A Multicenter Allelic Analysis of Diffuse Idiopathic Skeletal Hyperostosis: Nature Versus Nurture?

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is an incompletely defined disease process with no known unifying pathophysiological mechanism. OBJECTIVE: To our knowledge, no genetic studies have been performed in a North American population. To summarize genetic findings from previous studies and to comprehensively test for these associations in a novel and diverse, multi-institutional population. METHODS: Cross-sectional, single nucleotide polymorphism (SNP) analysis was performed in 55 of 121 enrolled patients with DISH. Baseline demographic data were available on 100 patients. Based on allele selection from previous studies and related disease conditions, sequencing was performed on COL11A2, COL6A6, fibroblast growth factor 2 gene, LEMD3, TGFB1, and TLR1 genes and compared with global haplotype rates. RESULTS: Consistent with previous studies, older age (mean 71 years), male sex predominance (80%), a high frequency of type 2 diabetes (54%), and renal disease (17%) were observed. Unique findings included high rates of tobacco use (11% currently smoking, 55% former smoker), a higher predominance of cervical DISH (70%) relative to other locations (30%), and an especially high rate of type 2 diabetes in patients with DISH and ossification of the posterior longitudinal ligament (100%) relative to DISH alone (100% vs 47%, P < .001). Compared with global allele rates, we found higher rates of SNPs in 5 of 9 tested genes ( P < .05). CONCLUSION: We identified 5 SNPs in patients with DISH that occurred more frequently than a global reference. We also identified novel environmental associations. We hypothesize that DISH represents a heterogeneous condition with both multiple genetic and environmental influences.

Assessment of the Reliability of the Fiberoptic Endoscopic Evaluation of Swallowing as an Outcome Measure in Patients Undergoing Revision Anterior Cervical Discectomy and Fusion.

BACKGROUND: Dysphagia is one of the most common complications of anterior cervical spine surgery, and there is a need to establish that the means of testing for it are reliable and valid. The objective of this study was to measure observer variability of the fiberoptic endoscopic evaluation of swallowing (FEES) test, specifically when used for evaluation of dysphagia in patients undergoing revisionary anterior cervical decompression and fusion (ACDF). METHODS: Images from patients undergoing revision ACDF at a single institution were collected from May 1, 2010, through July 1, 2014. Two senior certified speech pathologists independently evaluated the swallowing function of patients preoperatively and at 2 weeks postoperatively. Their numeric evaluations of the Rosenbeck Penetration-Aspiration Scale and the Swallowing Performance Scale during the FEES were then compared for interrater reliability. RESULTS: Positive agreement between raters was 94% for the preoperative Penetration-Aspiration Scale (prevalence-adjusted bias-adjusted κ, 0.77). The postoperative Penetration-Aspiration Scale showed reliability coefficients for κ, Kendall's W, and intraclass correlation coefficient (ICC) of 0.34 (fair agreement), 0.70 (extremely strong agreement), and 0.35 (poor agreement), respectively. The preoperative Swallowing Performance Scale showed strong agreement, with a Kendall's W coefficient of 0.68, and fair reliability, with an ICC of 0.40. The postoperative Swallowing Performance Scale indicated extremely strong agreement between raters, with a Kendall's W of 0.82, and good agreement, with an ICC of 0.53. CONCLUSIONS: The FEES test appears to be a reliable assessor of dysphagia in patients undergoing ACDF and may be a useful measure for exploring outcomes in this population.

Development of the Subdural Hematoma in the Elderly (SHE) score to predict mortality.

OBJECTIVE: The purpose of this study was to describe the development of a novel prognostic score, the Subdural Hematoma in the Elderly (SHE) score. The SHE score is intended to predict 30-day mortality in elderly patients (those > 65 years of age) with an acute, chronic, or mixed-density subdural hematoma (SDH) after minor, or no, prior trauma. METHODS: The authors used the Prognosis Research Strategy group methods to develop the clinical prediction model. The training data set included patients with acute, chronic, and mixed-density SDH. Based on multivariate analyses from a large data set, in addition to review of the extant literature, 3 components to the score were selected: age, admission Glasgow Coma Scale (GCS) score, and SDH volume. Patients are given 1 point if they are over 80 years old, 1 point for an admission GCS score of 5-12, 2 points for an admission GCS score of 3-4, and 1 point for SDH volume > 50 ml. The sum of points across all categories determines the SHE score. RESULTS: The 30-day mortality rate steadily increased as the SHE score increased for all SDH acuities. For patients with an acute SDH, the 30-day mortality rate was 3.2% for SHE score of 0, and the rate increased to 13.1%, 32.7%, 95.7%, and 100% for SHE scores of 1, 2, 3, and 4, respectively. The model was most accurate for acute SDH (area under the curve [AUC] = 0.94), although it still performed well for chronic (AUC = 0.80) and mixed-density (AUC = 0.87) SDH. CONCLUSIONS: The SHE score is a simple clinical grading scale that accurately stratifies patients' risk of mortality based on age, admission GCS score, and SDH volume. Use of the SHE score could improve counseling of patients and their families, allow for standardization of clinical treatment protocols, and facilitate clinical research studies in SDH.

