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Nonmissile penetrating spinal injury

Case report and review of the literature

Kiarash Shahlaie, Dongwoo John Chang and John T. Anderson

✓ Nonmissile penetrating spinal injuries (NMPSIs) are rare, even among the population of patients treated in large trauma centers. Patients who present with retained foreign body fragments due to stabbings represent an even smaller subset of NMPSI, and their optimal management is unclear.

The authors report the case of a 42-year-old man who presented to the University of California at Davis Medical Center with a retained knife blade after suffering a stab wound to the lower thoracic spine. They discuss this case in the context of a literature review and propose management options for patients with NMPSIs in whom fragments are retained.

A search of PubMed was undertaken for articles published between 1950 and 2006; the authors found 21 case reports and eight case series in the English-language literature but discovered no published guidelines on the management of cases of NMPSI with retained fragments.

After clinicians undertake appropriate initial trauma evaluation and resuscitation, they should obtain plain x-ray films and computerized tomography scans to delineate the anatomical details of the retained foreign body in relation to the stab wound. Neurosurgical consultation should be undertaken in all patients with an NMPSI, whether or not foreign body fragments are present. Surgical removal of a retained foreign body is generally recommended in these patients because the fragments may lead to a worse neurological outcome. Perioperative antibiotic therapy may be beneficial, but the result depends on the nature of the penetrating agent. There is no documentation in the literature to support the use of steroid agents in patients with NMPSIs.

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Marios C. Kaoutzanis, John W. Peterson, R. Rox Anderson, Daniel J. McAuliffe, Robert F. Sibilia and Nicholas T. Zervas

✓ Vasodilation of rabbit carotid arteries induced by a pulsed-eye laser was studied in vitro to clarify the underlying mechanism. Artery segments were double cannulated in a pressure-perfusion apparatus which, under physiological conditions, allows for differential application of various solutions, pharmacological agents, and pulsed-dye laser light. Vaso-constriction was activated using both pharmacological and nonpharmacological agonists.

Laser energy at a wavelength of either 480 or 575 nm was applied intraluminally in 1-µsec pulses, which caused dilation of the arteries if hemoglobin was present in the lumen at sufficient concentration. Induced vasodilation did not specifically require the presence of hemoglobin; the same phenomenon could be repeated using an inert dye such as Evans blue as an optical absorber of laser energy. The optical density of the absorber, the number of applied laser pulses, and total amount of applied energy directly influenced the vasodilatory response. Laser-induced vasodilation was possible in both normal vessels and vessels denuded of endothelium. Pulsed-dye laser-induced vasodilation is therefore not a phenomenon mediated through chemical processes, but is rather a purely physical process initiated by the optical absorption of laser energy by the intraluminal medium, which probably induces cavitation bubble formation and collapse, resulting in the vasodilatory response of the vessel.

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Craig G. van Horne, Jorge E. Quintero, John T. Slevin, Amelia Anderson-Mooney, Julie A. Gurwell, Andrew S. Welleford, John R. Lamm, Renee P. Wagner and Greg A. Gerhardt

OBJECTIVE

Currently, there is no treatment that slows or halts the progression of Parkinson’s disease. Delivery of various neurotrophic factors to restore dopaminergic function has become a focus of study in an effort to fill this unmet need for patients with Parkinson’s disease. Schwann cells provide a readily available source of such factors. This study presents a 12-month evaluation of safety and feasibility, as well as the clinical response, of implanting autologous peripheral nerve grafts into the substantia nigra of patients with Parkinson’s disease at the time of deep brain stimulation (DBS) surgery.

METHODS

Standard DBS surgery targeting the subthalamic nucleus was performed in 8 study participants. After DBS lead implantation, a section of the sural nerve containing Schwann cells was harvested and unilaterally grafted to the substantia nigra. Adverse events were continually monitored. Baseline clinical data were obtained during standard preoperative evaluations. Clinical outcome data were obtained with postoperative clinical evaluations, neuropsychological testing, and MRI at 1 year after surgery.

