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Biomedical subjects

W Hacke

Publications and source records attributed to W Hacke.

At least 199 records · Page 11Linked to original sources
PubMed1995

Neurocritical care for acute ischemic stroke.

Therapy for acute ischemic stroke includes general and specific measures. General management such as respiratory and cardiac care, fluid and electrolyte management, blood pressure control, and treatment of increased ICP is the basis of all stroke treatment. Specific treatment is directed to recanalization of the occluded vessel, control of life-threatening brain edema, and protection of neuronal tissue against the toxic effects of ischemia. Although controlled studies are still lacking, application of the proposed general interventions provides a high-quality standard in patients with acute stroke. Among specific therapies, medical thrombolysis has demonstrated instances of significant and sustained neurologic improvement. Several multicenter trials are underway to confirm these preliminary results. In addition to thrombolysis, cell-protecting drugs hold promise for the future. Presumably, a combination of thrombolytic and cell-protecting agents will be the treatment of choice in early stroke in the future.

Acute Disease↗
PubMed1995

[Craniectomy in space-occupying middle cerebral artery infarcts].

Space occupying supratentorial ischemic stroke has a high mortality. The benefit of decompressive surgery in these patients is still matter of debate. In a prospective study we performed craniectomy in 37 patients with acute middle cerebral artery infarction and progressive deterioration under conservative antiedematous therapy. Twenty-one patients treated conservatively during the same period served as control group. All survivors were reexamined between one to two years after surgical decompression. In addition, neuropsychological tests were performed, including an Aachener Aphasie Test (AAT) in those patients with infarction of speech-dominant hemisphere. Clinical evaluation was graded using the Barthel index (BI). Mortality rate in the operated group was 37%. Twenty-three patients survived acute stroke and were reexamined. Despite complete hemispheric infarction, no patient suffered from complete hemiplegia or was permanently wheel chair bound. In speech dominant hemispheric infarction (n = 8) only mild to moderate aphasia could be detected. Mean BI was 64. Mortality rate in the conservatively treated group was 76%. The clinical outcome following craniectomy for the treatment of severe ischemic hemispheric infarction is unexpectedly good. Therefore, decompressive surgery should be considered in cases of space-occupying hemispheric infarctions and conservatively uncontrollable intracranial pressure.

Adolescent↗
PubMed1995

[Treatment of ischemic cerebral infarct with glycerine].

Ischemic brain edema promotes focal cerebral ischemia by increasing intracranial pressure and thereby reducing perfusion pressure, obstructing capillaries and prolonging transport routes within ischemic tissue. There is clinical and experimental evidence that osmotic agents counteract these mechanisms. Moreover, glycerol may act as a free radical scavenger, antioxidant, and activator of plasma prostaglandin (PGI2), resulting in vasodilation. Improvements in ischemic brain energy metabolism after glycerol administration has also been postulated. Results of clinical trials on glycerol treatment of acute ischemic stroke were not conclusive: some demonstrated improved survival in the acute stage, in others survivors benefited in terms of neurological status and/or daily living activities. Other trials did not reveal any superiority of glycerol treatment over placebo. Glycerol is given intravenously as a 10% solution or orally. By the oral route higher intravascular glycerol concentration can be achieved with smaller quantities of fluid. Possible side effects include elevation of blood glucose level with subsequent lactate acidosis in the ischemic brain, serum hyperosmolarity after long-term glycerol administration and--when given intravenously--volume overload in patients with congestive heart failure and hemolysis that may cause renal failure.

Administration, Oral↗
PubMed1995

[Infarcts in the brain areas supplied by the posterior cerebral artery. Clinical aspects, pathogenesis and prognosis].

The clinical and neuroradiological features of 127 patients with ischemia of the posterior cerebral artery (PCA) and a positive CT scan (n = 122) or pathological angiography findings (n = 63) were analyzed. Unilateral headache was the most common presenting symptom (50%), making complicated migraine an important differential diagnosis. Clinical findings were visual field deficits (93%), sensory (29%), motor (28%), and neuropsychological deficits (25%). Infarcts, including the thalamus (n = 27), were mostly associated with sensory and slight motor deficits. Our findings suggest that motor deficits in PCA ischemia, particularly if minor and reversible, are likely to be due to ischemia-induced edema in the internal capsule adjacent to an associated thalamic infarct. Based on angiography, stroke etiology was considered embolic in 83/127 (65%), atherothrombotic in 20/126 (16%), and probably migrainous in 4 (3%) patients. In the remaining 20 patients (16%), the etiology was uncertain. Prognosis of PCA infarcts is usually good.

