Demographics of Cauda Equina Syndrome: A Population-Based Incidence Study.

INTRODUCTION: Cauda equina syndrome (CES) has significant medical, social, and legal consequences. Understanding the number of people presenting with CES and their demographic features is essential for planning healthcare services to ensure timely and appropriate management. We aimed to establish the incidence of CES in a single country and stratify incidence by age, gender, and socioeconomic status. As no consensus clinical definition of CES exists, we compared incidence using different diagnostic criteria. METHODS: All patients presenting with radiological compression of the cauda equina due to degenerative disc disease and clinical CES requiring emergency surgical decompression during a 1-year period were identified at all centres performing emergency spinal surgery across Scotland. Initial patient identification occurred during the emergency hospital admission, and case ascertainment was checked using ICD-10 diagnostic coding. Clinical information was reviewed, and incidence rates for all demographic and clinical groups were calculated. RESULTS: We identified 149 patients with CES in 1 year from a total population of 5.4 million, giving a crude incidence of 2.7 (95% CI: 2.3-3.2) per 100,000 per year. CES occurred more commonly in females and in the 30-49 years age range, with an incidence per year of 7.2 (95% CI: 4.7-10.6) per 100,000 females age 30-39. There was no association between CES and socioeconomic status. CES requiring catheterization had an incidence of 1.1 (95% CI: 0.8-1.5) per 100,000 adults per year. The use of ICD-10 codes alone to identify cases gave much higher incidence rates, but was inaccurate, with 55% (117/211) of patients with a new ICD-10 code for CES found not to have CES on clinical notes review. CONCLUSION: CES occurred more commonly in females and in those between 30 and 49 years and had no association with socioeconomic status. The incidence of CES in Scotland is at least four times higher than previous European estimates of 0.3-0.6 per 100,000 population per year. Incidence varies with clinical diagnostic criteria. To enable comparison of rates of CES across populations, we recommend using standardized clinical and radiological criteria and standardization for population structure.

The digital Cullen chart: a red colour perimetry aid for visual field examination.

BACKGROUND: 30 years ago, a paper chart was developed in Edinburgh by Cullen et al. and validated as a swift, supplementary method for perimetric evaluation of visual fields. We have re-developed this concept in digital form (on smartphone screen) and assessed its sensitivity and specificity in detecting visual field loss, by comparison with formal machine-based perimetry. METHODS: Patients with sellar and parasellar tumours, being managed in a single neurosurgical centre, underwent formal visual field perimetry as part of standard care. They also underwent assessment using the smartphone-based Cullen chart. 37 eye testing episodes were assessed, incorporating pre- and post-treatment assessments for a range of potentially compressive pathologies (non-secretory and secretory pituitary adenoma, craniopharyngioma, and parasellar meningioma). The smartphone-based Cullen chart was compared with formal machine-based perimetry for concordance in detecting visual field loss. RESULTS: The digital Cullen chart had a sensitivity of 75% and specificity of 98% compared with machine-based perimeters. The positive predictive value was 93% and the negative predictive value was 92%. CONCLUSIONS: For the visual field assessment of patients with sellar/parasellar tumours, this simple and swift smartphone-based chart shows good concordance with machine-based perimeters. With amendments to the user interface, there may be potential for telemetric patient-led visual field monitoring.

Are we neglecting sexual function assessment in suspected cauda equina syndrome?

OBJECTIVES: We assessed the documentation rates of signs and symptoms, including sexual function, in patients with suspected cauda equina syndrome and whether they can be improved by increasing local awareness. PATIENTS AND METHODS: We reviewed all electronic records of patients referred with suspected CES who required urgent MRI to our regional service over a 2 month period. We recorded the documentation rates of clinical signs and symptoms. The results were presented locally to increase awareness. A further 2 month period was then re-audited. 120 patients in total were included across both time periods. Chi-squared was used to compare documentation rates between time periods. RESULTS: 25 of 120 patients had radiological cauda equina compression. Lower limb neurology, urinary function and saddle sensation were almost universally documented. After the intervention, there was a significant increase (p < 0.05) in the documentation of bowel function and post-void residual but not sexual function. Sexual function was poorly documented with rates of 3% and 11% throughout the two audited periods. CONCLUSION: Certain clinical features of CES are well documented. Increasing awareness may improve documentation of certain symptoms/signs in patients with suspected cauda equina syndrome. Sexual function was poorly documented and increasing awareness alone is an inadequate intervention.

