Neurosurgery
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Endothelin (ET) immunoreactivity, ET production, and specific ET receptors have been identified in the brain. Changes in ET concentration or receptor expression have been implicated in the pathophysiological changes in vasospasm after subarachnoid hemorrhage and in cerebral neoplasia. In this study, we have characterized the ET(A) and ET(B) receptor subtypes present in human normal cerebral cortex (NCC) and two common central nervous system tumors, i.e., meningioma (MNG) and glioblastoma multiforme (GBM). A knowledge of the ET receptor subtypes present may provide a novel therapeutic target for newly developed ET antagonists. ⋯ ET(A) receptors are expressed in high concentrations in MNGs and in the vasculature of NCC and GBMs. The ET(A)-selective antagonist PD156707 may be of potential therapeutic value in vascular and neoplastic diseases of the central nervous system.
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Extraforaminal disc herniations today are operated on via the so-called lateral approach. Clinical experience has shown that in contrast to levels L2/3-L4/5, this approach may become extremely difficult at the L5-S1 level. According to new microanatomic studies, the previous lateral approaches at this level often do not allow access to the neuroforamen without partial or total destruction of the L5-S1 facet joint. Postoperatively, this may lead to joint irritation with consecutive low back and pseudoradicular pain. To preserve the facet joint, a new approach was developed based on an anatomic study. ⋯ Using this new approach, the L5-S1 joint remains intact. Space for instrumental manipulations is created in areas not essential for joint function. For this procedure, newly defined anatomic landmarks, such as the ileolumbar ligament, upper edge of the sacrum, lateral rim of the apophyseal joint, and para-articular notch, guide the operative route. In accordance with the preliminary anatomic studies, this approach was successfully used in 13 patients, and we think that it is a promising alternative that helps to preserve joint function and dorsal root ganglion integrity.
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Clinical Trial
Reassessment of the role of radiation therapy in the treatment of endocrine-inactive pituitary macroadenomas.
This prospective clinical trial was undertaken to assess the rate of tumor recurrence in patients with endocrine-inactive pituitary macroadenomas who underwent gross total surgical resection of their tumors and did not receive adjuvant radiotherapy. ⋯ This study demonstrates a 6% 5-year recurrence rate in patients with endocrine-inactive pituitary macroadenomas treated using gross total surgical resection alone. Reserving radiation therapy for the infrequent patient with recurrence and sparing the majority of patients the associated risks inherent in its use seems reasonable.
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Many studies have been conducted of the surgical anatomy of the frontotemporal branch of the facial nerve (FTBFN). However, very few have addressed the indications for interfascial dissection. When the zygomatic arch needs to be exposed, the interfascial approach is recommended to protect the FTBFN. With the transbasal or subfrontal approaches, however, when a bicoronal skin incision is used, the need for the interfascial approach is not clear. ⋯ Ahove the zygomatic arch, the FTBFN is not protected by the galea. During bicoronal approaches, if only the superolateral angle of the orbital rim needs to be exposed and not the zygomatic arch, there is no need to protect the FTBFN using an interfascial approach.
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Review Case Reports
Cervical myelopathy caused by hypoplasia of the atlas: two case reports and review of the literature.
Congenital anomalies of the posterior arch of the atlas (C1) are uncommon. They range from partial clefts to total agenesis of the posterior arch. Developmental cervical canal stenosis is a congenital anomaly that may cause cervical myelopathy. Myelopathy caused by cervical stenosis at the level of the atlas has been reported in only three cases. We present two cases of nontraumatic cervical myelopathy caused by spinal stenosis at the level of the atlas associated with a hypoplastic but complete posterior arch of C1. ⋯ The anomaly presented in our two cases differs from the established classification of congenital abnormalities of the posterior arch of the atlas, suggesting a different embryological defect. The hypoplastic posterior C1 arch created a congenitally narrowed spinal canal in our patients, rendering the spinal cord more susceptible to compression related to degenerative changes of the spine. Surgical removal of the shortened posterior C1 arch and surrounding degenerative ligaments is an effective treatment for symptomatic patients with this condition.