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D A Legemate

Publications and source records attributed to D A Legemate.

At least 55 records · Page 3Linked to original sources
PubMed2001

Interobserver variability in aortoiliac and femoropopliteal duplex scanning.

PURPOSE: The interobserver variability of aortoiliac and femoropopliteal duplex scanning in peripheral arterial occlusive disease was assessed. METHODS: Two experienced, independent vascular technologists investigated in random order 61 consecutive patients sent to the vascular laboratory for investigation of the aortoiliac or femoropopliteal arteries. In each aortoiliac vessel segment, the proximal, mid, and distal peak systolic velocities (PSVs) were measured, and corresponding PSV ratios were calculated. The superficial femoral artery was divided in 10-cm segments with a roll-centimeter taped from the upper patella margin. Interclass correlation coefficients (ICCs) were calculated as a means of appreciating the measurement variability of the PSV ratio values as a continuous variable and the Kappa value for the PSV ratio categories of less than 2.0, 2.0 through 3.0, more than 3.0, and occlusions. RESULTS: The overall ICC and Kappa values were 0.72 (95% CI, 0.63-0.79) and 0.53 for the aortoiliac tract and 0.85 (95% CI, 0.79-0.89) and 0.73 for the femoropopliteal tract. Agreement in the PSV ratio categories was 85% in the aortoiliac and 87% in the femoropopliteal tract. Interobserver variation increased markedly with increasing PSV ratio. In the PSV ratio category between 2.0 to 3.0, indicating a borderline stenosis, a substantial disagreement was found (aortoiliac, 1 of 8 agreement; femoropopliteal, 2 of 8 agreement). CONCLUSION: A moderate interobserver agreement was found in the duplex investigation of the aortoiliac and femoropopliteal arteries. One should be aware of this in clinical decision making, especially in cases of borderline stenoses. In these cases, repetition of the measurement or additional diagnostics is advocated.

Aorta, Abdominal↗
PubMed2001

Duplex scanning allows selective use of arteriography in the management of patients with severe lower leg arterial disease.

PURPOSE: Until April 1997 we routinely performed intra-arterial digital subtraction angiography (iaDSA) in all patients with severe lower leg ischemia requiring intervention. After a comparative study of duplex scanning (DS), pulsegenerated runoff, and iaDSA of the lower leg arteries, we postulated that management could be based on DS/pulse-generated runoff in 59% of patients. We prospectively evaluated the safety of such a noninvasive workup strategy. METHODS: All consecutive patients referred with severe lower leg ischemia between April 1997 and September 1998 were eligible. Management was based on DS with iaDSA being performed only on indication. Complications within 30 days and 12- and 24-month patency, survival, and limb salvage rates were recorded and compared with historical controls. RESULTS: A total of 125 limbs in 114 patients were evaluated (74% rest pain or tissue loss). In 97 (78%) of 125 limbs, management was based on DS. It comprised conservative treatment (n = 33, 0% after iaDSA), percutaneous transluminal angioplasty (n = 25, 16% iaDSA), femoropopliteal bypass graft (n = 29, 17% iaDSA), femorotibial bypass graft (n = 29, 62% iaDSA), and other surgical procedures (n = 8, 4% iaDSA). Overall, the mortality within 30 days was 4% (5/114), and 2-year survival was 83%. Two-year primary and secondary patency and limb salvage rates were 75%, 93%, and 93% after a femoropopliteal bypass operation, respectively. One-year primary and secondary patency and limb salvage rates were 35%, 73%, and 74%, respectively, after a femorocrural bypass operation. There were no differences in patient characteristics, indication for specific treatment, and immediate and intermediate term outcome between the study and reference population. CONCLUSION: In a vascular unit with wide expertise in DS of the lower leg arteries, management of patients with severe lower leg ischemia can be based on DS in most patients without negative effects on clinical outcome within 30 days and at 2-years' follow-up.