Does a history of lumbar spine surgery predict radiological cauda equina compression in patients undergoing MRI for suspected cauda equina syndrome?

Background: The clinical symptoms and signs of Cauda equina syndrome (CES) are non specific and poorly predictive of cauda equina compression on MRI. We aimed to establish whether a history of lumbar spine surgery predicts cauda equina compression on MRI in those presenting with suspected CES.Methods: A retrospective electronic record review was undertaken of 276 patients referred with clinically suspected CES who underwent a lumbosacral spine MRI. Those with a history of prior lumbar surgery were compared to those without. The likelihood of cauda equina compression was compared between the two groups.Results: About 78/276 (28%) patients with suspected CES had radiological compression of the cauda equina and went on to surgical decompression. A total of 54 (20%) patients had undergone prior lumbar surgery. Patients with a history of lumbar surgery were less likely to have cauda equina compression on MRI (χ2 - p = .035). Twenty six (9%) patients presented more than once with suspected CES. Patients with a history of lumbar surgery were more likely to re-present with suspected CES (χ2 - p = .002).Conclusions: Prior lumbar surgery was associated with a higher frequency of re-presentation with clinically suspected CES but a lower frequency of radiological cauda equina compression.

Evaluation of nationwide referral pathways, investigation and treatment of suspected cauda equina syndrome in the United Kingdom.

Purpose: Cauda equina syndrome (CES) is a spinal emergency with clinical symptoms and signs that have low diagnostic accuracy. National guidelines in the United Kingdom (UK) state that all patients should undergo an MRI prior to referral to specialist spinal units and surgery should be performed at the earliest opportunity. We aimed to evaluate the current practice of investigating and treating suspected CES in the UK. Materials and Methods: A retrospective, multicentre observational study of the investigation and management of patients with suspected CES was conducted across the UK, including all patients referred to a spinal unit over 6 months between 1st October 2016 and 31st March 2017. Results: A total of 28 UK spinal units submitted data on 4441 referrals. Over half of referrals were made without any previous imaging (n = 2572, 57.9%). Of all referrals, 695 underwent surgical decompression (15.6%). The majority of referrals were made out-of-hours (n = 2229/3517, 63.4%). Patient location and pre-referral imaging were not associated with time intervals from symptom onset or presentation to decompression. Patients investigated outside of the spinal unit experienced longer time intervals from referral to undergoing the MRI scan. Conclusions: This is the largest known study of the investigation and management of suspected CES. We found that the majority of referrals were made without adequate investigations. Most patients were referred out-of-hours and many were transferred for an MRI without subsequently requiring surgery. Adherence to guidelines would reduce the number of referrals to spinal services by 72% and reduce the number of patient transfers by 79%.

A national survey of thromboprophylaxis in traumatic brain injury in the United Kingdom.

INTRODUCTION: Patients with traumatic brain injury (TBI) are at increased risk of venous thromboembolic events (VTE). In this survey, we aimed to assess current practice in the United Kingdom and identify areas of variation for further investigation. METHODS: We distributed a case-based survey to neurosurgical consultants and trainees via e-mail. The survey included four index TBI cases commonly seen: a surgically treated acute extradural haematoma, bilateral frontal contusions treated conservatively, diffuse axonal injury requiring critical care and a conservatively managed small acute subdural haematoma. Each case vignette included questions looking at a range of areas regarding thromboprophylaxis. RESULTS: Sixty-two responses were collected among UK neurosurgeons with a good geographic distribution. In each case, over 90% of respondents would initiate mechanical prophylaxis (MTP) at admission. There was greater variation on the decision to commence pharmacological prophylaxis (PTP). Consultants showed a higher willing to commence PTP across all cases (84%) compared to trainees (77.4%). Low molecular weight heparin (LMWH) was the favoured PTP agent in over 90% of respondents. There was significant variability in the timing of initiation of PTP within and between cases. The median times to commence PTP across all four cases ranged from 1 to 7 days. CONCLUSION: This survey highlighted broad consensus on the use of MTP and choice of PTP agent, when used. However, the survey also demonstrated wide intra-case variation on whether to start PTP and particularly the timing of initiation. This discordance in practice shines light on the lack of evidence guiding thromboprophyalxis in TBI and adds weight to the need for prospective randomised trials to guide clinical management.

