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Objective: The natural history of ruptured high Spetzler-Martin grade IV and V brain arteriovenous malformations (bAVMs) is underreported given the scarcity of this pathology, and decision-making for patients with bAVMs remains unclarified. In this study, the authors sought to shed light on this topic., Methods: Patients harboring ruptured high-grade bAVMs were identified from an institutional database spanning from 1990 to 2020. The authors examined outcomes of annual hemorrhagic risk in natural history and after treatment, follow-up hemorrhage rate, bAVM obliteration, follow-up modified Rankin Scale (mRS) score > 2, worsened mRS score, and mortality., Results: After reviewing the charts of 1066 patients without hereditary hemorrhagic telangiectasia, 84 patients with ruptured high-grade bAVMs were included in the study for analysis. For cortical bAVMs, the annual risk of hemorrhage during natural history was 2.68%. Surgery decreased the risk to 0.74%, while radiosurgery increased the risk to 5.35%, and embolization only increased the risk to 16.96%. For deep-seated high-grade bAVMs, the annual risk of hemorrhage during natural history was 8.37%. Radiosurgery decreased the risk to 3.11%, surgery decreased the risk to 5.25%, and embolization only increased the risk to 22.33%. Poisson regression analysis demonstrated that embolization only increased the risk of hemorrhage in cortical bAVMs (rate ratio 4.745, 95% CI 1.365-12.819; p = 0.005) and deep-seated bAVMs (rate ratio 6.290, 95% CI 0.997-21.932; p = 0.013). Logistic regression analysis showed that surgery (OR 52.000, 95% CI 8.083-1046.127; p = 0.004) and radiosurgery (OR 11.142, 95% CI 1.804-217.650; p = 0.029) were predictors of obliteration in cortical and deep-seated bAVMs, respectively. The proportions of patients experiencing a worsened mRS score, a follow-up mRS score > 2, and mortality were similar between conservative and treatment groups., Conclusions: The natural history of cortical ruptured high-grade bAVMs bears a risk similar to that of incidental bAVMs, whereas deep-seated ruptured high-grade bAVMs have an increased risk of hemorrhage. With extremely prudent patient selection, surgery might be a viable option for cortical bAVMs to obliterate the bAVM and reduce hemorrhagic risk, while preserving functional status. Radiosurgery might be beneficial to lower hemorrhagic risk in deep-seated bAVMs. Embolization as a single modality should be avoided as it provides no benefit to reduce hemorrhagic risk.

Objective: The Glasgow Coma Scale-Pupils (GCS-P) score has been suggested to better predict patient outcomes compared with GCS alone, while avoiding the need for more complex clinical models. This study aimed to compare the prognostic ability of GCS-P versus GCS in a national cohort of traumatic subdural hematoma (SDH) patients., Methods: Patient data were obtained from the National Trauma Data Bank (2017-2019). Inclusion criteria were traumatic SDH diagnosis with available data on presenting GCS score, pupillary reactivity, and discharge disposition. Patients with severe polytrauma or nonsurvivable head injury at presentation were excluded. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of GCS-P versus GCS scores for inpatient mortality prediction were evaluated across the entire cohort, as well as in subgroups based on age and traumatic brain injury (TBI) type (blunt vs penetrating). Calibration curves were plotted based on predicted probabilities and actual outcomes., Results: A total of 196,747 traumatic SDH patients met the study inclusion criteria. Sensitivity (0.707 vs 0.702), specificity (0.821 vs 0.823), and AUC (0.825 vs 0.814, p < 0.001) of GCS-P versus GCS scores for prediction of inpatient mortality were similar. Calibration curve analysis revealed that GCS scores slightly underestimated inpatient mortality risk, whereas GCS-P scores did not. In patients > 65 years of age with blunt TBI (51.9%, n = 102,148), both GCS-P and GCS scores underestimated inpatient mortality risk. In patients with penetrating TBI (2.4%, n = 4,710), the AUC of the GCS-P score was significantly higher (0.902 vs 0.851, p < 0.001). In this subgroup, both GCS-P and GCS scores underestimated inpatient mortality risk among patients with lower rates of observed mortality and overestimated risk among patients with higher rates of observed mortality. This effect was more pronounced in the GCS-P calibration curve., Conclusions: The GCS-P score provides better short-term prognostication compared with the GCS score alone among traumatic SDH patients with penetrating TBI. The GCS-P score overestimates inpatient mortality risk among penetrating TBI patients with higher rates of observed mortality. For penetrating TBI patients, which comprised 2.4% of our SDH cohort, a low GCS-P score should not justify clinical nihilism or forgoing aggressive treatment.

Objective: Recently, two scoring systems have been developed for predicting pain-free outcomes after microvascular decompression (MVD). Evaluation of these scores on large external datasets has been limited. In this study, the authors aimed to evaluate the performance of published MVD scoring systems in predicting pain-free outcome., Methods: A total of 458 patients who underwent MVD for trigeminal neuralgia (TN) between 2007 and 2020 and had at least 6 months of follow-up were included in this study. Hardaway and Panczykowski scores were retrospectively computed for each patient and compared with postoperative pain recurrence and pain-free duration., Results: The mean ± SD area under the receiver operating characteristic curve for predicting any pain recurrence after MVD was 0.567 ± 0.081 using the Hardaway score and 0.546 ± 0.085 using the Panczykowski score. On log-rank tests and Kaplan-Meier analysis, the patients with Hardaway scores of 0-2 had significantly shorter pain-free survival times after MVD than did those with a score of 3. Patients with a Panczykowski score of 1 had a significantly shorter pain-free duration after surgery compared with both patients with scores of 2-3 and patients with scores of 4-5. Patients with Panczykowski scores of 2-3 also had significantly shorter pain-free duration compared with patients with scores of 4-5., Conclusions: Both the Hardaway and Panczykowski scores may be useful for predicting postoperative pain-free duration in TN patients, and their utility may be greatest when scores are clustered. Continued refinement of both scoring systems will help to improve our ability to predict patient outcomes after MVD.