Adult↗
PubMed2001

SonoVue in transcranial Doppler investigations of the cerebral arteries.

BACKGROUND AND PURPOSE: The authors investigated the safety and diagnostic potential of a new ultrasound contrast agent (SonoVue) using transcranial color-coded duplex sonography (TCCS). METHODS: Forty patients were enrolled in a multicenter, open-label (on-site), blind (off-site), randomized, dose-ranging crossover study. SonoVue was administered as an intravenous bolus injection of 4 different dosages (0.3, 0.6, 1.2, and 2.4 mL). Efficacy was evaluated as (1) off-site assessment of global quality of the Doppler investigation (based on color or power Doppler images and spectral analysis) at baseline and following each dose of SonoVue according to a 4-point scale (from very poor to excellent imaging of blood flow) and (2) duration of clinically useful signal enhancement and color or power Doppler visualization of blood flow. Additional on-site efficacy assessments performed following each dose of SonoVue included confidence in diagnosis and global consequences of contrast enhancement on diagnosis. Safety evaluations included clinical laboratory tests, neurological examination, injection site tolerability, and incidence of adverse events and their relationship to the study agent. RESULTS: All doses of SonoVue significantly improved the global quality of Doppler examinations (P < .05). The median duration of clinically useful enhancement was dose related (P < .001) and ranged from 2 to 6 minutes at the highest dose. The administration of the contrast agent changed a nondiagnostic study to a diagnostic one in 66% of patients and increased the confidence in diagnosis in 74% of cases. No serious adverse events were recorded following SonoVue administration. The observed adverse reactions were all transient and mild in intensity. CONCLUSIONS: The results obtained from this multicenter study demonstrate that the administration of SonoVue to patients with ischemic cerebrovascular disease who undergo TCCS examination of cerebral vessels improves the visualization of intracranial arteries, providing a dose-dependent contrast enhancement and a clinically useful duration of signal enhancement related to the dose. During this multicenter study, SonoVue proved to be a safe and well-tolerated compound.

Analysis of Variance↗
PubMed2000

Optimisation of the non-invasive assessment of critical limb ischaemia requiring invasive treatment.

OBJECTIVE: to assess the optimal cut-off values of toe blood pressure (TBP) and transcutaneous oxygen pressure (TcpO(2)) in the supine and sitting positions, in order to accurately detect the presence of severe leg ischaemia requiring invasive treatment. METHODS: in 49 consecutive patients (65 legs) with severe ischaemia according to clinical symptoms of Fontaine III or IV and a lowered ankle blood pressure, TBP and TcpO(2)were measured in the supine and sitting positions. Treatment within 6 weeks after the diagnosis was classified as either conservative or invasive (revascularisation or amputation). RESULTS: of the 65 legs, 38 (58%) required invasive treatment. The mean ankle pressure for this group was 70 mmHg. The optimal cut-off value for TBP was 38 mmHg and for TcpO(2)35 mmHg. A TBP of </=30 mmHg and a TcpO(2)</=25 mmHg while supine, showed likelihood ratios (LR) of 7.0 and 3.3, respectively, and when combined an LR of 12.4. Measurements in the sitting position did not enhance diagnostic power. CONCLUSIONS: the need for invasive therapy in patients with severe leg ischaemia might be predicted by measuring TBP and TcpO(2), using the above-mentioned cut-off values.

Aged↗
PubMed2000

The usefulness of a laser Doppler in the measurement of toe blood pressures.

