Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 1998
Effects of systemic hypothermia and selective brain cooling on ischemic brain damage and swelling.
The present study investigates the neuroprotective effects of temporary mild systemic hypothermia and selective brain cooling against focal cerebral infarction in the rat and the changes of cortical blood flow, and compares these two treatment modalities. In permanent middle cerebral artery (MCA) model, the treatments were induced 15 min following the artery occlusion. The animals were kept at the desired rectal or brain temperature (about 32 degrees C) for 30 min; (each, n = 6) and for 1 hr (each, n = 6), and then allowed to rewarm spontaneously, whereas control animals were kept at normothermia throughout the experiment. ⋯ However, in the selective brain cooling, the reduced blood flow increased from 40% to 70% of baseline value while the brain was rewarmed. The present study indicates that mild systemic hypothermia has much stronger protective effects against focal cerebral infarction and edema than selective brain cooling. The lack of protective effects of selective brain cooling may be caused by post-cooling cerebral hyperemia in the ischemia area.
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Acta Neurochir. Suppl. · Jan 1998
Increase in transcranial Doppler pulsatility index does not indicate the lower limit of cerebral autoregulation.
Transcranial Doppler pulsatility index was reported clinically to increase when cerebral perfusion pressure decreased, hypothetically marking the lower limit of cerebral autoregulation. We sought to investigate the relationship between pulsatility index, cerenbrovascular resistance, and cerebral perfusion pressure in various states of autoregulation in an animal model of moderate intracranial hypertension. ⋯ The increase in transcranial Doppler pulsatility index when cerebral perfusion pressure falls cannot be interpreted as a phenomenon able to mark the lower limit of cerebral autoregulation.
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Acta Neurochir. Suppl. · Jan 1997
Clinical TrialNear infrared spectroscopy (NIRS) in patients with severe brain injury and elevated intracranial pressure. A pilot study.
Near infrared spectroscopy (NIRS) was used to asses changes in regional cerebral oxygen saturation (rSO2) in 8 head injured patients with an intracranial pressure (ICP) higher or lower than 25 mmHg (n = 4 for each group). NIRS values in the high ICP group (> 25 mmHg) were significantly lower than in the low ICP group (< 25 mmHg). In contrast, arterial pO2, pCO2, peripheral oxygen saturation and transcranial Doppler sonography (TCD) values were similar in both groups. ⋯ However, rSO2 values in patients with an ICP > 25 mmHg were significant lower than in patients with an ICP < 25 mmHg after the hyperoxygenation period. In addition, patients with an ICP < 25 mmHg revealed a significant increase in rSO2 values at the end of the hyperoxygenation period, not detectable in patients with an ICP > 25 mmHg. Our results suggest that NIRS may be an additional diagnostic tool in the non-invasive evaluation of impaired cerebral microcirculation in patients with increased intracranial pressure.
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Board certification and accreditation of training programs began as measures of quality in the United States. Both functions were done initially by the American Board of Neurological Surgery (ABNS). In 1954, certification of trainees and accreditation of programs became separate functions in order to eliminate potential conflicts of interest. ⋯ Accreditation of training programs is a separate function administered by the Residency Review Committee (RRC) of the Accreditation Council for Graduate Medical Education. Individual programs are reviewed on a periodic basis for quality of the curriculum, facilities, faculty, and patient volume. The ABNS and the RRC are separate groups, both comprised of neurosurgeons with a strong commitment to the educational process.