✓ Patients with sleep apnea often are treated by sleep disorder specialists and are studied in a sleep laboratory. The authors present two such patients who ultimately were found to harbor large benign anterior skull base lesions that caused their obstructive sleep apnea (OSA). The first patient had a massive pituitary tumor and had undergone a tracheostomy before the lesion was diagnosed. The second patient had a large frontoethmoidal encephalocele that was diagnosed at the same time as a recommendation for continuous positive airway pressure therapy was being considered. Such therapy in the presence of an encephalocele can be dangerous and even fatal. Although there are case reports of tumors causing OSA, nearly all of these lesions have been large pharyngeal lipomas (some of which were palpable in the neck during physical examination) or growth hormone—secreting pituitary adenomas. The patients reported here were completely unaware of the presence of these large lesions until imaging studies and/or nasal endoscopy were performed. These cases illustrate the need to perform nasopharyngeal endoscopy and also to obtain magnetic resonance images of the head before prescribing therapy for OSA. Neurosurgeons must be aware that large skull base lesions sometimes present only with OSA.
Report of two cases and review of the literature
Raj Murali, Philippe Douyon and Ibrahim Omeis
Ibrahim Omeis, Joseph A. DeMattia, Virany Huynh Hillard, Raj Murali and Kaushik Das
In the past several decades methods have been developed to stabilize the subaxial cervical spine both posteriorly and anteriorly. Methods of posterior stabilization have progressed from interspinous wiring, through facet wiring and sublaminar wiring, to the lateral mass screws with plates and rods that are in use today. Plates for anterior stabilization have evolved from rigid plates requiring bicortical screws through those used with unicortical locking screws, to dynamic load-sharing plates used with variable angle screws. The original description of spinous process wiring was published by Hadra in 1891. In 1942 Rogers described the interspinous wiring method used for trauma-induced cervical instability, which was modified by Bohlman in 1985 (triple wiring technique). Luque rods with sublaminar wires were introduced in the late 1970s to address multilevel and occipitocervical instability. Facet wiring was developed in 1977 by Callahan to address the problem of stabilization when laminae are not present. Wiring remained the method used until Roy-Camille introduced the lateral mass screw–plate construct in the 1980s. The first plate for anterior stabilization was designed by Orozco and Llovet in 1970 and was later refined by Caspar; this was a rigid plate with bicortical screws. Morscher devised unicortical locking screws in the 1980s. The latest concept of dynamic load-sharing plates with variable angle screws was developed in 2000. In this article historical landmarks in surgical methods for the stabilization of the subaxial cervical spine are reviewed.
Oren N. Gottfried, Ibrahim Omeis, Vivek A. Mehta, Can Solakoglu, Ziya L. Gokaslan and Jean-Paul Wolinsky
Pelvic incidence (PI) directly regulates lumbar lordosis and is a key determinant of sagittal spinal balance in normal and diseased states. Pelvic incidence is defined as the angle between the line perpendicular to the S-1 endplate at its midpoint and the line connecting this point to a line bisecting the center of the femoral heads. It reflects an anatomical value that increases with growth during childhood but remains constant in adulthood. It is not altered by changes in patient position or after traditional lumbosacral spinal surgery. There are only 2 reports of PI being altered in adults, both in cases of sacral fractures resulting in lumbopelvic dissociation and sacroiliac (SI) joint instability. En bloc sacral amputation and sacrectomy are surgical techniques used for resection of certain bony malignancies of the sacrum. High, mid, and low sacral amputations result in preservation of some or the entire SI joint. Total sacrectomy results in complete disruption of the SI joint. The purpose of this study was to determine if PI is altered as a result of total or subtotal sacral resection.
The authors reviewed a series of 42 consecutive patients treated at The Johns Hopkins Hospital between 2004 and 2009 for sacral tumors with en bloc resection. The authors evaluated immediate pre- and postoperative images for modified pelvic incidence (mPI) using the L-5 inferior endplate, as the patients undergoing a total sacrectomy are missing the S-1 endplate postoperatively. The authors compared the results of total versus subtotal sacrectomies.