Objective: Microvascular decompression (MVD) is an effective intervention in patients with trigeminal neuralgia (TN). How prior rhizotomy can impact long-term pain outcomes following MVD is not well understood. In this study, the authors sought to compare pain outcomes in patients who had undergone primary MVD versus those who had undergone secondary MVD after a single or multiple rhizotomies., Methods: The authors retrospectively reviewed the data on all patients who had undergone MVD at their institution from 2007 to 2020. Patients were included in the study if they had undergone primary MVD or if their surgical history was notable for past rhizotomy. Barrow Neurological Institute (BNI) pain scores were assigned at preoperative and final follow-up appointments. Perioperative complications were noted for each patient, and evidence of pain recurrence was recorded as well. A history of rhizotomy as well as other variables that might influence TN pain recurrence were evaluated using a Cox proportional hazards model. The impact of prior rhizotomy on TN pain recurrence following MVD was further assessed using Kaplan-Meier survival analysis., Results: Of 1044 patients reviewed, 947 met the study inclusion criteria. Of these, 796 patients had undergone primary MVD, 84 had a history of a single rhizotomy before MVD, and 67 had a history of ≥ 2 rhizotomies prior to MVD. Patients in the single rhizotomy and multiple rhizotomies cohorts exhibited a greater frequency of preoperative numbness (p < 0.001), higher preoperative BNI pain scores (p < 0.005), and higher rates of postoperative numbness (p = 0.04). However, final follow-up BNI pain scores were not significantly different between the primary MVD and prior rhizotomy groups (p = 0.34). Cox proportional hazards analysis revealed that younger age, multiple sclerosis, and female sex independently predicted an increased risk of pain recurrence following MVD. Neither a history of a single prior rhizotomy nor a history of multiple prior rhizotomies independently increased the risk of pain recurrence. Furthermore, Kaplan-Meier analysis of pain-free survival among the 3 groups revealed no relationship between a history of prior rhizotomy and pain recurrence following MVD (p = 0.57)., Conclusions: Percutaneous rhizotomy does not complicate outcomes following subsequent MVD for TN pain. However, patients undergoing rhizotomy before MVD may have an increased risk of postoperative facial numbness compared to that in patients undergoing primary MVD.

Objective: Decision-making for the management of ruptured deep-seated brain arteriovenous malformations (bAVMs) is controversial. This study aimed to shed light on the treatment outcomes of patients with ruptured deep-seated bAVMs., Methods: Data on bAVM patients were retrieved from the authors' institutional database, spanning 1990-2021. The outcomes were annual hemorrhage risk (before and after intervention), number of follow-up hemorrhages, bAVM obliteration, poor modified Rankin Scale (mRS) score (i.e., mRS score > 2), worsened mRS score, and mortality. Multivariable Cox and logistic regression analyses were conducted to determine predictors of time-to-event and categorical outcomes, respectively., Results: Of the 1066 patients in the database with brain bAVM, 177 patients harboring ruptured deep-seated bAVMs were included. The pretreatment annual hemorrhage risk was 8.24%, and the posttreatment risk was lowered to 1.65%. In multivariable Cox regression analysis, a prenidal aneurysm (HR 2.388, 95% CI 1.057-5.398; p = 0.036) was associated with a higher risk of follow-up hemorrhage, while definitive treatment (i.e., either surgery or radiosurgery vs endovascular embolization or conservative management) (HR 0.267, 95% CI 0.118-0.602; p = 0.001) was associated with a lower risk of follow-up hemorrhage. In multivariable logistic regression analysis, Spetzler-Martin grades IV and V (OR 0.404, 95% CI 0.171-0.917; p = 0.033) and brainstem arteriovenous malformation (AVM) (OR 0.325, 95% CI 0.128-0.778; p = 0.014) were associated with lower odds of obliteration, while definitive treatment (OR 8.864, 95% CI 3.604-25.399; p = 0.008) was associated with higher obliteration odds. Controlling for baseline mRS score, cerebellar AVM (OR 0.286, 95% CI 0.098-0.731; p = 0.013) and definitive treatment (OR 0.361, 95% CI 0.160-0.807; p = 0.013) were associated with lower odds of a poor mRS score, and definitive treatment (OR 0.208, 95% CI 0.076-0.553; p = 0.001) was associated with lower odds of a worsened mRS score. Furthermore, smoking (OR 6.068, 95% CI 1.531-25.581; p = 0.01) and definitive treatment (OR 0.101, 95% CI 0.024-0.361; p = 0.007) were associated with higher and lower mortality odds, respectively., Conclusions: A definitive treatment strategy seems to be beneficial in achieving higher obliteration and lower hemorrhage rates while decreasing the odds of a poor mRS score, worsened mRS score, and mortality. In this category of patients, prenidal aneurysms warrant treatment, and smoking cessation should be encouraged.

Objective: Trigeminal neuralgia as the presenting symptom of brain arteriovenous malformation (bAVM) has been rarely reported. Treatment of reported cases has been skewed toward surgery for these scarce, deeply located bAVMs. Here, the authors report their management and outcomes of bAVM patients presenting with ipsilateral trigeminal neuralgia (TN) at their institution., Methods: This is a retrospective cohort study. The authors' institutional bAVM database was queried for non-hereditary hemorrhagic telangiectasia bAVMs in pontine, cistern, brainstem, trigeminal nerve, or tentorial locations. Patients with complete data were included in a search for trigeminal neuralgia or "facial pain" as the presenting symptom with TN being on the same side as the bAVM. Demographics, TN and bAVM characteristics, management strategies, and outcomes of bAVM and TN management were analyzed., Results: Fifty-seven peripontine bAVMs were identified; 8 (14.0%) of these bAVMs were discovered because of ipsilateral TN, including 4 patients (50%) with facial pain in the V2 distribution. Five patients (62.5%) were treated with carbamazepine as the initial medical therapy, 2 (25%) underwent multiple rhizotomies, and 1 (12.5%) underwent microvascular decompression. None of the patients with TN-associated bAVMs presented with hemorrhage, compared with 25 patients (51%) with bAVMs that were not associated with TN (p < 0.01). TN-associated bAVMs were overall smaller than non-TN-associated bAVMs, but the difference was not statistically significant (1.71 cm vs 2.22 cm, p = 0.117), and the Spetzler-Martin grades were similar. Six patients (75%) underwent radiosurgery to the bAVM (mean dose 1800 cGy, mean target volume 0.563 cm3) and had complete resolution of TN symptoms (100%). The mean time from radiosurgery to TN resolution was 193 (range 21-360) days, and 83.3% of treated TN-associated bAVMs were obliterated via radiosurgery. Two patients (12.5%) were recommended for conservative management, with one undergoing subsequent rhizotomies and another patient died of hemorrhage during follow-up., Conclusions: TN-associated bAVM is a rare condition with limited evidence for management guidance. Radiosurgery can be safe and effective in achieving durable TN control in patients with TN-associated bAVMs. Despite their deep location and unruptured presentation, obliteration can reach 83.3% with radiosurgery.

