intraventricular pressure, and lactate/pH levels in the cerebrospinal fluid (CSF) were measured in 38 patients with ruptured intracranial aneurysms between the 3rd and 13th day after subarachnoid hemorrhage (SAH). Angiography was performed following the rCBF study and t...
Chapter
The lower mean blood pressure limit of CBF autoregulation is about 60 torr in normal man. In hypertensive patients the lower limit is shifted towards higher blood pressures.
Chapter
Extra-intracranial bypass surgery (EIAB) was performed in 39 patients, who were selected for the operation on the basis of clinical and angiographic criteria. CBF measurements were carried out in all patients before surgery and again 3 months after surgery. The results of the flow studies did not influence the decision whether to operate. However,...
Article
In agreement with the results of Strandgaard our results indicate that the lower limit of the autoregulation in severe hypertension is shifted towards higher blood pressure values. In addition our results suggest that normalization of the autoregulation during antihypertensive therapy may take place during the first week of the treatment but that t...
Article
Continuous monitoring of intraventricular pressure (IVP) was performed before and during 13 recurrent hemorrhages occurring in 10 patients between the 3rd and 14th day after the initial rupture of an intracranial saccular aneurysm. Before re-rupture, nine patients were of Hunt and Hess' clinical Grade III of IV. Severe angiographic vasospasm was de...
Article
Lactate concentrations and pH were measured serially in the cerebrospinal fluid (CSF) of 52 patients with ruptured intracranial aneurysms. Measurements were made during continuous monitoring of the intraventricular pressure (IVP) in the first 12 days after the initial subarachnoid hemorrhage. A total of 226 samples of CSF were analyzed. The clinica...
Article
In 26 patients with recent rupture of an intracranial saccular aneurysm the CSF concentrations of serotonin (5-HT) were measured repeatedly by a radioimmunoassay. The 5-HT level in ventricular CSF collected between the 2nd and 15th day after SAH ranged between less than 2 and 5 nmol/l. These did not differ from the levels found in the ventricular C...
Article
Intraventricular pressure (IVP) was measured continuously by the method of Lundberg for an average period of 8 days in 52 patients with recent rupture of an intracranial saccular aneurysm. The patients were graded as follows according to the system of Hunt and Hess: 13 patients were Grades I–II, 19 patients Grades II–III, and 20 patients Grades III...
Article
The limitations of 2-dimensional isotope techniques in the study of focal cerebral ischemia were investigated using the intra-carotid 133 xenon injection method and a 254 multidetector scintillation camera. To make sure that the detectors "look" directly on infarcted areas, only patients with infarcts involving cortical surface structures were incl...
Article
In a consecutive study comprising 41 patients with completed stroke of less than 72 hours duration, cerebral angiography and measurements of the regional cerebral blood flow (rCBF) were performed within 24 hours after admission. The rCBF study was done using the 133-Xenon intracarotid injection method and a 254 multi-detector camera. CT scan was do...
Chapter
The clinical condition and the age of patients suffering from subarachnoid hemorrhage (SAH) caused by a ruptured intracranial aneurysm are well-known factors of prognostic importance. Complicating events, such as vasospasm, cerebral edema and hydrocephalus, substantially influence the operative risk and carry a high mortality and morbidity. The pat...
Article
In order to evaluate the reproducibility of regional cerebral blood flow (rCBF) measurements in pathological brain tissue, serial measurements were carried out in 13 determinations performed in patients who were comatose after severe head injuries within the first 2 weeks after the head trauma. The xenon-133 intra-arterial method was used for the f...
Article
Regional cerebral blood flow (rCBF), cerebral intraventricular pressure (IVP), systemic arterial blood pressure, and cerebral ventricular fluid (CSF) lactate and pH were studied repeatedly in 23 patients during the acute phase of severe brain injury lasting from 3 to 21 days after the trauma. Cerebrovascular autoregulation was tested repeatedly by...
Article
Bicompartmental analysis for the calculation of regional cerebral blood flow (rCBF) from 133Xe clearance in brain tissue has not been thoroughly explored in clinical studies. Most authors rely either on the average rCBF obtained by height/area analysis of the clearance curves or on the initial-slope flow index. Possibly the reason is that the valid...
Article
Clinical and angiographic findings in migraine are briefly reviewed in relation to cerebral hemodynamic changes shown by regional cerebral blood flow (rCBF) studies. Three cases of migraine studied by the intracarotid xenon 133 method during attacks are reported. In classic migraine, with typical prodromal symptoms, a decrease in cerebral blood flo...
Article
Cerebral ventricular fluid (CSF) lactate and pH were measured repeatedly in 21 comatose patients with severe head injury during the first three weeks after trauma. In addition, regional cerebral 133Xe blood flow (rCBF) was measured two to four times in each patient at various time intervals, depending on the indications for carotid angiography, and...
Article
The authors measured regional cerebral 133xenon (133Xe) blood flow (rCBF), intraventricular pressure (IVP), cerebrospinal fluid (CSF) pH and lactate, systemic arterial blood pressure (SAP), and arterial blood gases during the acute phase in 23 comatose patients with severe head injuries. The IVP was kept below 45 mm Hg. The rCBF was measured repeat...
Chapter
The aim of this study was to investigate the relation between intracranial pressure (ICP), regional cerebral blood flow (rCBF), and brain metabolism in patients with acute severe brain injuries in order to evaluate how much the intracranial pressure could be increased if brain ischemia was to be avoided.
Article
In 35 unconscious patients suffering from traumatic brain injury and subjected to controlled hyperventilation within 12 hours of the acute trauma, we measured continuously the intraventricular pressure (IVP), ventricular fluid lactate, pyruvate, L/P ratio, pH and bicarbonate during the first 4 posttraumatic days, and related the findings to the cli...