Twenty-two patients had appropriate images to measure pre- and postoperative mPI; 17 patients had high, mid, or low sacral amputations with sparing of some or the entire SI joint, and 5 patients underwent a total sacrectomy, with complete SI disarticulation. The mean change in mPI was statistically different (p < 0.001) for patients undergoing subtotal versus those undergoing total sacrectomy (1.6° ± 0.9° vs 13.6° ± 4.9° [± SD]). There was no difference between patients who underwent a high sacral amputation (partial SI resection, mean 1.6°) and mid or low sacral amputation (SI completely intact, mean 1.6°).
The PI is altered during total sacrectomy due to complete disarticulation of the SI joint and discontinuity of the spine and pelvis, but it is not changed if any of the joint is preserved. Changes in PI influence spinopelvic balance and may have postoperative clinical importance. Thus, the authors encourage attention to spinopelvic alignment during lumbopelvic reconstruction and fixation after tumor resection. Long-term studies are needed to evaluate the impact of the change in PI on sagittal balance, pain, and ambulation after total sacrectomy.
D. Ryan Ormond, Ibrahim Omeis, Avinash Mohan, Raj Murali and Prithvi Narayan
✓ Cysts occupying the third ventricle are rare lesions and may appear as an unusual cause of obstructive hydrocephalus. Various types of lesions occur in this location, and they generally have an arachnoidal, endodermal, or neuroepithelial origin. The authors present a case of acute hydrocephalus following minor trauma in a child due to cerebrospinal fluid outflow obstruction by a third ventricular cyst. Definitive diagnosis of this cystic lesion was possible only with contrast ventriculography and not routine computed tomography or magnetic resonance imaging. The investigation, treatment, and pathological findings are discussed.
Terence Verla, Jonathan G. Thomas, Vilmos Thomazy, Gregory N. Fuller, Aziz Shaibani and Ibrahim Omeis
Radiation therapy continues to play an extremely valuable role in the treatment of malignancy. The effects of radiation therapy on normal tissue can present in a delayed fashion, resulting in localized damage with pseudomalignant transformation, producing a compressive effect on the spinal cord or exiting nerve roots. Infiltration of inflammatory cells and the subsequent fibrotic response can result in the development of an inflammatory pseudotumor (benign tumor-like lesion) with subsequent mass effect. Herein, the authors present a rare case of inflammatory pseudotumor with fulminant cervicothoracic cord compression, developing 7 years after radiation therapy for breast cancer. The lesion recurred following resection but subsequently displayed complete and rapid resolution following steroid therapy. To the best of the authors' knowledge, no previous studies have reported such an incident.
Oren N. Gottfried, Scott L. Parker, Ibrahim Omeis, Ali Bydon, Ziya L. Gokaslan and Jean-Paul Wolinsky
Cervical spondylolysis is an uncommon disorder involving a cleft at the pars interarticularis. It is most often found at the C-6 level, and clinical presentations have included incidental radiographic findings, neck pain, and rarely neurological compromise. Although subaxial cervical spondylolysis has been described in 150 patients, defects at the C-2 pedicles are rare.
The authors present 2 new cases of C-2 spondylolysis in athletically active young persons who did not demonstrate instability or neurological deficits, were able to remain active, and are being managed conservatively with serial examinations and imaging. They also discuss the results of 22 previously reported cases of C-2 spondylolysis. Based on the literature and their own experience, the authors conclude that most patients with C-2 spondylolysis remain neurologically intact, maintain stability despite the bony defect, and can be managed conservatively. Surgery is reserved for patients who demonstrate severe instability or spinal cord compromise due to stenosis.