RESULTS

All 8 participants were implanted with DBS systems and grafts. Adverse event profiles were comparable to those of standard DBS surgery with the exception of 1 superficial infection at the sural nerve harvest site. Three participants also reported numbness in the distribution of the sural nerve distal to the harvest site. Motor scores on Unified Parkinson’s Disease Rating Scale (UPDRS) part III while the participant was off therapy at 12 months improved from baseline (mean ± SD 25.1 ± 15.9 points at 12 months vs 32.5 ± 9.7 points at baseline). An analysis of the lateralized UPDRS scores also showed a greater overall reduction in scores on the side contralateral to the graft.

CONCLUSIONS

Peripheral nerve graft delivery to the substantia nigra at the time of DBS surgery is feasible and safe based on the results of this initial pilot study. Clinical outcome data from this phase I trial suggests that grafting may have some clinical benefit and certainly warrants further study to determine if this is an efficacious and neurorestorative therapy.

Clinical trial registration no.: NCT01833364 (clinicaltrials.gov)

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Ryan P. Morton, Paul D. Ackerman, Marc T. Pisansky, Monika Krezalek, John P. Leonetti, Michael J.M. Raffin and Douglas E. Anderson

Object

Preservation of facial nerve function in vestibular schwannoma (VS) resections remains a significant operative challenge. Delayed facial palsy (DFP) is one specific challenge yet to be fully elucidated. The aim of this study was to evaluate DFP among VS resection cases to identify significant prognostic factors associated with its incidence and clinical recovery.

Methods

This investigation involves a retrospective review of 104 cases of VS resection that occurred between December 2005 and May 2007. Patients who developed DFP were compared with patients exhibiting no facial palsy postoperatively with regard to surgical approach, severity and day of palsy onset, tumor size, intraoperative facial nerve monitoring, and postoperative recovery and treatment. Patients who demonstrated immediate facial palsy (IFP) following VS resection were also analyzed. Furthermore, specific analyses were performed in 2 distinct DFP patient groups: those who developed DFP after postoperative Day 3 (“late onset DFP”), and those whose palsy worsened after initial DFP identification (“deteriorators”).

Results

Of the 104 patients who underwent VS resection, 25.0% developed DFP and 8.6% demonstrated IFP postoperatively. The DFP group did not differ significantly in any measure when compared with patients with no postoperative facial palsy. However, patients with DFP presented with significantly smaller tumor sizes than patients with IFP. This IFP group averaged significantly smaller intraoperative facial nerve responses than patients without facial palsy, and larger tumor sizes than both the DFP and no facial palsy groups. Within the DFP group, patients with late onset DFP showed diminished intraoperative facial nerve responses when compared with the total DFP patient population. In total, 25 (96.2%) of 26 patients with DFP and 7 (77.8%) of 9 patients with IFP recovered to normal or near-normal facial function (House-Brackmann Grade I or II) at longest clinical follow-up.

Conclusions

Although patients with DFP did not exhibit any distinguishable characteristics when compared with patients without postoperative facial palsy, our analysis identified significant differences in patients with palsy presenting immediately postoperatively. Further study of patients with DFP should be undertaken to predict its incidence following VS resection.

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Joshua J. Wind, John P. Leonetti, Michael J. M. Raffin, Marc T. Pisansky, Brian Herr, Justin D. Triemstra and Douglas E. Anderson

Object

No extant literature documents the analysis of patient perceptions of hearing as a corollary to objective audiometric measures in patients with vestibular schwannoma (VS), or acoustic neuroma. Therefore, using objective audiometric data and patient perceptions of hearing function as outlined on a questionnaire, the authors evaluated the hearing of patients who underwent VS resection.

Methods

This investigation involved a retrospective review of 176 patients who had undergone VS resections in which hearing preservation was a goal. Both pre- and postoperative audiometry, expressed as a speech discrimination score (SDS) and pure tone threshold average (PTA), were performed, and the results were analyzed. Intraoperative auditory brainstem responses were also recorded. Eighty-seven of the patients (49.4%) completed a postoperative questionnaire designed to assess hearing function in a variety of social and auditory situations. Multiple linear regression analyses were completed to compare available audiometric results with questionnaire responses for each patient.