Article
Since LUNDBERG’s introduction of a clinically applicable method for the continuous recording of intraventricular pressure (IVP) (1), the prognostic value of IVP has been subjected to several investigations (2,3). Thus, a high level of IVP has been claimed to give prognostic information (3).
Chapter
The use of the 133Xe technique, whether analyzed with two compartment method or initial slope index, gives rise to difficulties of interpretation in patients with markedly reduced cerebral blood flow. Unlike the normal clearance curves, the appearance of the clearance curves in patients with reduced cerebral blood flow becomes more or less monoexpo...
Chapter
Results of studies by REULEN et al. (1) suggest that dexamethasone exerts its beneficial action by decreasing peritumoural oedema, thereby enhancing the blood flow in the same region. However, as demonstrated by KULLBERG (2), the clinical effect of corticosteroids sets in before clearcut alterations in intraventricular pressure can be observed. Acc...

Citations

... For delineation of prognosis Vapalahti and Troupp (1971) have pointed to the poor outcome in most patients with an ICP above 60 mm Hg for any length of time. The appearance of waves of increased ICP implies a poor prognosis, especially if high amplitude waves occur frequently (Cold, Enevoldsen and Malmros, 1975). Extreme caution must be exercised, however, in using ICP measurement for assessing prognosis in individual patients (Miller, Garabi and Pickard, 1973). ...
... 24 However the clinical efficacy of revascularization surgery in decreasing this risk remains controversial. 25 As a potential benefit to neurocognition, extracranial-intracranial bypass has previously been reported to significantly improve cognitive function in steno-occlusive disease 26,27 ; our study suggests that WM reperfusion may contribute to the improvement. Additionally, revascularization surgery has been shown to improve cognitive function in patients with symptomatic primary carotid stenosis undergoing carotid endarterectomy and carotid artery stent placement 28 and in patients with ICA stenosis undergoing carotid endarterectomy. ...
... At best only minor gains in neuropsychological ability have been reported following CE or EC/IC arterial bypass surgery (Ariel & Strider, 1983;Baird et al., 1987;Brown et al., 1986;Nielsen, Hojer-Pederson, Gulliksen, Haase, & Enevoldsen, 1985;Parker et al., 1983;Wilson & Polido, 1986;Younkin et al., 1985). Postendarterectomy improvement on measures of neurocognitive ability may be due to the effect of practice (Casey, Ferguson, Kimura, & Hachinski, 1989). ...
... Similar effects, such as hyperphosphorylation of tau and activation of AEP through cleavage of I 2 PP2A and its translocation from the nucleus to the cytoplasm of neurons, were reported in rmTBI in 3xTg-AD mice. Overload of calcium and the release of excitatory amino acids, two major initiating events in secondary damage after TBI, can initiate ischemia, hypoxia, and increase in lactic acid [70], and thereby acidosis of the brain tissue [72] and lysosomal pathological changes [73]. These are all situations in which AEP can be activated and enhance the cleavage of I 2 PP2A [74] that is associated with a significant cytoplasmic translocation of I 2 ...
... These in vivo findings were compared to inherent aggregation properties of S100A9 observed in vitro and to the previous observations of S100A9 excessive production in the human TBI tissues [37]. Increasing evidence demonstrates that TBI profoundly alters the cerebral acid base homeostasis, leading to the brain tissue acidosis, which consequently causes neuronal damage and poor survival outcome [4,6,29,33]. Therefore, here we have conducted in vitro experiments under acidic conditions, examining their effect on S100A9 amyloid formation. ...
... При­ мерами могут служить компрессионный тест, инга­ ляции газами, тест с задержкой дыхания, манжетный тест и т.д. [12][13][14]. В результате проведения данные манипуляции позволяют математически рассчитать коэффициенты характеризующие состояние системы ауторегуляции церебральной гемодинамики. Стати­ ческий метод был открыт гораздо раньше динами­ ческого, его суть заключается в изучении не пара­ метров, характеризующих систему саморегуляции, а границ, в пределах которых эта система способна функционировать, удовлетворяя потребности голов­ ного мозга в кислороде и питательных веществах [15]. ...
... Our results on overall headache relief rate in cases support that VM may downregulate the vascular cascade, which finally induces migraine attack. The other idea mentioned in a study conducted by Frank and his colleagues is the rate of changes in cerebrovascular resistance [32], leading to a blood flow increase in the Middle Cerebral Artery(MCA). Although not so recent, this study propounds new points on how VM acts binary. ...
... While Lassen did not differentiate between CA mechanisms, the autoregulatory range is usually referred to in the context of the myogenic mechanism (2,31,48). One reason this contextual interpretation is implied is because the metabolic mechanism is not limited by the autoregulatory range, making it highly influential during hypo-or hypertensive events (2,(49)(50)(51). The autoregulatory range can be shifted or shortened substantially with injury (52) and other factors such as metabolites (53,54), chronic vasospasm(55), or chronic hypertension (56,57). ...
... Two measures of human cerebral function are regional cerebral blood flow (rCBF) and the EEG. rCBF has been measured in various patient groups (Hachinski et al., 1977;Weir et al., 1978;Enevoldsen and Jensen, 1978;Menon and Weir, 1979;York et al., 1979) and has been demonstrated to be clinically useful. Computerised frequency spectrum analysis of the EEG waveform has become more widely accepted as a reliable technique. ...
... This is possibly due to the fact that patient with intact autoregulation tolerate higher CPP level as suggested in the 2007 BTF guidelines. But, elevated blood pressure might still create edema in areas of the brain with blood brain barrier disruption (5). Are the authors able to comment about the outcome of patients according to the presence of cerebral contusions (heterogeneous brain disease) or diffuse axonal injury (homogeneous brain disease) and CPP above upper limit of autoregulation? ...