Reframing postconcussional syndrome as an interface disorder of neurology, psychiatry and psychology

A multidisciplinary approach to assessment and management of long COVID cognitive concerns

Cognitive dysfunction is a commonly reported feature of Long COVID (LC). With the overlap of assessment and treatment for cognitive concerns across multiple disciplines, coupled with current guidelines supporting interdisciplinary care, the aim of this clinically focused article is to provide a review of current guidelines and research related to assessment and interventions to address LC-related cognitive concerns within clinical practice from a multidisciplinary perspective, incorporating best practices for collaboration among Clinical Neuropsychologists, Rehabilitation Psychologists, and Speech-Language Pathologists. Current guidelines for assessment and interventions for cognitive functioning are provided, with clinical suggestions for best practices offered. Additional considerations related to diversity and variable patient presentations are identified. This article provides guidance based on current research and practice standards regarding the utilization of a multidisciplinary, collaborative approach to provide comprehensive assessment and treatment for individuals with LC-related cognitive concerns.

Promoting Growth in Behavioral Neurology: A Path Forward

Behavioral neurology & neuropsychiatry (BNNP) is a field that seeks to understand brain-behavior relationships, including fundamental brain organization principles and the many ways that brain structures and connectivity can be disrupted, leading to abnormalities of behavior, cognition, emotion, perception, and social cognition. In North America, BNNP has existed as an integrated subspecialty through the United Council for Neurologic Subspecialties since 2006. Nonetheless, the number of behavioral neurologists across academic medical centers and community settings is not keeping pace with increasing clinical and research demand. In this commentary, we provide a brief history of BNNP followed by an outline of the current challenges and opportunities for BNNP from the behavioral neurologist's perspective across clinical, research, and educational spheres. We provide a practical guide for promoting BNNP and addressing the shortage of behavioral neurologists to facilitate the continued growth and development of the subspecialty. We also urge a greater commitment to recruit trainees from diverse backgrounds so as to dismantle persistent obstacles that hinder inclusivity in BNNP-efforts that will further enhance the growth and impact of the subspecialty. With rapidly expanding diagnostic and therapeutic approaches across a range of conditions at the intersection of neurology and psychiatry, BNNP is well positioned to attract new trainees and expand its reach across clinical, research, and educational activities.

Functional Neurological Disorder Presenting After Concussion: A Retrospective Case Series

OBJECTIVE

Although a majority of individuals recover from a concussion within weeks of the index injury, a substantial minority of patients report persistent postconcussion symptoms. Some of these symptoms may reflect a diagnosis of functional neurological disorder (FND). The authors evaluated the relationship between persistent postconcussion symptoms and FND symptoms.

METHODS

In this retrospective chart review, the authors characterized demographic and clinical information from 50 patients with a confirmed diagnosis of FND whose functional neurological symptoms started after a concussion.

RESULTS

Patients who developed FND after a concussion had high rates of baseline risk factors for both persistent postconcussion symptoms and FND. After the concussive event, functional neurological symptoms presented abruptly or developed insidiously over time. Functional neurological symptoms ranged widely and included gait symptoms, seizures, speech and language symptoms, weakness, sensory symptoms, tremors, and vision and oculomotor symptoms.

CONCLUSIONS

Functional neurological symptoms can arise after a concussion. FND should be considered in the differential diagnosis of individuals presenting with neurological symptoms beginning after a concussion. By failing to recognize functional symptoms, clinicians may inadvertently reinforce negative health-related beliefs regarding a patient's injured brain.

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.

Longitudinal Associations Between Persistent Post-Concussion Symptoms and Blood Biomarkers of Inflammation and CNS-Injury After Mild Traumatic Brain Injury