A summary of assessment tools for patients suffering from cervical spondylotic myelopathy: a systematic review on validity, reliability and responsiveness.

PURPOSE: One of the objectives of this review is to summarize the important features of a good scale. A second aim is to conduct a systematic review to identify scales that can detect the presence of cervical myelopathy and to determine their psychometric properties including validity, reliability and responsiveness. METHODS: A thorough literature search was performed using MEDLINE, MEDLINE in process, EMBASE, and Cochrane Central Register of Controlled Trials. Articles were included in this study if they compared scale measurements between a control and a myelopathic patient population or if they discussed any psychometric property of a scale. RESULTS: An ideal scale should be one that is quantifiable, valid, sensitive, responsive and easy to perform, has high inter/intra-rater reliability, internal consistency and a suitable distribution, and is one-dimensional and relevant. In the context of cervical spondylotic myelopathy, it is essential that the scale also addresses the pathophysiology, its key signs and symptoms as well as its natural history. For the systematic review, the search yielded 5,745 citations. Of these, 37 met inclusion criteria, 10 explored the ability of a scale to detect myelopathy, 23 examined validity by assessing correlation between scales, 10 reported reliability, 8 analyzed responsiveness, and 6 discussed internal consistency. The most frequently reported scale was short form-36 (n = 16) followed by Nurick grade (n = 14), Japanese Orthopaedic Association (n = 13), (modified) Japanese Orthopaedic Association (n = 7) and grip and release test (n = 6). Four studies each presented results on the Cooper, Harsh and 30-m walking test. CONCLUSION: This review summarizes outcome measures used to assess the presence and severity of cervical myelopathy. It includes several validation studies as well as those that have reported the responsiveness and reliability of various measures.

A Critical Appraisal of the Congress of Neurological Surgeons Evidence-Based Guidelines on the Evaluation and Treatment of Patients With Thoracolumbar Spine Trauma.

Background and objective Thoracolumbar spine trauma (TST) is frequently associated with spinal cord injury and other soft tissue and bony injuries. The management of such injuries requires an evidence-based approach. This study used the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument to assess the methodological quality of clinical guidelines for the management of TST published by the Congress of Neurological Surgeons (CNS). Methods All clinical guidelines on TST published by CNS until 2020 were assessed. Five appraisers from three international centers evaluated the quality of eligible clinical guidelines by using AGREE II. Mean AGREE II scores for each domain were determined. In higher-quality domains, the scores for individual items were analyzed. Results A total of 12 guidelines published by CNS on TST were assessed. Mean scores for all six domains were as follows: Scope and Purpose (75.2%), Stakeholder Involvement (45.4%), Rigor of Development (57.0%), Clarity of Presentation (58.7%), Applicability (16.9%), and Editorial Independence (64.1%). The mean score for the overall quality of all CNS guidelines was 52.9% [95% confidence interval (CI): 52.2-53.5%]. The overall agreement among appraisers was excellent [intra-class correlation coefficients (ICCs) for each guideline ranged from 0.903 to 0.963]. Conclusions CNS guidelines for the management of TST demonstrated acceptable quality across most domains; however, the domains of Applicability and Stakeholder Involvement could be further improved in future guideline updates. The assessors concluded that all guidelines could still be recommended for clinical practice with or without modifications.