Adolescent↗
PubMed1994

Altered influence of polymorphonuclear leukocytes on coagulation in acute ischemic stroke.

Polymorphonuclear (PMN) and mononuclear (MN) leukocytes possess procoagulant and anticoagulant activity which could be involved in both formation and dissolution of thrombi. We investigated if coagulant properties of circulating leukocytes are altered in patients within three days after acute ischemic stroke (n = 22) as compared to a control group (n = 22) matched for sex and age. The recalcification time with autologous plasma did not differ between patients and control subjects. Circulating PMNs were procoagulant in all subjects, however, they were less procoagulant in patients (-18.1 [-13.4 - (-)22.8] % of control experiments; mean [95% confidence interval]) than in controls subjects (-31.9 [-27.4 - (-)36.4] %; p = 0.0002). In contrast, MNs were similarly procoagulant in both groups. In the activated partial thromboplastin time (aPTT), there was a non-significant trend to less procoagulant PMNs in patients (-6.7 [-5.1 - (-)8.2] %) than in control subjects (-8.4 [-6.4 - (-)10.5] %). The recalcification time with pooled human plasma showed similar results as with autologous plasma. The procoagulant activity of PMNs increased in follow-up measurements in patients. Upon stimulation with FMLP, the procoagulant activity of PMNs decreased in control subjects but did not change significantly in patients. In the acute stage after ischemic stroke, circulating PMNs exhibit a decreased capability to stimulate coagulation, a feature which reflects cell activation and which may be a reaction on thrombus formation and ischemic tissue damage.

Aged↗
PubMed1994

MRI in acute cerebral ischaemia: perfusion imaging with superparamagnetic iron oxide in a rat model.

An imaging technique capable of detecting ischaemic cerebral injury at an early stage could improve diagnosis in acute or transient cerebral ischaemia. We compared the ability of superparamagnetically contrast-enhanced MRI and conventional T2-weighted MRI to detect ischaemic injury early after unilateral occlusion of the middle cerebral artery in 12 male Wistar rats. Permanent vessel occlusion was achieved by a transvascular approach, which has the advantage of not requiring a craniectomy. At 45-60 min after the procedure, the animals had conventional T2-weighted MRI before and after administration of a superparamagnetic contrast agent (iron oxide particles). Unenhanced images were normal in all animals. After administration of iron oxide particles, the presumed ischaemic area was clearly visible, as relatively increased signal, in all animals; this high signal area corresponded to the area of ischaemic brain infarction seen on histological studies. Magnetic susceptibility effects of iron particles cause low signal in normally perfused cerebral tissue, whereas tissue with reduced or absent blood flow continues to give relatively high signal. Our results suggest that superparamagnetic iron particles may significantly reduce the interval between an ischaemic insult and the appearance of parenchymal changes on MRI.

Acute Disease↗
PubMed1994

Laser Doppler flowmetry of focal ischaemia and reperfusion in deep brain structures in rats.

Monitoring cerebral blood flow during focal ischaemia and reperfusion with established techniques such as hydrogen clearance and autoradiography is difficult. Laser Doppler flowmetry is a new technique, it allows one to continuously measure blood flow in small tissue samples. The objective of this study was to compare laser Doppler flowmetry with hydrogen clearance using a new single fiber probe to obtain measurements in deep brain structures and then to show the temporal profile of cerebral blood flow during focal ischaemia and after reperfusion. First, the single fiber laser Doppler method was compared with the hydrogen clearance method in ten Wistar rats. Second, focal cerebral ischaemia was induced in fifteen Wistar rats using a model of middle cerebral artery occlusion based on the intravascular insertion of a nylon suture; reperfusion occurred after withdrawal of the suture. The laser Doppler probe was placed in the lateral caudatoputamen, and local cerebral blood flow was measured continuously before and during occlusion as well as after reperfusion. The relative blood flow values obtained by the laser Doppler method and the hydrogen clearance method showed a good correlation (r = 0.76) and a linear relationship. A rapid decrease in laser Doppler flowmetry to 42 +/- 16% of former baseline values was seen with occlusion of the middle cerebral artery; during occlusion cerebral blood flow remained at this level. Reperfusion resulted in a heterogeneous pattern of cerebral blood flow as laser Doppler flowmetry values ranged from 25% to 134% of baseline values. The effects of middle cerebral artery occlusion and reperfusion on cerebral blood flow can be monitored on-line with laser Doppler flowmetry.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Modification of platelet aggregation by leukocytes in acute ischemic stroke.