Objective: The goal of this study was to provide a comprehensive overview of the current understanding of molecular and genetic mechanisms underlying the pathophysiology of trigeminal neuralgia (TN)., Methods: The authors searched PubMed systematically for primary research literature investigating specific molecular mechanisms from samples derived from patients with TN. The genes/molecules of interest from the selected literature were then cross-referenced with corresponding studies in animal models of TN., Results: From approximately 345 articles, a total of 12 articles were selected and included in the review, focusing on ionotropic channel expressivity and mutations, reactive oxygen species expressivity, inflammatory marker expressivity, and microRNA expressivity. Of the 12 included articles, only 4 had studies completed in other animal models regarding the corresponding TN mechanism found in humans., Conclusions: The current literature does not suggest a conclusive disease mechanism for TN in humans. In addition to neurovascular conflict/compression of the trigeminal nerve, recent studies have indicated that TN may be linked to inflammatory and reactive oxygen species signaling as well. Recent genetic studies in patients with TN have yet to be investigated further in animal models.

Objective: The optimal surgical approach for patients with multilevel degenerative cervical myelopathy (DCM) remains unknown. This systematic review and meta-analysis sought to compare anterior cervical discectomy and fusion (ACDF) versus posterior decompression (PD) in patients with DCM spanning ≥ 2 levels without ossification of the posterior longitudinal ligament., Methods: MEDLINE and PubMed were searched from inception to February 22, 2022. The primary outcomes were Neck Disability Index (NDI), SF-36 Physical Component Summary (PCS), modified Japanese Orthopaedic Association (mJOA) scale, visual analog scale (VAS), and EQ-5D scores. Secondary outcomes were operative bleeding, operative duration, hospital length of stay (LOS), postoperative morbidity (including hematoma, surgical site infection [SSI], CSF leakage, dysphagia, dysphonia, C5 palsy, and fusion failure), mortality, readmission, reoperation, and Cobb angle., Results: Nineteen studies comprising 8340 patients were included, of whom 4118 (49.4%) and 4222 (50.6%) underwent ACDF and PD, respectively. The mean number of involved spinal levels was comparable between the groups (3.1 vs 3.5, p = 0.15). The mean differences (MDs) of the primary outcomes were the mean of each index in the ACDF group minus that of the PD group. At the 1-year follow-up, the MDs of the NDI (-1.67 [95% CI -3.51 to 0.18], p = 0.08), SF-36 PCS (2.48 [95% CI -0.59 to 5.55], p = 0.11), and VAS (-0.32 [95% CI -0.97 to 0.34], p = 0.35) scores were similar between the groups. While the MDs of the mJOA (0.71 [95% CI 0.27 to 1.16], p = 0.002) and EQ-5D (0.04 [95% CI 0.01 to 0.08], p = 0.02) scores were greater in the ACDF group, the differences were not clinically significant given the minimal clinically important differences (MCIDs) of 2 and 0.05 points, respectively. In the ACDF group, the MDs for operative bleeding (-102.77 ml [95% CI -169.23 to -36.30 ml], p = 0.002) and LOS (-1.42 days [95% CI -2.01 to -0.82 days], p < 0.00001) were lower, the dysphagia OR (11.10 [95% CI 5.43-22.67], p < 0.0001) was higher, and the ORs for SSI (0.43 [95% CI 0.24-0.78], p = 0.006) and C5 palsy (0.32 [95% CI 0.15-0.70], p = 0.004) were lower. The other outcomes were similar between the groups. Overall evidence according to the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) approach was moderate., Conclusions: ACDF and PD are similar regarding functional outcomes. ACDF is beneficial in terms of less bleeding, shorter LOS, and lower odds of SSI and C5 palsy, while the procedure carries higher odds of dysphagia. The authors recommend individualized treatment decision-making.

Objective: Pain outcomes by race in trigeminal neuralgia (TN) are not well investigated. The authors aimed to compare microvascular decompression (MVD) outcomes in TN patients on the basis of self-identified race., Methods: The authors retrospectively reviewed all patients with TN who underwent MVD at their institution from 2007 to 2020. Each patient's self-reported race was recorded, and Barrow Neurological Institute (BNI) scores for pain and numbness were compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions., Results: Of 1011 patients, 925 reported their racial demographic characteristics, and patients who identified as Native American or American Indian and Native Hawaiian or Pacific Islander were excluded due to small sample sizes. Of the resulting 921 patients, 697 (75.7%) patients identified as White, 108 (11.7%) as Black or African American, 39 (4.2%) as Asian, and 77 (8.4%) as other. Compared with White patients, Black TN patients were more likely to present with type 1 TN (p = 0.02). At final follow-up, the mean BNI pain score of Black patients was significantly higher (p < 0.001) compared with that of White patients, although pain scores did not differ preoperatively. The adjusted multivariate ordinal regression model showed that Black patients were associated with higher BNI pain scores at final follow-up (p = 0.01). Furthermore, compared with White patients, Black patients were at increased risk for postoperative pain recurrence (p = 0.04), which additionally occurred after a shorter median pain-free duration (p = 0.03)., Conclusions: TN patients who identify as Black or African American exhibit worse postoperative pain outcomes after MVD compared with White patients. Future studies investigating the factors driving these racial differences are warranted.

Objective: Pediatric deep brain arteriovenous malformations (bAVMs) represent a unique management challenge given their higher cumulative risk of hemorrhage as well as a higher risk of treatment. Better understanding of hemorrhage risk in this patient population will lead to a better decision-making process for patient management., Methods: The authors retrospectively reviewed their institutional bAVM database from 1990 to 2019 and included patients younger than 21 years who had deep-seated bAVMs. They present the annual hemorrhage risk, during the natural history and after treatment, and functional outcomes., Results: Thirty-one pediatric patients were included in this study (13 males and 18 females) with a mean age of 11.8 (SD 4.4) years. The most frequent presenting symptoms were headache (54.8%), weakness (38.7%), and seizure (22.6%). The mean follow-up duration was 13.14 (SD 12.5) years, during which 7 (22.6%) AVMs were obliterated, 10 (32.3%) individuals experienced hemorrhage, and the modified Rankin Scale score worsened in 8 (25.8%) patients. The annual natural history risk of hemorrhage was 3.24% per patient, and the overall annual hemorrhage risk after treatment was 1.98% per patient. In particular, the risk was reduced to 0.64% per patient in the stereotactic radiosurgery (SRS) group. Non-White race showed a trend of higher rupture at presentation (OR 5 [95% CI 0.84-41.68], p = 0.09). Female sex was associated with higher odds (OR 13.076 [95% CI 1.424-333.591], p = 0.048) and SRS was associated with lower odds (OR 0.122 [95% CI 0.011-0.862], p = 0.049) of follow-up hemorrhage., Conclusions: Given the substantial cumulative risk of lifelong hemorrhagic stroke in pediatric patients, timely definitive treatment is warranted. SRS may be beneficial when the risk-benefit profile is deemed acceptable.

