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Background Reporting complications and/or adverse events after spinal surgical procedures enables the estimation of their prevalence and of their impact on patient outcomes. However, the documentation of complications is relatively infrequent and highly heterogeneous. The purpose of this study was to evaluate the quality of complication and adverse event reporting in spinal surgery literature. Methods A systematic review of the literature from 5 international, peer-reviewed, indexed spinal journals was performed. Included studies were published between January and December 2020 and reported the surgical results of spinal procedures. Data on the level of evidence and study design were collected and analyzed as well as whether the studies were single-center or multicenter studies. The quality of complication reports was evaluated through a 5-item checklist, with 5 questions divided into 3 parts: definition, evaluation, and report. Results Complications associated with spinal surgical procedures were reported in 292 studies. According to the level of evidence, significantly higher reporting quality was seen in level I and II studies compared with level III and IV studies (P = 0.003). Regarding the 5-item checklist, 49% (143/292) of studies fulfilled the definition section, 16.4% (48/292) fulfilled the evaluation section, and 92% (270/292) fulfilled the report section. Conclusions Overall quality assessment when reporting complications in surgical spinal studies showed that only 13% (38/292) of publications that reported complications as part of the outcomes exhibited all items of the 5-item checklist. Additionally, significantly better reports were observed in level I studies compared with level II–IV studies.

Osteoporotic vertebral compression fractures of the thoracolumbar spine can progress to Kummell’s disease, an avascular vertebral osteonecrosis. Vertebral augmentation (VA)—vertebroplasty and/or kyphoplasty—is the main treatment modality, but additional short-segment fixation (SSF) has been recommended concomitant to VA. The aim is to compare clinical and radiological outcomes of VA + SSF versus VA alone. Systematic review, including comparative articles in Kummell’s disease, was performed. This study assessed the following outcome measurements: visual analog scale (VAS), Oswestry Disability Index (ODI), anterior vertebral height (AVH), local kyphotic angle (LKA), operative time, blood loss, length of stay, and cement leakage. Six retrospective studies were included, with 126 patients in the VA + SSF group and 152 in VA alone. Pooled analysis showed the following: VAS, non-significant difference favoring VA + SSF: MD –0.61, 95% CI (–1.44, 0.23), I2 91%, p = 0.15; ODI, non-significant difference favoring VA + SSF: MD –9.85, 95% CI (–19.63, –0.07), I2 96%, p = 0.05; AVH, VA + SSF had a non-significant difference over VA alone: MD –3.21 mm, 95% CI (–7.55, 1.14), I2 92%, p = 0.15; LKA, non-significant difference favoring VA + SSF: MD –0.85°, 95% CI (–5.10, 3.40), I2 95%, p = 0.70. There were higher operative time, blood loss, and hospital length of stay for VA + SSF (p

Background: Thoracic and lumbar spine injuries may require surgical management, particularly AO Spine types B and C injuries. Open reduction and fixation using pedicle screws, with or without fusion and/or decompression, is the gold standard surgical treatment for unstable injuries. Recent advances in instrumentation design have resulted in less-invasive surgeries. However, the literature is sparse about the effectiveness of these procedures for types B and C injuries. The objective is to compare the outcomes of conventional open surgery versus minimally invasive spine surgery (MISS) for the treatment of AO Spine types B and C thoracolumbar injuries. Methods: A systematic review of published literature in PubMed, Web of Science, and Scopus was performed to identify studies comparing outcomes achieved with open versus minimally invasive surgery in AO Spine types B and C thoracolumbar injury patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used. Results: Five retrospective case-control studies and 3 prospective studies met selection criteria. In general, most of the studies demonstrated that minimally invasive spine surgery is feasible for types B and C injuries, and associated with potential advantages like reduced blood loss, postoperative pain, and muscle injury, and shorter hospital stays. However, no differences were detected in major outcomes, like neurological status or disability. Conclusions: Published literature currently suggests that minimally invasive spine surgery is a valid alternative for treating types B and C thoracolumbar injuries. However, further comparative prospective randomized clinical trials are necessary to establish the superiority of one approach over the other. Level of Evidence: 3.

Objective We sought to compare the outcomes of single-position (SP) circumferential lumbar interbody fusion in lateral decubitus versus dual-position (DP) fusion. Methods A systematic literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in PubMed, Web of Science, and Scopus databases to identify comparative studies reporting the outcomes of SP lumbar interbody fusion versus DP. For risk of bias assessment, the ROBINS-I (risk of bias in nonrandomized studies of interventions) tool was used. Results Four comparative studies were included from an initial search of 3780 papers. All 4 studies were retrospective cohort studies comparing outcomes of SP versus DP LLIF. A total of 349 patients were operated using SP versus 254 using DP. All studies involved reported operating time, estimated blood loss, length of stay, change in segmental lordosis, and complications. From a general perspective, baseline variables were similar in both groups in all the studies and all reported a significant decrease in operative time and length of stays with SP. Conclusions Literature comparing SP versus lateral-then-prone lumbar fusion shows a tendency toward shorter operating time and hospital stays in SP lumbar fusion while maintaining similar perioperative outcomes.

BACKGROUND: In patients co-infected with HIV and tuberculosis, antiretroviral therapy options are limited due to drug—drug interactions with rifampicin. A previous phase 2 trial indicated that raltegravir 400 mg twice a day or efavirenz 600 mg once a day might have similar virological efficacy in patients given rifampicin. In this phase 3 trial, we assessed the non-inferiority of raltegravir to efavirenz. METHODS: We did a multicentre, open-label, non-inferiority, randomised, phase 3 trial at six sites in Côte d'Ivoire, Brazil, France, Mozambique, and Vietnam. We included antiretroviral therapy (ART)-naive adults (aged ≥18 years) with confirmed HIV-1 infection and bacteriologically confirmed or clinically diagnosed tuberculosis who had initiated rifampicin-containing tuberculosis treatment within the past 8 weeks. Using computerised random numbers, we randomly assigned participants (1:1; stratified by country) to receive raltegravir 400 mg twice daily or efavirenz 600 mg once daily, both in combination with tenofovir and lamivudine. The primary outcome was the proportion of patients with virological suppression at week 48 (defined as plasma HIV RNA concentration

