In-hospital neurologic deterioration following fractures of the ankylosed spine: a single-institution experience.

OBJECTIVE: To determine the rate and severity of in-hospital neurologic deterioration following vertebral fractures of spinal hyperostosis. METHODS: A retrospective review of 92 fractures in 81 patients with diffuse idiopathic skeletal hyperostosis (42%) or ankylosing spondylitis (58%) was performed. Data on demographics, comorbidities, and fracture and treatment characteristics were recorded. Neurologic presentation and outcomes were categorized using American Spinal Injury Association grades and the modified Rankin Scale. Univariate and multivariate analyses were used to identify risk factors for neurologic deterioration or poor outcome (modified Rankin Scale 4-6). RESULTS: Most fractures (66%) occurred after falls of standing height or less. Presentation was delayed in 41% of patients (median 7 days), and diagnosis was delayed in 21% (median 8 days). Most fractures were extension (60%) or distraction (78%) injuries involving all 3 spinal columns. Median Subaxial Cervical Spine Injury Classification and Thoracolumbar Injury Severity Scale scores were 6 (interquartile range 5-7) and 7 (interquartile range 6-8), respectively. Of patients, 62% underwent open operative fusion either as initial therapy or after failed conservative treatment, 20% had percutaneous instrumentation, and 27% were treated in an external orthosis (52% required open fusion). Neurologic deterioration after presentation occurred in 7 patients (8.6%); 5 of these patients deteriorated after surgical treatment, constituting a 7.6% surgical risk. The presenting American Spinal Injury Association grade and patient age predicted poor outcome at 1-year outcome (P < 0.001). Death occurred in 17 patients within 1 year of injury (23%). CONCLUSIONS: Neurologic deterioration during the initial hospitalization after spinal fractures in the setting of diffuse idiopathic skeletal hyperostosis or ankylosing spondylitis is common, and 1-year mortality is high.

Significance of cochlear dose in the radiosurgical treatment of vestibular schwannoma: controversies and unanswered questions.

BACKGROUND: Cochlear dose has been identified as a potentially modifiable contributor to hearing loss after stereotactic radiosurgery (SRS) for vestibular schwannoma (VS). OBJECTIVE: To evaluate the association between computed tomography-based volumetric cochlear dose and loss of serviceable hearing after SRS, to assess intraobserver and interobserver reliability when determining modiolar point dose with the use of magnetic resonance imaging and computed tomography, and to discuss the clinical significance of the cochlear dose with regard to radiosurgical planning strategy. METHODS: Patients with serviceable pretreatment hearing who underwent SRS for sporadic VS between the use of Gamma Knife Perfexion were studied. Univariate and multivariate associations with the primary outcome of time to nonserviceable hearing were evaluated. RESULTS: A total of 105 patients underwent SRS for VS during the study period, and 59 (56%) met study criteria and were analyzed. Twenty-one subjects (36%) developed nonserviceable hearing at a mean of 2.2 years after SRS (SD, 1.0 years; median, 2.1 years; range 0.6-3.8 years). On univariate analysis, pretreatment pure tone average, speech discrimination score, American Academy of Otolaryngology-Head and Neck Surgery hearing class, marginal dose, and mean dose to the cochlear volume were statistically significantly associated with time to nonserviceable hearing. However, after adjustment for baseline differences, only pretreatment pure tone average was statistically significantly associated with time to nonserviceable hearing in a multivariable model. CONCLUSION: Cochlear dose is one of many variables associated with hearing preservation after SRS for VS. Until further studies demonstrate durable tumor arrest with reduced dose protocols, routine tumor dose planning should not be modified to limit cochlear dose at the expense of tumor control.

Moving forward: advances in the treatment of movement disorders with deep brain stimulation.

