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.

Perspectives on the diagnosis and management of functional cognitive disorder: An international Delphi study.

BACKGROUND: Current proposed criteria for functional cognitive disorder (FCD) have not been externally validated. We sought to analyse the current perspectives of cognitive specialists in the diagnosis and management of FCD in comparison with neurodegenerative conditions. METHODS: International experts in cognitive disorders were invited to assess seven illustrative clinical vignettes containing history and bedside characteristics alone. Participants assigned a probable diagnosis and selected the appropriate investigation and treatment. Qualitative, quantitative and inter-rater agreement analyses were undertaken. RESULTS: Eighteen diagnostic terminologies were assigned by 45 cognitive experts from 12 countries with a median of 13 years of experience, across the seven scenarios. Accurate discrimination between FCD and neurodegeneration was observed, independently of background and years of experience: 100% of the neurodegenerative vignettes were correctly classified and 75%-88% of the FCD diagnoses were attributed to non-neurodegenerative causes. There was <50% agreement in the terminology used for FCD, in comparison with 87%-92% agreement for neurodegenerative syndromes. Blood tests and neuropsychological evaluation were the leading diagnostic modalities for FCD. Diagnostic communication, psychotherapy and psychiatry referral were the main suggested management strategies in FCD. CONCLUSIONS: Our study demonstrates the feasibility of distinguishing between FCD and neurodegeneration based on relevant patient characteristics and history details. These characteristics need further validation and operationalisation. Heterogeneous labelling and framing pose clinical and research challenges reflecting a lack of agreement in the field. Careful consideration of FCD diagnosis is advised, particularly in the presence of comorbidities. This study informs future research on diagnostic tools and evidence-based interventions.

What is brain fog?

BACKGROUND: The term 'brain fog' is increasingly used colloquially to describe difficulties in the cognitive realm. But what is brain fog? What sort of experiences do people talk about when they talk about brain fog? And, in turn, what might this tell us about potential underlying pathophysiological mechanisms? This study examined first-person descriptions in order to better understand the phenomenology of brain fog. METHODS: Posts containing 'brain fog' were scraped from the social media platform Reddit, using python, over a week in October 2021. We examined descriptions of brain fog, themes of containing subreddits (topic-specific discussion forums), and causal attributions. RESULTS: 1663 posts containing 'brain fog' were identified, 717 meeting inclusion criteria. 141 first person phenomenological descriptions depicted forgetfulness (51), difficulty concentrating (43), dissociative phenomena (34), cognitive 'slowness' and excessive effort (26), communication difficulties (22), 'fuzziness' or pressure (10) and fatigue (9). 50% (363/717) posts were in subreddits concerned with illness and disease: including COVID-19 (87), psychiatric, neurodevelopmental, autoimmune and functional disorders. 134 posts were in subreddits about drug use or discontinuation, and 44 in subreddits about abstention from masturbation. 570 posts included the poster's causal attribution, the most frequent attribution being long COVID in 60/570 (10%). CONCLUSIONS: 'Brain fog' is used on Reddit to describe heterogeneous experiences, including of dissociation, fatigue, forgetfulness and excessive cognitive effort, and in association with a range of illnesses, drugs and behaviours. Encouraging detailed description of these experiences will help us better understand pathophysiological mechanisms underlying cognitive symptoms in health and disease.

Functional neurological disorder is a feminist issue.

Functional neurological disorder (FND) is a common and disabling disorder, often misunderstood by clinicians. Although viewed sceptically by some, FND is a diagnosis that can be made accurately, based on positive clinical signs, with clinical features that have remained stable for over 100 years. Despite some progress in the last decade, people with FND continue to suffer subtle and overt forms of discrimination by clinicians, researchers and the public. There is abundant evidence that disorders perceived as primarily affecting women are neglected in healthcare and medical research, and the course of FND mirrors this neglect. We outline the reasons why FND is a feminist issue, incorporating historical and contemporary clinical, research and social perspectives. We call for parity for FND in medical education, research and clinical service development so that people affected by FND can receive the care they need.

Functional neurological disorder is common in patients attending chronic pain clinics.

