Acta neurochirurgica. Supplement
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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
ReviewMicrodialysis in traumatic brain injury--methodology and pathophysiology.
The application of clinical microdialysis to monitor changes in cerebral extracellular chemistry is now well established in several neurosurgical units worldwide. In neuro-intensive care the technique has been predominantly applied to patients with traumatic brain injury and subarachnoid haemorrhage. ⋯ This involves establishing the relationship between microdialysis and outcome, and the effect of therapeutic manoeuvres on the chemistry. This manuscript describes the place of microdialysis in traumatic brain injury in terms of the fundamental principles, methodology, pathophysiology and clinical application.
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In neurorehabilitation, transcranial magnetic stimulation (TMS) offers information regarding prognosis and pathophysiology and could also be useful for therapeutic purposes. Numerous studies have indicated that, after stroke, the absence of motor evoked potentials is associated with a poor motor recovery. In contrast, MEPs obtained in the paretic muscle with low stimulus intensities suggest a good restitution of motor function. ⋯ Stroke patients participating in a Constraint-induced movement therapy show an enlargement of the motor output area in the affected hemisphere after therapy. This enhancement of motor excitability is associated with an improvement of motor function. Some evidence is emerging that the application of low frequency repetitive TMS over the non-lesioned hemisphere improves neglect phenomena by down-regulation of the excitability of the non-lesioned hemisphere.
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Acta Neurochir. Suppl. · Jan 2005
Randomized Controlled TrialThe influence of mild hypothermia on ICP, CPP and outcome in patients with primary and secondary brain injury.
Aim of this study was to examine the hypothesis that only a subgroup of patients with lesser primary brain damage after severe head injury may benefit from therapeutic hypothermia. We prospectively analysed 72 patients with severe head injury, randomized into groups with (n = 37) and without (n = 35) hypothermia of 34 degrees C maintained for 72 hours. The influence of hypothermia on ICP, CPP and neurological outcome was analysed in the context of the extent of primary brain damage. ⋯ Patients with hypothermia and extracerebral hematomas (n = 14): GCS 5, ICP 13.2, CPP 78, GOS 5. Hypothermia decreased ICP and increased CPP regardless of the type of brain injury. Hypothermia was not able to improve outcome in patients with primary brain lesions but this pilot study suggests that it significantly improves outcome in patients with extracerebral hematomas.
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Acta Neurochir. Suppl. · Jan 2005
ReviewNear infrared spectroscopy in brain injury: today's perspective.
The technique of near infrared spectroscopy (NIRS) is based on the principle of light attenuation by the chromophores oxyhaemoglobin (HbO2), deoxyhaemoglobin (Hb) and cytochrome oxidase. Changes in the detected light levels can therefore represent changes in concentrations of these chromophores. Clinical use of NIRS in the brain has been well established in neonates where transillumination is possible. ⋯ Recent technical advances have led to the development of compact, portable instruments that detect changes in optical attenuation of several wavelengths of light. Near infrared spectroscopy is an evolving technology that holds significant potential for technical advancement. In particular, NIRS shows future promise as a clinical tool for bedside cerebral blood flow measurements and as a cerebral imaging modality for mapping structure and function.