Integrating Digital and Ancillary Technologies in the Modern Clinical Evaluation of Chorea

Chorea is a complex hyperkinetic movement disorder characterized by its random, unpredictable, continuously ongoing movements that can affect various body parts. Its name, derived from the Greek word for “dance,” reflects its dance‐like movements, often manifest as restless or fidgety. ¹ A notable feature of chorea is motor impersistence, which refers to the difficulty in maintaining voluntary muscle contraction and is exemplified by symptoms such as a darting tongue and a milkmaid's grip. ¹

Despite its distinctive symptoms, chorea presents significant diagnostic challenges, especially when co‐occurring with other hyperkinetic movements. Monitoring changes in severity and guiding treatment are also difficult, largely due to the limitations of traditional clinical assessments. Conventional clinical assessments of chorea are limited by subjectivity, inter‐examiner variability, limited quantification, and the momentary nature of evaluations, which may fail to capture the fluctuating nature of symptoms. Herein, we discuss the challenges of traditional clinical methods for evaluating chorea, the potential advantages of digital and ancillary tools in overcoming these challenges, and future perspectives on their development and implementation.

Advantages and Limitations of Traditional Clinical Evaluation of Chorea

To date, conventional clinical assessments of chorea, which are primarily based on observational techniques and semi‐quantitative rating scales, remain widely used. ² Their ability to engage holistically with patients further enhances the diagnostic process. Through direct interaction, clinicians can evaluate non‐verbal cues, emotional states, and other subtle indicators that remain challenging for digital systems to capture accurately. ³ Furthermore, the traditional approach is inherently adaptable; physicians can modify treatment strategies in real time based on patient feedback or unexpected findings during examinations. Another significant advantage of traditional methods is their reliability in low‐tech settings. In contrast to automated systems that rely on sophisticated technology and infrastructure, human‐led approaches are accessible and effective in environments with limited technological resources and underserved areas. ⁴

However, the traditional clinical evaluation of chorea has several limitations that may hinder accurate recognition, diagnosis, severity monitoring, and effective management. Validated rating scales are notably only available for a limited number of choreiform disorders (Table 1). There is no standardized rating scale recommended for chorea of unspecified etiology. Another major concern is the variability in clinical presentation and the subjective nature of observer ratings, which can lead to inconsistencies between raters and within the same rater over time. Subtle or occasional movements might also be overlooked during brief clinical evaluations conducted in a clinic setting. For instance, while widely used, the Unified Huntington's Disease Rating Scale (UHDRS) ⁵ shows variability in interrater reliability, particularly for symptoms such as ocular movements and dystonia, which can complicate the accurate monitoring of disease progression. ² The scales available for HD may also not be sensitive enough to detect minor changes over time or in pre‐manifest HD.

TABLE 1.

Currently available rating scales and digital tools to evaluate chorea

Rating scales to evaluate chorea
Choreiform Disorder	Rating Scale/Available	Use/Application	Reference
Huntington's Disease	Unified Huntington's Disease Rating Scale (UHDRS)	Developed primarily for Huntington's disease Composed of six sections: Motor, Cognitive, Behavioral, Functional Assessment, Independence Scale, and Total Functional Capacity	5
	Unified Huntington's Disease Rating Scale‐Total Motor Score (UHDRS‐TMS)	Motor Section of the UHDRS Includes Total Maximal Chorea (TMC) score, which assesses chorea severity in seven body regions (face, mouth, arms, and legs)	5
	Marsden and Quinn Chorea Severity Scale	An expert‐based estimation of chorea severity across different body parts Includes five items evaluating speech, gait, postural stability, manual dexterity, and overall chorea severity	6
	Quantified Neurological Examination	Standardized clinician‐rated scale specifically developed to assess motor dysfunction and disease progression in HD Has two core subscales: chorea scale, motor impairment scale An eye‐movement subscale is also included	7
	Huntington's disease health‐related quality of life questionnaire (HDQoL)	Patient‐derived instrument designed to measure the health‐related quality of life in individuals with HD Consists of four primary domains: Physical‐ Functional, Cognitive, Mood‐Self, Worries	8
Sydenham's Chorea (SC)	Universidade Federal de Minas Gerais Sydenham's Chorea Rating Scale (USCRS)	Designed to evaluate motor function, behavioral abnormalities, and activities of daily living in patients with SC and related disorders	9
Tardive Dyskinesia (TD)	Abnormal Involuntary Movement Scale (AIMS)	Developed specifically to measure and monitor TD, but also used in other disorders (eg, HD) Evaluates (1) involuntary movements across various body regions; (2) global judgments on the severity of movements, incapacitation caused by them, and the patient's awareness or distress; (3) dental status	10

Digital tools to evaluate chorea
Choreiform disorder	Digital tool	Use /Application	Current technology adoption level	References
Huntington's Disease (HD)	Wearable Sensors (eg, accelerometer‐based devices on the wrists, trunk, and limbs)	Wearable sensors can be combined with machine learning algorithms to track limb function and predict clinical scores for HD patients. Chorea Index‐ quantifies truncal chorea by measuring the amplitude of jerky movements	Used in phase III trials; has undergone multi‐center validation studies; needs standardized protocols and regulatory approvals before widespread clinical utilization	11, 12, 13, 14, 15, 16, 17
	BioDigit Speech Software	Digital speech assessments to detect and monitor HD by analyzing audio recordings of participants performing reading and counting tasks.	An academic research tool in a single center, with promising future clinical application; needs validation in larger and more diverse populations	18
	GEORGE Smartphone Application	Captures upper body movements using a smartphone and smartwatch while participants hold the phone still in an outstretched arm; designed to evaluate multiple aspects of HD, including chorea severity, balance, gait, and voice.	Academic research tool, evaluated in a pilot study to assess its feasibility and effectiveness for Huntington's disease symptom monitoring	19
	HDQLIFE Chorea Computer Adaptive Test (CAT)	A self‐reported tool to capture the subjective experience of chorea and its impact on daily life. It complements objective measures with strong psychometric properties.	Used in research studies and clinical trials, with potential for broader clinical deployment	20
	Roche HD Digital Monitoring Platform	A smartphone‐ and smartwatch‐based system designed to assess motor, cognitive, behavioral, and functional domains in HD. Includes active tests and passive monitoring of gait, chorea, and activity levels; validated in clinical trials for HD.	Currently limited to academic and clinical research studies; validated in multi‐center studies; not yet clinically deployed for routine clinical use	21