Objective: In microvascular decompression (MVD) surgery through the retrosigmoid approach, the surgeon may have to sacrifice the superior petrosal vein (SPV). However, this is a controversial maneuver. To date, high-level evidence comparing the operative outcomes of patients who underwent MVD with and without SPV sacrifice is lacking. Therefore, this study sought to bridge this gap., Methods: The authors searched the Medline and PubMed databases with appropriate Medical Subject Heading (MeSH) terms and keywords. The primary outcome was vascular-related complications; secondary outcomes were new neurological deficit, cerebrospinal fluid (CSF) leak, and neuralgia relief. The pooled proportions of outcomes and OR (95% CI) for categorical data were calculated by using the logit transformation and Mantel-Haenszel methods, respectively., Results: Six studies yielding 1143 patients were included, of which 618 patients had their SPV sacrificed. The pooled proportion (95% CI) values were 3.82 (0.87-15.17) for vascular-related complications, 3.64 (1.0-12.42) for new neurological deficits, 2.85 (1.21-6.58) for CSF leaks, and 88.90 (84.90-91.94) for neuralgia relief. The meta-analysis concluded that, whether the surgeon sacrificed or preserved the SPV, the odds were similar for vascular-related complications (2.5% vs 1.5%, OR [95% CI] 1.01 [0.33-3.09], p = 0.99), new neurological deficits (1.2% vs 2.8%, OR [95% CI] 0.55 [0.18-1.66], p = 0.29), CSF leak (3.1% vs 2.1%, OR [95% CI] 1.16 [0.46-2.94], p = 0.75), and neuralgia relief (86.6% vs 87%, OR [95% CI] 0.96 [0.62-1.49], p = 0.84)., Conclusions: SPV sacrifice is as safe as SPV preservation. The authors recommend intentional SPV sacrifice when gentle retraction fails to enhance surgical field visualization and if the surgeon encounters SPV-related neurovascular conflict and/or anticipates impeding SPV-related bleeding.

Objective: Internal neurolysis (IN) and intraoperative glycerin rhizotomy (ioGR) are emerging surgical options for patients with trigeminal neuralgia without neurovascular contact. The objective of this study was to compare the neurological outcomes of patients who underwent IN with those of patients who underwent ioGR., Methods: The authors retrospectively reviewed all patients who underwent IN or ioGR for trigeminal neuralgia at our institution. Patient demographic characteristics and immediate postoperative outcomes, as well as long-term neurological outcomes, were compared., Results: Of 1044 patients who underwent open surgical treatment for trigeminal neuralgia, 56 patients underwent IN and 91 underwent ioGR. Of these 147 patients, 37 had no evidence of intraoperative neurovascular conflict. All patients who underwent IN and 96.7% of patients who underwent ioGR had immediate postoperative pain relief. At last follow-up, patients who underwent IN had lower Barrow Neurological Institute (BNI) pain intensity scores (p = 0.05), better BNI facial numbness scores (p < 0.01), and a greater degree of pain improvement (p = 0.05) compared with those who underwent ioGR. Patients who underwent IN also had significantly lower rates of symptomatic pain recurrence (p < 0.01) at last follow-up over an average of 9.5 months., Conclusions: IN appears to provide patients with a greater degree of pain relief, lower rates of facial numbness, and lower rates of pain recurrence compared with ioGR. Future prospective studies will better characterize long-term pain recurrence and outcomes.

Objective: Pediatric intracranial aneurysms are rare. Most large series in the last 15 years reported on an average of only 39 patients. The authors sought to report their institutional experience with pediatric intracranial aneurysms from 1991 to 2021 and to compare pediatric patient and aneurysm characteristics with those of a contemporaneous adult cohort., Methods: Pediatric (≤ 18 years of age) and adult patients with one or more intracranial aneurysms were identified in a prospective database. Standard epidemiological features and outcomes of each pediatric patient were retrospectively recorded. These results were compared with those of adult aneurysm patients managed at a single institution over the same time period., Results: From a total of 4500 patients with 5150 intracranial aneurysms admitted over 30 years, there were 47 children with 53 aneurysms and 4453 adults with 5097 aneurysms; 53.2% of children and 36.4% of adults presented with a subarachnoid hemorrhage (SAH). Pediatric aneurysms were significantly more common in males, more likely giant (≥ 25 mm), and most frequently located in the middle cerebral artery. Overall, 85.1% of the pediatric patients had a modified Rankin Scale score ≤ 2 at the last follow-up (with a mean follow-up of 65.9 months), and the pediatric mortality rate was 10.6%; all 5 patients who died had an SAH. The recurrence rate of treated aneurysms was 6.7% (1/15) in the endovascular group but 0% (0/31) in the microsurgical group. No de novo aneurysms occurred in children (mean follow-up 5.5 years)., Conclusions: Pediatric intracranial aneurysms are significantly different from adult aneurysms in terms of sex, presentation, location, size, and outcomes. Future prospective studies will better characterize long-term aneurysm recurrence, rebleeds, and de novo aneurysm occurrences. The authors currently favor microsurgical over endovascular treatment for pediatric aneurysms.