Many efforts are expended to improve health care quality in the surgical treatment of spinal conditions. However, the prevalence of reporting complications in spinal surgeries is highly heterogeneous, which is partially due to the lack of a universal and comprehensive system.A systematic review of the literature was performed in 5 international and indexed spine journals from January to December 2020. All clinical studies that had surgical procedures in any spinal region were classified according to level of evidence, study design, category of spinal condition, and primary outcome. The prevalence and quality of complication reporting were evaluated through a checklist.Of 455 articles screened, complications were reported in 64.2% (292 articles). A significant higher prevalence of reports was observed in randomized compared with nonrandomized studies (P0.05). In 89 articles, at least 1 classification was used to report complications, with 12 different classification systems employed in the total sample. Timing to record complications was as follows: 47 (16.1%) articles reported complications at 30 days, 31 (10.6%) reported complications at 90 days, and 88 (30.1%) reported complications during all follow-ups. In 126 (43.1%) articles, complications were not mentioned.Almost one-third of spine surgical studies did not report complications in their results despite reporting clinical outcomes. The evidence quality of the study was directly related with the reporting of complications. A high heterogeneity regarding complication reporting was seen in the literature.

Background Two-dimensional fluoroscopy-guided percutaneous pedicle screw placement is currently the most widely applied instrumentation for minimally invasive treatment of spinal injuries requiring stabilization. Although this technique has advantages over open instrumentation, it also presents new challenges and specific complications. The objective of this study was to provide recommendations developed from the experience of several spinal surgeons at different minimally invasive spine surgery reference centers to solve specific problems and prevent complications during the learning curve of this technique. Methods An AO Spine Latin America minimally invasive spine surgery study group analyzed the most frequent complications and challenges occurring during the placement of >14,000 two-dimensional fluoroscopy–guided percutaneous pedicle screws at different centers over 15 years. Twenty tips considered most relevant to performing this technique, excluding problems directly related to specific brands of instruments, were presented. Results The 20 tips included the following: (1) positioning; (2) clean and painless; (3) fewer x-rays; (4) check the clock; (5) beveled tip; (6) transverse-rib-pedicle; (7) double Jamshidi; (8) hammer the Kirschner wire; (9) bent tip; (10) too loose, too tight; (11) new trajectory; (12) manual control; (13) start over; (14) Kirschner wire first; (15) adhesive drape control; (16) bend the rod; (17) lower rods; (18) freehand inner; (19) posterior fusion; (20) revision. Conclusions Implementation of these tips might improve performance of this technique and reduce the complications related to percutaneous pedicle screw placement.

A classification system was recently developed by the international association AO Spine for assessing subaxial cervical spine fractures. Significant variability exists between users of the facet component, which consists of four morphological types (F1–F4). The primary aims of this study were to assess the diagnostic accuracy and reliability of this new system’s facet injury morphological classifications. A survey consisting of 16 computed tomography (CT) scans of patients with cervical facet fractures was distributed to spine surgeon members of AO Spine Latin America. To provide a gold standard diagnosis for comparison, all 16 injuries had been classified previously by six co-authors and only were included after total consensus was achieved. Demographic and surgical practice characteristics of all respondents were analyzed, and diagnostic accuracy calculated. Inter- and intra-observer agreement rates were calculated across two survey rounds, conducted one month apart. A total of 135 surgeons completed both surveys, among whom the mean age was 41.6 years (range 26–71), 130 (96.3%) were men, and 83 (61.5%) were orthopedic surgeons. The mean time in practice as a spine surgeon was 9.7 years (1–30). The overall diagnostic accuracy of all responses was 65.4%. Inter-observer and intra-observer agreement rates for F1/F2/F3/F4 were 55.4%/47.6%/64.0%/94.7% and 60.0%/49.1%/58.0%/93.0%, respectively. This study evaluates the AO Spine Classification System specifically for facet injuries involving the subaxial cervical spine in a large sample of spine surgeons. There was significant variability in diagnostic accuracy for F1 through F3-type fractures, whereas almost universal agreement was achieved for F4-type injuries.

Study Design: Multicentric retrospective study, Level of evidence III. Objective: The objective of this multicentric study was to analyze the prevalence and risk factors of early postoperative complications in adult spinal deformity patients treated with fusion. Additionally, we studied the impact of complications on unplanned readmission and hospital length of stay. Methods: Eight spine centers from 6 countries in Latin America were involved in this study. Patients with adult spinal deformity treated with fusion surgery from 2017 to 2019 were included. Baseline and surgical characteristics such as age, sex, comorbidities, smoking, number of levels fused, number of surgical approaches were analyzed. Postoperative complications at 30 days were recorded according to Clavien-Dindo and Glassman classifications. Results: 172 patients (120 females/52 males, mean age 59.4 ± 17.6) were included in our study. 78 patients suffered complications (45%) at 30 days, 43% of these complications were considered major. Unplanned readmission was observed in 35 patients (20,3%). Risk factors for complications were: Smoking, previous comorbidities, number of levels fused, two or more surgical approaches and excessive bleeding. Hospital length of stay in patients without and with complications was of 7.8 ± 13.7 and 17 ± 31.1 days, respectively ( P 0.0001). Conclusion: The prevalence of early postoperative complications in adult spinal deformity patients treated with fusion was of 45% in our study with 20% of unplanned readmissions at 30 days. Presence of complications significantly increased hospital length of stay.

Study Design: Literature review and transversal study. Objective: Advances in new technologies give the surgeons confidence to manage complex spine conditions with a lower morbidity rate. This has changed the expectations of patients and medical payers and foreshadows the shift now underway: the use of minimally invasive techniques. The ethical considerations of learning directly on patients require a change in the education and training programs. Methods: The education paradigm has changed, and surgical training on minimally invasive surgery of the spine (MISS) techniques should follow a “curriculum.” The assessment of skill proficiency while learning the MISS techniques must be measurable to objectively show the performance gained over time and the changes that should be performed during training. Different strategies include “ex vivo” and “in vivo” training. Results: We have worked on a curriculum in which the participants can perceive the growth in their knowledge through the different educational opportunities. There are 3 levels: basic, advanced, and masters. Conclusions: We developed an educational curriculum for MISS rationale and techniques, that showed to be effective and interesting in our region.

