ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Elevated blood flow velocity (BFV), measured by transcranial Doppler (TCD), has been associated with hyperemia and cerebral vasospasm. This study examined whether the lack of a diastolic notch within the TCD waveform was associated with relative hyperemia within 5 days after injury in 35 traumatic brain injured (TBI) patients. Hyperemia (avDO2of < 4 ml/dL) was present in 16 patients and absent in 19 patients. Two clinicians independently coded TCD waveforms based on the presence of a diastolic notch (88% agreement). There was no significant difference in the presence of a diastolic notch by group; a diastolic notch was present in 57% (11/19) of patients without hyperemia and 81% (13/16) of patients with hyperemia. Sensitivity and specificity of detecting hyperemia using the diastolic notch was 18.7% and 57.9% respectively. The results showed that relative hyperemia was present without an elevation in blood flow velocities, and that the lack of a diastolic notch did not detect the presence of hyperemia in the TBI patient.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

When shunts are selectively used during carotid endarterectomy, the adequacy of collateral cerebral blood flow (CBF) after the carotid artery is clamped is determined by monitors based on different physiologic measurements. In this series of three patients, we used electroencephalography (EEG) to measure neuronal electrical activity and transcranial Doppler ultrasonography (TCD) to measure CBF velocity. In each of our cases, the EEG was unchanged from preclamp values, while TCD CBF velocity was dramatically reduced. All three patients had transient neuropsychometric or neurologic changes after surgery, which resolved.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Sevoflurane is a volatile anesthetic agent that reduces cerebral metabolism and thereby may reduce neuronal damage during energy deprivation. We have examined the effect of sevoflurane on hypoxic neuronal damage in rat hippocampal slices. Slices were subjected to 0%, 2%, or 4% sevoflurane 10 minutes before, during, and 10 minutes after hypoxia. The Schaffer collateral pathway was stimulated every 10 seconds and the evoked population spike recorded in the CA1 pyramidal cell region throughout the experiment. During hypoxia, the postsynaptic evoked response was blocked. The time until the blockade of this response in the 0% sevoflurane group was 158 seconds. Sevoflurane (4%) significantly delayed the loss of the evoked response during hypoxia (242 seconds). The percent recovery of the postsynaptic population spike was calculated by dividing the size of the response 120 minutes after hypoxia by its prehypoxic, presevoflurane amplitude. There was no recovery of the population spike in the 0% sevoflurane group 120 minutes after the end of 5 minutes of hypoxia (6 ± 6%); there was significantly better recovery after 5 minutes of hypoxia in the sevoflurane (4%) treated group (40 ± 9%). A lower concentration of sevoflurane (2%) delayed the loss of evoked response during hypoxia (191 seconds), but it did not significantly affect recovery of the population spike after hypoxia (7 ± 7%). Hypoxia irreversibly damages electrophysiologic activity. A high, but clinically usable, concentration of sevoflurane increases the time during hypoxia until the postsynaptic evoked response is blocked and improves recovery of this response after 5 minutes of hypoxia.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

We report continuous bilateral intracranial pressure (ICP) monitoring immediately after transtentorial herniation in a patient with massive cerebral infarction to: 1) determine presence and time course of compartmental ICP differences, and 2) to study effects of therapy on both hemispheres. A 55-year-old man admitted with watershed infarctions in the left anterior-middle-posterior cerebral arteries distribution. Initial investigations demonstrated highly narrowed left extracranial internal carotid artery. Eight days later he developed unexplained lethargy and anisocoria. Head computerized tomography (CT) showed massive left hemispheric infarction, edema, and midline shift. Bilateral subarachnoid bolts demonstrated equally elevated ICP in both hemispheres. Hyperventilation and osmotic therapy produced near-identical ICP reduction bilaterally with resolution of anisocoria. Later, plateau waves and autonomic instability developed. Shortly before loss of brainstem function, interhemispheric ICP gradients (left greater than right) of 30–40 mm Hg developed. Intracranial pressure did not equalize prior to brain death determination. Bilateral ICP monitoring did not reveal an interhemispheric ICP gradient soon after transtentorial herniation in massive MCA infarction. The presence of interhemispheric ICP gradients in massive stroke remains unproven and further clinical study is necessary.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Elevated body temperature increases mortality and worsens outcome in acute stroke patients. In animal models of stroke, even slight hypothermia was shown to be neuroprotective. Pharmacological treatment alone (paracetamol, metamizol) usually fails to lower core body temperature below 37°C. The purpose of this study was to establish the feasibility and safety of continuous body surface cooling towards low normothermic temperatures in noncomatose, nonventilated stroke unit patients.Eighteen acute stroke patients (15 ischemic infarcts, 3 hemorrhages) with baseline body core temperatures >37.0°C (taken in the urinary bladder) were laid on a water-perfused cooling mattress and received pethidine and dihydroergotoxine in order to avoid shivering and peripheral vasoconstriction. The target range for core body temperature was between 36 and 37°C for 24 hours. None of the patients was treated with antipyretic drugs during the cooling period.Median baseline National Institutes of Health Stroke Scale score (NIHSSS) was 15.5 (8–24). Three patients had core temperatures >38°C. A temperature in the target range could be reached within 3.3 hours (median) and maintained in all but two patients. Major procedure-related adverse events were vomiting (n = 2), drop in mean arterial blood pressure >20% (n = 2), pneumonia (n = 2), and a rise in central venous pressure >20 cm H2O (n = 3) totaling 9 events in 8 of 18 patients (44%). No patient died within the first week; mortality after three months was 12%.Continuous body core temperature reduction of 1–2°C may safely be attained by a cooling mattress in nonventilated stroke unit patients. Critically high temperature values can be avoided. The neuroprotective potential of this method has to be assessed in a controlled trial.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

We report the case of two patients involved in a car crash and victims of multiple injuries. The diagnosis of bilateral dissection of the internal carotid arteries was only evoked belatedly in view of the increase of the neurologic symptoms. They benefitted from anticoagulant treatment. The clinical evolution was good. Dissection of both carotid arteries from blunt head or neck trauma has been reported but is unusual. Diagnosis and treatment are discussed.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

We report an unusual case of fatal intracranial hypertension following tracheostomy due to the obstruction of the internal jugular veins (left side: thrombosis after central venous cannulation, right side: hypoplastic vein) and their collaterals. Principal cerebral outflow through the internal jugular veins can be substituted by the internal and external vertebral vein plexus because blood drains from the brain by two major routes: the internal jugular veins and the vertebral venous plexus. We suggest transcranial color-coded duplexsonography as a simple bedside method to detect patients with significant reduction of venous drainage who are at risk of developing massive cerebral venous congestion as a result of reduced intracranial elastance.

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID

ISSN:0898-4921    

出版商:OVID    

年代:2002

数据来源: OVID