Results

One hundred forty-two patients (80.7%) had PTA and SDS audiometric data pertaining to the surgically treated ear; 94 of these patients (66.2%) had measurable postoperative hearing, as defined by a PTA < 120 dB or SD > 0%. Eighty-seven patients (49.4%) completed the retrospective questionnaire, and 74 of them had complete audiometric data and thus were included in a comparative analysis. Questionnaire data showed major postoperative subjective hearing decrements, even among patients with the same pre- and postoperative objective audiometric hearing status. Moreover, the subscore reflecting hearing while exposed to background noise, or the “cocktail party effect,” characterized the most significant patient-perceived hearing deficit following VS resection.

Conclusions

The authors' analysis of a patient-perceived hearing questionnaire showed that hearing during exposure to background noise, or the cocktail party effect, represents a significant postoperative hearing deficit and that patient perception of this deficit has a strong relation with audiometric data. Furthermore, questionnaire responses revealed a significant disparity between subjective hearing function and standard audiometrics such that even with similar levels of audiometric data, subjective measures of hearing, especially the cocktail party effect, decreased postoperatively. The authors posit that the incorporation of patient-perceived hearing function evaluation along with standard audiometry is an illustrative means of identifying subjective hearing deficits after VS resection and may ultimately aid in specific and subsequent treatment for these patients.

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Ian A. Anderson, Anand Goomany, David T. Bonthron, Maggie Bellew, Mark I. Liddington, Ian M. Smith, John L. Russell, Lachlan M. Carter, Velupandian Guruswamy, John R. Goodden and Paul D. Chumas

Object

There are no published papers examining the role of ethnicity on suture involvement in nonsyndromic craniosynostosis. The authors sought to examine whether there is a significant difference in the epidemiological pattern of suture(s) affected between different ethnic groups attending a regional craniofacial clinic with a diagnosis of nonsyndromic craniosynostosis.

Methods

A 5-year retrospective case-notes analysis of all cases involving patients attending a regional craniofacial clinic was undertaken. Cases were coded for the patients' declared ethnicity, suture(s) affected by synostosis, and the decision whether to have surgical correction of synostosis. The chi-square test was used to determine whether there were any differences in site of suture affected between ethnic groups.

Results

A total of 312 cases were identified. Of these 312 cases, ethnicity data were available for 296 cases (95%). The patient population was dominated by 2 ethnic groups: white patients (222 cases) and Asian patients (56 cases). There were both more cases of complex synostosis and fewer cases of sagittal synostosis than expected in the Asian patient cohort (χ2 = 9.217, p = 0.027).

Conclusions

There is a statistically significant difference in the prevalence of the various sutures affected within the nonsyndromic craniosynostosis patient cohort when Asian patients are compared with white patients. The data from this study also suggest that nonsyndromic craniosynostosis is more prevalent in the Asian community than in the white community, although there may be inaccuracies in the estimates of the background population data. A larger-scale, multinational analysis is needed to further evaluate the relationship between ethnicity and nonsyndromic craniosynostosis.

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James S. Harrop, Alexander R. Vaccaro, R. John Hurlbert, Jared T. Wilsey, Eli M. Baron, Christopher I. Shaffrey, Charles G. Fisher, Marcel F. Dvorak, F. C. Öner, Kirkham B. Wood, Neel Anand, D. Greg Anderson, Moe R. Lim, Joon Y. Lee, Christopher M. Bono, Paul M. Arnold, Y. Raja Rampersaud, Michael G. Fehlings and The Spine Trauma Study Group

Object

A new classification and treatment algorithm for thoracolumbar injuries was recently introduced by Vaccaro and colleagues in 2005. A thoracolumbar injury severity scale (TLISS) was proposed for grading and guiding treatment for these injuries. The scale is based on the following: 1) the mechanism of injury; 2) the integrity of the posterior ligamentous complex (PLC); and 3) the patient’s neurological status. The reliability and validity of assessing injury mechanism and the integrity of the PLC was assessed.

Methods

Forty-eight spine surgeons, consisting of neurosurgeons and orthopedic surgeons, reviewed 56 clinical thoracolumbar injury case histories. Each was classified and scored to determine treatment recommendations according to a novel classification system. After 3 months the case histories were reordered and the physicians repeated the exercise. Validity of this classification was good among reviewers; the vast majority (> 90%) agreed with the system’s treatment recommendations. Surgeons were unclear as to a cogent description of PLC disruption and fracture mechanism.

