Motor assessment of X-linked dystonia parkinsonism via machine-learning-based analysis of wearable sensor data.

X-linked dystonia parkinsonism (XDP) is a neurogenetic combined movement disorder involving both parkinsonism and dystonia. Complex, overlapping phenotypes result in difficulties in clinical rating scale assessment. We performed wearable sensor-based analyses in XDP participants to quantitatively characterize disease phenomenology as a potential clinical trial endpoint. Wearable sensor data was collected from 10 symptomatic XDP patients and 3 healthy controls during a standardized examination. Disease severity was assessed with the Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS) and Burke-Fahn-Marsden dystonia scale (BFM). We collected sensor data during the performance of specific MDS-UPDRS/BFM upper- and lower-limb motor tasks, and derived data features suitable to estimate clinical scores using machine learning (ML). XDP patients were at varying stages of disease and clinical severity. ML-based algorithms estimated MDS-UPDRS scores (parkinsonism) and dystonia-specific data features with a high degree of accuracy. Gait spatio-temporal parameters had high discriminatory power in differentiating XDP patients with different MDS-UPDRS scores from controls, XDP freezing of gait, and dystonic/non-dystonic gait. These analyses suggest the feasibility of using wearable sensor data for deriving reliable clinical score estimates associated with both parkinsonian and dystonic features in a complex, combined movement disorder and the utility of motion sensors in quantifying clinical examination.

Objective Assessment of Upper-Extremity Motor Functions in Spinocerebellar Ataxia Using Wearable Sensors.

The study presents a novel approach to objectively assessing the upper-extremity motor symptoms in spinocerebellar ataxia (SCA) using data collected via a wearable sensor worn on the patient's wrist during upper-extremity tasks associated with the Assessment and Rating of Ataxia (SARA). First, we developed an algorithm for detecting/extracting the cycles of the finger-to-nose test (FNT). We extracted multiple features from the detected cycles and identified features and parameters correlated with the SARA scores. Additionally, we developed models to predict the severity of symptoms based on the FNT. The proposed technique was validated on a dataset comprising the seventeen (n = 17) participants' assessments. The cycle detection technique showed an accuracy of 97.6% in a Bland-Altman analysis and a 94% accuracy (F1-score of 0.93) in predicting the severity of the FNT. Furthermore, the dependency of the upper-extremity tests was investigated through statistical analysis, and the results confirm dependency and potential redundancies in the upper-extremity SARA assessments. Our findings pave the way to enhance the utility of objective measures of SCA assessments. The proposed wearable-based platform has the potential to eliminate subjectivity and inter-rater variabilities in assessing ataxia.

Assessment of gait and balance impairment in people with spinocerebellar ataxia using wearable sensors.

OBJECTIVE: To explore the use of wearable sensors for objective measurement of motor impairment in spinocerebellar ataxia (SCA) patients during clinical assessments of gait and balance. METHODS: In total, 14 patients with genetically confirmed SCA (mean age 61.6 ± 8.6 years) and 4 healthy controls (mean age 49.0 ± 16.4 years) were recruited through the Massachusetts General Hospital (MGH) Ataxia Center. Participants donned seven inertial sensors while performing two independent trials of gait and balance assessments from the Scale for the Assessment and Rating of Ataxia (SARA) and Brief Ataxia Rating Scale (BARS2). Univariate analysis was used to identify sensor-derived metrics from wearable sensors that discriminate motor function between the SCA and control groups. Multivariate linear regression models were used to estimate the subjective in-person SARA/BARS2 ratings. Spearman correlation coefficients were used to evaluate the performance of the model. RESULTS: Stride length variability, stride duration, cadence, stance phase, pelvis sway, and turn duration were different between SCA and controls (p < 0.05). Similarly, sway and sway velocity of the ankle, hip, and center of mass differentiated SCA and controls (p < 0.05). Using these features, linear regression models showed moderate-to-strong correlation with clinical scores from the in-person rater during SARA assessments of gait (r = 0.73, p = 0.003) and stance (r = 0.90, p < 0.001) and the BARS2 gait assessment (r = 0.74, p = 0.003). CONCLUSION: This study demonstrates that sensor-derived metrics can potentially be used to estimate the level of motor impairment in patient with SCA quickly and objectively. Thus, digital biomarkers from wearable sensors have the potential to be an integral tool for SCA clinical trials and care.

Assessment of Emergency Department and Inpatient Use and Costs in Adult and Pediatric Functional Neurological Disorders.