BACKGROUND AND PURPOSE: Platelet aggregation plays an important role in the pathogenesis of thromboembolic cerebrovascular disease. Leukocytes can efficiently stimulate as well as inhibit platelet aggregability. We studied the influence of leukocytes on collagen-induced platelet aggregation in patients with acute ischemic stroke. METHODS: We investigated 23 patients within 2 days after stroke and 23 healthy age- and sex-matched control subjects and determined collagen-induced platelet aggregation in platelet-rich plasma with or without addition of polymorphonuclear or mononuclear leukocytes. RESULTS: Platelet aggregation without leukocytes tended to be lower in patients than in control subjects (P = .06). Mononuclear leukocytes reduced (P = .018) and polymorphonuclear leukocytes tended to reduce (P = .06) platelet aggregation in patients. Leukocytes did not significantly alter platelet aggregation in control subjects. In the presence of either mononuclear or polymorphonuclear leukocytes, platelet aggregation was significantly lower in patients than in control subjects (P = .004 and P = .008). The ratio of polymorphonuclear leukocytes to platelets in venous blood was higher in patients than in control subjects (P < .001). CONCLUSIONS: Mononuclear--and less clearly polymorphonuclear-leukocytes possess a platelet aggregation-inhibiting potential in the early stages after ischemic stroke, a feature with possible antithrombotic effects.

Acute Disease↗
PubMed1994

[Therapeutic hypothermia after cerebral ischemia. Theoretical principles and possible clinical applications].

In animal models of cerebral ischemia hypothermia has been shown to have a beneficial effect. Reduction of infarct size, fewer potentially neurotoxic metabolites, and a better neurological outcome were observed compared to sham-operated animals. In clinical practice hypothermia has been widely used in cardiovascular surgery and occasionally in neurosurgery. The first trials with hypothermia in patients with severe head injury have also shown beneficial results. However, studies on therapeutic hypothermia in the clinical management of acute stroke are not yet available.

Animals↗
PubMed1994

Sensitivity and prognostic value of early CT in occlusion of the middle cerebral artery trunk.

PURPOSE: To investigate the incidence and prognostic value of local brain swelling, the extent of parenchymal hypodensity, and the hyperdense middle cerebral artery sign as shown by CT within the first 5 hours after the onset of symptoms in patients with angiographically proved middle cerebral artery trunk occlusions. METHODS: Fifty-three patients were studied prospectively with CT 46 to 292 minutes (median, 120; mean, 134 +/- 59) after symptom onset and scored clinically at admission and 4 weeks later. All patients were treated with recombinant tissue plasminogen activator (30 to 100 mg). RESULTS: Early CT showed parenchymal hypodensity in 43 patients (81%), local brain swelling in 20 patients (38%), and hyperdensity of the middle cerebral artery trunk in 25 patients (47%). Hypodensity covering more than 50% of the middle cerebral artery territory had an 85%, local brain swelling a 70%, and the hyperdense middle cerebral artery sign a 32% positive predictive value for fatal clinical outcome. Specificity of these findings for fatal outcome was 94%, 83%, and 51%, respectively, and sensitivity was 61%, 78% and 44%, respectively. CONCLUSIONS: Early CT in acute middle cerebral artery trunk occlusion is highly predictive for fatal clinical outcome if there is extended hypodensity or local brain swelling despite aggressive therapeutic attempts such as thrombolysis or decompressive surgery.

Adult↗
PubMed1993

Prospective evaluation of the prognostic significance of evoked potentials in acute basilar occlusion.