Purpose The management of cervical facet dislocation injuries remains controversial. The main purpose of this investigation was to identify whether a surgeon’s geographic location or years in practice influences their preferred management of traumatic cervical facet dislocation injuries. Methods A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. The survey included clinical case scenarios of cervical facet dislocation injuries and asked responders to select preferences among various diagnostic and management options. Results A total of 189 complete responses were received. Over 50% of responding surgeons in each region elected to initiate management of cervical facet dislocation injuries with an MRI, with 6 case exceptions. Overall, there was considerable agreement between American and European responders regarding management of these injuries, with only 3 cases exhibiting a significant difference. Additionally, results also exhibited considerable management agreement between those with ≤ 10 and > 10 years of practice experience, with only 2 case exceptions noted. Conclusion More than half of responders, regardless of geographical location or practice experience, identified MRI as a screening imaging modality when managing cervical facet dislocation injuries, regardless of the status of the spinal cord and prior to any additional intervention. Additionally, a majority of surgeons would elect an anterior approach for the surgical management of these injuries. The study found overall agreement in management preferences of cervical facet dislocation injuries around the globe.

STUDY DESIGN Global cross-sectional survey. OBJECTIVE To validate the AO Spine Subaxial Cervical Spine Injury Classification by examining the perceived injury severity by surgeon across AO geographical regions and practice experience. SUMMARY OF BACKGROUND DATA Previous subaxial cervical spine injury classifications have been limited by subpar interobserver reliability and clinical applicability. In an attempt to create a universally validated scheme with prognostic value, AO Spine established a subaxial cervical spine injury classification involving four elements: (1) injury morphology, (2) facet injury involvement, (3) neurologic status, and (4) case-specific modifiers. METHODS A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. Respondents graded the severity of each variable of the classification system on a scale from zero (low severity) to 100 (high severity). Primary outcome was to assess differences in perceived injury severity for each injury type over geographic regions and level of practice experience. RESULTS A total of 189 responses were received. Overall, the classification system exhibited a hierarchical progression in subtype injury severity scores. Only three subtypes showed a significant difference in injury severity score among geographic regions: F3 (floating lateral mass fracture, p:0.04), N3 (incomplete spinal cord injury, p:0.03), and M2 (critical disk herniation, p:0.04). When stratified by surgeon experience, pairwise comparison showed only 2 morphological subtypes, B1 (bony posterior tension band injury, p:0.02) and F2 (unstable facet fracture, p:0.03), and one neurologic subtype (N3, p:0.02) exhibited a significant difference in injury severity score. CONCLUSIONS The AO Spine Subaxial Cervical Spine Injury Classification System has shown to be reliable and suitable for proper patient management. The study shows this classification is substantially generalizable by geographic region and surgeon experience; and provides a consistent method of communication among physicians while covering the majority of subaxial cervical spine traumatic injuries.Level of Evidence: 4.

Study Design: Cross-sectional survey. Objectives: Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture. Methods: A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures. Results: There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%. Conclusions: Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures.

Objective We sought to identify delays for surgery to stabilize unstable thoracolumbar fractures and the main reasons for them across Latin America. Methods We reviewed the charts of 547 patients with type B or C thoracolumbar fractures from 21 spine centers across 9 Latin American countries. Data were collected on demographics, mechanism of trauma, time between hospital arrival and surgery, type of hospital (public vs. private), fracture classification, spinal level of injury, neurologic status (American Spinal Injury Association impairment scale), number of levels instrumented, and reason for delay between hospital arrival and surgical treatment. Results The sample included 403 men (73.6%) and 144 women (26.3%), with a mean age of 40.6 years. The main mechanism of trauma was falls (44.4%), followed by car accidents (24.5%). The most frequent pattern of injury was B2 injuries (46.6%), and the most affected level was T12-L1 (42.2%). Neurologic status at admission was 60.5% intact and 22.9% American Spinal Injury Association impairment scale A. The time from admission to surgery was >72 hours in over half the patients and over a week in >25% of them. The most commonly reported reasons for surgical delay were clinical instability (22.9%), lack of operating room availability (22.7%), and lack of hardware for spinal instrumentation (e.g., screws/rods) (18.8%). Conclusions Timing for surgery in this sample of unstable fractures was over 72 hours in more than half of the sample and longer than a week in about a quarter. The main reasons for this delay were clinical instability and lack of economic resources. There is an apparent need for increased funding for the treatment of spinal trauma patients in Latin America.

OBJECTIVE Optimal management of A3 and A4 cervical spine fractures, as defined by the AO Spine Subaxial Injury Classification System, remains controversial. The objectives of this study were to determine whether significant management variations exist with respect to 1) fracture location across the upper, middle, and lower subaxial cervical spine and 2) geographic region, experience, or specialty. METHODS A survey was internationally distributed to 272 AO Spine members across six geographic regions (North America, South America, Europe, Africa, Asia, and the Middle East). Participants’ management of A3 and A4 subaxial cervical fractures across cervical regions was assessed in four clinical scenarios. Key characteristics considered in the vignettes included degree of neurological deficit, pain severity, cervical spine stability, presence of comorbidities, and fitness for surgery. Respondents were also directly asked about their preferences for operative management and misalignment acceptance across the subaxial cervical spine. RESULTS In total, 155 (57.0%) participants completed the survey. Pooled analysis demonstrated that surgeons were more likely to offer operative intervention for both A3 (p < 0.001) and A4 (p < 0.001) fractures located at the cervicothoracic junction compared with fractures at the upper or middle subaxial cervical regions. There were no significant variations in management for junctional incomplete (p = 0.116) or complete (p = 0.342) burst fractures between geographic regions. Surgeons with more than 10 years of experience were more likely to operatively manage A3 (p < 0.001) and A4 (p < 0.001) fractures than their younger counterparts. Neurosurgeons were more likely to offer surgical stabilization of A3 (p < 0.001) and A4 (p < 0.001) fractures than their orthopedic colleagues. Clinicians from both specialties agreed regarding their preference for fixation of lower junctional A3 (p = 0.866) and A4 (p = 0.368) fractures. Overall, surgical fixation was recommended more often for A4 than A3 fractures in all four scenarios (p < 0.001). CONCLUSIONS The subaxial cervical spine should not be considered a single unified entity. Both A3 and A4 fracture subtypes were more likely to be surgically managed at the cervicothoracic junction than the upper or middle subaxial cervical regions. The authors also determined that treatment strategies for A3 and A4 subaxial cervical spine fractures varied significantly, with the latter demonstrating a greater likelihood of operative management. These findings should be reflected in future subaxial cervical spine trauma algorithms.

