Orthogonal polarization spectral imaging is a suitable method to study cerebral microcirculation during surgery. In patients with SAH, capillary density is significantly decreased and small arteries and arterioles of the cortical surface exhibit vasospasm that cannot be detected by angiography or transcranial Doppler sonography. These changes may contribute to the initial clinical symptoms and may have an influence on the clinical postoperative course.
One- and two-level ACDF with stand-alone empty PEEK cages achieved very high fusion rates and a low rate of follow-up operations. The rate of good clinical outcome is highly satisfactory. Younger age was the single most influential factor associated with better clinical outcome.
Summary:The contribution of leukocytes to secondary brain damage after cerebral ischemia is still under discussion. The purpose of the present study was to examine the pial microcir culation after global cerebral ischemia while focusing on leu kocyte-endothelium interactions during the early and late reperfusion period of up to 4 days. A closed cranial window technique that leaves the dura mater intact was used. Global cerebral ischemia of J 5 minutes' duration was induced in male Mongolian gerbils (n = 91). Pial microcirculation was ob served by intravital fluorescence microscopy. Leukocyte endothelium interactions (LEIs) in pial venules, vessel diam eters, capillary density, and regional microvascular blood flow measured by laser Doppler flowmetry were quantified during 3 hours of reperfusion and in intervals up to 4 days after isch emia. Within 3 hours of reperfusion, the number of leukocytes (cellsllOO ILm x minute) rolling along or adhering to the venular endothelium increased from 0.1 ± 0.2 to 28.4 ± 17.4 (P The activation of leukocytes during postischemic reperfusion is a pathophysiologic phenomenon that oc curs in a variety of peripheral organs as well as in brain tissue (del Zoppo et aI., 1991; Engler et aI., 1983; Hal lenbeck et aI., 1986; Menger et al., 1992). The attach ment of leukocytes to the venular endothelium and sub sequent emigration of the cells into the brain parenchyma may contribute to the development of secondary brain damage after the primary ischemic insult (Kochanek and Hallenbeck, 1992). This hypothesis, however, is mainly Abbreviations used: GCI, global cerebral ischemia; LEI, leukocyte endothelium interaction; rCBF, regional cerebral blood flow.
979< 0.01 vs. control) and from 0.2 ± 0.2 to 4.0 ± 3.8 (P < 0.05), respectively. There was no capillary plugging by leukocytes; capillary density remained unchanged. In the late reperfusion period, at 7 hours after ischemia, LEIs had returned to baseline values. Furthermore, from 12 hours to 4 days after ischemia, no LEIs were observed. Changes in regional microvascular blood flow did not correlate with LEIs. Global cerebral ischemia of 15 minutes' duration induces transient LEIs that reach a maxi mum within 3 hours of reperfusion and return to baseline at 7 hours after ischemia. LEIs are not related to changes in micro vascular perfusion, which suggests mainly that the expression of adhesion receptors is necessary to induce LEIs rather than rheologic factors. It seems unlikely that this short-lasting acti vation of leukocytes can play a role in the development of secondary brain damage.
Patients with amyotrophic lateral sclerosis (ALS) can lose all muscle-based routes of communication as motor neuron degeneration progresses, and ultimately, they may be left without any means of communication. While others have evaluated communication in people with remaining muscle control, to the best of our knowledge, it is not known whether neural-based communication remains possible in a completely locked-in state. Here, we implanted two 64 microelectrode arrays in the supplementary and primary motor cortex of a patient in a completely locked-in state with ALS. The patient modulated neural firing rates based on auditory feedback and he used this strategy to select letters one at a time to form words and phrases to communicate his needs and experiences. This case study provides evidence that brain-based volitional communication is possible even in a completely locked-in state.
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