Pain and functional neurological disorder: a systematic review and meta-analysis.

BACKGROUND: Functional neurological disorder (FND) is characterised by neurological symptoms, such as seizures and abnormal movements. Despite its significance to patients, the clinical features of chronic pain in people with FND, and of FND in people with chronic pain, have not been comprehensively studied. METHODS: We systematically reviewed PubMed, Embase and PsycINFO for studies of chronic pain in adults with FND and FND in patients with chronic pain. We described the proportions of patients reporting pain, pain rating and timing, pain-related diagnoses and responsiveness to treatment. We performed random effects meta-analyses of the proportions of patients with FND who reported pain or were diagnosed with pain-related disorders. RESULTS: Seven hundred and fifteen articles were screened and 64 were included in the analysis. Eight case-control studies of 3476 patients described pain symptoms in a higher proportion of patients with FND than controls with other neurological disorders. A random effects model of 30 cohorts found that an estimated 55% (95% CI 46% to 64%) of 4272 patients with FND reported pain. Random effects models estimated diagnoses of complex regional pain syndrome in 22% (95% CI 6% to 39%) of patients, irritable bowel syndrome in 16% (95% CI 9% to 24%) and fibromyalgia in 10% (95% CI 8% to 13%). Five studies of FND diagnoses among 361 patients with chronic pain were identified. Most interventions for FND did not ameliorate pain, even when other symptoms improved. CONCLUSIONS: Pain symptoms and pain-related diagnoses are common in FND. Classification systems and treatments should routinely consider pain as a comorbidity in patients with FND.

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.

Anomalies in the review process and interpretation of the evidence in the NICE guideline for chronic fatigue syndrome and myalgic encephalomyelitis.

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disabling long-term condition of unknown cause. The National Institute for Health and Care Excellence (NICE) published a guideline in 2021 that highlighted the seriousness of the condition, but also recommended that graded exercise therapy (GET) should not be used and cognitive-behavioural therapy should only be used to manage symptoms and reduce distress, not to aid recovery. This U-turn in recommendations from the previous 2007 guideline is controversial.We suggest that the controversy stems from anomalies in both processing and interpretation of the evidence by the NICE committee. The committee: (1) created a new definition of CFS/ME, which 'downgraded' the certainty of trial evidence; (2) omitted data from standard trial end points used to assess efficacy; (3) discounted trial data when assessing treatment harm in favour of lower quality surveys and qualitative studies; (4) minimised the importance of fatigue as an outcome; (5) did not use accepted practices to synthesise trial evidence adequately using GRADE (Grading of Recommendations, Assessment, Development and Evaluations trial evidence); (6) interpreted GET as mandating fixed increments of change when trials defined it as collaborative, negotiated and symptom dependent; (7) deviated from NICE recommendations of rehabilitation for related conditions, such as chronic primary pain and (8) recommended an energy management approach in the absence of supportive research evidence.We conclude that the dissonance between this and the previous guideline was the result of deviating from usual scientific standards of the NICE process. The consequences of this are that patients may be denied helpful treatments and therefore risk persistent ill health and disability.

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.

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.

Long-term mental wellbeing and functioning after surgery for cauda equina syndrome.

INTRODUCTION: Cauda Equina Syndrome (CES) can cause persisting life-changing dysfunction. There is scarce literature regarding the long-term assessment of CES symptoms, and rarer still is the impact of these symptoms on mental wellbeing investigated. This study assessed the long-term patient reported mental wellbeing outcomes of post-operative CES patients. METHODS: Patients who underwent surgery for CES between August 2013 and November 2014 were identified using an ethically approved database. They then completed validated questionnaires over the telephone assessing their mental and physical functioning (Short-Form 12 Questionnaire), generating the Physical Component Summary (PCS) and Mental Component Summary (MCS). Bladder, bowel and sexual function were also assessed using validated questionnaires. MCS scores were compared to both the Scottish mean and previously published cut-offs indicating patients at risk of depression. Correlations of MCS with bladder, bowel, sexual and physical dysfunction were examined and multifactorial regression to predict MCS from these variables analysed. Independent t-tests assessed the mean difference in MCS between patients presenting with incomplete CES (CES-I) and CES with retention (CES-R) and between those with radiologically confirmed and impending CES. RESULTS: Forty-six participants with a mean follow-up time of 43 months completed the study. The mean (±SD) MCS was 49 (±11.8) with 22% demonstrating poor mental health related quality of life in comparison to the Scottish mean. Overall, 37% had scores consistent with being at risk for depression with in the last 30 days, and 45% within the last 12 months. MCS was significantly correlated with Urinary Symptoms Profile (USP) score (-0.608), NBDS score (-0.556), ASEX score (-0.349) and PCS score (0.413) with worse bladder, bowel, sexual and physical dysfunction associated with worse MCS score. Multifactorial regression analysis demonstrated both urinary (USP score p = 0.031) and bowel function (NBDS score p = 0.009) to be significant predictive variables of mental health related quality of life. There were no significant mean differences in MCS between those presenting with CES-I and CES-R or those with radiologically complete and impending CES. DISCUSSION: This study demonstrates a high frequency of being at risk for depression in patients with CES and identifies outcome measures (physical, sexual and more so bladder and bowel dysfunction) associated with poorer mental wellbeing. Our large cohort and long follow-up highlight that CES patients should be considered at risk of depression, and the need to consider mental health outcomes following CES surgery.