BACKGROUND AND PURPOSE: Chronic pain is a common comorbidity in those with functional neurological disorder (FND); however, the prevalence and characteristics of FND in those with chronic pain is unknown. METHODS: A retrospective electronic records review was made of consecutive new patients attending a chronic pain clinic of a regional service. Clinical features, medication for and outcome of chronic pain, any lifetime diagnoses of functional disorders, FND, and psychiatric disorders, and undiagnosed neurological symptoms were recorded. RESULTS: Of 190 patients attending the chronic pain clinic, 32 (17%) had a lifetime diagnosis of FND and an additional 11 (6%) had undiagnosed neurological symptoms. Pain patients with comorbid FND were more likely to have chronic primary pain (88% with FND, 44% without FND, p < 0.0001), widespread chronic primary pain (53%, 15%, p < 0.00001), and depression (84%, 52%, p < 0.005) and less likely to have a pain-precipitating event (19% vs. 56%, p < 0.001). However, there was no significant difference between these patients in opiate prescription, benzodiazepine prescription, or pain outcome. CONCLUSIONS: This first study of FND in a chronic pain patient population found a remarkably high prevalence of FND (17%) and is possibly an underestimation. The size of the overlap indicates that FND and chronic pain research fields are likely to have a lot to learn from each other.

Performance validity tests in nonlitigant patients with functional motor disorder.

BACKGROUND AND PURPOSE: Performance validity tests (PVTs) are used in neuropsychological assessments to detect patterns of performance suggesting that the broader evaluation may be an invalid reflection of an individual's abilities. Data on functional motor disorder (FMD) are currently poor and conflicting. We aimed to examine the rate of failure on three different PVTs of nonlitigant, non-compensation-seeking FMD patients, and we compared their performance to that of healthy controls and controls asked to simulate malingering (healthy simulators). METHODS: We enrolled 29 nonlitigant, non-compensation-seeking patients with a clinical diagnosis of FMD, 29 healthy controls, and 29 healthy simulators. Three PVTs, the Coin in the Hand Test (CIH), the Rey 15-Item Test (REY), and the Finger Tapping Test (FTT), were employed. RESULTS: Functional motor disorder patients showed low rates of failure on the CIH and REY (7% and 10%, respectively) and slightly higher rates on the FTT (15%, n = 26), which implies a motor task. Their performance was statistically comparable to that of healthy controls but statistically different from that of healthy simulators (p < 0.001). Ninety-three percent of FMD patients, 7% of healthy simulators, and 100% of healthy controls passed at least two of the three tests. CONCLUSIONS: Performance validity test performance of nonlitigant, non-compensation-seeking patients with FMD ranged from 7% to 15%. Patients' performance was comparable to that of controls and significantly differed from that of simulators. This simple battery of three PVTs could be of practical utility and routinely used in clinical practice.

Functional cognitive disorders: clinical presentations and treatment approaches.

Functional cognitive disorders (FCDs) are a common cause of subjective and mild cognitive impairment. Isolated FCDs commonly present to the cognitive clinic, but examination of the nature of the symptoms suggests that they can also be understood as a transdiagnostic feature of many other conditions. This article examines methods of formulating the cognitive difficulties in order to identify treatment targets in people with FCDs.

Rates of Appropriate Treatment and Follow-Up Testing After a Gonorrhea and/or Chlamydia Infection in an Urban Network of Federally Qualified Health Center Systems.

BACKGROUND: Reinfection and partner transmission are common with Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT). We assessed treatment and follow-up laboratory testing for GC and CT and evaluated associations with patient- and system-level factors. METHODS: The analysis included positive GC and/or CT nucleic acid amplification test results from patients aged 14 to 24 years at a federally qualified health center system site in Denver, CO, from January 2018 to December 2019. Outcomes assessed include treatment within 14 days, HIV/syphilis testing within 6 months, and repeat GC and CT testing within 2 to 6 months. Bivariate and multivariable regression modeling assessed associated factors. RESULTS: Among 27,168 GC/CT nucleic acid amplification tests performed, 1.8% (484) were positive for GC and 7.8% (2125) were positive for CT. Within the assessed time frames, 87% (2275) of patients were treated, 54.1% (1411) had HIV testing, 50.1% (1306) had syphilis testing, and 39.9% (1040) had GC and CT retesting. Older patients were more likely to receive treatment (adjusted odds ratio 1.13; 95% confidence interval, 1.00-1.27; P = 0.05) than younger patients, whereas males were less likely to receive GC and CT retesting (adjusted odds ratio, 0.19; 95% confidence interval, 0.11-0.33; P < 0.001) than females. Patients treated on the day of testing were less likely to receive follow-up laboratory tests than those treated 2 to 14 days after. CONCLUSIONS: Although most patients received antibiotic treatment, only about half received HIV/syphilis testing and less than half received GC and CT retesting. It is critical to find innovative strategies to improve treatment and follow-up management of these infections to decrease complications, reduce transmission, and combat the rising rates of sexually transmitted infections.