Education level as a prognostic indicator at 12 months following decompression surgery for symptomatic lumbar spinal stenosis.

OBJECTIVEThe goal of this study was to analyze the effect of patient education level on functional outcomes following decompression surgery for symptomatic lumbar spinal stenosis.METHODSPatients with surgically decompressed symptomatic lumbar stenosis were collected in a prospective observational registry at a single institution between 2012 and 2014. Patient education level was compared to surgical outcomes to elucidate any relationships. Outcomes were defined using the Oswestry Disability Index score, back and leg pain visual analog scale (VAS) score, and the EuroQol-5 Dimensions questionnaire score.RESULTSOf 101 patients with symptomatic lumbar spinal stenosis, 27 had no college education and 74 had a college education (i.e., 2-year, 4-year, or postgraduate degree). Preoperatively, patients with no college education had statistically significantly greater back and leg pain VAS scores when compared to patients with a college education. However, there was no statistically significant difference in quality of life or disability between those with no college education and those with a college education. Postoperatively, patients in both cohorts improved in all 4 patient-reported outcomes at 3 and 12 months after treatment for symptomatic lumbar spinal stenosis.CONCLUSIONSDespite their education level, both cohorts showed improvement in their functional outcomes at 3 and 12 months after decompression surgery for symptomatic lumbar spinal stenosis.

Association between payer status and patient-reported outcomes in adult patients with lumbar spinal stenosis treated with decompression surgery.

OBJECTIVE: Insurance disparities can have relevant effects on outcomes after elective lumbar spinal surgery. The aim of this study was to evaluate the association between private/public payer status and patient-reported outcomes in adult patients who underwent decompression surgery for lumbar spinal stenosis. METHODS: A sample of 100 patients who underwent surgery for lumbar spinal stenosis from 2012 to 2014 was evaluated as part of the prospectively collected Quality Outcomes Database at a single institution. Outcome measures were evaluated at 3 months and 12 months, analyzed in regard to payer status (private insurance vs Medicare/Veterans Affairs insurance), and adjusted for potential confounders. RESULTS: At baseline, patients had similar visual analog scale back and leg pain, Oswestry Disability Index, and EQ-5D scores. At 3 months postintervention, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.11, p < 0.001) and more leg pain (mean difference 1.26, p = 0.05). At 12 months, patients with government-funded insurance reported significantly worse quality of life (mean difference 0.14, p < 0.001). There were no significant differences at 3 months or 12 months between groups for back pain (p = 0.14 and 0.43) or disability (p = 0.19 and 0.15). Across time points, patients in both groups showed improvement at 3 months and 12 months in all 4 functional outcomes compared with baseline (p < 0.001). CONCLUSIONS: Both private and public insurance patients had significant improvement after elective lumbar spinal surgery. Patients with public insurance had slightly less improvement in quality of life after surgery than those with private insurance but still benefited greatly from surgical intervention, particularly with respect to functional status.

Outcomes of Subdural Hematoma in the Elderly with a History of Minor or No Previous Trauma.

BACKGROUND: Subdural hematoma (SDH) in the elderly is an increasingly common entity because of increased use of antithrombotic medications, an aging population, and increasing frequency of geriatric trauma. The present study describes the functional outcomes and mortality of SDH in an elderly population and to identify potential prognostic factors. METHODS: Patients >65 years of age with SDH who were treated at our institution from 2005 to 2015 were identified. Patients with a history of preceding high-velocity trauma were excluded. Electronic medical records were retrospectively reviewed. The outcomes of interest were mortality, length of stay, and discharge Glasgow Outcome Score. RESULTS: A total of 671 patients were included in final statistical analyses. For patients with acute SDH, survival was 74.9%, 72.3%, and 69.8% at 30, 60, and 100 days, respectively. With respect to chronic SDH, survival was 87.0%, 83.7%, and 80.3% at 30, 60, and 100 days, respectively. On multivariate analysis, admission Glasgow Coma Scale (GCS) score was significantly predictive of mortality in both the acute and chronic populations. In the acute cohort, admission GCS score was a significant predictor of increased length of stay, whereas age >80 years, admission GCS score, contusion volume >10 cm3, SDH volume >50 cm3, and antiplatelet use were significant predictors of discharge functional status. CONCLUSIONS: SDH in the elderly carries high morbidity and mortality and several prognostic factors were identified. These results can be used to guide discussions with family regarding prognosis and perhaps aid in treatment decisions.

Association between preoperative activity level and functional outcome at 12 months following surgical decompression for lumbar spinal stenosis.