Objective: The authors aimed to determine whether differences exist in presentation and natural history when comparing Asian patients with moyamoya disease (MMD) to those of other ethnicities in North America., Methods: A database of 137 patients with MMD presenting to their institution between 1994 and 2015 was reviewed. Baseline characteristics and outcome variables, including stroke and functional outcome, were compared between Asian and non-Asian patients. Unadjusted Kaplan-Meier survival analysis and adjusted Cox regression models were used to compare stroke-free survival and stroke hazard after diagnosis among hemispheres of both racial groups. The analysis was stratified by age group, and censoring was performed until last follow-up or at the time of surgery. Because the relative rate of stroke changed between Asian and non-Asian adults after 1.5 years of follow-up, a time-segmented analysis focusing on the period 1.5 years after diagnosis was performed., Results: The cohort comprised 23% (31/137) Asian and 77% (106/137) non-Asian patients with MMD with a bimodal age distribution. Non-Asian patients had a higher prevalence of increased BMI (p = 0.02) and smoking (p = 0.04). Among patients who presented with stroke (n = 90), hemorrhage was significantly more common among Asians (p = 0.02). The natural history analysis included 250 hemispheres: 67 pediatric and 183 adult hemispheres. The overall mean follow-up duration since diagnosis was 3.3 years. Among adults, Asian patients had a higher incidence of stroke (8.0 per 100 person-years vs 3.0 per 100 person-years) over a mean follow-up of 3.3 years, but results were not statistically significant (p = 0.45). In the period beginning 1.5 years after diagnosis, Asian adults had a significantly higher hazard of stroke over a mean follow-up of 7.7 years, while controlling for sex, hypertension, and stroke before diagnosis (hazard ratio 8.8, p = 0.02). Among pediatric patients, Asians also had a higher stroke incidence (10.0 per 100 person-years vs 3.5 per 100 person-years) over a mean follow-up of 3.2 years; however, results did not reach statistical significance (p = 0.40). Functional outcome was similar between both ethnic groups at last follow-up (p = 0.57)., Conclusions: This study suggests a comparatively more progressive course of MMD in Asians. Further studies are required to fully characterize the phenotypic distinctions between different races and underlying pathophysiological mechanisms.

Objective: Phenotypic differences between moyamoya disease (MMD) and moyamoya syndrome (MMS) remain unclear. The purpose of this study was to evaluate whether such differences exist when presentation, procedure-related, and outcome variables are compared quantitatively., Methods: The study cohort included 185 patients with moyamoya presenting to the Johns Hopkins Medical Institutions between 1994 and 2015. Baseline demographic, angiographic, and clinical characteristics were compared between patients with MMS and MMD, in addition to procedure-related complications and length of stay (LOS) after surgery. Stroke-free survival was compared between both disease variants after diagnosis. Kaplan-Meier analysis and Cox proportional hazards regression were used to compare stroke-free survival between surgically treated and conservatively managed hemispheres in both types of disease, while evaluating interaction between disease variant and management., Results: The cohort consisted of 137 patients with MMD (74%) with a bimodal age distribution and 48 patients with MMS (26%) who were mostly under 18 years of age (75%). Underlying diseases included sickle cell disease (48%), trisomy 21 (12%), neurofibromatosis (23%), and other disorders (17%). Patients with MMS were younger (p < 0.001) and less likely to be female (p = 0.034). Otherwise, baseline characteristics were statistically comparable. The rate of surgical complications was 33% in patients with MMD and 16% in patients with MMS (p = 0.097). Both groups of patients had a similar LOS after surgery (p = 0.823). Survival analysis (n = 330 hemispheres) showed similar stroke-free survival after diagnosis (p = 0.856) and lower stroke hazard in surgically managed patients in both MMD (hazard ratio [HR] 0.29, p = 0.028) and MMS (HR 0.62, p = 0.586). The disease variant (MMD vs MMS) did not affect the relationship between management approach (surgery vs conservative) and stroke hazard (p = 0.787)., Conclusions: MMD and MMS have largely comparable clinical and angiographic phenotypes with analogously favorable responses to surgical revascularization.

OBJECTIVE Flow diversion requires neointimal stent overgrowth to deliver aneurysm occlusion. The existing literature on aneurysm occlusion is limited by heterogeneous follow-up, variable antiplatelet regimens, noninvasive imaging modalities, and nonstandard occlusion assessment. Using a large, single-center cohort with low attrition and standardized antiplatelet tapering, the authors evaluated outcomes after flow diversion of anterior circulation aneurysms to identify predictors of occlusion and aneurysm persistence. METHODS Data from a prospective, IRB-approved database was analyzed for all patients with anterior circulation aneurysms treated by flow diversion with the Pipeline embolization device (PED) at the authors' institution. Follow-up consisted of catheter cerebral angiography at 6 and 12 months postembolization. Clopidogrel was discontinued at 6 months and aspirin was reduced to 81 mg daily at 12 months. Occlusion was graded as complete, trace filling, entry remnant, or aneurysm filling. Multivariate logistic regression was performed to identify predictors of aneurysm persistence. RESULTS Follow-up catheter angiography studies were available for 445 (91%) of 491 PED procedures performed for anterior circulation aneurysms between August 2011 and August 2016. Three hundred eighty-seven patients accounted for these 445 lesions with follow-up angiography. The population was 84% female; mean age was 56 years and mean aneurysm size was 6.6 mm. Aneurysms arose from the internal carotid artery (83%), anterior cerebral artery (13%), and middle cerebral artery (4%). Morphology was saccular in 90% of the lesions, and 18% of the aneurysms has been previously treated. Overall, complete occlusion was achieved in 82% of cases at a mean follow-up of 14 months. Complete occlusion was achieved in 72%, 78%, and 87% at 6, 12, and 24 months, respectively. At 12 months, adjunctive coiling predicted occlusion (OR 0.260, p = 0.036), while male sex (OR 2.923, p = 0.032), aneurysm size (OR 3.584, p = 0.011), and incorporation of a branch vessel (OR 2.206, p = 0.035) predicted persistence. Notable variables that did not predict aneurysm occlusion were prior treatments, vessel of origin, fusiform morphology, and number of devices used. CONCLUSIONS This is the largest single-institution study showing high rates of anterior circulation aneurysm occlusion after Pipeline embolization. Predictors of persistence after flow diversion included increasing aneurysm size and incorporated branch vessel, whereas adjunctive coiling predicted occlusion.

Intracranial aneurysms in the pediatric population are rare entities. The authors recently treated a 9-month-old infant with a 19-mm recurrent, previously ruptured, and coil-embolized left middle cerebral artery (MCA) pseudoaneurysm, which was treated definitively with single-stage Pipeline-assisted coil embolization. The patient was 5 months old when she underwent resection of a left temporal Grade 1 desmoplastic infantile ganglioglioma at an outside institution, which was complicated by left MCA injury with a resultant 9-mm left M1 pseudoaneurysm. Within a month, the patient had two aneurysmal rupture events and underwent emergency craniectomy for decompression and evacuation of subdural hematoma. The pseudoaneurysm initially underwent coil embolization; however, follow-up MR angiography (MRA) revealed aneurysm recanalization with saccular enlargement to 19 mm. The patient underwent successful flow diversion-assisted coil embolization at 9 months of age. At 7 months after the procedure, follow-up MRA showed complete aneurysm occlusion without evidence of in-stent thrombosis or stenosis. Experience with flow diverters in the pediatric population is still in its early phases, with the youngest reported patient being 22 months old. In this paper the authors report the first case of such a technique in an infant, whom they believe to be the youngest patient to undergo cerebral flow diversion treatment.