Cognitive Behavioral Therapy: Principles, Science, and Patient Selection in Neurology.

Cognitive behavioral therapy (CBT) is a widely used therapeutic modality in general psychiatric practice. In this review, we consider its application to neurological disorders. We examine the basic framework of CBT-that symptoms, emotions, thoughts, and behaviors are all interrelated and that therapeutic interventions that lead to change in thoughts or behavior may have the potential to reduce symptoms or emotional distress. We also outline specific methodological issues to consider when reading or planning studies of CBT interventions, highlighting important topics pertaining to quality control, control group selection, dropouts, and generalizability. We then review the evidence base for CBT's use across a range of neurological disorders. In doing so, we highlight where there is a clear evidence base, and where it is a technique with potential. The review is targeted at a general neurology audience as introduction to the topic not as an advanced guide for expert practitioners.

Identifying functional cognitive disorder: a proposed diagnostic risk model.

BACKGROUND: Functional cognitive disorders (FCD) are an important differential diagnosis of neurodegenerative disease. The utility of suggested diagnostic features has not been prospectively explored in "real world" clinical populations. This study aimed to identify positive clinical markers of FCD. METHODS: Adults with cognitive complaints but not dementia were recruited from memory, neurology, and neuropsychiatry clinics. Participants underwent structured interview, Mini International Neuropsychiatric Interview, Montreal Cognitive Assessment, Luria 3-step, interlocking fingers, digit span and Medical Symptom Validity Test, Patient Health Questionnaire 15, Hospital Anxiety and Depression Scale, Multifactorial Memory Questionnaire, and Pittsburgh Sleep Quality Inventory. Potential diagnostic variables were tested against expert consensus diagnosis using logistic regression. RESULTS: FCD were identified in 31/49 participants. Participants with FCD were younger, spoke for longer when prompted "Tell me about the problems you've been having," and had more anxiety and depression symptoms and psychiatric diagnoses than those without FCD. There were no significant differences in sex, education, or cognitive scores. Younger age and longer spoken response predicted FCD diagnosis in a model which explained 74% of diagnostic variability and had an area under the curve (AUC) of 94%. CONCLUSIONS: A detailed description of cognitive failure is a sensitive and specific positive feature of FCD, demonstrating internal inconsistency between experienced and observed function. Cognitive and performance validity tests appear less helpful in FCD diagnosis. People with FCD are not "worried well" but often perform poorly on tests, and have more anxiety, depression, and physical symptoms than people with other cognitive disorders. Identifying diagnostic profiles is an important step toward parity of esteem for FCDs, as differential diagnoses of neurodegenerative disease and an independent target for clinical trials.

The frequency and framing of cognitive lapses in healthy adults.

OBJECTIVE: Many people present to health services with concern about cognitive symptoms. In a significant proportion those symptoms are not the result of pathologically defined brain disease. In some they are part of a functional cognitive disorder (FCD). We assessed the frequency of cognitive lapses in a non-clinical sample in order to consider the utility of frequency of cognitive lapses in diagnosing cognitive disorders. METHODS: Healthy adults, who had never sought help for cognitive symptoms, completed a questionnaire, distributed via social media, about self-evaluation of cognitive function, frequency of cognitive lapses, and use of memory aids, including Schmitdke and Metternich's functional memory disorder (FMD) inventory. RESULTS: One hundred and twenty-four adults, aged 18-59 (median 23), most with further or higher education, responded. Thirty-one (25%) reported "fair" or "poor" memory. Forty-eight (39%) reported memory worse than 5 years ago, and 30 (24%) reported memory worse than others the same age. Participants endorsed a mean 13/18 specific cognitive lapses at least monthly. One hundred and eleven (89%) scored ≥4, the suggested cutoff for the FMD inventory. CONCLUSIONS: Cognitive lapses described in FCDs are common in highly educated adults. The high frequency of lapses in this healthy population suggests self-reported frequency of lapses alone cannot discriminate FCDs from "normal" experiences. Further research is required to clarify the role of abnormal metacognition in FCD. Better understanding of the factors moderating subjective interpretation of cognitive failures will also aid development of better clinical risk-stratification methods in people concerned about future dementia.