Conclusions

The TLISS demonstrated acceptable reliability in terms of intra- and interobserver agreement on the algorithm’s treatment recommendations. Replacing injury mechanism with a description of injury morphology and better definition of PLC injury will improve inter- and intraobserver reliability of this injury classification system.

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Jennifer M. Strahle, Rukayat Taiwo, Christine Averill, James Torner, Chevis N. Shannon, Christopher M. Bonfield, Gerald F. Tuite, Tammy Bethel-Anderson, Jerrel Rutlin, Douglas L. Brockmeyer, John C. Wellons III, Jeffrey R. Leonard, Francesco T. Mangano, James M. Johnston, Manish N. Shah, Bermans J. Iskandar, Elizabeth C. Tyler-Kabara, David J. Daniels, Eric M. Jackson, Gerald A. Grant, Daniel E. Couture, P. David Adelson, Tord D. Alden, Philipp R. Aldana, Richard C. E. Anderson, Nathan R. Selden, Lissa C. Baird, Karin Bierbrauer, Joshua J. Chern, William E. Whitehead, Richard G. Ellenbogen, Herbert E. Fuchs, Daniel J. Guillaume, Todd C. Hankinson, Mark R. Iantosca, W. Jerry Oakes, Robert F. Keating, Nickalus R. Khan, Michael S. Muhlbauer, J. Gordon McComb, Arnold H. Menezes, John Ragheb, Jodi L. Smith, Cormac O. Maher, Stephanie Greene, Michael Kelly, Brent R. O’Neill, Mark D. Krieger, Mandeep Tamber, Susan R. Durham, Greg Olavarria, Scellig S. D. Stone, Bruce A. Kaufman, Gregory G. Heuer, David F. Bauer, Gregory Albert, Jeffrey P. Greenfield, Scott D. Wait, Mark D. Van Poppel, Ramin Eskandari, Timothy Mapstone, Joshua S. Shimony, Ralph G. Dacey Jr., Matthew D. Smyth, Tae Sung Park and David D. Limbrick Jr.

OBJECTIVE

Scoliosis is frequently a presenting sign of Chiari malformation type I (CM-I) with syrinx. The authors’ goal was to define scoliosis in this population and describe how radiological characteristics of CM-I and syrinx relate to the presence and severity of scoliosis.

METHODS

A large multicenter retrospective and prospective registry of pediatric patients with CM-I (tonsils ≥ 5 mm below the foramen magnum) and syrinx (≥ 3 mm in axial width) was reviewed for clinical and radiological characteristics of CM-I, syrinx, and scoliosis (coronal curve ≥ 10°).

RESULTS

Based on available imaging of patients with CM-I and syrinx, 260 of 825 patients (31%) had a clear diagnosis of scoliosis based on radiographs or coronal MRI. Forty-nine patients (5.9%) did not have scoliosis, and in 516 (63%) patients, a clear determination of the presence or absence of scoliosis could not be made. Comparison of patients with and those without a definite scoliosis diagnosis indicated that scoliosis was associated with wider syrinxes (8.7 vs 6.3 mm, OR 1.25, p < 0.001), longer syrinxes (10.3 vs 6.2 levels, OR 1.18, p < 0.001), syrinxes with their rostral extent located in the cervical spine (94% vs 80%, OR 3.91, p = 0.001), and holocord syrinxes (50% vs 16%, OR 5.61, p < 0.001). Multivariable regression analysis revealed syrinx length and the presence of holocord syrinx to be independent predictors of scoliosis in this patient cohort. Scoliosis was not associated with sex, age at CM-I diagnosis, tonsil position, pB–C2 distance (measured perpendicular distance from the ventral dura to a line drawn from the basion to the posterior-inferior aspect of C2), clivoaxial angle, or frontal-occipital horn ratio. Average curve magnitude was 29.9°, and 37.7% of patients had a left thoracic curve. Older age at CM-I or syrinx diagnosis (p < 0.0001) was associated with greater curve magnitude whereas there was no association between syrinx dimensions and curve magnitude.

CONCLUSIONS

Syrinx characteristics, but not tonsil position, were related to the presence of scoliosis in patients with CM-I, and there was an independent association of syrinx length and holocord syrinx with scoliosis. Further study is needed to evaluate the nature of the relationship between syrinx and scoliosis in patients with CM-I.