Objective: Hydrocephalus associated with subdural hygromas is a rare complication after decompression of Chiari malformation type I (CM-I). There is no consensus for management of this complication. The authors present a series of 5 pediatric patients who underwent CM-I decompression with placement of a dural graft complicated by posterior fossa hygromas and hydrocephalus that were successfully managed nonoperatively., Methods: A retrospective review over the last 5 years of patients who presented with hydrocephalus and subdural hygromas following foramen magnum decompression with placement of a dural graft for CM-I was conducted at 2 pediatric institutions. Their preoperative presentation, perioperative hospital course, and postoperative re-presentation are discussed with attention to their treatment regimen and ultimate outcome. In addition to reporting these cases, the authors discuss all similar cases found in their literature review., Results: Over the last 5 years, the authors have encountered 194 pediatric cases of CM-I decompression with duraplasty equally distributed at the 2 institutions. Of those cases, 5 pediatric patients with a delayed postoperative complication involving hydrocephalus and subdural hygromas were identified. The 5 patients were managed nonoperatively with acetazolamide and high-dose dexamethasone; dosages of both drugs were adjusted to the age and weight of each patient. All patients were symptom free at follow-up and exhibited resolution of their pathology on imaging. Thirteen similar pediatric cases and 17 adult cases were identified in the literature review. Most reported cases were treated with CSF diversion or reoperation. There were a total of 4 cases previously reported with successful nonoperative management. Of these cases, only 1 case was reported in the pediatric population., Conclusions: De novo hydrocephalus, in association with subdural hygromas following CM-I decompression, is rare. This presentation suggests that these complications after posterior fossa decompression with duraplasty can be treated with nonoperative medical management, therefore obviating the need for CSF diversion or reoperation.

OBJECTIVE Sickle cell disease (SCD) in combination with moyamoya syndrome (MMS) represents a rare complication of SCD, with potentially devastating neurological outcomes. The effectiveness of surgical revascularization in this patient population is currently unclear. The authors' aim was to determine the effectiveness of surgical intervention in their series of SCD-MMS patients by comparing stroke recurrence in those undergoing revascularization and those undergoing conservative transfusion therapy. METHODS The authors performed a retrospective chart review of patients with MMS who were seen at the Johns Hopkins Medical Institution between 1990 and 2013. Pediatric patients (age < 18 years) with confirmed diagnoses of SCD and MMS were included. Intracranial stroke occurrence during the follow-up period was compared between surgically and conservatively managed patients. RESULTS A total of 15 pediatric SCD-MMS patients (28 affected hemispheres) were included in this study, and all were African American. Seven patients (12 hemispheres) were treated with indirect surgical revascularization. The average age at MMS diagnosis was 9.0 ± 4.0 years, and 9 patients (60.0%) were female. Fourteen patients (93.3%) had strokes before diagnosis of MMS, with an average age at first stroke of 6.6 ± 3.9 years. During an average follow-up period of 11.6 years, 4 patients in the conservative treatment group experienced strokes in 5 hemispheres, whereas no patient undergoing the revascularization procedure had any strokes at follow-up (p = 0.029). Three patients experienced immediate postoperative transient ischemic attacks, but all recovered without subsequent strokes. CONCLUSIONS Indirect revascularization is suggested as a safe and effective alternative to the best medical therapy alone in patients with SCD-MMS. High-risk patients managed on a regimen of chronic transfusion should be considered for indirect revascularization to maximize the effect of stroke prevention.

OBJECTIVE The purpose of this study was to report the long-term clinical outcomes following 3- and 4-level anterior cervical discectomy and fusion (ACDF). METHODS A retrospective review of all adult neurosurgical patients undergoing elective ACDF for degenerative disease at a single institution between 1996 and 2013 was performed. Patients who underwent first-time 3- or 4-level ACDF were included; patients with previous cervical spine surgery, those undergoing anterior/posterior approaches, and those with corpectomy were excluded. Outcome measures included perioperative complication rates, fusion rates, need for revision surgery, Nurick Scores, Odom's criteria, symptom resolution, neck visual analog scale (VAS) pain score, and persistent narcotics usage. RESULTS Seventy-one patients who underwent 3-level ACDF and 26 patients who underwent 4-level ACDF were identified and followed for an average of 7.6 ± 4.2 years. There was 1 case (3.9%) of deep wound infection in the 4-level group and 1 case in the 3-level group (1.4%; p = 0.454). Postoperatively, 31% of patients in the 4-level group complained of dysphagia, compared with 12.7% in the 3-level group (p = 0.038). The fusion rate was 84.6% after 4-level ACDF and 94.4% after 3-level ACDF (p = 0.122). At last follow-up, a significantly higher proportion of patients in the 4-level group continued to have axial neck pain (53.8%) than in the 3-level group (31%; p = 0.039); the daily oral morphine equivalent dose was significantly higher in the 4-level group (143 ± 97 mg/day) than in the 3-level group (25 ± 10 mg/day; p = 0.030). Outcomes based on Odom's criteria were also different between cohorts (p = 0.044), with a significantly lower proportion of patients in the 4-level ACDF group experiencing an excellent/good outcome. CONCLUSIONS In this study, patients who underwent 4-level ACDF had significantly higher rates of dysphagia, postoperative neck pain, and postoperative narcotic usage when compared with patients who underwent 3-level ACDF. Pseudarthrosis and deep wound infection rates were also higher in the 4-level group, although this did not reach statistical significance. Additionally, a smaller proportion of patients achieved a good/excellent outcome in the 4-level group than in the 3-level group. These findings suggest a significant increase of perioperative morbidity and worsened outcomes for patients who undergo 4- versus 3-level ACDF.