The modern era of stereotactic and functional neurosurgery has ushered in state of the art technologies for the treatment of movement disorders, particularly Parkinson's disease (PD), tremor, and dystonia. After years of experience with various surgical therapies, the eventual shortcomings of both medical and surgical treatments, and several serendipitous discoveries, deep brain stimulation (DBS) has risen to the forefront as a highly effective, safe, and reversible treatment for these conditions. Idiopathic advanced PD can be treated with thalamic, globus pallidus internus (GPi), or subthalamic nucleus (STN) DBS. Thalamic DBS primarily relieves tremor while GPi and STN DBS alleviate a wide range of Parkinsonian symptoms. Thalamic DBS is also used in the treatment of other types of tremor, particularly essential tremor, with excellent results. Both primary and various types of secondary dystonia can be treated very effectively with GPi DBS. The variety of anatomical targets for these movement disorders is indicative of the network-level dysfunction mediating these movement disturbances. Despite an increasing understanding of the clinical benefits of DBS, little is known about how DBS can create such wide sweeping neuromodulatory effects. The key to improving this therapeutic modality and discovering new ways to treat these and other neurologic conditions lies in better understanding the intricacies of DBS. Here we review the history and pertinent clinical data for DBS treatment of PD, tremor, and dystonia. While multiple regions of the brain have been targeted for DBS in the treatment of these movement disorders, this review article focuses on those that are most commonly used in current clinical practice. Our search criteria for PubMed included combinations of the following terms: DBS, neuromodulation, movement disorders, PD, tremor, dystonia, and history. Dates were not restricted.

Imaging features of glomus tumors.

OBJECTIVE: To describe the imaging findings with pathologic correlation and clinical presentation of glomus tumors. MATERIALS AND METHODS: We retrospectively searched the surgical pathology database from January 1, 1997, to April 30, 2010, for cases of pathologically proven glomus tumor. Patients who had imaging results available for review were included in the study. RESULTS: Glomus tumors presented with a prolonged history of focal and often debilitating pain, with a mean duration of symptoms of 7.2 years. Mean tumor size was 13 mm. The upper extremity was involved in 12/25 (48%) of the tumors, the lower extremity in 12/25 (48%), and one case (4%) was within the trachea. Lesions appeared well circumscribed on ultrasonography, with marked vascularity on color Doppler evaluation. Magnetic resonance imaging (MRI) with a marker placed in the region of point tenderness was the best method for identifying small glomus tumors. These tumors had a high T2 signal and uniform enhancement after gadolinium administration. CONCLUSIONS: The diagnosis of glomus tumor is suggested by imaging features of a small circumscribed mass at the site of point tenderness that show marked vascularity on Doppler evaluation or diffuse contrast medium enhancement on MRI, or both. Early tumor recognition allows surgical resection that completely resolves the crippling, chronic pain of these lesions.

Importance of the vasculature in cyst formation after spinal cord injury.

OBJECT: Glial scar and cystic formation greatly contribute to the inhibition of axonal regeneration after spinal cord injury (SCI). Attempts to promote axonal regeneration are extremely challenging in this type of hostile environment. The objective of this study was to examine the surgical methods that may be used to assess the factors that influence the level of scar and cystic formation in SCI. METHODS: In the first part of this study, a complete transection was performed at vertebral level T9-10 in adult female Sprague-Dawley rats. The dura mater was either left open (control group) or was closed using sutures or hyaluronic acid. In the second part of the study, complete or subpial transection was performed, with the same dural closure technique applied to both groups. Histological analysis of longitudinal sections of the spinal cord was performed, and the percentage of scar and cyst formation was determined. RESULTS: Dural closure using sutures resulted in significantly less glial scar formation (p = 0.0248), while incorporation of the subpial transection surgical technique was then shown to significantly decrease cyst formation (p < 0.0001). CONCLUSIONS: In this study, the authors demonstrated the importance of the vasculature in cyst formation after spinal cord trauma and confirmed the importance of dural closure in reducing glial scar formation.

Rigid fixation of the spinal column improves scaffold alignment and prevents scoliosis in the transected rat spinal cord.