OBJECTIVE: The purpose of this study was to evaluate the clinical value and reproducibility of laser Doppler (LD) versus photoplethysmography (PPG) in the measurement of the systolic toe blood pressure. METHODS: Toe blood pressure was measured in 60 patients in different stages of peripheral vascular disease with simultaneous digital sampling of PPG and two LD signals, each with a different filter setting (3 second [LD(3)] and 0.03 second [LD(0.03)]), and cuff pressure. These measurements were repeated after 1 week. The signals were analyzed with previous results ignored. The agreement of the PPG and LD pressures and reproducibility after 1 week were assessed by calculating the intraclass correlation coefficient (ICC). The agreement variation across the range of pressure values was visually explored by means of difference plots. RESULTS: In 19 legs with a very low pressure only LD could adequately measure the pressure, whereas PPG did not. The ICCs between PPG and LD(3) and LD(0.03) were 0.95 or more. The ICCs of the 1-week reproducibility of the PPG, LD(3), and LD(0.03) pressures were 0.92, 0.88, and 0.86, respectively. The variation was equally distributed across the range of pressures in all three methods. CONCLUSION: LD is a reliable alternative to PPG to measure toe blood pressures. Furthermore, LD is able to measure low pressures, which is relevant in the assessment of the presence of critical ischemia.

Aged↗
PubMed2000

Collateral configuration of the circle of Willis: transcranial color-coded duplex ultrasonography and comparison with postmortem anatomy.

BACKGROUND AND PURPOSE: The anterior communicating artery (AcoA) and posterior communicating arteries (PcoA) of the circle of Willis provide the main route for collateral blood flow in cases of carotid artery obstruction. Transcranial color-coded duplex ultrasonography (TCCD) allows real-time measurement of the collateral function of the AcoA and PcoA. The primary objective of this study was to determine the collateral artery threshold diameters for supplying collateral flow. METHODS: In 12 acute stroke patients with a median age of 75 years (51 to 91 years), the collateral integrity of the circle of Willis as assessed by TCCD and carotid compression tests was compared with their postmortem anatomy. The lengths and diameters of the collateral arteries were measured. RESULTS: TCCD demonstrated absent anterior collateral flow in 3 patients. In 1 of these patients, absence of anterior cross-flow was due to an occluded anterior cerebral artery, which was revealed at autopsy. Absent posterior collateral flow was found in 14 hemispheres. In 2 of these hemispheres, autopsy revealed a fetal configuration of the posterior cerebral artery hampering posterior collateral flow. The median (range) diameters as found at autopsy of the functional (n=19) and nonfunctional (n=16) collateral arteries of the circle of Willis were 1.1 (0.4 to 2.0) and 0.5 (0.3 to 0.7) mm, respectively (P=0.003). PcoA diameters were found to correlate negatively (rho=-0. 50, P=0.01) to the diameters of their accessory P1 segments. CONCLUSIONS: The threshold diameter allowing for cross-flow through the primary collateral arteries of the circle of Willis is between 0. 4 and 0.6 mm.

Adult↗
PubMed2000

Collateral variations in circle of willis in atherosclerotic population assessed by means of transcranial color-coded duplex ultrasonography.

BACKGROUND AND PURPOSE: Transcranial color-coded duplex ultrasonography combined with common carotid artery (CCA) compression can be used to assess the collateral function of the circle of Willis. The aim of this study was to assess the unknown fraction of hemodynamic functional anterior and posterior communicating arteries (AcoA and PcoA, respectively) in an atherosclerotic population with no cerebrovascular symptoms. METHODS: In 76 patients with a mean age of 61 (35 to 89) years, the blood flow velocity changes in the precommunicating parts (A1 and P1, respectively) of the anterior and posterior cerebral arteries were measured during CCA compression. The AcoA was defined as functional if blood flow was reversed in the ipsilateral A1 and enhanced in the contralateral A1 during CCA compression. The PcoA was defined as functional if the flow velocity in the P1 was enhanced >20% during ipsilateral CCA compression. RESULTS: It was possible to assess cross flow through the anterior part of the circle of Willis in 95% of the subjects. Failure of this collateral pathway was caused by a hypofunctional AcoA in 4% and a hypofunctional A1 in 1% of the subjects. Anomalies in the posterior part of the circle of Willis hampering collateral flow from the basilar to the internal carotid artery were found in 45% of the hemispheres. Thirty-eight percent of PcoAs were hypofunctional, and 7% of the posterior cerebral arteries had a persistent fetal anatomy. CONCLUSIONS: We found that in subjects with no cerebrovascular symptoms, the anterior collateral pathway of the circle of Willis was nearly always functional. In contrast, the posterior collateral pathway was nonfunctional in almost half of the total number of hemispheres. Comparing these basic data with data from patients with cerebral ischemic disease might further help to elucidate the importance of the collateral capacity of the circle of Willis.