Importance: There is limited information about health care use and costs in patients with functional neurological disorders (FNDs). Objective: To assess US emergency department (ED) and inpatient use and charges for FNDs. Design, Setting, and Participants: This economic evaluation used Healthcare Cost and Utilization Project data to assess all-payer (1) adult (age, ≥18 years) hospitalizations (2008-2017), (2) pediatric (age, 5-17 years) hospitalizations (2003, 2006, 2009, 2012, and 2016), and (3) adult and pediatric ED evaluations (2008-2017). International Classification of Diseases, Ninth Revision, Clinical Modification code 300.11 (conversion disorder) or 306.0 (musculoskeletal malfunction arising from mental factors) and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Clinical Modification codes for conversion disorder/functional neurological symptom disorder (F44.4 to F44.7) were used to conservatively define FNDs and to compare them with other neurological disorders that are associated with high levels of health care use. Analysis was performed between January 2019 and July 2020. Main Outcomes and Measures: Admission traits (eg, demographic characteristics of patients, length of stay, and discharge disposition) and hospital charges. Results: Compared with other neurological disorders in 2017, emergency FND evaluations of 36 359 adults (25 807 women [71.0%] and 3800 children (2733 girls [71.9%]) more frequently resulted in inpatient admissions (22 895 adult admissions [69.2% female] and 1264 pediatric admissions [73.4% ]). These FND admissions had a shorter mean (SEM) hospital length of stay (5.21 [0.15] days vs 6.03 [0.03] days, P < .001) but higher workup rates than admissions for comparable neurological diagnoses. Admissions for FNDs had low rates of inpatient physical therapy, occupational therapy, speech and language pathology, and psychiatric consultation. The total annual costs (a proxy for total costs in 2017 US dollars) were $1066 million (95% CI, $971-$1160 million) for adult FND inpatient charges in 2017 compared with $1241 million (95% CI, $1132-$1351 million) for anterior horn cell disease; $75 million (95% CI, $57-$92 million) for pediatric FND inpatient charges in 2012 compared with $86 million (95% CI, $63-$108 million) for demyelinating diseases; and $163 million (95% CI, $144-$182 million) for adult and pediatric ED visits in 2017 compared with $135 million (95% CI $111-$159 million) for refractory epilepsy. Total charges per admission for ED care of FNDs were higher than the other comparison groups in adults. Total costs and costs per admission for FNDs increased from 2008 to 2017 at a higher rate than that of other neurological disorders. Conclusions and Relevance: This economic evaluation found that the more than $1.2 billion and increasing annual costs for ED and inpatient care of FNDs were similar to other investigation-intensive and pharmacologically demanding neurological disorders. Unnecessary investigations and iatrogenic harm inflate costs at the expense of necessary but neglected psychiatric and rehabilitative treatments.

A Review and Expert Opinion on the Neuropsychiatric Assessment of Motor Functional Neurological Disorders.

Functional neurological (conversion) disorder (FND) is a prevalent and disabling condition at the intersection of neurology and psychiatry. Advances have been made in elucidating an emerging pathophysiology for motor FND, as well as in identifying evidenced-based physiotherapy and psychotherapy treatments. Despite these gains, important elements of the initial neuropsychiatric assessment of functional movement disorders (FND-movt) and functional limb weakness/paresis (FND-par) have yet to be established. This is an important gap from both diagnostic and treatment planning perspectives. In this article, the authors performed a narrative review to characterize clinically relevant variables across FND-movt and FND-par cohorts, including time course and symptom evolution, precipitating factors, medical and family histories, psychiatric comorbidities, psychosocial factors, physical examination signs, and adjunctive diagnostic tests. Thereafter, the authors propose a preliminary set of clinical content that should be assessed during early-phase patient encounters, in addition to identifying physical signs informing diagnosis and potential use of adjunctive tests for challenging cases. Although clinical history should not be used to make a FND diagnosis, characteristics such as acute onset, precipitating events (e.g., injury and surgery), and a waxing and waning course (including spontaneous remissions) are commonly reported. Active psychiatric symptoms (e.g., depression and anxiety) and ongoing psychosocial stressors also warrant evaluation. Positive physical examination signs (e.g., Hoover's sign and tremor entrainment) are key findings, as one of the DSM-5 diagnostic criteria. The neuropsychiatric assessment proposed emphasizes diagnosing FND by using "rule-in" physical signs while also considering psychiatric and psychosocial factors to aid in the development of a patient-centered treatment plan.

Functional (Psychogenic) Neurological Disorders: Assessment and Acute Management in the Emergency Department.

Functional neurological disorders (FND) are complex and prevalent neuropsychiatric conditions. Importantly, some patients with FND develop acute onset symptoms requiring emergency department (ED) evaluations. Historically, FND was a "rule-out" diagnosis, making assessment and management in the ED difficult. While the rapid triage of potential neurological emergencies remains the initial task, advancements have altered the approach to FND. FND is now a "rule-in" diagnosis based on validated neurological examination signs and semiological features. In this perspective article, we review signs and semiological features that can help guide the initial assessment of FND in the acute setting. Thereafter, we outline potential approaches to introduce a suspected diagnosis of FND to patients in the ED, while emphasizing the need for a comprehensive neurological evaluation. Physical and occupational therapy may be useful adjunct assessments in some individuals. Notably, clinicians in the ED setting are important members of the interdisciplinary approach to FND.

The Inpatient Assessment and Management of Motor Functional Neurological Disorders: An Interdisciplinary Perspective.

BACKGROUND: Motor functional neurologic disorders (FND)-previously termed "hysteria" and later "conversion disorder"-are exceedingly common and frequently encountered in the acute hospital setting. Despite their high prevalence, patients with motor FND can be challenging to diagnose accurately and manage effectively. To date, there is limited guidance on the inpatient approach to the neuropsychiatric evaluation of patients with functional (psychogenic) neurologic symptoms. OBJECTIVE: The authors outline an inpatient multidisciplinary approach, involving neurology, psychiatry, and physical therapy, for the assessment and acute inpatient management of motor FND. METHODS: A vignette of a patient with motor FND is presented followed by a discussion of general assessment principles. Thereafter, a detailed description of the neurologic and psychiatric assessments is outlined. Delivery of a "rule-in" diagnosis is emphasized and specific guidance for what can be accomplished postdiagnosis in the hospital is suggested. DISCUSSION: We encourage an interdisciplinary approach beginning at the early stages of the diagnostic assessment once an individual is suspected of having motor FND. CONCLUSIONS: Practical suggestions for the inpatient assessment of motor FND are presented. It is also important to individualize the diagnostic assessment. Future research should be conducted to test best practices for motor FND management in the acute inpatient hospital setting.