The aim of our study was to investigate the biological underpinnings of persistent post-concussion symptoms (PPCS) at 3 months following mild traumatic brain injury (mTBI). Patients (n = 192, age 16-60 years) with mTBI, defined as Glasgow Coma Scale (GCS) score between 13 and 15, loss of consciousness (LOC) <30 min, and post-traumatic amnesia (PTA) <24 h were included. Blood samples were collected at admission (within 72 h), 2 weeks, and 3 months. Concentrations of blood biomarkers associated with central nervous system (CNS) damage (glial fibrillary acidic protein [GFAP], neurofilament light [NFL], and tau) and inflammation (interferon gamma [IFNγ], interleukin [IL]-8, eotaxin, macrophage inflammatory protein-1-beta [MIP]-1β, monocyte chemoattractant protein [MCP]-1, interferon-gamma-inducible protein [IP]-10, IL-17A, IL-9, tumor necrosis factor [TNF], basic fibroblast growth factor [FGF]-basic platelet-derived growth factor [PDGF], and IL-1 receptor antagonist [IL-1ra]) were obtained. Demographic and injury-related factors investigated were age, sex, GCS score, LOC, PTA duration, traumatic intracranial finding on magnetic resonance imaging (MRI; within 72 h), and extracranial injuries. Delta values, that is, time-point differences in biomarker concentrations between 2 weeks minus admission and 3 months minus admission, were also calculated. PPCS was assessed with the British Columbia Post-Concussion Symptom Inventory (BC-PSI). In single variable analyses, longer PTA duration and a higher proportion of intracranial findings on MRI were found in the PPCS group, but no single biomarker differentiated those with PPCS from those without. In multi-variable models, female sex, longer PTA duration, MRI findings, and lower GCS scores were associated with increased risk of PPCS. Inflammation markers, but not GFAP, NFL, or tau, were associated with PPCS. At admission, higher concentrations of IL-8 and IL-9 and lower concentrations of TNF, IL-17a, and MCP-1 were associated with greater likelihood of PPCS; at 2 weeks, higher IL-8 and lower IFNγ were associated with PPCS; at 3 months, higher PDGF was associated with PPCS. Higher delta values of PDGF, IL-17A, and FGF-basic at 2 weeks compared with admission, MCP-1 at 3 months compared with admission, and TNF at 2 weeks and 3 months compared with admission were associated with greater likelihood of PPCS. Higher IL-9 delta values at both time-point comparisons were negatively associated with PPCS. Discriminability of individual CNS-injury and inflammation biomarkers for PPCS was around chance level, whereas the optimal combination of biomarkers yielded areas under the curve (AUCs) between 0.62 and 0.73. We demonstrate a role of biological factors on PPCS, including both positive and negative effects of inflammation biomarkers that differed based on sampling time-point after mTBI. PPCS was associated more with acute inflammatory processes, rather than ongoing inflammation or CNS-injury biomarkers. However, the modest discriminative ability of the models suggests other factors are more important in the development of PPCS.

Toward a Unified Classification System for Brain-Mind Disorders: Putting Calls for Integrated Clinical Neuroscience Into Action

Dividing the brain-mind into the specialized fields of neurology and psychiatry has produced many granular advantages, but these silos have imposed barriers to comprehensively understanding and contextualizing the fundamentals governing mental life and its maladies. Scientific inquiry into these fundamentals cannot reach its full potential without interdigitating the boundaries of two specialties of the same organ for both scholarship and clinical practice. We propose that to truly integrate disorders of the brain and the mind for research and clinical care, we must carefully reexamine the classification of its disorders (nosology) as an instrument to develop a coherent pathological and psychological framework. We call on professional organizations from neurology, psychiatry, behavioral neurology, neuropsychiatry, neuropsychology, and other relevant subspecialties (eg, geriatric psychiatry) to convene a multidisciplinary task force to define the current classification principles of their subspecialties and work toward developing an integrated nosology. The effect of a shared classification system, which we acknowledge is a difficult proposition philosophically and politically, would have transformative potential across educational, clinical, scientific, programmatic, and sociocultural realms. If accomplished, this initiative would provide a definitive step toward reducing stigma (and promoting reimbursement parity) for the full spectrum of complex brain disorders (regardless of traditional neurologic vs psychiatric conceptualizations).

Developing a Curriculum for Functional Neurological Disorder in Neurology Training: Questions and Answers

Functional neurologic disorder (FND) is a common condition for which neurology residents often receive little to no formal teaching. Using a question-and-answer format, this article puts forward a case for why an FND curriculum is needed and aims to provide guidance on possible curricular content including medical knowledge, clinical skills, communication, and team-based collaboration. The authors also discuss methods for teaching and evaluating this knowledge and associated clinical skills, linking this to current Accreditation Council for Graduate Medical Education neurology milestones. Finally, the authors consider how to better engage and energize neurology trainees around this underserved yet challenging patient population.

Functional Gait Disorders: Clinical presentations, Phenotypes and Implications for treatment

BACKGROUND

Functional Gait Disorders (FGD) are a common presentation of motor-Functional Neurological Disorders (motor-FND) that affect walking ability.

AIM

To provide a narrative review of the current literature on FGD.

METHODS

A narrative overview of published literature was undertaken, based on a systematic search of relevant databases, authoritative texts and citation tracking.