STUDY DESIGN: A controlled study to evaluate a new technique for spinal rod fixation after spinal cord injury in rats. Alignment of implanted tissue-engineered scaffolds was assessed radiographically and by magnetic resonance imaging. OBJECTIVE: To evaluate the stability of implanted scaffolds and the extent of kyphoscoliotic deformities after spinal fixation. SUMMARY OF BACKGROUND DATA: Biodegradable scaffolds provide an excellent platform for the quantitative assessment of cellular and molecular factors that promote regeneration within the transected cord. Successful delivery of scaffolds to the damaged cord can be hampered by malalignment following transplantation, which in turn, hinders the assessment of neural regeneration. METHODS: Radio-opaque barium sulfate-impregnated poly-lactic-co-glycolic acid scaffolds were implanted into spinal transection injuries in adult rats. Spinal fixation was performed in one group of animals using a metal rod fixed to the spinous processes above and below the site of injury, while the control group received no fixation. Radiographic morphometry was performed after 2 and 4 weeks, and 3-dimensional magnetic resonance microscopy analysis 4 weeks after surgery. RESULTS: Over the course of 4 weeks, progressive scoliosis was evident in the unfixed group, where a Cobb angle of 8.13 +/- 2.03 degrees was measured. The fixed group demonstrated significantly less scoliosis, with a Cobb angle measurement of 1.89 +/- 0.75 degrees (P = 0.0004). Similarly, a trend for less kyphosis was evident in the fixed group (7.33 +/- 1.68 degrees ) compared with the unfixed group (10.13 +/- 1.46 degrees ). Quantitative measurements of the degree of malalignment of the scaffolds were also significantly less in the fixed group (5 +/- 1.23 degrees ) compared with the unfixed group (11 +/- 2.82 degrees ) (P = 0.0143). CONCLUSION: Radio-opaque barium sulfate allows for visualization of scaffolds in vivo using radiographic analysis. Spinal fixation was shown to prevent scoliosis, reduce kyphosis, and reduce scaffold malalignment within the transected rat spinal cord. Using a highly optimized model will increase the potential for finding a therapy for restoring function to the injured cord.

Epidermoids of the cerebellopontine angle: a 20-year experience.

BACKGROUND: There is considerable debate within the current literature whether total or subtotal removal of CPA epidermoids yields better long-term outcomes. The aim of this study was to review our experience with cerebellopontine-angle epidermoid tumors, as well as the current literature, focusing on the correlation between long-term outcome and the extent of surgical removal. METHODS: We performed a retrospective review of 24 patients with epidermoid tumors of the CPA surgically treated at our institution between 1985 and 2005. RESULTS: The mean duration from onset of symptoms to surgery was 3.1 years. Cranial nerve dysfunction was noted in 83% of patients preoperatively. Total removal was achieved in 13 patients, near total removal in 6 patients, and subtotal removal in 5 patients. Patients who underwent total removal had a median MRS score of 0, whereas those who underwent near/subtotal removal had a median MRS score of 1. The rate of recurrence was 23% in tumors considered totally removed and 27% in those near/subtotally removed. Of the 6 patients with recurrences, 5 underwent a second operation. The mean duration of follow-up was 4.2 years. CONCLUSIONS: Total removal of CPA epidermoids does not result in significantly increased morbidity and mortality and should be the goal of surgical treatment. However, near/subtotal resection of lesions that extend far beyond the CPA or are densely adherent to neurovascular structures is justified, as there is no significant difference in the rate of recurrence.

Clinical features of multiple glomus tumors.

BACKGROUND: While glomus tumors are usually solitary, multiple glomus tumors do occur. The purpose of this study was to review the clinical characteristics and outcomes in a series of patients with multiple glomus tumors presenting to our institution. METHODS: A retrospective review of patients with multiple glomus tumors seen at our institution over the past 25 years was performed. RESULTS: Twenty-two patients with multiple glomus tumors were identified. Initial diagnosis was blue rubber nevus syndrome and hemangioma in 10 and 7 patients, respectively. The mean duration from onset of symptoms until correct diagnosis was 14.6 years. Involvement of an extremity was noted in 90.9% of the patients. An autosomal dominant pattern of inheritance was noted in 13 of 22 patients. The classic triad of symptoms in solitary glomus tumors--pain, pinpoint tenderness, and cold hypersensitivity--was noted in only 1 of the 22 patients; pain and pinpoint tenderness were simultaneously identified in 14 patients, 8 with visible lesions but no symptoms. Symptoms were relieved by surgical excision in most patients. CONCLUSION: Patients with multiple glomus tumors are frequently misdiagnosed. Proper recognition and diagnosis would lead to improved management.

The use of a video interview to enhance gross anatomy students' understanding of professionalism.