Management of functional communication, swallowing, cough and related disorders: consensus recommendations for speech and language therapy.

Communication problems (eg, dysphonia, dysfluency and language and articulation disorders), swallowing disorders (dysphagia and globus), cough and upper airway symptoms, resulting from functional neurological disorder (FND), are commonly encountered by speech and language professionals. However, there are few descriptions in the literature of the most effective practical management approaches. This consensus document aims to provide recommendations for assessment and intervention that are relevant to both adults and young people. An international panel of speech and language professionals with expertise in FND were approached to take part. Participants responded individually by email to a set of key questions regarding best practice for assessment and interventions. Next, a video conference was held in which participants discussed and debated the answers to these key questions, aiming to achieve consensus on each issue. Drafts of the collated consensus recommendations were circulated until consensus was achieved. FND should be diagnosed on the basis of positive clinical features. Speech and language therapy for FND should address illness beliefs, self-directed attention and abnormal movement patterns through a process of education, symptomatic treatment and cognitive behavioural therapy within a supportive therapeutic environment. We provide specific examples of these strategies for different symptoms. Speech and language professionals have a key role in the management of people with communication and related symptoms of FND. It is intended that these expert recommendations serve as both a practical toolkit and a starting point for further research into evidence-based treatments.

Functional cognitive disorder: dementia's blind spot.

An increasing proportion of cognitive difficulties are recognized to have a functional cause, the chief clinical indicator of which is internal inconsistency. When these symptoms are impairing or distressing, and not better explained by other disorders, this can be conceptualized as a cognitive variant of functional neurological disorder, termed functional cognitive disorder (FCD). FCD is likely very common in clinical practice but may be under-diagnosed. Clinicians in many settings make liberal use of the descriptive term mild cognitive impairment (MCI) for those with cognitive difficulties not impairing enough to qualify as dementia. However, MCI is an aetiology-neutral description, which therefore includes patients with a wide range of underlying causes. Consequently, a proportion of MCI cases are due to non-neurodegenerative processes, including FCD. Indeed, significant numbers of patients diagnosed with MCI do not 'convert' to dementia. The lack of diagnostic specificity for MCI 'non-progressors' is a weakness inherent in framing MCI primarily within a deterministic neurodegenerative pathway. It is recognized that depression, anxiety and behavioural changes can represent a prodrome to neurodegeneration; empirical data are required to explore whether the same might hold for subsets of individuals with FCD. Clinicians and researchers can improve study efficacy and patient outcomes by viewing MCI as a descriptive term with a wide differential diagnosis, including potentially reversible components such as FCD. We present a preliminary definition of functional neurological disorder-cognitive subtype, explain its position in relation to other cognitive diagnoses and emerging biomarkers, highlight clinical features that can lead to positive diagnosis (as opposed to a diagnosis of exclusion), and red flags that should prompt consideration of alternative diagnoses. In the research setting, positive identifiers of FCD will enhance our recognition of individuals who are not in a neurodegenerative prodrome, while greater use of this diagnosis in clinical practice will facilitate personalized interventions.

Suspecting dementia: canaries, chameleons and zebras.

The early and accurate diagnosis of dementia is more important than ever before but remains challenging. Dementia is increasingly the business of neurologists and, with ageing populations worldwide, will become even more so in future. Here we outline a practical, symptom-led, bedside approach to suspecting dementia and its likely diagnosis, inspired by clinical experience and based on recognition of characteristic syndromic patterns. We show how clinical intuition reflects underlying signature profiles of brain involvement by the diseases that cause dementia and suggest next steps that can be taken to define the diagnosis. We propose 'canaries' that provide an early warning signal of emerging dementia and highlight the 'chameleons' that disguise or mimic this, as well as the 'zebras' that herald a rare (and sometimes curable) diagnostic opportunity.

Performance validity test failure in clinical populations-a systematic review.

