Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2005
Clinical TrialMRI study of cerebral blood flow and CSF flow dynamics in an upright posture: the effect of posture on the intracranial compliance and pressure.
Postural related changes in cerebral hemodynamics and hydrodynamics were studied using Magnetic Resonance Imaging (MRI) measurements of cerebral blood flow and cerebrospinal fluid (CSF) flow dynamics. Ten healthy volunteers (mean age 29 +/- 7) were studied in supine and upright (sitting) postures. A Cine phase-contrast MRI technique was used to image the pulsatile blood flow to the brain, the venous outflow through the internal jugular, epidural, and vertebral veins, and the bi-directional CSF flow between the cranium and the spinal canal. ⋯ A considerable smaller amount of CSF flow between the cranium and the spinal canal (58%), a much larger intracranial compliance (a 2.8-fold increase), and a corresponding decrease in the MRI-derived ICP were also measured in the sitting position. These changes suggest that the increased cerebrovascular and intracranial compliances in the upright posture are primarily due to reduced amounts of blood and CSF residing in their respective intracranial compartments in the upright position. This work demonstrates the ability to quantify neurophysiologic parameters associated with regulation of cerebral hemodynamics and hydrodynamics from dynamic MR imaging of blood and CSF flows.
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Acta Neurochir. Suppl. · Jan 2005
Clinical TrialParaspinal approach to the far lateral disc herniations: retrospective study on 42 cases.
Forty-two patients underwent surgery for far-lateral disc herniations. Average patient age was 45.1 years, 28 patients were male and 14 female. The level concerned most was L4-5 disc (55%). ⋯ It requires minimal soft-tissue and bone resection and the herniated disc is directly visualized. Moreover, it contains minimal manipulation of the neuro-vascular structures and avoids significant muscle retraction. However, it requires an adequate learning curve and good familiarity with microsurgical techniques.
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Acta Neurochir. Suppl. · Jan 2005
Clinical TrialRe-defining the ischemic threshold for jugular venous oxygen saturation--a microdialysis study in patients with severe head injury.
Neurological change is more likely to occur when jugular venous oxygen saturation (SjvO2) is less than 50%. However, the value indicating cellular damage has not been clearly defined. We determined the critical SjvO2 value below which intracerebral extracellular metabolic abnormalities occurred in 25 patients with severe head injury. ⋯ Analysis of variance showed that there were rapid increases in glutamate, glycerol and lactate when SjvO2 dropped below 40, 43 and 45% respectively. Extracellular glucose decreased when SjvO2 dropped below 42%. Our findings suggested that the ischemic threshold for SjvO2 in patients with severe head injury is 45%, below which secondary brain damage occurred.
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1) Numerous of the so-called "unpredictable" post-operative complications are likely to be related to the lack of prevention or non-recognition of venous problems, especially damages to the dangerous venous structures, namely: the major dural sinuses, the deep cerebral veins and some of the dominant superficial veins like the vein of Labbé. 2) Tumors invading the major dural sinuses (superior sagittal sinus, torcular, transverse sinus)--especially meningiomas--leave the surgeon confronted with a dilemma: leave the fragment invading the sinus and have a higher risk of recurrence, or attempt at total removal with or without venous reconstruction and expose the patient to a potentially greater operative danger. Such situations have been encountered in 106 patients over the last 25 years. For decision-making, meningiomas were classified into six types according to the degree of sinus invasion. ⋯ Type V: this type can be recognized from type VI only by direct surgical exploration of the sinus lumen. Opposite wall to the tumor side is free of tumor, it is possible to reconstruct the two resected walls with patch. Type VI: removal of involved portion of sinus and restoration with venous bypass. 3) As 20% of the patients presenting with manifestations of intracranial hypertension due to occlusion of posterior third of the superior sagittal sinus, torcular, predominant lateral sinus or internal jugular vein(s) develop severe intracranial hypertension, venous revascularisation by sino-jugular bypass--implanted proximally to the occlusion and directed to the jugular venous system (external or internal jugular vein)--can be a solution.
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Acta Neurochir. Suppl. · Jan 2005
ReviewAssessment of health-related quality of life in persons after traumatic brain injury--development of the Qolibri, a specific measure.
Health-related quality of life (HRQOL) associated or not with the measurement of neuropsychological functioning is a relatively new outcome variable in the field of traumatic brain injury (TBI). In both cases, accuracy and precision are increased in outcome estimation. Validation of generic, cross-culturally (cc) administered HRQOL measures in persons after TBI is not yet well established. Disease-specific HRQOL instruments do not exist in an international context. The objective here is to present the TBI consensus group's (QOLIBRI-Group) approach in cc development of a specific HRQOL measure--the QOLIBRI (Quality of Life after Brain Injury). ⋯ In TBI patients, generic and disease-specific aspects of HRQOL need to be assessed with measures of adequate psychometric quality, applicable across different populations and cultural conditions. The QOLIBRI is a promising instrument for sensitive patient-centered specific outcome evaluation after TBI.