Objective To evaluate incidence and types of implant failure observed in a series of patients with spinal metastases (SM) treated with minimally invasive stabilization surgery without fusion. Methods In this multicenter, retrospective, observational study, we reviewed the files of patients >18 years old who underwent surgery for SM using percutaneous spinal stabilization without fusion with a minimum 3-month follow-up. The following variables were included: demographics, clinical findings, prior radiation history, SM location, epidural spinal cord compression scale, Spinal Instability Neoplastic Scale, neurological examination, and surgery-related data. Primary outcome measure was implant failure rate, as observed in patients' last computed tomography scan. Multivariable analysis was performed to identify baseline factors and factors associated with implant failure. Results Analysis included 72 patients. Mean age of patients was 62 years, 39 patients were men, and 75% of patients had an intermediate Spinal Instability Neoplastic Scale score. Tumor separation surgery was performed in 48.6% of patients. Short instrumentation was indicated in 54.2% of patients. Three patients (4.2%) experienced implant failure (2 screw loosening, 1 screw cut-out); none of them required revision surgery. In 73.6% of cases, survival was >6 months. No significant predictors of failure were identified in the multivariate analysis. Conclusions A low implant failure rate was observed over the short and medium term, even when short instrumentations without fusion were performed. These findings suggest that minimally invasive stabilization surgery without fusion may be an effective and safe way to treat complicated SM.

Study Design: Diagnostic study, level of evidence III. Objective: Pyogenic spondylodiscitis can cause deformity, neurological compromise, disability, and death. Recently, a new classification of spondylodiscitis based on magnetic resonance imaging was published. The objective of this study is to perform an independent reliability analysis of this new classification. Methods: We selected 35 cases from our database of different spine centers in Latin America and from the literature; 8 observers evaluated the classification and graded the scenarios according to the methodological grading of the classification developed by Pola et al. Cases were sent to the observers in a random sequence after 3 weeks to assess intraobserver reliability. The interobserver and intraobserver reliabilities were performed with Fleiss and Cohen statistics, respectively. Results: The overall Fleiss κ value for interobserver agreement was substantial, with 0.67 (95% CI = 0.43-0.91) in the first reading and 0.67 (95% CI = 0.45-0.89) in second reading for the main types of classification. The Cohen κ value for intraobserver agreement was also substantial, with 0.68 (95% CI = 0.45-0.92). The interobserver agreement analysis for the subtypes of this classification was overall substantial, with 0.60 (95% CI = 0.37-0.83) in the first reading and 0.61 (95% CI = 0.41-0.81) in the second reading. The overall intraobserver agreement for subtypes of the classification was also substantial, with 0.63 (95% CI = 0.34-0.93). Conclusion: The new classification developed by Pola et al showed substantial interobserver and intraobserver agreements. More studies are required to validate the usefulness of this classification especially in clinical practice.

Study Design: Cross-sectional study. Objective: The aim of this study was to evaluate the impact of the COVID-19 outbreak in spine surgeons in Latin America. Methods: A questionnaire was sent to Latin American spine surgeons from April 4 to 6, 2020. Surgeon characteristics were recorded. The impact of COVID-19 on economic well-being, work, and mental health were also determined. All variables were compared and analyzed. Results: Two hundred four surgeons answered the complete survey; most of them were male (96.6%), the average age was 47.7 years; 58.8% (n = 120) were orthopedic surgeons and 41.2% (n = 84) were neurosurgeons. The majority of the respondents were from Argentina (59.8%, n = 122), followed by Brazil (17.2%, n = 35), Chile (6.4%, n = 13), and Mexico (5.9%, n = 12). Most of the surgeons reported performing emergency procedures only during the pandemic (76.5%, n = 156). Half used telemedicine or online consultation modalities (54.4%, n = 111). The average concern about the financial situation due to the pandemic was 7.53 in a scale of 1 to 10 (10 being the worst scenario). Twenty-two percent (n = 45) of the surgeons had a score over 10 in the Patient Health Questionnaire (PHQ-9; scores higher than 10 needs referral to confirm depression diagnosis). Young age and neurosurgery as a specialty were associated with higher PHQ-9 scores. Conclusions: COVID-19 has an impact in the daily working practice and financial situation of spine surgeons in Latin America. The long-term psychological impact should be taken into consideration to avoid a heavier burden for health care providers.

Objective To evaluate access to the technologies and education needed to perform minimally invasive spine surgery (MISS) in Latin America. Methods We designed a questionnaire to evaluate surgeons’ practice characteristics, access to different technologies, and training opportunities for MISS techniques. The survey was sent to members and registered users of AO Spine Latin from January 6–20, 2020. The major variables studied were nationality, specialty (orthopedics or neurosurgery), level of hospital (primary, secondary, tertiary), number of surgeries performed per year by the spine surgeon, types of spinal pathologies commonly managed, and number of MISS performed per year. Other variables involved specific access to different technologies: intraoperative fluoroscopy, percutaneous screws, cages, tubular retractors, microscopy, intraoperative computed tomography, neuronavigation imaging, and bone morphogenetic protein. Finally, participants were asked about main obstacles to performing MISS and their access to education on MISS techniques in their region. Results The questionnaires were answered by 306 members of AO Spine Latin America across 20 different countries. Most answers were obtained from orthopedic surgeons (57.8%) and those with over 10 years of experience (42.4%). Most of the surgeons worked in private practice (46.4%) and performed >50 surgeries per year (44.1%), but only 13.7% performed >50 MISS per year, mainly to manage degenerative pathologies (87.5%). Most surgeons always had access to fluoroscopy (79%). Only 26% always had access to percutaneous screws, 24% to tubular retractors, 34.3% to cages (anterior lumbar interbody fusion, lateral lumbar interbody fusion, or transforaminal lumbar interbody fusion), and 43% to microscopy. Regarding technologies, 71% reported never having access to navigation, 83% computed tomography, and 69.3% bone morphogenetic protein. The main limitations expressed for widely used MISS technologies were the high implant costs (69.3%) and high navigation costs (49.3%). Most surgeons claimed access to online education activities (71%), but only 44.9% reported access to face-to-face events and 28.8% to hands-on activities, their limited access largely because the courses were expensive (62.7%) or few courses were available on MISS in their region (51.3%). Conclusions Most surgeons in Latin America have limited resources to perform MISS, even in private practice. The main constraints are implant costs, access to technologies, and limited face-to-face educational opportunities.

