Current intraoperative devices to reduce visual loss after spine surgery.

Postoperative visual loss (POVL) after spine surgery performed with the patient prone is a rare but devastating postoperative complication. The incidence and the mechanisms of visual loss after surgery are difficult to determine. The 4 recognized causes of POVL are ischemic optic neuropathy (approximately 89%), central retinal artery occlusion (approximately 11%), cortical infarction, and external ocular injury. There are very limited guidelines or protocols on the perioperative practice for "prone-position" surgeries. However, new devices have been designed to prevent mechanical ocular compression during prone-position spine surgeries. The authors used PubMed to perform a literature search for devices used in prone-position spine surgeries. A total of 7 devices was found; the authors explored these devices' features, advantages, and disadvantages. The cause of POVL seems to be a multifactorial problem with unclear pathophysiological mechanisms. Therefore, ocular compression is a critical factor, and eliminating any obvious compression to the eye with these devices could possibly prevent this devastating perioperative complication.

Endoscopic image-guided transoral approach to the craniovertebral junction: an anatomic study comparing surgical exposure and surgical freedom obtained with the endoscope and the operating microscope.

OBJECTIVE: The transoral approach is the most direct and commonly used method to access the ventral craniocervical junction. Recently, an endonasal, endoscopic approach to the craniovertebral junction was proposed. We reasoned that the coupling of the endoscope with the direct transoral approach and image guidance could result in a minimally invasive, simple approach to the ventral craniovertebral junction. We investigated the potential usefulness of such an approach in a cadaver model. METHODS: A direct transoral approach to the craniovertebral junction was performed using computed tomography-based image guidance in 9 fresh adult head specimens. Endoscopic odontoidectomy was performed in 5 specimens. In the remaining 4 specimens, the surgical working area and surgical freedom associated with an endoscopic and a microscopic approach to the ventral craniovertebral junction were evaluated and compared. In these 4 specimens, we also measured and compared the exposure of the clivus provided by the endoscope and by the operating microscope without splitting the soft palate. RESULTS: With variously angled endoscopic assistance and image guidance, it was possible to tailor the excision of the anterior arch of the atlas and to precisely identify the odontoid process and its related ligaments intraoperatively, resulting in a complete and controlled odontoidectomy. The surgical area exposed over the posterior pharyngeal wall was significantly improved using the endoscope (606.5 +/- 127.4 mm3) compared with the operating microscope (425.7 +/- 100.8 mm3), without any compromise of surgical freedom (P < 0.05). The extent of the clivus exposed with the endoscope (9.5 +/- 0.7 mm) without splitting the soft palate was significantly improved compared with that associated with microscopic approach (2.0 +/- 0.4 mm) (P < 0.05). CONCLUSION: With the aid of the endoscope and image guidance, it is possible to approach the ventral craniovertebral junction transorally with minimal tissue dissection, no palatal splitting, and no compromise of surgical freedom. In addition, the use of an angled-lens endoscope can significantly improve the exposure of the clivus without splitting the soft palate. An endoscope-assisted transoral approach is a direct and powerful tool for the treatment of surgical pathology at the craniovertebral junction.

Merged imaging and expanded target selection in gamma knife radiosurgical ablation of the sphenopalatine ganglion.

Sphenopalatine neuralgia, or Sluder's neuralgia, refers to a consistent clustering of clinical symptoms: intermittent episodes of vasomotor hyperactivity causing conjuctival injection, lacrimation, serous nasal discharge and unilateral nasal mucosal inflammation, sensory disturbances of the palate and oropharynx with distorted gustatory sensations, and lancing, unilateral pain most often located in the area of the inferomedial orbit and nasal base or at the region of the mastoid process. This particular clinical entity has also proven difficult to manage effectively, especially when not clearly secondary to other medical conditions such as paranasal sinus infection or bony nasal deformities. This condition has been treated with success using Gamma Knife radiosurgery in at least 1 other case reported in the literature. We present a second patient whose sphenopalatine neuralgia was treated successfully with stereotactic radiosurgery and discuss the possibilities of this modality as an option for patients with a refractory condition.

Vision loss after spine surgery: review of the literature and recommendations.

In recent studies spinal surgery has replaced cardiac surgery as a leading cause of postoperative vision loss (POVL). Estimates of the incidence of POVL after spinal surgery range from 0.028 to 0.2%, but with advances in complex spinal instrumentation and the rise in annual spinal operations, POVL may see an ominous increase in its incidence. Postoperative vision loss is an uncommon but devastating complication, with unknown origin and pathogenesis. The authors undertook a literature review and summarize the current understanding of its pathophysiology, highlight the limitations of existing knowledge, and recommend practical guidelines for avoiding this devastating outcome.

The Eastern heart and Galen's ventricle: a historical review of the purpose of the brain.

The seat of consciousness has not always been thought to reside in the brain. Its "source" is as varied as the cultures of those who have sought it. At present, although most may agree that the central nervous system is held to be the root of individualism in much of Western philosophy, this has not always been the case, and this viewpoint is certainly not unanimously accepted across all cultures today. In this paper the authors undertook a literary review of ancient texts of both Eastern and Western societies as well as modern writings on the organic counterpart to the soul. The authors have studied both ancient Greek and Roman material as well as Islamic and Eastern philosophy. Several specific aspects of the human body have often been proposed as the seat of consciousness, not only in medical texts, but also within historical documents, poetry, legal proceedings, and religious literature. Among the most prominently proposed have been the heart and breath, favoring a cardiopulmonary seat of individualism. This understanding was by no means stagnant, but evolved over time, as did the role of the brain in the definition of what it means to be human. Even in the 21st century, no clear consensus exists between or within communities, scientific or otherwise, on the brain's capacity for making us who we are. Perhaps, by its nature, our consciousness--and our awareness of our surroundings and ourselves--is a function of what surrounds us, and must therefore change as the world changes and as we change.