Adult↗
PubMed1999

Effects of a branched-chain amino acid-enriched diet on chronic hepatic encephalopathy in dogs.

A decreased ratio of branched-chain amino acids (BCAA) to aromatic amino acids (AAA) is considered an important pathogenetic factor in hepatic encephalopathy (HE). A relationship between the deranged BCAA/AAA ratio and dopaminergic dysfunction through the formation of "false" neurotransmitters has been postulated. The intermediate lobe of the pituitary is more pronounced in dogs than in humans and because it is primarily under dopaminergic inhibitory influence, it may serve as an indicator of alterations in dopaminergic neurotransmission. We investigated the effects of a diet with a high BCAA/AAA ratio (HR) and an isonitrogenous diet with a low BCAA/AAA ratio (LR) on several physical and biochemical parameters including pituitary function in dogs with portocaval shunts and 40% hepatectomy and in sham-operated pair-fed controls, in a double-blind, randomized cross-over study. Portocaval-shunted dogs had hyperammonemia (33+/-3 microM (mean +/- SEM) before and 214+/-21 after surgery)) and signs of HE. Their BCAA/AAA ratio in plasma and CSF decreased from 4.3+/-0.3 and 2.3+/-0.3 before surgery to 1.3+/-0.1 and 0.5+/-0.1 after surgery, respectively. These parameters remained unaltered in the control dogs. The consumption of the LR diet was significantly higher than consumption of the HR diet. In the portocaval-shunted dogs, plasma ammonia concentration was higher on the HR diet than on the LR diet (344+/-52 v 246+/-45) and the HE grade was worse. The BCAA/AAA ratio remained abnormal in HE dogs during the feeding of both diets. The basal and haloperidol-stimulated release of alpha-melanotropin and cortisol in plasma were not significantly different between or within groups during any period. In contrast, urinary cortisol excretion was increased in the HE dogs after surgery (urinary cortisol:creatinine ratio (x10(-6)) 8.5+/-1.4 before and 30.4+/-8.9 after surgery). The basal plasma concentration of adrenocorticotropin in HE dogs was decreased after surgery (68.3+/-10.2 ng/L before and 40.8+/-4.4 after surgery). This indicates a non-pituitary-dependent hyperresponsiveness of the adrenals. We conclude from these results that chronic HE in dogs is not associated with an abnormal dopaminergic neurotransmission at least at the level of the pituitary, and that it is not the content of the dietary neutral amino acids but rather the total protein intake that may have a beneficial effect on HE.

Adrenocorticotropic Hormone↗
PubMed1999

Influence of the collateral function of the circle of Willis on hemispherical perfusion during carotid occlusion as assessed by transcranial colour-coded duplex ultrasonography.

