Journal of neurosurgery
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Journal of neurosurgery · Jun 2010
Case ReportsSpontaneous involution of Rathke cleft cysts: is it rare or just underreported?
Rathke cleft cysts (RCCs) are benign cystic lesions of the sella that arise from the remnants of Rathke pouch. Although most are asymptomatic, symptoms can result from mass effect and commonly include headache, endocrinopathy, or visual field disturbance. ⋯ Spontaneous involution of an RCC may be more common than the paucity of prior reports would suggest, especially because the natural history of both symptomatic and asymptomatic RCCs is poorly understood. The potential for spontaneous involution, together with the clinical course of the patients reported here, supports a conservative approach for patients with symptomatic RCCs presenting solely with headache.
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Journal of neurosurgery · Jun 2010
Case ReportsNovel technique to improve vessel mismatch when using saphenous vein bypass grafts for intracranial revascularization procedures.
Cerebral bypass procedures in the posterior circulation are difficult to perform and are considered to be high-risk surgery. Venous grafts, like that formed using the saphenous vein (SV), are simple to obtain without posing a high risk of morbidity. The main disadvantage of these high-flow grafts is the mismatch in vessel diameter between donor and recipient vessels in the posterior circulation. ⋯ The bypass was patent; after a prolonged stay in the intensive care unit, the patient recovered gradually. This technique of linear venotomy along the distal 2.5 cm of the vein and subsequent tapering down of the diameter diminishes the circumference of the distal end of the graft, facilitating bypass to smaller vessels. This is a novel and feasible technique to eliminate vessel mismatch in cerebral bypass procedures in the difficult accessible vessels of the posterior circulation.
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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.