There is much room for innovation in teaching medical students professionalism. The goal of this exercise was to enhance first-year Gross Anatomy students' understanding of professionalism, including the attributes of confidentiality, respectful behavior and humanism in medicine through a video interview with a donor family member. Survey results demonstrated that students generally agreed that the video helped them better understand professionalism in the context of the gross anatomy laboratory and gave them a deeper respect for donors. Most students strongly agreed that future medical students would benefit from viewing this video interview.

The clinico-anatomic explanation for tibial intraneural ganglion cysts arising from the superior tibiofibular joint.

OBJECTIVE: To demonstrate that tibial intraneural ganglia in the popliteal fossa are derived from the posterior portion of the superior tibiofibular joint, in a mechanism similar to that of peroneal intraneural ganglia, which have recently been shown to arise from the anterior portion of the same joint. DESIGN: Retrospective clinical study and prospective anatomic study. MATERIALS: The clinical records and MRI findings of three patients with tibial intraneural ganglion cysts were analyzed and compared with those of one patient with a tibial extraneural ganglion cyst and one volunteer. Seven cadaveric limbs were dissected to define the articular anatomy of the posterior aspect of the superior tibiofibular joint. RESULTS: The condition of the three patients with intraneural ganglia recurred because their joint connections were not identified initially. In two patients there was no cyst recurrence when the joint connection was treated at revision surgery; the third patient did not wish to undergo additional surgery. The one patient with an extraneural ganglion had the joint connection identified at initial assessment and had successful surgery addressing the cyst and the joint connection. Retrospective evaluation of the tibial intraneural ganglion cysts revealed stereotypic features, which allowed their accurate diagnosis and distinction from extraneural cases. The intraneural cysts had tubular (rather than globular) appearances. They derived from the postero-inferior portion of the superior tibiofibular joint and followed the expected course of the articular branch on the posterior surface of the popliteus muscle. The cysts then extended intra-epineurially into the parent tibial nerves, where they contained displaced nerve fascicles. The extraneural cyst extrinsically compressed the tibial nerve but did not directly involve it. All cadaveric specimens demonstrated a small single articular branch, which derived from the tibial nerve to the popliteus. The branch coursed obliquely across the posterior surface of the popliteus muscle before innervating the postero-inferior aspect of the superior tibiofibular joint. CONCLUSIONS: The clinical, MRI and anatomic features of tibial intraneural ganglion cysts are the posterior counterpart of the peroneal intraneural ganglion cysts arising from the anterior portion of the superior tibiofibular joint. These predictable features can be exploited and have implications for the pathogenesis of these intraneural cysts and treatment outcomes. These ganglion cysts are joint-related and provide further evidence to support the unifying articular theory. In each case the joint connection needs to be identified preoperatively, and the articular branches and the superior tibiofibular joint should be addressed operatively to prevent cyst recurrence.

Extradigital glomus tumors: a 20-year experience.

OBJECTIVE: To review a large series of extradigital glomus tumors in order to gain a better understanding of their presentation and provide guidelines to aid in their diagnosis and treatment. PATIENTS AND METHODS: We performed a retrospective review of all extradigital glomus tumors seen at our institution during a 20-year period (1985-2005) to document the incidence of the classic triad of symptoms, the duration of symptoms, the contribution of imaging to making a definitive diagnosis, and the effectiveness of treatment. RESULTS: Fifty-six different patients with extradigital glomus tumors presented as follows: glomus tumors in the hand (3), wrist (4), forearm (11), elbow (4), arm (4), shoulder (2), buttock (1), thigh (5), knee (10), leg (3), ankle (2), foot (2), back (1), nose (1), cheek (1), ear lobe (1), and trachea (1). Forty-eight patients presented with pain and localized tenderness, but only 1 patient presented with cold Intolerance. The average duration of symptoms was greater than 7 years, with most patients being evaluated previously and having their conditions misdiagnosed. Magnetic resonance imaging proved to be the most useful modality for localization of these lesions. Surgical resection was the definitive treatment and generally provided immediate and sustained pain relief. CONCLUSIONS: Extradigital glomus tumors are not a rare subgroup of glomus tumors. Treatment outcomes are excellent, but misdiagnosis and delayed diagnosis are common. Improved guidelines regarding symptoms and diagnosis of these neoplasms may reduce the morbidity, ensuing chronic pain, and psychiatric consequences of delayed diagnosis or misdiagnosis.