Background: Intraoperative neurophysiological monitoring (IOM) has become valuable in spine surgery. Unfortunately, it is not always available in many spine centers, especially in developing countries. Our aim was to evaluate the accessibility and barriers to IOM in spine surgery in Latin America. Methods: We designed a questionnaire to evaluate the characteristics of surgeons and their opinions on the usefulness of IOM for different spine operations. The survey was sent to 9616 members and registered users of AO Spine Latin America (AOSLA) from August 1, 2019, to August 21, 2019. Major variables studied included nationality, years of experience, specialty (orthopedics or neurosurgery), level of complexity of the hospital, number of spine surgeries performed per year by the spine surgeon, the types of spinal pathologies commonly managed, and how important IOM was to the individual surgeon. General questions to evaluate use included accessibility, limitations of IOM usage, management of IOM changes, and the legal value of IOM. The results were analyzed and compared between neurosurgeon and orthopedics, level of surgeon experience, and country of origin. Results: Questionnaires were answered by 200 members of AOSLA from 16 different countries. The most common responses were obtained from orthopedic surgeons (62%), those with more than 10 years of practice (54%); majority of surgeons performed more than 50 spine surgeries per year (69%) and treated mainly spine degenerative diseases (76%). Most surgeons think that IOM has a real importance during surgeries (92%) and not just a legal value. Although surgeons mostly considered IOM essential to scoliosis surgery in adolescents (70%), thoracolumbar kyphosis correction (68%), and intramedullary tumors (68%), access to IOM was limited to 57% for economic reasons. Of interest, in 64% of cases, where IOM was available and significant change occurred, the actual operative procedures were significantly altered. Conclusion: Despite the fact that 68% of spine surgeons believe IOM to be indispensable for complex spine surgery, cost remains the main barrier to its use/availability in Latin America.

Cervical deformity, particularly kyphosis, is frequently encountered in surgical practice. While many cases are asymptomatic, some patients may have significant pain and disability. We provide a brief review of the pathophysiology of cervical deformity and the technical aspects of deformity correction in the cervical spine. Anterior techniques reviewed here include anterior cervical discectomy and fusion (ACDF), anterior corpectomy and fusion (ACCF) and anterior osteotomy (ATO). Posterior techniques include laminectomy and fusion, posterior column osteotomy (PCO) and pedicle subtraction osteotomy (PSO). This is a fast-evolving field as our understanding of cervical deformity matures and longer-term surgical outcomes are available.

Spine surgery is more complex and common as technological advances allow for more aggressive procedures in older and more frail patients. Intraoperative neurophysiological monitoring (ION) is an important surgical adjuvant tool that allows for the assessment of neurological functions, particularly in situations of morphological change during surgery or spinal instability. In this chapter, we provide a brief overview of current applications of ION in complex spine surgery and discuss its applications and limitations with clinical examples, including a monitoring loss protocol for use during spine surgery.

Background: Our aim was to evaluate differences in neurosurgeons versus orthopedists access to technologies needed to perform minimally invasive spine surgeries (MISS) in Latin America. Methods: We sent a survey to members of AO Spine Latin America (January 2020), and assessed the following variables; nationality, level of hospital (primary, secondary, and tertiary), number of spinal operations performed per year, spinal pathologies addressed, the number of minimally invasive spine operations performed/year, and differences in access to MISS spinal technology between neurosurgeons and orthopedists. Results: Responses were returned from 306 (25.6) members of AO Spine Latin America representing 20 different countries; 57.8% of respondents were orthopedic surgeons and 42.4% had over 10 years of experience. Although both specialties reported a lack of access to most of the technologies, the main difference between the two was greater utilization/access of neurosurgeons to operating microscope (e.g., 84% of the neurosurgeons vs. 39% of orthopedic spine surgeons). Conclusion: Although both specialties have limited access to MISS spinal technologies, orthopedic spine surgeons reported significantly lower access to operating microscopes versus neurosurgeons (P < 0.01).

Background: The perception of major versus minor complications may vary according to surgeons, institutions, and different specialties. Here, we analyzed the geographic distribution of the different types/severities of the most frequent complications in spinal surgery, and assessed how the perception of spine surgeons about postoperative complications differed. Methods: We performed a cross-sectional study using a questionnaire, we developed to encompass different clinical scenarios of surgeons’ perceptions of spine surgery complications. The survey involved the members of AOSpine Latin America (LA) (January 28, 2017–March 15, 2017). The main variables studied included: specialty, age, years of experience, country, individual surgeon’s perception of different clinical scenarios, and the surgeon’s classification of complications for each scenario (e.g., major, minor, or none). Our results from LA were then analyzed and compared to North American (NA) responses. Results: Orthopedic surgeons represented about 58.2% (n = 412) of the 708 questionnaires answered. Of interest, 45.6% (n = 323) of those responding had >10 years of experience. The countries analyzed included Brazil (31.5%), Mexico (17.5%), Argentina (14.4%), Colombia (8.0%), and Venezuela (7.6%). Four of the 11 scenarios showed consensus in the results (e.g., average being over 82.5%). A tendency toward consensus was present in 45.4% of the clinical cases, while two out of 11 clinical cases did not present a consensus among surgeons. Of interest, the perception of complications was similar between cohorts (LA 85% vs. NA 80%). Conclusion: Significant consensus in the perception of complications was observed in most of the analyzed scenarios for both LA and NA. However, within the LA data, responses to different clinical scenarios varied.

