Neurosurgery
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Clinical observations of patients with both Chiari Malformation Type I (CIM) and tethered spinal cord (TSC), have led some to speculate that there may be an association between the two entities. However, the level of evidence for this association is anecdotal. We examined a large group of subjects to evaluate the association between CIM and TSC. ⋯ There was no statistically significant association between CIM and low conus position. We conclude that patients with CIM do not have lower conus position compared with matched normals, and that TSC is not associated with CIM for most patients.
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Considerable evidence points to cortico-striato-thalamo-cortical circuits in cognitive, limbic, and motor functions. Specifically, the connections between caudate, nucleus accumbens (NAc), and prefrontal cortex have been implicated in behavioral learning and motivation. Precisely timed stimulation of the caudate during a behavioral task enhances learning beyond baseline in normal primates. We test the overarching hypothesis that combined intermittent stimulation of the caudate and NAc leads to enhanced learning. Our specific hypothesis is that there are 2 streams of information processing in the anterior striatum, dorsal and ventral, that perform complementary but different roles. We believe that the dorsal stream, which includes the caudate, is involved in the executive aspect of associative learning, whereas the ventral stream, which includes the NAc, is involved in providing the motivation for the performance of learned behavior. ⋯ Enhancing visuomotor performance may be beneficial to patients who have cognitive-motor deficits caused by traumatic brain injury. Deep brain stimulation strategies augmenting learning and motivational processes could be used in humans to enhance a broad range of functions including gross motor movements and decision making.
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Darbepoetin alpha is a hypersialylated analogue of erythropoietin effective on activating erythropoietin receptors. This study investigated the vasodilator and neuroprotective effects of darbepoetin alpha on experimental subarachnoid hemorrhage model and compared them with erythropoietin. ⋯ Our findings, for the first time, showed that darbepoetin alpha can prevent vasospasm and provides neuroprotection following experimental subarachnoid hemorrhage. Moreover, darbepoetin alpha showed better results when compared with erythropoietin.