Cost-effectiveness of decellularised bone allograft compared with fresh-frozen bone allograft for acetabular impaction bone grafting during a revision hip arthroplasty in the UK.

OBJECTIVES: Fresh-frozen allograft is the gold-standard bone graft material used during revision hip arthroplasty. However, new technology has been developed to manufacture decellularised bone with potentially better graft incorporation. As these grafts cost more to manufacture, the aim of this cost-effectiveness study was to estimate whether the potential health benefit of decellularised bone allograft outweighs their increased cost. STUDY DESIGN: A Markov model was constructed to estimate the costs and the quality-adjusted life years of impaction bone grafting during a revision hip arthroplasty. SETTING: This study took the perspective of the National Health Service in the UK. PARTICIPANTS: The Markov model includes patients undergoing a revision hip arthroplasty in the UK. INTERVENTION: Impaction bone grafting during a revision hip arthroplasty using either decellularised bone allograft or fresh-frozen allograft. MEASURES: Outcome measures included: total costs and quality-adjusted life years of both interventions over the lifetime of the model; and incremental cost-effectiveness ratios for both graft types, using base case parameters, univariate sensitivity analysis and probabilistic analysis. RESULTS: The incremental cost-effectiveness ratio for the base case model was found to be £270 059 per quality-adjusted life year. Univariate sensitivity analysis found that changing the discount rate, the decellularised bone graft cost, age of the patient cohort and the revision rate all had a significant effect on the incremental cost-effectiveness ratio. CONCLUSIONS: As there are no clinical studies of impaction bone grafting using a decellularised bone allograft, there is a high level of uncertainty around the costs of producing a decellularised bone allograft and the potential health benefits. However, if a decellularised bone graft was manufactured for £2887 and lowered the re-revision rate to less than 64 cases per year per 10 000 revision patients, then it would most likely be cost-effective compared with fresh-frozen allograft.

Cauda equina syndrome.

Aims: Patients with cauda equina syndrome (CES) require emergency imaging and surgical decompression. The severity and type of symptoms may influence the timing of imaging and surgery, and help predict the patient's prognosis. Categories of CES attempt to group patients for management and prognostication purposes. We aimed in this study to assess the inter-rater reliability of dividing patients with CES into categories to assess whether they can be reliably applied in clinical practice and in research. Methods: A literature review was undertaken to identify published descriptions of categories of CES. A total of 100 real anonymized clinical vignettes of patients diagnosed with CES from the Understanding Cauda Equina Syndrome (UCES) study were reviewed by consultant spinal surgeons, neurosurgical registrars, and medical students. All were provided with published category definitions and asked to decide whether each patient had 'suspected CES'; 'early CES'; 'incomplete CES'; or 'CES with urinary retention'. Inter-rater agreement was assessed for all categories, for all raters, and for each group of raters using Fleiss's kappa. Results: Each of the 100 participants were rated by four medical students, five neurosurgical registrars, and four consultant spinal surgeons. No groups achieved reasonable inter-rater agreement for any of the categories. CES with retention versus all other categories had the highest inter-rater agreement (kappa 0.34 (95% confidence interval 0.27 to 0.31); minimal agreement). There was no improvement in inter-rater agreement with clinical experience. Across all categories, registrars agreed with each other most often (kappa 0.41), followed by medical students (kappa 0.39). Consultant spinal surgeons had the lowest inter-rater agreement (kappa 0.17). Conclusion: Inter-rater agreement for categorizing CES is low among clinicians who regularly manage these patients. CES categories should be used with caution in clinical practice and research studies, as groups may be heterogenous and not comparable.

Presentation, management, and outcomes of cauda equina syndrome up to one year after surgery, using clinician and participant reporting: A multi-centre prospective cohort study.