OBJECTIVES: to investigate the collateral potential of the circle of Willis with transcranial colour-coded duplex ultrasonography and common carotid artery (CCA) compression. MATERIALS AND METHODS: in 46 atherosclerotic patients without cerebrovascular disease, the functional patency of the collaterals of the circle of Willis, the anterior and posterior communicating arteries, was assessed. The Peak Systolic Velocity (PSV) decrease in the middle cerebral artery (MCA) during CCA compression between complete and incomplete circles was compared. RESULTS: in 10 (22%) patients a complete and in 36 (78%) patients an incomplete circle of Willis was found, mainly due to non-functioning posterior communicating arteries. In hemispheres with collateral supply through both the anterior and the posterior communicating artery, the median PSV decrease in the MCA during CCA compression was 43%. When the posterior, anterior or both communicating arteries (1 hemisphere) were missing the PSV decrease was 58% (p =0.003), 70% (p =0.001) and 75%, respectively. CONCLUSIONS: collateral flow from the basilar to the carotid territory is often hampered by non-functioning posterior communicating arteries. A non-functioning anterior communicating artery is rare. A complete collateral circulation provides better perfusion of the MCA during carotid occlusion as compared with collateral supply through only the anterior or the posterior communicating artery in the case of an incomplete circle of Willis.

Adult↗
PubMed1999

Quantitative measurements of venous reflux by duplex scanning of the incompetent long saphenous vein before and after high ligation at the saphenofemoral junction.

OBJECTIVE: To assess the effect of high ligation of the saphenofemoral junction (SFJ) on the amount of reflux in the long saphenous vein using quantitative duplex scanning. DESIGN: Prospective study. SETTING: Teaching hospital, The Netherlands. SUBJECTS: 23 patients presented with 29 limbs showing signs of isolated insufficiency of the long saphenous vein. INTERVENTION: High ligation of the SFJ. MAIN OUTCOME MEASURES: Duration of reflux (s), peak velocity (m/s), mean velocity (m/s) and mean flow (ml/s) at the SFJ, and in the mid-thigh, the distal thigh and the proximal lower leg before and four weeks after high ligation. RESULTS: All variables except duration of reflux improved significantly at all levels in the 29 limbs studied. One limb showed no improvement in flow at the level of the SFJ, 9 in the mid-thigh, 13 in the distal thigh, and 15 in the proximal lower leg (just below the knee). CONCLUSION: High ligation was effective in reducing reflux at the SFJ, but in about half the limbs the distal reflux in the long saphenous vein remained.

Female↗
PubMed1999

Success rate of transcranial color-coded duplex ultrasonography in visualizing the basal cerebral arteries in vascular patients over 60 years of age.

BACKGROUND AND PURPOSE: Clinically important atherosclerotic cerebrovascular disease is mainly found in patients aged >60 years. Transcranial color-coded duplex ultrasonography (TCCD) is a relatively new technique for investigating the basal cerebral arteries; however, it is often hampered by impenetrable ultrasound windows. The aim of this study was to ascertain the as yet unknown success rate of TCCD regarding visualization of the basal cerebral arteries in patients >60 years, to provide reference data, and to compare any possible male/female differences. METHODS: In 112 atherosclerotic white patients >60 years of age, the anterior, middle, and posterior cerebral arteries and the vertebral and basilar arteries were insonated. RESULTS: In men, 99% of the temporal and 94% of the suboccipital windows could be penetrated by ultrasound compared with 77% and 95%, respectively, in women. The male versus female vessel detection rates were 91% versus 58% for the anterior cerebral artery, 97% versus 73% for the middle cerebral artery, 97% versus 68% for the posterior cerebral artery, 94% versus 93% for the vertebral artery, and 91% versus 79% for the basilar artery. In 77% of men but only 33% of women could all vascular segments be investigated. All intracranial arteries were insonated at a deeper level in men. The women showed significantly higher blood flow velocities than the men. CONCLUSIONS: In elderly white men the vessel detection rate is >90%. In women there is a much lower detection rate, due to impenetrable temporal windows. Visualization of all major intracranial arteries is possible in only one third of female patients >60 years of age.

Aged↗
PubMed1998

Reduced renal failure following thoracoabdominal aortic aneurysm repair by selective perfusion.