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%.

Screening for functional neurological disorders by questionnaire.

OBJECTIVE: Diagnostic screening for functional neurological disorders (FNDs) continues to pose a challenge. Simple symptom counts fail clearly to discriminate patients with FND but there is increasing recognition of 'positive' features which are useful diagnostically during face-to-face assessments. A self-completed questionnaire evaluating specific features of FNDs would be useful for screening purposes in clinical and research settings. METHODS: The Edinburgh Neurosymptoms Questionnaire (ENS) is a 30-item survey of presence and nature of: blackouts, weakness, hemisensory syndrome, memory problems, tremor, pain, fatigue, globus, multiple medical problems, and operations constructed via literature review and expert consensus. We conducted a pilot of the ENS on new general neurology clinic attendees at a large regional neuroscience centre. Patients were grouped according to consultant neurologist impression as having symptoms that were 'Not at all', 'Somewhat', 'Largely' or 'Completely' due to a functional disorder. RESULTS: Blackouts, weakness and memory questions provided reasonable diagnostic utility (AUROC = 0.94, 0.71, 0.74 respectively) in single symptom analysis. All other symptoms lacked discriminating features. A multivariate linear model with all symptoms predicted functional classification with moderate diagnostic utility (AUROC = 0.83), specificity of 0.97, sensitivity of 0.47. Pain and blackout scores provided the most accurate predictor of functional classification. CONCLUSION: The ENS questionnaire provides some utility in differentiating patients presenting with functional blackouts but failed to provide diagnostic value in other types of FND, highlighting the limitations of this self-report tool.

Understanding foreign accent syndrome.

OBJECTIVE: Foreign accent syndrome (FAS) is widely understood as an unusual consequence of structural neurological damage, but may sometimes represent a functional neurological disorder. This observational study aimed to assess the prevalence and utility of positive features of functional FAS in a large group of individuals reporting FAS. METHODS: Participants self-reporting FAS recruited from informal unmoderated online support forums and via professional networks completed an online survey. Speech samples were analysed in a subgroup. RESULTS: Forty-nine respondents (24 UK, 23 North America, 2 Australia) reported FAS of mean duration 3 years (range 2 months to 18 years). Common triggers were: migraine/severe headache (15), stroke (12), surgery or injury to mouth or face (6) and seizure (5, including 3 non-epileptic). High levels of comorbidity included migraine (33), irritable bowel syndrome (17), functional neurological disorder (12) and chronic pain (12). Five reported structural lesions on imaging. Author consensus on aetiology divided into, 'probably functional (n=35.71%), 'possibly structural' (n=4.8%) and 'probably structural' (n=10.20%), but positive features of functional FAS were present in all groups. Blinded analysis of speech recordings supplied by 13 respondents correctly categorised 11 (85%) on the basis of probable aetiology (functional vs structural) in agreement with case history assignment. CONCLUSIONS: This largest case series to date details the experience of individuals with self-reported FAS. Although conclusions are limited by the recruitment methods, high levels of functional disorder comorbidity, symptom variability and additional linguistic and behavioural features suggest that chronic FAS may in some cases represent a functional neurological disorder, even when a structural lesion is present.

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.

Fowler's syndrome of urinary retention: A retrospective study of co-morbidity.

AIMS: To study the frequency of pain, psychological, or functional disorders in patients with Fowler's syndrome. METHODS: We carried out a retrospective chart review of patients with a diagnosis of Fowler's syndrome attending the Uro-Neurology centre at the National Hospital for Neurology and Neurosurgery between 2009 and 2013 looking at triggering events, physical and psychological comorbidities. RESULTS: Of 62 patients with clinical and electromyographic diagnosis of Fowler's syndrome, 31 (50%) had unexplained chronic pain syndromes, 12 (19%) of these were taking opiates. Fifteen (24%) had "functional" neurological symptoms. Abdominopelvic surgery with general anesthesia was the leading trigger (n = 21, 35%). CONCLUSIONS: We found high levels of co-morbidity with patients having some form of pain (50%), a probable functional disorder (24%), or psychological symptoms (31%). There are several potential explanations for this association including the effect of developing an apparently unexplained distressing condition, confounding effect of opiate use or referral bias. The findings suggest a need for prospective systematic study of comorbidity for this disabling condition. Neurourol. Urodynam. 35:601-603, 2016. © 2015 Wiley Periodicals, Inc.