Ibrahim Omeis, Weiliam Chen, Meena Jhanwar-Uniyal, Renato Rozental, Raj Murali and John M. Abrahams
One mechanism that contributes to cerebral vasospasm is the impairment of potassium channels in vascular smooth muscles. Adenosine triphosphate–sensitive potassium channel openers (PCOs) appear to be particularly effective for dilating cerebral arteries in experimental models of subarachnoid hemorrhage (SAH). A mode of safe administration that provides timed release of PCO drugs is still a subject of investigation. The authors tested the efficacy of locally delivered intrathecal cromakalim, a PCO, incorporated into a controlled-release system to prevent cerebral vasospasm in a rat model of SAH.
Cromakalim was coupled to a viscous carrier, hyaluronan, 15% by weight. In vitro release kinetics studies showed a steady release of cromakalim over days. Fifty adult male Sprague-Dawley rats weighing 350–400 g each were divided into 10 groups and treated with various doses of cromakalim or cromakalim/hyaluronan in a rat double SAH model. Treatment was started 30 minutes after the second SAH induction. Animals were killed 3 days after treatment, and the basilar arteries were processed for morphometric measurements and histological analysis.
Controlled release of cromakalim from the cromakalim/hyaluronan implant at a dose of 0.055 mg/kg significantly increased lumen patency in a dose-dependent manner up to 94 ± 8% (mean ± standard error of the mean) of the basilar arteries of the sham group compared with the empty polymer group (p = 0.006). Results in the empty polymer group were not different from those in the SAH-only group, with a lumen patency of 65 ± 12%. Lumen patencies of the cromakalim-only groups did not differ in statistical significance at low (64 ± 9%) or high (66 ± 7%) doses compared to the SAH-only group.
Treatment of SAH with a controlled-release cromakalim/hyaluronan implant prevented experimental cerebral vasospasm in this rat double hemorrhage model; this inhibition was dose-dependent. The authors' results confirm that sustained delivery of cromakalim perivascularly to cerebral vessels could be an effective therapeutic strategy in the treatment of cerebral vasospasm after SAH.
C. Rory Goodwin, Pablo F. Recinos, Ibrahim Omeis, Eric N. Momin, Timothy F. Witham, Ali Bydon, Ziya L. Gokaslan and Jean-Paul Wolinsky
Sacral neoplasm resection is managed via partial or total sacrectomy that is performed via the Kraske approach. The combination of the patients positioning and the relatively long operative time required for this procedure increase the risk of pressure ulcers. Facial pressure ulcers can cause tissue necrosis and/or ulceration in a highly visible area, leading to a cosmetically disfiguring lesion. Here, the authors report the use of a Mayfield clamp in the positioning of patients undergoing sacral tumor resection to prevent facial pressure ulceration. After the patient is placed prone in the Kraske or Jackknife position, the hips and knees are flexed with arms to the side. Then while in the prone position, the patient is physically placed in pins, and the Mayfield clamp is fixated at the center of the metal arch via the Mayfield sitting adapter to the Andrews frame, suspending the head (and face) over the table. The authors find that this technique prevents the development of facial pressure ulcers, and it has the potential to be used in patients positioned in the Kraske position for other surgical procedures.
Ibrahim Omeis, Ashley L. Siems, William Harrington, Livette S. Johnson, Sylvie Destian and Joseph A. DeMattia
✓ Kaposi sarcoma (KS) is one of the most common tumors in patients with human immunodeficiency virus (HIV), which characteristically presents with cutaneous lesions. The authors report a rare case of spinal KS with no cutaneous manifestation in a 32-year-old man with the acquired immunodeficiency syndrome who presented with abdominal pain. A computed tomography scan revealed incidental lesions in his lumbar spine, and additional imaging studies revealed numerous lesions in the lumbosacral spine and pelvis. An open biopsy was performed, and histopathological examination of the lesion confirmed the diagnosis of KS. At the time of presentation, the patient had no skin lesion or any other manifestation indicative of KS. The authors suggest that in HIV-positive patients who present with spinal lesions, KS should be included in the differential diagnosis.