Sacral chordomas are infrequent tumors that arise from remnants of the notochord. They are most often found in the sacrum and skull-base.1,2 These lesions rarely metastasize and usually have an indolent and oligosymptomatic clinical course. Chordomas show low sensitivity to standard radiation therapy and chemotherapy. Operative resection with wide resection margins offers the best long-term prognosis, including longer survival and local control.1,3 However, achieving a complete resection with oncological margins may be difficult because of the anatomic complexity of the sacrococcygeal region.4 The main complications of sacral resection include infections, wound closure defects, and anorectal and urogenital dysfunction. The rate of these complications is significantly increased when the tumor involves the S2 level or above. We report the case of a 64-yr-old male who presented with progressive sacrococcygeal pain and a feeling of incomplete evacuation. A heterogeneous, osteolytic lesion was found at the sacrococcygeal region. Full body imaging tests were negative for other lesions. A computed tomography (CT) guided biopsy was made. We usually use the midline approach in case we have to include the needle path in the resection. The pathology confirmed a sacrococcygeal, low-grade chordoma. We decided to perform an en bloc resection. A posterior, partial sacrectomy was planned distal to the S4 level.

Background: The Gorham–Stout syndrome (GSS), also known as phantom bone disease, is a rare bone condition of unknown etiology. Involvement of the spine is described in

International audience; BackgroundThe OPTIPRIM-ANRS 147 trial compared intensive combination ART (darunavir/ritonavir, tenofovir disoproxil fumarate/emtricitabine, raltegravir and maraviroc) started early during primary HIV-1 infection with standard tritherapy with darunavir/ritonavir, tenofovir disoproxil fumarate and emtricitabine. From month 6 to 18, the percentage of viral load values

Background: Spine fractures may involve the ligamentum flavum (LF). Here, we utilized the “ligamentum flavum gap,” defined by the discontinuity of the LF at the level of a vertebral fracture, to document a vertebral fracture. Methods: Utilizing X-rays, computed tomography (CT), and magnetic resonance (MR) studies, 10 patients with type B vertebral fractures were diagnosed with the ligamentum flavum gap (LFG: discontinuity of the LF) at the fracture levels. The fractures were located in 2 patients in the cervical and 8 in the thoracolumbar spine. Results: All 10 patients with vertebral fractures had complained of axial pain. Four also showed progressive thoracic kyphosis. Notably, all demonstrated a loss of continuity in the LF at the level of fracture “ligamentum flavum gap.” T2-weighted and short tau inversion recovery (STIR) MR sagittal studies were best at locating LFG at the level of a fracture. Conclusion: Here, we identified best on sagittal T2 and STIR-weighted MR studies 10 patients for whom discontinuity of the ligamentum flavum (LFG) correlated with the location of type B vertebral fractures.

Bichat Hospital's free and anonymous Voluntary Counseling and Testing centre in Paris is widely visited, with a high rate of HIV-positive diagnosis. This study proposed, in this centre, to describe the HIV newly-diagnosed patients over an 8-year period and to determinate risk factors for failure to return for a positive result. Higher risk for failure to return was found among the heterosexual subjects regardless of their socio-economic background.

Objective: to describe and assess 30 cases of microendoscopic decompression (MED) of the lumbar spine. Introduction: degenerative lumbar spinal stenosis is one of the most common surgical conditions of the spine in the elderly. This condition affects quality of life and impairs function. Surgery leads to a better outcome than non surgical treatment. This condition occurs mostly in elderly patients, so it is vital to reduce operative time, hospital length of stay and the probability of complications. Minimally invasive techniques differ from “open” procedures on a reduced stress on healthy tissues, and so this translates into less postoperative pain, a shorter hospital stay and a low complication rate. Material and methods: we performed a retrospective analysis of 30 patients undergoing surgery. Twelve patients presented claudication, 13 had unilateral sciatic involvement, and the rest of the patients presented a combination of symptoms. Instability was rule out with dinamics X-rays. The Visual Analog Scale of pain (VAS) was compared at the pre and postsurgical period. Claudication was assessed according to patient´s answer: resolved, better, the same. One level MED was performed with a 18 mm diameter tube on every case. Results: pre and post surgical VAS had an average predictive value of 66.27% (p < 0.01). Claudication improved in three cases, and resolved completely in the rest of the cases. No worsening was seen. Mean hospital stay was 22.6 hours (12-48h) with a mean time of 24 hours. Mean post-surgery follow up was 22.36 months (18-26). Conclusion: in our series of 30 patients undergoing minimally invasive endoscopic lumbar decompression good pain management, improved claudication, a shorter hospital stay and a lower complication rate were observed.

Background The paraspinal, posterolateral, or Wiltse approach is an old technique that observes the principles of an MIS procedure. The aim of this study was to provide a step-by-step description from the literature of the Wiltse paraspinal approach and analyze its main advantages and limitations. Methods Here, we provide a step-by-step description of the Wiltse approach. Utilizing PubMed and Lilacs and the Mesh terms "Wiltse approach," "paraspinal approach," "muscle sparing approach," and "lumbar spine," we identified 10 papers. We then put together, based on these publications, a step-by-step analysis of the preparation, patient positioning, skin incision, fascial opening, dissection, bone identification, retractors, deperiostization, decompression, discectomy, instrumentation, arthrodesis, and closure for the Wiltse technique. Results Most papers underscored the minimally invasive aspects of the typical Wiltse approach. Advantages included minimal intraoperative bleeding, a shorter hospital length of stay, and a low infection rate. Conclusion The classical approach described by Wiltse is essentially minimally invasive, sparing both the muscle planes and soft tissues, allowing for ample far lateral lumbar decompression, including discectomy and fusion, with a low complication rate.