Ventriculosubgaleal shunts at Columbus Children's Hospital: Neurosurgical implant placement in the neonatal intensive care unit.

OBJECT: The authors review all cases in which ventriculosubgaleal (VSG) shunts were placed at Columbus Children's Hospital for the treatment of posthemorrhagic hydrocephalus in order to assess the surgical procedure, effectiveness of surgery, and complications of cerebrospinal fluid diversion to the subgaleal space. The purpose of the review is to make a comparison between cases in which shunts were placed in the operating room (OR) and those in which they were placed in the neonatal intensive care unit (NICU). Considerations and complications specific to patient transport to the OR or surgical implantation in the NICU are discussed. METHODS: Seventeen infants with posthemorrhagic hydrocephalus were treated with VSG shunt placement over a period of 4 years. A retrospective analysis of these cases was performed to evaluate multiple aspects of the procedure. Specifically, the surgical procedure, duration of shunt function prior to shunt conversion, neuroimaging changes, operative complications, and risk of infection are discussed. The authors also performed a comparative analysis of shunt placement in the NICU and the OR. RESULTS: The length of the procedure was similar in the two locations. No differences in perioperative or intraoperative risks and no increased risk of infection were seen in either location in this pilot study. Interestingly, the mean lifespan of primary implants placed in the NICU (73 days) was longer than that of those placed in the OR (43 days). CONCLUSIONS: Ventriculosubgaleal shunt placement offers a safe and effective temporary means of treating post-hemorrhagic hydrocephalus and can be reliably and safely performed at the bedside.

Use of intraoperative sodium tetradecyl sulfate for the treatment of a spinal epidural hemangioma. Technical note.

Spinal hemangiomas can be categorized into three different groups based on location. Vertebral body (VB) hemangiomas are frequent incidental findings on magnetic resonance (MR) imaging. There is a subdivision of these with spinal epidural extension that have been reported in the literature. Spinal hemangiomas can also be epidural without VB involvement; these are extremely rare with few reported cases in the thoracic epidural spinal column. The diagnosis and imaging characteristics as well as the surgical tools used in gross-total resection of spinal epidural hemangioma are not well understood. The authors present a detailed characterization of a spinal epidural hemangioma in a 30-year-old woman who presented with complaints of gradual onset of low-back pain that worsened over 1 year. The MR imaging findings indicated a large L2-S1 epidural spinal mass causing thecal sac compression. The patient underwent an L2-S1 laminectomy, and a vascular extradural mass was noted on the posterior aspect of the dura mater. Preoperative spinal angiography as well as intraoperative angiography was performed. Total resection of the tumor was achieved using intraoperative embolization with sodium tetradecyl sulfate and microscopic dissection. The postoperative MR imaging findings and clinical outcome were excellent. The findings and use of sodium tetradecyl sulfate in gross-total resection are discussed. The authors also review treatment modalities and demonstrate the utility and effectiveness of intraoperative sodium tetradecyl sulfate in grosstotal resection of large difficult spinal epidural hemangiomas.

C2/C3 pathologic fractures from polyostotic fibrous dysplasia of the cervical spine treated with percutaneous vertebroplasty.

We will discuss a potential role of percutaneous vertebroplasty (PVP) in the management of patients with severe fibrous dysplasia of the spine with multiple cervical lesions and C2-C3 pathologic fractures that may not be a good surgical candidate. Polyostotic fibrous dysplasia involvement of the cervical spine is rare. Review of literature indicates only few reported cases of surgical management with one case of mortality indicating increased risks associated with surgical intervention. While PVP is commonly used for the treatment of osteoporotic thoracolumbar vertebral compression fractures, its role in vertebral stabilization for fibrous dysplasia has not been reported. A 35-year-old man with McCune-Albright syndrome and severe polyostotic fibrous dysplasia of C2 and C3 vertebrae presented with severe neck pain, radiculopathy, quadriparesis and myelopathy. The lesion had pathologic fractures, and there was an os odontoideum with cervical cord atrophy at the C1 level. After discussing need for aggressive surgical management and potential complications, we offered PVP due to surgical risks involved. PVP was performed with a posterolateral transpedicular approach without complication. The patient had remarkable improvement in clinical relief of neck pain and improvement of myelopathic symptoms at 1-year follow-up. We present a case that illustrates a potential use of PVP in the management of a patient with symptomatic spinal fibrous dysplasia with associated pathologic fractures who was poor surgical candidate.

Predictive accuracy of standard computed tomography scanning in the diagnosis of Chiari malformation Type I in children.

OBJECT: In this study, retrospective data analysis was performed to analyze the utility of head computed tomography (CT) scanning in the diagnosis of Chiari malformation Type I (CM-I) in the pediatric population. METHODS: The authors conducted a retrospective review of radiology charts describing head CT results obtained at Columbus Children's Hospital between January 2004 and January 2005. The records were searched for the key words "Chiari," "cerebellar ectopy," or "tonsillar ectopy." The exclusion criteria included patients with previously known Chiari malformation Type I or Type II or those who had undergone follow-up magnetic resonance (MR) imaging at other institutions. Head CT and MR images for the remaining patients were reviewed to verify accuracy. RESULTS: Of the 72 patients with suspicious findings of tonsillar ectopy on CT, only 37 (51.4%) had MR imaging findings consistent with CM-I. The tonsillar ectopy in these patients ranged from 3 mm to 17 mm below the foramen magnum. CONCLUSIONS: The authors' findings indicate that incidental standard CT scans of the head have limited value in identifying CM-I.