Background: Cauda equina syndrome (CES) results from nerve root compression in the lumbosacral spine, usually due to a prolapsed intervertebral disc. Evidence for management of CES is limited by its infrequent occurrence and lack of standardised clinical definitions and outcome measures. Methods: This is a prospective multi-centre observational cohort study of adults with CES in the UK. We assessed presentation, investigation, management, and all Core Outcome Set domains up to one year post-operatively using clinician and participant reporting. Univariable and multivariable associations with the Oswestry Disability Index (ODI) and urinary outcomes were investigated. Findings: In 621 participants with CES, catheterisation for urinary retention was required pre-operatively in 31% (191/615). At discharge, only 13% (78/616) required a catheter. Median time to surgery from symptom onset was 3 days (IQR:1-8) with 32% (175/545) undergoing surgery within 48 h. Earlier surgery was associated with catheterisation (OR:2.2, 95%CI:1.5-3.3) but not with admission ODI or radiological compression. In multivariable analyses catheter requirement at discharge was associated with pre-operative catheterisation (OR:10.6, 95%CI:5.8-20.4) and one-year ODI was associated with presentation ODI (r = 0.3, 95%CI:0.2-0.4), but neither outcome was associated with time to surgery or radiological compression. Additional healthcare services were required by 65% (320/490) during one year follow up. Interpretation: Post-operative functional improvement occurred even in those presenting with urinary retention. There was no association between outcomes and time to surgery in this observational study. Significant healthcare needs remained post-operatively. Funding: DCN Endowment Fund funded study administration. Castor EDC provided database use. No other study funding was received.

Reproducing the Biomechanical Environment of the Chondrocyte for Cartilage Tissue Engineering.

It is well known that the biomechanical and tribological performance of articular cartilage is inextricably linked to its extracellular matrix (ECM) structure and zonal heterogeneity. Furthermore, it is understood that the presence of native ECM components, such as collagen II and aggrecan, promote healthy homeostasis in the resident chondrocytes. What is less frequently discussed is how chondrocyte metabolism is related to the extracellular mechanical environment, at both the macro and microscale. The chondrocyte is in immediate contact with the pericellular matrix of the chondron, which acts as a mechanocoupler, transmitting external applied loads from the ECM to the chondrocyte. Therefore, components of the pericellular matrix also play essential roles in chondrocyte mechanotransduction and metabolism. Recreating the biomechanical environment through tuning material properties of a scaffold and/or the use of external cyclic loading can induce biosynthetic responses in chondrocytes. Decellularized scaffolds, which retain the native tissue macro- and microstructure also represent an effective means of recapitulating such an environment. The use of such techniques in tissue engineering applications can ensure the regeneration of skeletally mature articular cartilage with appropriate biomechanical and tribological properties to restore joint function. Despite the pivotal role in graft maturation and performance, biomechanical and tribological properties of such interventions is often underrepresented. This review outlines the role of biomechanics in relation to native cartilage performance and chondrocyte metabolism, and how application of this theory can enhance the future development and successful translation of biomechanically relevant tissue engineering interventions. Impact statement Physiological cartilage function is a key criterion in the success of a cartilage tissue engineering solution. The in situ performance is dependent on the initial scaffold design as well as extracellular matrix deposition by endogenous or exogenous cells. Both biological and biomechanical stimuli serve as key regulators of cartilage homeostasis and maturation of the resulting tissue-engineered graft. An improved understanding of the influence of biomechanics on cellular function and consideration of the final biomechanical and tribological performance will help in the successful development and translation of tissue-engineered grafts to restore natural joint function postcartilage trauma or osteoarthritic degeneration, delaying the requirement for prosthetic intervention.

Duration of External Neck Stabilisation (DENS) following odontoid fracture in older or frail adults: protocol for a randomised controlled trial of collar versus no collar.