OBJECTIVES: Renal failure and visceral ischemia are feared complications following thoracoabdominal aortic aneurysm (TAAA) repair, significantly contributing to mortality. This prospective study describes volume- and pressure-controlled perfusion of the renal and visceral arteries during TAAA surgery. METHODS: In 73 consecutive patients (mean age 59 years), TAAA repair (27 type I, 28 type II, 8 type III and 10 type IV) was performed, using retrograde and selective organ perfusion. Sixteen patients had impaired renal function with blood creatinine higher than 100 mmol/l. During the thoracic part of the procedure, the mean distal aortic pressure was kept above 60 mm Hg by means of left-heart bypass. After opening the abdominal aorta, the renal and visceral arteries were individually perfused by means of perfusion catheters (9 French) in the first 33 patients (group I). Volume flow through each catheter was assessed with ultrasound flow meters and maintained at least at 60 ml/min. In addition to volume flow measurements, catheters with pressure sensors were used in the last 40 patients (group II), allowing pressure-controlled selective perfusion. The extent of the aneurysm was comparable in both groups. RESULTS: Mean cross-clamp time for the thoracic part was 46 min, including proximal anastomosis and reattachment of intercostal arteries. Mean cross-clamp time for the abdominal part was 74 min, including re-implantation of intestinal and renal arteries and selective dacron grafts to the celiac-axis arteries (n = 5), superior mesenteric arteries (n = 8) and renal arteries (n = 25), through which the catheters guaranteed continuous perfusion during the time the anastomosis was performed. Urine output was uninterrupted in all patients, irrespective of cross-clamp time. In group I, one patient (3%) developed renal failure and three patients (9%) required temporary peritoneal dialysis. In group II, no patients developed renal failure and two patients (5%) required temporary peritoneal dialysis. Thirteen patients with pre-existing renal impairment did not deteriorate. No patients developed visceral ischemia or multiple-organ failure. Total in-hospital mortality was 6/73 (8%) and was related to cardiopulmonary complications. CONCLUSIONS: Renal and visceral ischemia can be reduced significantly by continuous perfusion during cross-clamping in TAAA repair. Not only sufficient volume flow but also adequate arterial pressure appears to be essential in maintaining renal function.

Aortic Aneurysm, Abdominal↗
PubMed1998

Aortoiliac reconstructive surgery based upon the results of duplex scanning.

OBJECTIVE: To evaluate whether duplex scanning can replace angiography in patients operated for aortoiliac obstructive disease. DESIGN: Retrospective. MATERIALS AND METHODS: Between January 1995 and October 1996, 44 patients underwent vascular surgery of the aortoiliac tract. The study population was divided into two groups; patients operated upon the results of duplex scanning only and patients who also underwent angiography prior to surgery. The additional value of angiography and the differences between both groups concerning unexpected peroperative findings, early postoperative failures and the need for additional radiological or surgical interventions in the first three postoperative months were studied. RESULTS: Duplex scan group: 22 patients were operated upon the results of duplex scanning only. In two patients surgical strategy had to be changed. Early postoperative graft occlusion occurred in one case. A haemodynamically significant graft stenosis within 3 months of surgery occurred in one patient. Duplex/angiography group: 22 patients underwent both duplex scanning and angiography. Six patients underwent diagnostic angiography after failed duplex scanning. In 10 patients angiography was part of percutaneous transluminal angioplasty prior to surgery. In six patients angiograms were performed after successful duplex scanning. Angiography failed in two patients and added information in four of 16 patients. Unexpected findings at operation occurred in four patients. Graft stenosis within 3 months was detected in three patients. CONCLUSION: After successful duplex scanning information obtained by angiography has only a limited impact on therapeutic decision-making. In the majority of patients vascular reconstructive surgery of aortoiliac arteries can be planned based on duplex scanning only.

Adult↗
PubMed1998

Can cruropedal colour duplex scanning and pulse generated run-off replace angiography in candidates for distal bypass surgery.