RESULTS

FGD is multidimensional and disabling, with numerous phenotypes described in the literature, including 'knee buckling,' 'astasia-abasia' and 'excessive slowness.' Motor symptoms such as weakness or tremor, and non-motor symptoms, such as pain and fatigue may contribute to the disability and distress in FGD. Phenotypic features and clinical signs are seen in FGD that demonstrate inconsistency and incongruity with structural disease. A limited number of treatment studies have specifically focussed on FGD, however, reporting of outcomes from motor-FND cohorts has demonstrated short and long-term improvements in walking ability through multidisciplinary rehabilitation.

CONCLUSIONS

The relative contribution of motor and non-motor symptoms in FGD remains unknown, but it is likely that non-motor symptoms increase the illness burden and should be considered during assessment and treatment. Recommended treatment for FGD involves multidisciplinary rehabilitation, but optimum treatment elements are yet to be determined.

Review on the Role of Salivary Biomarkers in the Diagnosis of Mild Traumatic Brain Injury and Post-Concussion Syndrome

(1) Background: While mild traumatic brain injuries (TBIs) are a major public health issue, post-concussion syndrome (PCS) remains a controversial entity. In both cases, the clinical diagnosis is mainly based on the symptoms and brain imaging evaluation. The current molecular biomarkers were described from blood and cerebrospinal fluid (CSF), yet both fluid collection methods are invasive. Saliva could be preferred in molecular diagnosis due to its non-invasive and non-expensive methods of acquisition, transport, and samples processing. (2) Objectives: In the present study, we aimed to review the latest developments in salivary biomarkers and their potential role in diagnosing mild TBIs, and PCS. (3) Results: In TBIs and PCS, a few novel studies focusing on salivary biomarkers have emphasized their importance in diagnosis. The previous studies mainly focused on micro RNAs, and only a few on extracellular vesicles, neurofilament light chain, and S100B. (4) Conclusions: The combination between salivary biomarkers, clinical history and examination, self-reported symptoms, and cognitive/balance testing can provide a non-invasive alternative diagnostic methodology, as compared to the currently approved plasma and cerebrospinal fluid biomarkers.

Management of Psychological Complications Following Mild Traumatic Brain Injury

PURPOSE OF REVIEW

It has been clear for decades that psychological factors often contribute to mild traumatic brain injury (mTBI) outcome, but an emerging literature has begun to clarify which specific factors are important, when, for whom, and how they impact recovery. This review aims to summarize the contemporary evidence on psychological determinants of recovery from mTBI and its implications for clinical management.

RECENT FINDINGS

Comorbid mental health disorders and specific illness beliefs and coping behaviors (e.g., fear avoidance) are associated with worse recovery from mTBI. Proactive assessment and intervention for psychological complications can improve clinical outcomes. Evidence-based treatments for primary mental health disorders are likely also effective for treating mental health disorders after mTBI, and can reduce overall post-concussion symptoms. Broad-spectrum cognitive-behavioral therapy may modestly improve post-concussion symptoms, but tailoring delivery to individual psychological risk factors and/or symptoms may improve its efficacy. Addressing psychological factors in treatments delivered primarily by non-psychologists is a promising and cost-effective approach for enhancing clinical management of mTBI. Recent literature emphasizes a bio-psycho-socio-ecological framework for understanding mTBI recovery and a precision rehabilitation approach to maximize recovery. Integrating psychological principles into rehabilitation and tailoring interventions to specific risk factors may improve clinical management of mTBI.

Relationship between psychosocial and psychiatric risk factors and poor long-term outcome following mild traumatic brain injury: A systematic review

BACKGROUND AND PURPOSE

Mild traumatic brain injury (mTBI) has an estimated worldwide incidence of >60 million per year, and long-term persistent postconcussion symptoms (PPCS) are increasingly recognized as being predicted by psychosocial variables. Patients at risk for PPCS may be amenable to closer follow-up to treat modifiable symptoms and prevent chronicity. In this regard, similarities seem to exist with psychosocial risk factors for chronicity in other health-related conditions. However, as opposed to other conditions, no screening instruments exist for mTBI.

METHODS

A systematic search of the literature on psychological and psychiatric predictors of long-term symptoms in mTBI was performed by two independent reviewers using PubMed, Embase, and Web of Science.

RESULTS

Fifty papers were included in the systematic analysis. Anxiety, depressive symptoms, and emotional distress early after injury predict PPCS burden and functional outcome up to 1 year after injury. In addition, coping styles and preinjury psychiatric disorders and mental health also correlate with PPCS burden and functional outcome. Associations between PPCS and personality and beliefs were reported, but either these effects were small or evidence was limited.

CONCLUSIONS

Early psychological and psychiatric factors may negatively interact with recovery potential to increase the risk of chronicity of PPCS burden after mTBI. This opens opportunities for research on screening tools and early intervention in patients at risk.