Object: A number of imaging techniques have been introduced to minimize the risk of pedicle screw placement. Intraoperative CT has been recently introduced to assist in spinal instrumentation. The aim of this study was to study the effectiveness of intraoperative CT in enhancing the safety and accuracy of pedicle screw placement., Methods: The authors included all cases from December 2009 through July 2012 in which intraoperative CT scanning was used to confirm pedicle screw placement., Results: A total of 203 patients met the inclusion criteria. Of 1148 screws, 103 screws (8.97%) were revised intraoperatively in 72 patients (35.5%): 14 (18.42%) were revised in the cervical spine (C-2 or C-7), 25 (7.25%) in the thoracic spine, and 64 (8.80%) in the lumbar spine. Compared with screws in the thoracic and lumbar regions, pedicle screws placed in the cervical region were statistically more likely to be revised (p = 0.0061). Two patients (0.99%) required reoperations due to undetected misplacement of pedicle screws., Conclusions: The authors describe one of the first North American experiences using intraoperative CT scanning to confirm the placement of pedicle screws. Compared with a similar cohort of patients from their institution who had pedicle screws inserted via the free-hand technique with postoperative CT, the authors found that the intraoperative CT lowers the threshold for pedicle screw revision, resulting in a statistically higher rate of screw revision in the thoracic and lumbar spine (p < 0.0001). During their 2.5-year experience with the intraoperative CT, the authors did not find a reduction in rates of reoperation for misplaced pedicle screws.

Object: The aim of this study was to study the long-term outcomes of patients undergoing instrumented posterior fusion of the lumbar spine., Methods: The authors present 511 patients who underwent instrumented arthrodesis for lumbar degenerative disease over a 23-year period at a single institution. Patients underwent follow-up for an average of 39.73 ± 46.52 months (± SD) after the index lumbar arthrodesis procedure., Results: The average patient age was 59.45 ± 13.48 years. Of the 511 patients, 502 (98.24%) presented with back pain, 379 (74.17%) with radiculopathy, 76 (14.87%) with motor weakness, and 32 (6.26%) with preoperative bowel/bladder dysfunction. An average of 2.04 ± 1.03 spinal levels were fused. Postoperatively, patients experienced a significant improvement in back pain (p < 0.0001) and radiculopathy (p < 0.0001). Patients with fusions excluding the sacrum (floating fusions) were statistically more likely to develop adjacent-segment disease (ASD) than those with fusion constructs ending at S-1 distally (p = 0.030) but were less likely to develop postoperative radiculopathy (p = 0.030). In the floating fusion cohort, 31 (12.11%) of 256 patients had cephalad ASD, whereas 39 (15.29%) of 255 patients in the lumbosacral cohort had cephalad ASD development; this was not statistically different (p = 0.295). This suggests that caudad ASD development in the floating fusion cohort is due to the added risk of an unfused L5-S1 vertebral level. Because of the elevated risk of symptomatic radiculopathy but lower risk of ASD, patients in the lumbosacral fusion cohort had a reoperation rate similar to those undergoing floating fusions (p = 0.769)., Conclusions: In this paper, the authors present one of the largest cohorts in the Western literature of patients undergoing instrumented fusion for degenerative lumbar spine disease. Patients who had floating lumbar fusions were statistically more likely to develop ASD over time than those who had lumbosacral fusions incorporating the S-1 spinal segment, but were less likely to experience postoperative radicular symptoms. Additional prospective studies may more clearly delineate the long-term risks of instrumented posterolateral fusions of the lumbar spine.

Object: Unintended durotomies are a common complication of spine surgery and are often correlated with increased postoperative morbidity. Recently, ultrasonic bone curettes have been introduced in spine surgery as a possible alternative to the conventional high-speed drill, offering the potential for greater bone-cutting precision and less damage to surrounding soft tissues. To date, however, few studies have investigated the safety and efficacy of the ultrasonic bone curette in reducing the rates of incidental durotomy compared with the high-speed drill., Methods: The authors retrospectively reviewed the records of 337 consecutive patients who underwent posterior cervical or thoracic decompression at a single institution between January 2009 and September 2011. Preoperative pathologies, the location and extent of spinal decompression, and the use of an ultrasonic bone curette versus the high-speed drill were noted. The rates of incidental durotomy, as well as hospital length of stay (LOS) and perioperative outcomes, were compared between patients who were treated using the ultrasonic bone curette and those treated using a high-speed drill., Results: Among 88 patients who were treated using an ultrasonic bone curette and 249 who were treated using a high-speed drill, 5 (5.7%) and 9 (3.6%) patients had an unintentional durotomy, respectively. This finding was not statistically significant (p = 0.40). No patients in either cohort experienced statistically higher rates of perioperative complications, although patients treated using an ultrasonic bone curette tended to have a longer hospital LOS. This difference may be attributed to the fact that this series contained a statistically higher number of metastatic tumor cases (p < 0.0001) in the ultrasonic bone curette cohort, likely increasing the LOS for that patient population. In 13 patients, the dural defect was repaired intraoperatively. No patients who experienced an incidental durotomy had new-onset or permanent neurological deficits postoperatively., Conclusions: The safety and efficacy of ultrasonic bone curettes in spine surgery has not been well established. This study shows that the ultrasonic bone curette has a similar safety profile compared with the high-speed drill, although both are capable of causing iatrogenic dural tears during spine surgery.

Object: The aim of this study was to conduct the first in vitro biomechanical comparison of immediate and postcyclical rigidities of C-7 lateral mass versus C-7 pedicle screws in posterior C4-7 constructs., Methods: Ten human cadaveric spines were treated with C4-6 lateral mass screw and C-7 lateral mass (5 specimens) versus pedicle (5 specimens) screw fixation. Spines were potted in polymethylmethacrylate bone cement and placed on a materials testing machine. Rotation about the axis of bending was measured using passive retroreflective markers and infrared motion capture cameras. The motion of C-4 relative to C-7 in flexion-extension and lateral bending was assessed uninstrumented, immediately after instrumentation, and following 40,000 cycles of 4 Nm of flexion-extension and lateral bending moments at 1 Hz. The effect of instrumentation and cyclical loading on rotational motion across C4-7 was analyzed for significance., Results: Preinstrumented spines for the 2 cohorts were comparable in bone mineral density and range of motion in both flexion-extension (p = 0.33) and lateral bending (p = 0.16). Lateral mass and pedicle screw constructs significantly reduced motion during flexion-extension (11.3°-0.26° for lateral mass screws, p = 0.002; 10.51°-0.30° for pedicle screws, p = 0.008) and lateral bending (7.38°-0.27° for lateral mass screws, p = 0.003; 11.65°-0.49° for pedicle screws, p = 0.03). After cyclical loading in both cohorts, rotational motion over C4-7 was increased during flexion-extension (0.26°-0.68° for lateral mass screws; 0.30°-1.31° for pedicle screws) and lateral bending (0.27°-0.39° and 0.49°-0.80°, respectively), although the increase was not statistically significant (p > 0.05). There was no statistical difference in postcyclical flexion-extension (p = 0.20) and lateral bending (0.10) between lateral mass and pedicle screws., Conclusions: Both C-7 lateral mass and C-7 pedicle screws allow equally rigid fixation of subaxial lateral mass constructs ending at C-7. Immediately and within a simulated 6-week postfixation period, C-7 lateral mass screws may be as effective as C-7 pedicle screws in biomechanically stabilizing long subaxial lateral mass constructs.

