Journal of neurosurgery
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Journal of neurosurgery · Jun 2010
ReviewThe critical role of hemodynamics in the development of cerebral vascular disease.
Atherosclerosis and intracranial saccular aneurysms predictably localize in areas with complex arterial geometries such as bifurcations and curvatures. These sites are characterized by unique hemodynamic conditions that possibly influence the risk for these disorders. One hemodynamic parameter in particular has emerged as a key regulator of vascular biology--wall shear stress (WSS). ⋯ In addition, multiple studies indicate that disturbed flow and low WSS predispose patients to extracranial atherosclerosis, and particularly to carotid artery disease. Conversely, in the case of intracranial atherosclerosis, more studies are needed to provide a firm link between hemodynamics and atherogenesis. The recognition of WSS as an important factor in cerebral vascular disease may help to identify individuals at risk and guide treatment options.
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Journal of neurosurgery · Jun 2010
Burst stimulation of the auditory cortex: a new form of neurostimulation for noise-like tinnitus suppression.
Tinnitus is an auditory phantom percept related to tonic and burst hyperactivity of the auditory system. Two parallel pathways supply auditory information to the cerebral cortex: the tonotopically organized lemniscal system, and the nontonotopic extralemniscal system, which fire in tonic and burst mode, respectively. Electrical cortex stimulation is a method capable of modulating activity of the human cortex by delivering stimuli in a tonic or burst way. Burst firing is shown to be more powerful in activating the cerebral cortex than tonic firing, and bursts may activate neurons that are not activated by tonic firing. ⋯ Burst stimulation is a new form of neurostimulation that might be helpful in treating symptoms that are intractable to conventional tonic stimulation. Further exploration of this new stimulation design is warranted.
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Journal of neurosurgery · Jun 2010
Alleviation of off-period dystonia in Parkinson disease by a microlesion following subthalamic implantation.
A collision/implantation or microlesion effect is commonly described after subthalamic nucleus (STN) implantation for high-frequency stimulation, and this is presumed to reflect disruption of cells and/or fibers. Off-period dystonia, a frequent cause of disability in patients with advanced Parkinson disease, can lead to the need for surgical treatment. The authors assessed the early effect of this microlesion on off-period dystonia. ⋯ The author postulated that off-period dystonia alleviation may reflect both a microsubthalamotomy and micropallidotomy effect. They hypothesize, moreover, that the microlesion could play a role in the 6-month postoperative outcome.
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Journal of neurosurgery · Jun 2010
Biography Historical ArticleA unique experiment in neurological surgery: intracerebral injection of antitoxin for tetanus.
The discipline of neurological surgery was considered primarily "hopeless" and, at best, experimental in the late 19th century. Harvey Cushing's efforts during his initial uncharted voyage through the surgery of the human cranium were rudimentary and exploratory. ⋯ This case represents the intersection of neurosurgery and tetanus treatment in Dr. Cushing's intracerebral injection of antitoxin to treat generalized tetanus.
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A wide range of devices is used to obtain intracranial electrocorticography recordings in patients with medically refractory epilepsy, including subdural strip and grid electrodes and depth electrodes. Penetrating depth electrodes are required to access some brain regions, and 1 target site that presents a particular technical challenge is the first transverse temporal gyrus, or Heschl gyrus (HG). The HG is located within the supratemporal plane and has an oblique orientation relative to the sagittal and coronal planes. ⋯ In this report, the authors describe an alternative method for implantation. They use frameless stereotaxy and an oblique insertion trajectory that does not require angiography and allows for the simultaneous placement of subdural grid arrays. Results in 19 patients demonstrate the safety and efficacy of the method.