Performance validity tests (PVTs) are widely used in attempts to quantify effort and/or detect negative response bias during neuropsychological testing. However, it can be challenging to interpret the meaning of poor PVT performance in a clinical context. Compensation-seeking populations predominate in the PVT literature. We aimed to establish base rates of PVT failure in clinical populations without known external motivation to underperform. We searched MEDLINE, EMBASE and PsycINFO for studies reporting PVT failure rates in adults with defined clinical diagnoses, excluding studies of active or veteran military personnel, forensic populations or studies of participants known to be litigating or seeking disability benefits. Results were summarised by diagnostic group and implications discussed. Our review identified 69 studies, and 45 different PVTs or indices, in clinical populations with intellectual disability, degenerative brain disease, brain injury, psychiatric disorders, functional disorders and epilepsy. Various pass/fail cut-off scores were described. PVT failure was common in all clinical groups described, with failure rates for some groups and tests exceeding 25%. PVT failure is common across a range of clinical conditions, even in the absence of obvious incentive to underperform. Failure rates are no higher in functional disorders than in other clinical conditions. As PVT failure indicates invalidity of other attempted neuropsychological tests, the finding of frequent and unexpected failure in a range of clinical conditions raises important questions about the degree of objectivity afforded to neuropsychological tests in clinical practice and research.

Testing the 'seizure scaffold': What can experimental simulation tell us about functional seizures?

INTRODUCTION: It has been suggested for over 100 years that patterns of neurological symptoms and signs in functional neurological disorders may be shaped at a neural level by underlying ideas or preconceptions how neurological symptoms present. This study used experimental simulation to probe ideas about seizures in healthy volunteers, with a view to compare with features commonly observed in functional and epileptic seizure disorders. METHODS: Sixty healthy volunteers were instructed to simulate an epileptic seizure. The episodes were video-recorded and assessed by three qualified markers for the presence of clinical features commonly observed in functional seizures (FS), epileptic seizures, and syncope. RESULTS: Simulated seizures were hyperkinetic (83%), hypokinetic (7%), or staring (10%). Fifty-two percent had their eyes open and 45% eyes closed. Tremor was observed in 70%, while clonic jerking was only present in 17%. The majority of volunteers maintained a normal or floppy body posture. Head shaking side-to-side was observed in 38%, while guttural cries, stertorous breathing, tearfulness, and hyperventilation were absent in all volunteers. DISCUSSION: Our results suggest that simulated seizures not only resemble FS more closely than epileptic seizures but also show some important differences. Subjective seizure experiences in people with FS, not captured by this experimental simulation, remain a core determinant of semiology.

I think, therefore I forget - using experimental simulation of dementia to understand functional cognitive disorders.

BACKGROUND: Symptoms of functional neurological disorder have traditionally been thought to depend, in part, on patients' ideas about symptoms rather than on the rules of pathophysiology. The possibility that functional cognitive symptoms might similarly reflect ideas of dementia has not been explored. We aimed to assess beliefs, through performance, about symptoms of dementia in healthy non-medical adults with the intention of identifying potential markers of functional cognitive disorders. METHODS: Healthy volunteers were asked to simulate symptoms of mild dementia during testing with the Montreal Cognitive Assessment (MoCA), coin-in-hand forced-choice test, short digit span trials, Luria 3-step test and interlocking finger test. Family history of dementia was recorded. RESULTS: In 50 participants aged 18-27, simulating dementia, mean MoCA score was 16 (SD 5.5, range 5-26). Delayed recall was the most frequently failed item (100%) and cube drawing least frequently failed (42%). Twenty-six percent failed forward three-digit span and 36% failed reverse two-digit span. On the coin-in-hand test, 32% scored at or below chance level. Inconsistent response patterns were common. CONCLUSIONS: Cognitively healthy young adults simulating mild dementia perform similarly to older adults with mild dementia, demonstrating beliefs that dementia is associated with significant global impairment, including attention, motor function, and letter vigilance, but preservation of cube drawing. Inconsistent response patterns were common. Contrary to expectation, family history of dementia did not influence performance. Two and three digit span showed particular promise as a bedside test for simulation. Further investigation will establish whether similar patterns of results are produced in individuals with functional cognitive symptoms.

Management of mild traumatic brain injury.

Mild traumatic brain injury (TBI) is common and associated with a range of diffuse, non-specific symptoms including headache, nausea, dizziness, fatigue, hypersomnolence, attentional difficulties, photosensitivity and phonosensitivity, irritability and depersonalisation. Although these symptoms usually resolve within 3 months, 5%-15% of patients are left with chronic symptoms. We argue that simply labelling such symptoms as 'postconcussional' is of little benefit to patients. Instead, we suggest that detailed assessment, including investigation, both of the severity of the 'mild' injury and of the individual symptom syndromes, should be used to tailor a rehabilitative approach to symptoms. To complement such an approach, we have developed a self-help website for patients with mild TBI, based on neurorehabilitative and cognitive behavioural therapy principles, offering information, tips and tools to guide recovery: www.headinjurysymptoms.org.

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.