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Martin Zonenshayn, Mark A. Edgar and Michael H. Lavyne

✓ The authors describe a patient with Carney's complex who presented with sciatica due to a lumbar nerve root sheath tumor. A far-lateral approach was used to resect a nonpsammomatous melanotic schwannoma. Neurosurgeons surgically treating peripheral nerve sheath tumors should be aware of the features of Carney complex because the extent of the preoperative evaluation and postoperative management of an otherwise routine surgical condition can be significantly affected.

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Martin Strowitzki, Michael Kiefer and Wolf-Ingo Steudel

✓ The authors present a newly designed device for ultrasonic guidance of neuroendoscopic procedures. It consists of a puncture adapter that attaches to a rigid endoscope having an outer diameter of 6 mm and is mounted on a small, bayonet-shaped ultrasound probe. This adapter directs the movement of the endoscope precisely within the ultrasonic field of view. The targeted region is identified by transdural insonation via an enlarged single burr-hole approach, and the endoscope is tracked in real time throughout its approach to the target. The procedure has been performed in 10 patients: endoscopic ventriculocystostomy in four cases; removal of a colloid cyst of the third ventricle in two cases; and intraventricular tumor biopsy, intraventricular tumor resection, third ventriculostomy, and removal of an intraventricular hematoma in one case each. The endoscope was depicted on ultrasonograms as a hyperechoic line without disturbing echoes and, consequently, the target (cyst, ventricle, or tumor) was safely identified in all but one case, in which intraventricular air hid a colloid cyst in the foramen of Monro.

The method presented by the authors proved to be very effective in the guidance and control of neuroendoscopic procedures. Combining this method with image guidance is recommended to define the entry point of the endoscope precisely.

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Michael L. Levy, Thomas C. Chen and Martin H. Weiss

✓ A case report of monostotic fibrous dysplasia of the clivus in a postadolescent woman is described. Although fibrous dysplasia of craniofacial structures is well documented, involvement of the clivus has not been reported. Diagnosis by clinical, radiographic, and histopathological features is detailed. Implications for the role of surgery and management are discussed.

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Michael D. Martin, Christopher M. Boxell and David G. Malone

Lumbar disc degeneration occurs because of a variety of factors and results in a multitude of conditions. Alterations in the vertebral endplate cause loss of disc nutrition and disc degeneration. Aging, apoptosis, abnormalities in collagen, vascular ingrowth, loads placed on the disc, and abnormal proteoglycan all contribute to disc degeneration. Some forms of disc degeneration lead to loss of height of the motion segment with concomitant changes in biomechanics of the segment. Disc herniation with radiculopathy and chronic discogenic pain are the result of this degenerative process.

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Acoustic neurilemmoma

Clinicoanatomical study of 103 patients

Vira Kasantikul, Martin G. Netsky, Michael E. Glasscock III and James W. Hays

✓ Clinical data in 103 patients with acoustic neurilemmoma were correlated with anatomical findings. The tumors were more common in women. Peak prevalence was in the fifth and sixth decade without difference between the sexes. The neoplasms were divided into four sizes: small, medium, large, and giant. Small (intracanalicular) tumors occurred more often in men, were of equal frequency in the decades from 20 to 70 years, were generally associated with long duration of illness, were highly cellular, and had few blood vessels. They, therefore, differed from extracanalicular neurilemmomas, and are better considered as “minimal” rather than “early” tumors. Large and giant lesions occurred more often in women, were more heavily vascularized and collagenized, were more liable to bleed, contained fewer cells, and were often associated with symptoms of short duration. The length of illness ranged from 1 month with a 6-cm lesion, to 30 years with a 1-cm mass. It is suggested that although most tumors enlarge slowly, the rate of growth may vary widely. The unilateral acoustic neurilemmoma that rarely occurs in the first two decades of life may be a limited form of von Reckinghausen's disease. Mortality in this series was nil, and hence was unrelated to size of tumor as described in earlier reports. Angiomas were found in 24 schwannomas, and microscopic calcification in four. Vascular spaces resembling cysts often were formed by tumor cells. The histological development of acoustic neurilemmoma is hypothetically reconstructed.

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Theodore Kurze, Michael L. J. Apuzzo, Martin H. Weiss and James S. Heiden

✓ The authors discuss the properties, use, and advantages of collagen sponge as a microneurosurgical adjunct. Experience with the material in over 300 operative cases has demonstrated its value for protecting the surface of the brain during exposure and retraction in neurosurgical procedures.

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Theodore Kurze, Michael L. J. Apuzzo, Martin H. Weiss and James S. Heiden

✓ Experiments were conducted to assess the feasibility of both paraformaldehyde and ethylene oxide gas sterilization of the operating microscope. From these experiments and practical experience, it is concluded that ethylene oxide sterilization of the operating microscope is a feasible and desirable alternative to cumbersome draping techniques.

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Fredric A. Helmer, Lieutenant Commander, Michael H. Sukoff, Lieutenant Commander and Martin R. Plaut

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Michael L. J. Apuzzo, Milton D. Heifetz, Martin H. Weiss and Theodore Kurze

✓ The authors report their application of the Hopkins telescope to various neurosurgical procedures, and describe the technique and advantages of its employment.

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Aria Nouri, Allan R. Martin, David Mikulis and Michael G. Fehlings

Degenerative cervical myelopathy encompasses a spectrum of age-related structural changes of the cervical spine that result in static and dynamic injury to the spinal cord and collectively represent the most common cause of myelopathy in adults. Although cervical myelopathy is determined clinically, the diagnosis requires confirmation via imaging, and MRI is the preferred modality. Because of the heterogeneity of the condition and evolution of MRI technology, multiple techniques have been developed over the years in an attempt to quantify the degree of baseline severity and potential for neurological recovery. In this review, these techniques are categorized anatomically into those that focus on bone, ligaments, discs, and the spinal cord. In addition, measurements for the cervical spine canal size and sagittal alignment are also described briefly. These tools have resulted collectively in the identification of numerous useful parameters. However, the development of multiple techniques for assessing the same feature, such as cord compression, has also resulted in a number of challenges, including introducing ambiguity in terms of which methods to use and hindering effective comparisons of analysis in the literature. In addition, newer techniques that use advanced MRI are emerging and providing exciting new tools for assessing the spinal cord in patients with degenerative cervical myelopathy.