Object: The most common spinal procedure performed in the US is lumbar discectomy for disc herniation. Longterm disc degeneration and height loss occur in many patients after lumbar discectomy. The incidence of mechanical back pain following discectomy varies widely in the literature, and its associated health care costs are unknown. The authors set out to determine the incidence of and the health care costs associated with mechanical back pain attributed to segmental degeneration or instability at the level of a prior discectomy performed at their institution., Methods: The authors retrospectively reviewed the data for 111 patients who underwent primary, single-level lumbar hemilaminotomy and discectomy for radiculopathy. All diagnostic modalities, conservative therapies, and operative treatments used for the management of postdisectomy back pain were recorded. Institutional billing and accounting records were reviewed to determine the billed costs of all diagnostic and therapeutic measures., Results: At a mean follow-up of 37.3 months after primary discectomy, 75 patients (68%) experienced minimal to no back pain, 26 (23%) had moderate back pain requiring conservative treatment only, and 10 (9%) suffered severe back pain that required a subsequent fusion surgery at the site of the primary discectomy. The mean cost per patient for conservative treatment alone was $4696. The mean cost per patient for operative treatment was $42,554. The estimated cost of treatment for mechanical back pain associated with postoperative same-level degeneration or instability was $493,383 per 100 cases of first-time, single-level lumbar discectomy ($4934 per primary discectomy)., Conclusions: Postoperative mechanical back pain associated with same-level degeneration is not uncommon in patients undergoing single-level lumbar discectomy and is associated with substantial health care costs.

Epidural steroid injections are relatively safe procedures, although the risk of hemorrhagic complications in patients undergoing long-term anticoagulation therapy is higher. The American Society for Regional Anesthesia and Pain Medicine has specific guidelines for treatment of these patients when they undergo neuraxial anesthetic procedures. In this paper, the authors present a case in which the current American Society for Regional Anesthesia and Pain Medicine guidelines were strictly followed with respect to withholding and reintroducing warfarin and enoxaparin after an epidural steroid injection, but the patient nevertheless developed a spinal epidural hematoma requiring emergency surgical evacuation. The authors compare the case with the 8 other published cases of postinjection epidural hematomas in patients with coagulopathy, and the specific risk factors that may have contributed to the hemorrhagic complication in this patient is analyzed.

Object: Adequate decompression of the thoracic spinal cord often requires a complete vertebrectomy. Such procedures can be performed from an anterior/transthoracic, posterior, or combined approach. In this study, the authors sought to compare the clinical outcomes of patients with spinal metastatic tumors undergoing anterior, posterior, and combined thoracic vertebrectomies to determine the efficacy and operative morbidity of such approaches., Methods: A retrospective review was conducted of all patients undergoing thoracic vertebrectomies at a single institution over the past 7 years. Characteristics of patients and operative procedures were documented. Neurological status, perioperative variables, and complications were assessed and associations with each approach were analyzed., Results: Ninety-one patients (mean age 55.5 +/- 13.7 years) underwent vertebrectomies via an anterior (22 patients, 24.2%), posterior (45 patients, 49.4%), or combined anterior-posterior approach (24 patients, 26.4%) for metastatic spinal tumors. The patients did not differ significantly preoperatively in terms of neurological assessments on the Nurick and American Spinal Injury Association Impairment scales, ambulatory ability, or other comorbidities. Anterior approaches were associated with less blood loss than posterior approaches (1172 +/- 1984 vs 2486 +/- 1645 ml, respectively; p = 0.03) or combined approaches (1172 +/- 1984 vs 2826 +/- 2703 ml, respectively; p = 0.05) but were associated with a similar length of stay compared with the other treatment cohorts (11.5 +/- 9.3 [anterior] vs 11.3 +/- 8.6 [posterior] vs 14.3 +/- 6.7 [combined] days; p = 0.35). The posterior approach was associated with a higher incidence of wound infection compared with the anterior approach cohort (26.7 vs 4.5%, respectively; p = 0.03), and patients in the posterior approach group experienced the highest rates of deep vein thrombosis (15.6% [posterior] vs 0% [other 2 groups]; p = 0.02). However, the posterior approach demonstrated the lowest incidence of pneumothorax (4.4%; p < 0.0001) compared with the other 2 cohorts. Duration of chest tube use was greater in the combined patient group compared with the anterior approach cohort (8.8 +/- 6.2 vs 4.7 +/- 2.3 days, respectively; p = 0.01), and the combined group also experienced the highest rates of radiographic pleural effusion (83.3%; p = 0.01). Postoperatively, all groups improved neurologically, although functional outcome in patients undergoing the combined approach improved the most compared with the other 2 groups on both the Nurick (p = 0.04) and American Spinal Injury Association Impairment scales (p = 0.03)., Conclusions: Decisions regarding the approach to thoracic vertebrectomy may be complex. This study found that although anterior approaches to the thoracic vertebrae have been historically associated with significant pulmonary complications, in our experience these rates are nevertheless quite comparable to that encountered via a posterior or combined approach. In fact, the posterior approach was found to be associated with a higher risk for some perioperative complications such as wound infection and deep vein thromboses. Finally, the combined anteriorposterior approach may provide greater ambulatory and neurological improvements in properly selected patients.

Abnormal ossification of spinal ligaments is a well-known cause of myelopathy in East Asian populations, with ossification of the ligamentum flavum (OLF) and the posterior longitudinal ligament being the most prevalent. In Caucasian populations, OLF is rare, and there has been only 1 documented case of the disease affecting more than 5 spinal levels. In this report, the authors describe the clinical presentation, imaging characteristics, and management of the second published case of a Caucasian man with OLF affecting almost the entire thoracic spine. The literature is then reviewed with regard to OLF epidemiology, pathogenesis, presentation, and treatment.