INTRODUCTION: Fractures of the odontoid process frequently result from low impact falls in frail or older adults. These are increasing in incidence and importance as the population ages. In the UK, odontoid fractures in older adults are usually managed in hard collars to immobilise the fracture and promote bony healing. However, bony healing does not always occur in older adults, and bony healing is not associated with quality of life, functional, or pain outcomes. Further, hard collars can cause complications such as skin pressure ulcers, swallowing difficulties and difficulties with personal care. We hypothesise that management with no immobilisation may be superior to management in a hard collar for older or frail adults with odontoid fractures. METHODS AND ANALYSES: This is the protocol for the Duration of External Neck Stabilisation (DENS) trial-a non-blinded randomised controlled trial comparing management in a hard collar with management without a collar for older (≥65 years) or frail (Rockwood Clinical Frailty Scale ≥5) adults with a new odontoid fracture. 887 neurologically intact participants with any odontoid process fracture type will be randomised to continuing with a hard collar (standard care) or removal of the collar (intervention). The primary outcome is quality of life measured using the EQ-5D-5L at 12 weeks. Secondary outcomes include pain scores, neck disability index, health and social care use and costs, and mortality. ETHICS AND DISSEMINATION: Informed consent for participation will be sought from those able to provide it. We will also include those who lack capacity to ensure representativeness of frail and acutely unwell older adults. Results will be disseminated via scientific publication, lay summary, and visual abstract. The DENS trial received a favourable ethical opinion from the Scotland A Research Ethics Committee (21/SS/0036) and the Leeds West Research Ethics Committee (21/YH/0141). TRIAL REGISTRATION NUMBER: NCT04895644.

Scan-Negative Cauda Equina Syndrome: A Prospective Cohort Study.

OBJECTIVE: To describe clinical features relevant to diagnosis, mechanism, and etiology in patients with "scan-negative" cauda equina syndrome (CES). METHODS: We carried out a prospective study of consecutive patients presenting with the clinical features of CES to a regional neurosurgery center comprising semi-structured interview and questionnaires investigating presenting symptoms, neurologic examination, psychiatric and functional disorder comorbidity, bladder/bowel/sexual function, distress, and disability. RESULTS: A total of 198 patients presented consecutively over 28 months. A total of 47 were diagnosed with scan-positive CES (mean age 48 years, 43% female). A total of 76 mixed category patients had nerve root compression/displacement without CES compression (mean age 46 years, 71% female) and 61 patients had scan-negative CES (mean age 40 years, 77% female). An alternative neurologic cause of CES emerged in 14/198 patients during admission and 4/151 patients with mean duration 25 months follow-up. Patients with scan-negative CES had more positive clinical signs of a functional neurologic disorder (11% scan-positive CES vs 34% mixed and 68% scan-negative, p < 0.0001), were more likely to describe their current back pain as worst ever (41% vs 46% and 70%, p = 0.005), and were more likely to have symptoms of a panic attack at onset (37% vs 57% and 70%, p = 0.001). Patients with scan-positive CES were more likely to have reduced/absent bilateral ankle jerks (78% vs 30% and 12%, p < 0.0001). There was no significant difference between groups in the frequency of reduced anal tone and urinary retention. CONCLUSION: The first well-phenotyped, prospective study of scan-negative CES supports a model in which acute pain, medication, and mechanisms overlapping with functional neurologic disorders may be relevant.

Surgery for cervical radiculopathy or myelopathy.