OBJECTIVE: This study defines the association of preoperative physical activity level with functional outcomes at 3 and 12 months following surgical decompression for lumbar spinal stenosis. METHODS: Data were collected as a prospective observational registry at a single institution from 2012 through 2015, and then analyzed with a retrospective cohort design. Patients who were able to participate in activities outside the home preoperatively were compared to patients who did not participate in such activities, with respect to 3-month and 12-month functional outcomes postintervention, adjusted for relevant confounders. RESULTS: Ninety-nine patients were included. At baseline, sedentary/inactive patients (n = 55) reported greater back pain, lower quality of life, and higher disability than similarly treated patients who were active preoperatively. Both cohorts experienced significant improvement from baseline in back pain, leg pain, disability, and quality of life at both 3 and 12 months after lumbar decompression surgery. At 3 months postintervention, sedentary/inactive patients reported more leg pain and worse disability than patients who performed activities outside the home preoperatively. However, at 12 months postintervention, there were no statistically significant differences between the two cohorts in back pain, leg pain, quality of life, or disability. Multivariate analysis revealed that sedentary/inactive patients had improved disability and higher quality of life after surgery compared to baseline. Active patients experienced greater overall improvement in disability compared to inactive patients. CONCLUSIONS: Sedentary/inactive patients have a more protracted recovery after lumbar decompression surgery for spinal stenosis, but at 12 months postintervention can expect to reach similar long-term outcomes as patients who are active/perform activities outside the home preoperatively.

Voice and swallowing outcomes following reoperative anterior cervical discectomy and fusion with a 2-team surgical approach.

OBJECTIVE Dysphagia and vocal cord palsy (VCP) are common complications after anterior cervical discectomy and fusion (ACDF). The reported incidence rates for dysphagia and VCP are variable. When videolaryngostroboscopy (VLS) is performed to assess vocal cord function after ACDF procedures, the incidence of VCP is reported to be as high as 22%. The incidence of dysphagia ranges widely, with estimates up to 71%. However, to the authors' knowledge, there are no prospective studies that demonstrate the rates of VCP and dysphagia for reoperative ACDF. This study aimed to investigate the incidence of voice and swallowing disturbances before and after reoperative ACDF using a 2-team operative approach with comprehensive pre- and postoperative assessment of swallowing, direct vocal cord visualization, and clinical neurosurgical outcomes. METHODS A convenience sample of sequential patients who were identified as requiring reoperative ACDF by the senior spinal neurosurgeon at the University of Alabama at Birmingham were enrolled in a prospective, nonrandomized study during the period from May 2010 until July 2014. Sixty-seven patients undergoing revision ACDF were enrolled using a 2-team approach with neurosurgery and otolaryngology. Dysphagia was assessed both preoperatively and postoperatively using the MD Anderson Dysphagia Inventory (MDADI) and fiberoptic endoscopic evaluation of swallowing (FEES), whereas VCP was assessed using direct visualization with VLS. RESULTS Five patients (7.5%) developed a new postoperative temporary VCP after reoperative ACDF. All of these cases resolved by 2 months postoperatively. There were no new instances of permanent VCP. Twenty-five patients had a new swallowing disturbance detected on FEES compared with their baseline assessment, with most being mild and requiring no intervention. Nearly 60% of patients showed a decrease in their postoperative MDADI scores, particularly within the physical subset. CONCLUSIONS A 2-team approach to reoperative ACDF was safe and effective, with no new cases of VCP on postoperative VLS. Dysphagia rates as assessed through the MDADI scale and FEES were consistent with other published reports.

Recurrent laryngeal nerve injury following reoperative anterior cervical discectomy and fusion: a meta-analysis.

OBJECTIVE Recurrent laryngeal nerve (RLN) injury is one of the most frequent complications of anterior cervical discectomy and fusion (ACDF) procedures. The frequency of RLN is reported as 1%-11% in the literature. (4 , 15) The rate of palsy after reoperative ACDF surgery is not well defined. This meta-analysis was performed to review the current medical evidence on RLN injury after ACDF surgery and to determine a relative rate of RLN injury after reoperative ACDF. METHODS MEDLINE, PubMed, and Google Scholar searches were performed using several key words and phrases related to ACDF surgery. Included studies were written in English, addressed revisionary ACDF surgery, and studied outcomes of RLN injury. Statistical analysis was then performed using a random-effects model to calculate a pooled rate of RLN injury. The heterogeneity of the studies was assessed using Cochran's Q statistic and I(2) statistic, and a funnel plot was constructed to evaluate publication bias. RESULTS The search initially identified 345 articles on this topic. Eight clinical articles that met all inclusion criteria were included in the meta-analysis. A total of 238 patients were found to have undergone reoperative ACDF. Thirty-three of those patients experienced an RLN injury. This analysis identified a rate of RLN injury in the literature after reoperative ACDF of 14.1% (95% confidence interval [CI] 9.8%-19.1%). CONCLUSIONS The rate of RLN palsy of 14.1% was greater than any published rate of RLN injury after primary ACDF operations, suggesting that there is a greater risk of hoarseness and dysphagia with reoperative ACDF surgeries than with primary procedures as reported in these studies.