Background Our study describes the prevalence of transmitted drug resistance (TDR) among 1318 French patients diagnosed at the time of primary HIV-1 infection (PHI) in 2007–12. Methods HIV-1 resistance-associated mutations (RAMs) were characterized using both the 2009 WHO list of mutations and the French ANRS algorithm. A genotypic susceptibility score was estimated for each first-line recommended ART combination. Results Patients were mainly MSM (72.6%). Non-B variants were identified in 33.7% of patients. The proportion of TDR was estimated as 11.7% (95% CI 10.0–13.5). The prevalences of PI-, NRTI-, first-generation NNRTI and etravirine/rilpivirine-associated RAMs were 2.5%, 5.2%, 3.9% and 3.2%, respectively. Single, dual and triple class resistance was found in 9.6%, 1.0% and 1.1% of cases, respectively. Additionally, 5/331 strains isolated in 2010–12 had integrase inhibitor (II)-related RAMs (isolated E157Q mutation in all cases). TDR was more common among MSM than in other groups (12.9% versus 8.6%, P = 0.034), and in case of B versus non-B subtype infections (13.6% versus 7.9%, P = 0.002). The proportions of fully active combinations were ≥99.2%, ≥97.3% and ≥95.3% in cases of PI-, II- and NNRTI-based regimens, respectively. In 2010–12, the proportion of fully active efavirenz-based ART was lower in cases of subtype B versus non-B infection (P = 0.021). Conclusions Compared with our previous studies, the proportion of NRTI- and first-generation NNRTI-related TDR has continued to decline in French seroconverters. However, subtype B-infected MSM could drive the spread of resistant HIV strains. Finally, we suggest preferring PI- or II- to NNRTI-based combinations to treat PHI patients.

The Cornell Net Carbohydrate and Protein System model was used to formulate a low-protein mixed grass hay and corn diet predicted to create a ruminal N deficiency of 33% in 250-kg Holstein steers. Nitrogen metabolism, digestibility and metabolic status responses were compared between this control diet and a similar diet supplemented with 1.7% urea to compensate for the ruminal N deficiency. A 4 × 4 Latin square design was used to analyze main effects of diet and subcutaneous administration of 500 μg estradiol-17β (E2) twice a day. Urea supplementation increased N intake from 60 to 93 g d-1, improved N balance from 10.1 to 17.7 g d-1, and improved total tract digestibility of N, neutral detergent fiber (NDF), organic matter (OM), and dry matter (DM) (all P < 0.05), but there was no effect of urea supplementation on total tract digestibility of non-structural carbohydrate (NSC) and N retention (percent of N intake). Plasma urea N increased fourfold (P < 0.05) and plasma insulin increased from 0.32 to 0.50 ng mL-1 (P = 0.06) when the urea diet was fed. Administration of E2 did not alter N metabolism or plasma metabolites and insulin at either level of protein intake. It is concluded that supplementing a fiber-rich grass-hay-based diet with urea to achieve ruminal N balance increases digestibility of fiber fractions without altering dietary N utilization. Under these nutritional conditions the use of estrogenic growth promoters remains ineffective independent of ruminal N balance. Key words: Steers, nutrition, fiber, urea, estradiol, nitrogen balance

We summarized experimental data to quantify the change in final BW due to a particular implant strategy when cattle are adjusted to the same final body composition. The database developed for this study included 13 implant trials involving a total of 13,640 animals (9,052 steers and 4,588 heifers). Fifteen different implant strategies were used among these trials, including no implant (control), single implants, and combinations of implants. Individual carcass data collected at slaughter were used to calculate the adjusted final shrunk BW at 28% empty body fat (AFBW) for each treatment group within a trial, then the implant treatments were grouped into categories according to their effect on weight at 28% empty body fat (four groups for steers and two groups for heifers). All differences in AFBW between categories were significant (P < 0.01), indicating an incremental anabolic implant dose response in AFBW over unimplanted animals. Values for AFBW ranged from 520 kg in unimplanted steers to 564 kg in steers implanted and reimplanted with Revalor-S. For heifers, AFBW ranged from 493 kg in unimplanted heifers to 535 kg in heifers implanted and reimplanted with Revalor-H. After accounting for differences in mean BW and composition of gain, implanted steers and heifers had 4.2 and 3.1% higher apparent diet ME values, respectively. Increasing the anabolic implant dose increases the weight at which animals reach a common body composition. This study indicates that anabolic implant response is due to a combination of a reduced proportion of the DMI required for maintenance, reduced energy content of gain, and efficiency of use of absorbed energy.

Objectives To compare the posterolateral Wiltse approach and conventional Midline approach in short lumbosacral fusions in terms of the angle of convergence of pedicle screws. Methods We retrospectively reviewed computed tomography (CT) images of 76 lumbar and sacral pedicular screws that had been placed using a conventional midline approach (CA) (n = 38) and a Wiltse posterolateral approach (WA) (n = 38). All patients underwent short lumbosacral fusions from L3 to S1 for degenerative spinal disease. Screws with a bone gap >4 mm in any direction, cases with previous pedicular implants, and those with coronal plane curves >20° were excluded. Results Considering all implants, the angle of convergence was 23.3° (±15.8). The mean angulation in the WA group was 29.3° (±9.7), whereas in the CA group it was 17.2° (±0.6). This difference was statistically significant (P < 0.05). Conclusions In short, lumbosacral fusion employing the Wiltse approach allowed placement of pedicle implants with more convergence than the conventional midline approach. The clinical relevance of this is unknown, and prospective randomized studies are needed to clarify this.

Laparoendoscopic single-site (LESS) surgery has been established for various procedures. Shortcomings of LESS surgery include loss of triangulation, instrument collisions, and poor ergonomics, making advanced laparoscopic tasks especially challenging. We compared a LESS system with a robotic single-site surgery platform in performance of a suturing and knot-tying task under clinically simulated conditions. Each of five volunteer minimally invasive surgeons was tasked with suturing a 5 cm longitudinal enterotomy in porcine small intestine with square knots at either end, using a laparoendoscopic or da Vinci robotic single-site surgery platform, within a 20 min time limit. A saline leak test was then performed. Each surgeon performed the task twice using each system. The time to completion of the task and presence of a leak were noted. Fisher’s exact test was used to compare the overall completion rate within the defined time limit, and a Wilcoxon rank test was used to compare the specific times to complete the task. A p value of