PURPOSE: To compare the diagnostic accuracy of duplex scanning (DS) and pulse generated run-off (PGR) with ia-DSA for the assessment of cruropedal outflow and explore the reliability of clinical decision making based on a work-up with DS/PGR in candidates for peripheral bypass surgery. METHODS: Popliteal, crural and pedal arteries were evaluated independently with DS and ia-DSA in 126 limbs of 120 consecutive patients for claudication (16%) or critical ischaemia (84%). Arterial segments were graded with DS and ia-DSA as normal, stenosed, or occluded and compared using weighted kappa (kappa) analysis. PGR was used to select the best crural artery for bypass. Proposed management based on DS/PGR and, if applicable, anastomosis site were compared to definitive treatment based on ia-DSA. RESULTS: Overall agreement between DS and ia-DSA for popliteal and crural arteries was moderate (kappa 0.51, 95% CI 0.48-0.55) with good agreement within the popliteal (kappa 0.67) and anterior tibial (kappa 0.61) arteries. Agreement was moderate within the pedal arterieds (kappa 0.32, 95% CI 0.24-0.40). In 74/126 (59%) limbs proposed management with DS/PGR was identical to ia-DSA. In 23/29 (79%) femoropopliteal and 15/37 (41%) femorocrural bypasses DS/PGR agreed perfectly with ia-DSA with regard to acceptor artery and anastomosis site. CONCLUSION: DS can accurately assess the popliteal and anterior tibial arteries. In a substantial number of patients with severe lower limb ischaemia decisions for conservative management, PTA and femoropopliteal bypass can be based on a DS/PGR work-up.

Adult↗
PubMed1998

Improvement of chronic hepatic encephalopathy in dogs by the benzodiazepine-receptor partial inverse agonist sarmazenil, but not by the antagonist flumazenil.

Therapeutic modulation of the increased GABAergic tone in chronic hepatic encephalopathy (HE) by the benzodiazepine receptor (BR) antagonist flumazenil (F) has led to conflicting results in humans and animal models for HE. The BR inverse agonist sarmazenil (S) has only been used in animal models of acute HE. Therefore we investigated the effects of intravenous injection of F and S in dogs with chronic HE 8 to 12 weeks after placement of a portocaval shunt and 40% hepatectomy (n=7), compared to sham-operated pair-fed controls (n=7). The HE dogs had hyperammonemia (298 +/- 48 microM v 33 +/- 3 before surgery (mean +/- SEM)) and signs of HE at the start of the experiments (0.9 +/- 0.1 (scale 0-4)). Three (S3) and 8 (S8) mg/kg of S resulted in a significant improvement of encephalopathy (grade 0.9 +/- 0.2 immediately before v 0.5 +/- 0.1 after injection (S3) and 0.7 +/- 0.1 v 0.3 +/- 0.1 (S8)) and increase in mean dominant frequency of the EEG (MDF; 9.1 +/- 0.7 Hz v 11.1 +/- 0.3 (S3) and 8.9 +/- 0.5 v 11.0 +/- 0.3 (S8)) in HE dogs, whereas 15 mg/kg of S, 3 and 8 mg/kg of F, and the vehicle had no significant effects. The efficacy of S in these dogs is consistent with an increased GABAergic tone in the pathogenesis of chronic HE. The lack of effects of F makes a role for endogenous benzodiazepines herein unlikely.

Ammonia↗
PubMed1997

[Cerebral hyperperfusion syndrome following carotid endarterectomy].

Three patients with a severe symptomatic carotid stenosis developed headache, epileptic seizures and focal neurologic deficits several days after carotid endarterectomy. CT of the brain revealed hypodensities, indicative of cerebral oedema with haemorrhagic components. This is caused by cerebral hyperperfusion, a complication after carotid endarterectomy as a result of increased cerebral perfusion on the side of the operated carotid stenosis. Dysfunction of the cerebral autoregulation believed to be the cause of this hyperperfusion. Sometimes these complications are incorrectly attributed to one of the better known types of stroke.

Aged↗