BACKGROUND: Cervical spondylosis causes pain and disability by compressing the spinal cord or roots. Surgery to relieve the compression may reduce the pain and disability, but is associated with a small but definite risk. . OBJECTIVES: To determine whether: 1) surgical treatment of cervical radiculopathy or myelopathy is associated with improved outcome, compared with conservative management and 2) timing of surgery (immediate or delayed pending persistence/progression of relevant symptoms and signs) has an impact on outcome. SEARCH STRATEGY: We searched CENTRAL, MEDLINE, and EMBASE to 1998 for the original review. A revised search was run in CENTRAL (The Cochrane Library 2008, Issue 2), MEDLINE, EMBASE, and CINAHL (January 1998 to June 2008) to update the review.Authors of the identified randomised controlled trials were contacted for additional published or unpublished data. SELECTION CRITERIA: All randomised or quasi-randomised controlled trials allocating patients with cervical radiculopathy or myelopathy to 1) "medical management" or "decompressive surgery (with or without fusion) plus medical management" 2) "early decompressive surgery" or "delayed decompressive surgery". DATA COLLECTION AND ANALYSIS: Two authors independently selected trials, assessed risk of bias and extracted data. MAIN RESULTS: Two trials (N = 149) were included. In both trials, allocation concealment was inadequate and arrangements for blinding of outcome assessment were unclear.One trial (81 patients with cervical radiculopathy) found that surgical decompression was superior to physiotherapy or cervical collar immobilization in the short-term for pain, weakness or sensory loss; at one year, there were no significant differences between groups.One trial (68 patients with mild functional deficit associated with cervical myelopathy) found no significant differences between surgery and conservative treatment in three years following treatment. A substantial proportion of cases were lost to follow-up. AUTHORS' CONCLUSIONS: Both small trials had significant risks of bias and do not provide reliable evidence on the effects of surgery for cervical spondylotic radiculopathy or myelopathy. It is unclear whether the short-term risks of surgery are offset by long-term benefits. Further research is very likely to have an impact on the estimate of effect and our confidence in it.There is low quality evidence that surgery may provide pain relief faster than physiotherapy or hard collar immobilization in patients with cervical radiculopathy; but there is little or no difference in the long-term.There is very low quality evidence that patients with mild myelopathy feel subjectively better shortly after surgery, but there is little or no difference in the long-term.

Sellar Remodeling after Surgery for Nonfunctioning Pituitary Adenoma: Intercarotid Distance as a Predictor of Recurrence.

Introduction As they grow, pituitary adenoma can remodel the sella turcica and alter anatomical relationships with adjacent structures. The intercarotid distance (ICD) at the level of the sella is a measure of sella width. The purpose of this study was to (1) assess how ICD changes after transsphenoidal surgery and (2) explore whether the extent of ICD change is associated with tumor recurrence. Methods A retrospective analysis of preoperative and postoperative coronal magnetic resonance imaging (MRI) scans was carried out by two independent assessors on patients who underwent transsphenoidal surgery for nonfunctioning pituitary macroadenomas. Preoperative tumor volume and any change in ICD following surgery were recorded and compared between groups. Logistic regression models of recurrence were generated. Results In 36 of 42 patients, ICD fell after surgery (mean = 1.8 mm) and six cases were static. At time of follow-up (mean = 77 months), 25 had not required further intervention and 17 had undergone second surgery or radiosurgery. In patients in whom no further intervention has yet been necessary, the postoperative reduction in ICD was significantly smaller than in those who required repeat intervention (1.1 vs. 2.7 mm respectively, p < 0.01). ICD decrease was weakly correlated with tumor volume ( r = 0.35). ICD decrease was a significant predictor of recurrence (odds ratio [OR] = 3.15; 95% confidence interval [CI]: 1.44-6.87), largely independent of tumor volume. Conclusion For most patients, ICD falls following surgical excision of a nonfunctioning pituitary macroadenoma. A greater reduction in ICD postsurgery appears to predict recurrence. Change in ICD shows promise as a radiographic tool for prognosticating clinical course after surgery.

Compressive Pressure Versus Time in Cauda Equina Syndrome: A Systematic Review and Meta-Analysis of Experimental Studies.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: To examine the relationship between compressive pressure and its duration in cauda equina compression, and the effects of subsequent decompression, on neurophysiological function, and pathophysiology in animal studies. We further aim to investigate these relationships with systemic blood pressure to assess whether a vascular component in the underlying mechanism may contribute to the clinical heterogeneity of this disease. SUMMARY OF BACKGROUND DATA: The complex relationship between preoperative factors and outcomes in cauda equina syndrome (CES) suggests heterogeneity within CES which may inform better understanding of pathophysiological process, their effect on neurological function, and prognosis. METHODS: Systematic review identified 17 relevant studies including 422 animals and reporting electrophysiological measures (EP), histopathology, and blood flow. Modeling using meta-regression analyzed the relationship between compressive pressure, duration of compression, and electrophysiological function in both compression and decompression studies. RESULTS: Modeling suggested that electrophysiological dysfunction in acute cauda equina compression has a sigmoidal response, with particularly deterioration when mean arterial blood pressure is exceeded and, additionally, sustained for approximately 1 hour. Accounting for pressure and duration may help risk-stratify patients pre-decompression. Outcomes after decompression appeared to be related more to the degree of compression, where exceeding systolic blood pressure tended to result in an irreversible lesion, rather than duration of compression. Prognosis was most strongly associated with residual pre-decompression function. CONCLUSION: Compressive pressure influences effects and outcomes of cauda equina compression. We suggest the presence of two broad phenotypic groups within CES defined by the degree of ischaemia as a potential explanatory pathophysiological mechanism. LEVEL OF EVIDENCE: 1.