Transmissible mink encephalopathy (TME), a naturally occurring subacute spongiform encephalopathy in commercially ranch-reared mink (Mustela vision), is characterized neuropathologically by spongiform changes in the neuropil, intracytoplasmic neuronal vacuolation and astrocytic hypertrophy and hyperplasia. Amyloid deposits have not been observed in brain tissue sections from animals with natural and experimental TME using conventional histochemical stains such as Congo red. To determine if amyloid deposits could be visualized by immunocytochemical techniques, we stained formalin-fixed, formic acid-treated brain tissue sections from several animal species with natural and experimental TME, using a rabbit antiserum directed against scrapie amyloid (PrP27–30). Scrapie amyloid-immunoreactive deposits were found in golden Syrian hamsters experimentally infected with TME, but were absent in mink with natural and experimental TME, as well as in ferrets and squirrel monkeys with experimental TME. The scrapie amyloid-immunoreactive deposits, which were non-congophilic and non-birefringent, were distributed in the subependymal, subpial and perivascular regions of the brain, as in hamsters infected with the 263K strain of scrapie. Ultrastructurally, scrapie amyloid-immunoreactive deposits revealed a collection of degenerating neurites with numerous abnormal mitochondria and degenerating synapses. Amyloid fibrils were not observed. Anti-scrapie amyloid antibodies immunoabsorbed with scrapie amyloid abolished immunostaining. Our data indicate the presence of scrapie amyloid lacking the molecular conformation of amyloid fibrils in hamsters with experimental TME.

Living cells sense the rigidity of their environment and adapt their activity to it. In particular, cells cultured on elastic substrates align their shape and their traction forces along the direction of highest stiffness and preferably migrate towards stiffer regions. Although numerous studies investigated the role of adhesion complexes in rigidity sensing, less is known about the specific contribution of acto-myosin based contractility. Here we used a custom-made single-cell technique to measure the traction force as well as the speed of shortening of isolated myoblasts deflecting microplates of variable stiffness. The rate of force generation increased with increasing stiffness and followed a Hill force–velocity relationship. Hence, cell response to stiffness was similar to muscle adaptation to load, reflecting the force-dependent kinetics of myosin binding to actin. These results reveal an unexpected mechanism of rigidity sensing, whereby the contractile acto-myosin units themselves can act as sensors. This mechanism may translate anisotropy in substrate rigidity into anisotropy in cytoskeletal tension, and could thus coordinate local activity of adhesion complexes and guide cell migration along rigidity gradients.

Scrapie amyloid-immunoreactive plaques are present in brain tissues of captive mule deer with chronic wasting disease (CWD), a progressive neurological disorder characterized neuropathologically by widespread spongiform change of the neuropil, intracytoplasmic vacuolation in neuronal perikarya and astrocytic hypertrophy and hyperplasia. We report here the immunolocalization of scrapie amyloid (PrP27-30) in plaques observed in brain tissues of Rocky Mountain elk (Cervus elaphus nelsoni) and hybrids of mule deer and white-tailed deer (Odocoileus virginianus) naturally affected with CWD. Similar findings have been shown in kuru, Creutzfeldt-Jakob disease, and Gerstmann-Sträussler syndrome in humans. Our data corroborate that CWD in Rocky Mountain elk and hybrids of mule deer and white-tailed deer belongs to the subacute spongiform virus encephalopathies (transmissible cerebral amyloidoses).

Cerebral vascular amyloid deposits, senile plaques and neurofibrillary tangles have been found in subcortical arteriosclerotic encephalopathy (Binswanger disease). A mouse antiserum, prepared against a 43-amino acid synthetic peptide homologous to the amyloid β-protein of Alzheimer disease (anti-SP43), revealed immunoreactive amyloid deposits in meningeal and intracortical blood vessels, senile plaques, intraneuronal amyloid and preamyloid in a neuropathologically confirmed case of Binswanger disease previously reported to have cerebral vascular amyloid deposits. These lesions contained sulfated glycosaminoglycans as determined by the Alcian blue/critical electrolyte concentration method. Similar findings were not observed in a case of Binswanger encephalopathy without cerebral amyloid deposits. Our study indicates that amyloidotic lesions in Binswanger encephalopathy with cerebral amyloid deposits contain amyloid β-protein and sulfated glycosaminoglycans.

We developed a new versatile micron-scale rheometer allowing us to measure the creep or the relaxation function (time analysis), as well as to determine the dynamical complex modulus (frequency analysis) of a single living cell. In this setup, a microscopic sample can be stretched or compressed uniaxially between two parallel microplates: one rigid, the other flexible. The flexible microplate is used as a nanonewton force sensor of calibrated stiffness, the force being simply proportional to the plate deflection. An original design of the microplates allows us to achieve an efficient feedback control of either strain or stress applied to the cell. Controlling the flexible plate deflection with a typical precision of less than 200nm, we are able to apply stresses ranging from a few pascals to thousands of pascals with a precision better than 2%. The control of the flexible plate deflexion is achieved by direct imaging of the plate tip on a photosensitive detector mounted on the phototube of an inverted mic...

Resume Douze patients sur les 35 presentant une demence severe ont ete retenus car suffisamment autonomes pour deambuler et pouvant participer a une reeducation avec une cooperation suffisante. Les 12 patients ont pu etre inclus dans le programme de reeducation mictionnelle (tous ont eu un bilan clinique, cinq un bilan urodynamique dont trois complets). La formation du personnel soignant avec l'aide du calendrier mictionnel comme methode de reeducation comportementale est efficace et suffisante pour ameliorer sept patients sur 12: deux patients ont ete totalement gueris, deux ont ete tres ameliores: une fuite nocturne uniquement, trois ameliores: reduction du nombre de fuites.

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) in captive and free-ranging cervids in the USA; its origin is obscure. Archival formalin-fixed and paraffin-embedded specimens of 16 captive mule deer brains with CWD were analyzed using immunocytochemistry for the disease-associated prion protein (PrP). The most prominent pattern of PrP deposition were plaque-like structures, a substantial proportion of which were florid plaques surrounded by a rim of spongiform vacuoles. The percentage of florid plaques was highly variable according to region, ranging from 0% to 52.7%. The highest percentage was observed in the medulla and basal ganglia, the lowest in the cerebral cortex. Only three brains contained no florid plaques. There were also punctate synaptic-type and perivascular deposits, particularly in areas of severe spongiform change, and subpial and subependymal plaque-like deposits, whereas cerebellar involvement was mild. Thus, CWD brain pathology prominently features florid PrP plaques, as does variant Creutzfeldt-Jakob disease (vCJD), but differs in other characteristics from vCJD.