OBJECTIVE: To establish valid prognostic parameters in patients with acute basilar artery occlusive disease. DESIGN: A prospective study. SETTING: Neurocritical care unit at the University of Heidelberg. PATIENTS: Twenty-three patients (12 male, 11 female; 32 to 69 yrs of age, median 54) with acute basilar occlusions. INTERVENTIONS: Angiography, brainstem auditory and somatosensory evoked potentials. MEASUREMENTS AND MAIN RESULTS: Clinical and electrophysiologic data were obtained before angiography and thrombolytic therapy. Outcome was classified according to a slightly modified Glasgow Outcome Scale at discharge from the intensive care unit (ICU). Level of consciousness was determined in four classes: awake (n = 4); somnolence (n = 7); stupor (n = 4); and coma (n = 8). Bilateral recordings of brainstem auditory and somatosensory evoked potentials were ranked in three categories: normal; one side normal; and both sides abnormal. Of 23 sets of evoked potential recordings, brainstem auditory evoked potentials were normal in seven patients, one side abnormal in four patients, and both sides abnormal in 12 patients. Somatosensory evoked potentials were normal in eight patients, one side abnormal in eight patients, and both sides abnormal in seven patients. A combination of both evoked potential modalities demonstrated normal results in three patients, one side abnormal recordings in six patients, and both sides abnormal findings in 14 patients. Outcome was ranked in three groups: five individuals had a good recovery or moderate disability; two patients remained severely disabled; and 16 patients persisted either in a locked-in state or died. Statistical analysis using Fisher's exact test demonstrated a significant correlation between the initial brainstem auditory evoked potential findings and outcome (p < .005), while for the initial somatosensory evoked potentials a significant correlation with outcome was not identified (p = .089). All patients with normal brainstem auditory and somatosensory evoked potential findings did well, whereas all patients with bilateral (both sides) abnormal brainstem auditory evoked potential and bilateral abnormal somatosensory evoked potential remained locked-in or died. CONCLUSION: Initial brainstem auditory evoked potential and somatosensory evoked potential testing are valid prognostic parameters on which to base therapeutic decisions in patients with acute basilar occlusion.

Acute Disease↗
PubMed1993

Prognostic and clinical relevance of pupillary responses, intracranial pressure monitoring, and brainstem auditory evoked potentials in comatose patients with acute supratentorial mass lesions.

OBJECTIVE: To test the hypothesis that the clinical condition and outcome in patients with acute supratentorial mass lesions can be assessed by determination of pupillary abnormalities, measurement of intracranial pressure, and results of brainstem auditory evoked potentials. DESIGN: Prospective case series of 55 patients presenting with supratentorial mass lesions. SETTING: Neurologic and neurosurgical intensive care unit of a tertiary care center. PATIENTS: Fifty-five comatose patients (26 female/29 male; 9 to 70 yrs of age [mean 44]). INTERVENTIONS: Pupillary abnormalities were rated "normal," "unilaterally enlarged," "unilaterally fixed," and "bilaterally abnormal." The outcome was rated using the Glasgow Outcome Scale. Intracranial pressure values were graded into five categories. Brainstem auditory evoked potentials were rated "bilaterally normal," "unilaterally abnormal," or "bilaterally abnormal," according to normative data. Statistical evaluation was performed by frequency analysis (Fisher's exact test, two-tailed) and calculation of contingency coefficients. MEASUREMENTS AND MAIN RESULTS: Outcome was poor in 24 patients, good in eight patients, and 23 patients were severely disabled. Statistical analysis showed prognostic significance of both pupillary abnormalities (p = .0000542; contingency coefficient = .589) and increased intracranial pressure (p = .0084; contingency coefficient = .352). Brainstem auditory evoked potential categories correlated significantly with pupillary abnormalities (p = .000276; contingency coefficient = .505) and increased intracranial pressure (p = .0301; contingency coefficient = .502) but did not predict outcome (p = .645; contingency coefficient = .321). CONCLUSIONS: Pupillary abnormalities may serve as a reliable parameter, which may even be superior to brainstem auditory evoked potential testing and intracranial pressure monitoring for prediction of outcome in comatose individuals with supratentorial mass lesions. Brainstem auditory evoked potentials can be used to support the clinical relevance of abnormal pupillary status and increased intracranial pressure but are of no prognostic value. Increased intracranial pressure is associated with abnormalities in pupillary status and brainstem auditory evoked potentials. Examination for pupillary abnormalities in combination with intracranial pressure monitoring and brainstem auditory evoked potential testing seems to be a useful strategy in managing patients with supratentorial mass lesions in critical care units.

Acute Disease↗
PubMed1993

[Experiences with high dosage immunoglobulin G in neuromuscular diseases].

High-dose intravenous immunoglobulin G (IVIG) was used as alternative treatment in 39 patients with crisis in myasthenia gravis (MG), acute polyneuritis (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP). Of 10 patients with MG, 3 recovered completely, 5 patients improved except for long-standing ocular signs, 1 patient was weaned from artificial ventilation, and one patient did not improve after IVIG, but did so after plasma exchange. 25 GBS patients were treated with IVIG, progression of weakness was stopped in 24; 12 showed complete or near complete recovery and 6 improved markedly. Of 4 patients with CIDP, 2 responded definitely. The majority of patients with MG, GBS, CIDP, respond to IVIG treatment. The effect seems to be equivalent to plasma exchange. In GBS, IVIG may be superior. Side effects of IVIG are negligible, and there is no risk of transmission of AIDS-, hepatitis-, or other viruses.

Adult↗