The clinical features and outcome of scan-negative and scan-positive cases in suspected cauda equina syndrome: a retrospective study of 276 patients.

BACKGROUND: The majority of patients presenting with suspected clinical cauda equina syndrome (CES) have no identifiable structural cause for their symptoms ('scan-negative' CES). Understanding these patients aids clinical differentiation and management in CES. METHODS: A retrospective electronic note review was undertaken of patients presenting with suspected CES, defined as ≥ 1 of acute bladder, bowel, sexual dysfunction or saddle numbness, to a regional neurosciences centre. We investigated radiology, clinical features, psychiatric and functional disorder comorbidities and outcome of patients with 'scan-negative' CES and patients with MRI confirmed compression of the cauda equina ('scan-positive' CES). RESULTS: 276 patients were seen over 16 months. There were three main radiologically defined patient groups: (1) 'scan-positive' CES (n = 78, mean age 48 years, 56% female), (2) 'scan-negative' CES without central canal stenosis but with lumbosacral nerve root compression not explaining the clinical presentation (n = 87, mean age 43 years, 68% female) and (3) 'scan-negative' CES without neural compromise (n = 104, mean age 42 years, 70% female). In the two 'scan-negative' groups (no neural compromise and nerve root compression), there were higher rates of functional disorders (37% and 29% vs. 9%), functional neurological disorders (12% and 11% vs 0%) and psychiatric comorbidity (53% and 40% vs 20%). On follow-up (mean 13-16 months), only 1 of the 191 patients with 'scan-negative' CES was diagnosed with an explanatory neurological disorder (transverse myelitis). CONCLUSIONS: The data support a model in which scan-negative cauda equina syndrome arises as an end pathway of acute pain, sometimes with partly structural findings and vulnerability to functional disorders.

Understanding cauda equina syndrome: protocol for a UK multicentre prospective observational cohort study.

INTRODUCTION: Cauda equina syndrome (CES) is a potentially devastating condition caused by compression of the cauda equina nerve roots. This can result in bowel, bladder and sexual dysfunction plus lower limb weakness, numbness and pain. CES occurs infrequently, but has serious potential morbidity and medicolegal consequences. This study aims to identify and describe the presentation and management of patients with CES in the UK. METHODS AND ANALYSIS: Understanding Cauda Equina Syndrome (UCES) is a prospective and collaborative multicentre cohort study of adult patients with confirmed CES managed at specialist spinal centres in the UK. Participants will be identified using neurosurgical and orthopaedic trainee networks to screen referrals to spinal centres. Details of presentation, investigations, management and service usage will be recorded. Both patient-reported and clinician-reported outcome measures will be assessed for 1 year after surgery. This will establish the incidence of CES, current investigation and management practices, and adherence to national standards of care. Outcomes will be stratified by clinical presentation and patient management. Accurate and up to date information about the presentation, management and outcome of patients with CES will inform standards of service design and delivery for this important but infrequent condition. ETHICS AND DISSEMINATION: UCES received a favourable ethical opinion from the South East Scotland Research Ethics Committee 02 (Reference: 18/SS/0047; IRAS ID: 233515). All spinal centres managing patients with CES in the UK will be encouraged to participate in UCES. Study results will be published in medical journals and shared with local participating sites. TRIAL REGISTRATION NUMBER: ISRCTN16828522; Pre-results.