Additionally, traditional assessments often fail to capture the dynamic and fluctuating characteristics of chorea, which can vary significantly over time and even within a single day. This limitation is particularly problematic in HD, where chorea can worsen over time, leading to functional impairments such as falls, poor dexterity, and difficulty swallowing. ²² Traditional methods typically involve momentary evaluations in the clinic rather than continuous monitoring, which can result in underestimating the severity of chorea and its impact on patients’ lives. ²² Besides, the clinic setting may influence a patient's movement patterns due to stress or the observer effect, potentially leading to behaviors that do not accurately reflect their typical actions in daily life. Moreover, self‐reported measures of chorea have been lacking, which is crucial for understanding the impact of chorea on health‐related quality of life (HDQLIFE), affecting daily functioning and social interactions. ^{22 , 23} Self‐reported data can provide valuable insights into how chorea affects daily activities and quality of life from the patient's perspective, complementing clinical assessments and offering a more comprehensive understanding of the condition. The modern assessment encompasses digitally administered patient‐reported outcomes and quality of life measures through patient portals, natural language processing of free‐text symptom descriptions, and blockchain‐secured data sharing across care teams, enabling the real‐time integration of data with sensor‐derived metrics.

Currently Available Digital Sensors and Tools for Evaluating Chorea

In the context of HD, various digital tools have proven effective for assessing chorea, offering a more comprehensive and objective evaluation of this intricate motor symptom compared to traditional rating scales, including those used in recent clinical trials (Table 1). ^{11 , 24} While most digital tools for chorea are currently validated for symptom monitoring and quantification, there is emerging evidence for diagnostic potential, such as wearable sensor kinematic analysis distinguishing chorea from other hyperkinetic movements. ¹² Wearable devices and smartphone‐based experimental digital platforms are being investigated for hand movement tracking, voice analysis, and computer vision gait assessment to support diagnostic workflows, but key gaps remain: most tools are validated only in HD, often with small research cohorts, and lack standardized diagnostic cutoffs, limiting immediate clinical use. ^{12 , 13 , 18 , 25}

Wearable sensors have been mainly instrumental in longitudinal studies, where they have been used to quantify truncal chorea through a novel Chorea Index. ¹⁴ This index measures the amplitude of jerky movements in the trunk region, providing a reliable and objective assessment of chorea severity. This is particularly important among individuals with HD, where there is substantial variability in truncal chorea, which may even be present in the prodromal stages of the disease. ¹¹ Smartphone applications, such as GEORGE, have further expanded the scope of chorea evaluation by assessing multiple facets of HD, including chorea, balance, gait, and voice. ¹⁹ These applications are versatile and suitable for both clinical and home settings, thereby enhancing the accessibility and convenience of chorea assessments. By facilitating real‐time data collection, these tools provide valuable insights into how chorea affects daily activities and quality of life. Moreover, studies have explored the potential of using chorea prediction models based on data from smartphones and wearable devices. These models have shown promising sensitivity and specificity in detecting chorea, which can assist in identifying patterns of chorea and predicting its occurrence. This predictive capability may aid in developing more proactive management strategies for patients with HD. ¹⁵ The HDQLIFE Chorea computer adaptive test (CAT) has been developed to address the need for self‐reported measures of chorea. ²⁰ It was created through rigorous measurement standards, including qualitative data collection, cognitive interviews, and factor analyses, resulting in a 6‐item short form with strong psychometric properties. The HDQLIFE Chorea CAT offers a valuable tool for capturing the subjective experience of chorea and its impact on daily life, complementing the objective assessments provided by digital tools. ²⁰ This is a digitally administered patient‐reported outcome tool with cloud‐based administration and automated scoring. It utilizes adaptive item selection based on item response theory, disease‐specific content derived from HD experiences, and validation against chorea severity metrics (eg, UHDRS, wearable sensors). This tailored approach minimizes patient burden while precisely measuring the psychosocial impacts of chorea, which is crucial for HD populations with cognitive challenges.

Currently, these digital tools are primarily utilized in research and academic settings, with potential for wider clinical application. The Roche HD Digital Monitoring Platform has been utilized in phase III trials and multi‐center validations. ²¹ The HDQLIFE Chorea CAT remains a validated research tool primarily used in academic settings. ²⁰ Additionally, experimental prototypes, such as artificial intelligence‐based differential diagnosis models, have demonstrated promising accuracy in a few studies. ¹² Wearable sensors are also employed to differentiate chorea from other movement disorders through kinematic analysis. ¹⁶ These digital tools provide significant potential for chorea assessment by integrating objective and subjective measures to enhance our understanding of chorea.

Digital and Ancillary Tools Can Help Overcome the Challenges of Traditional Clinical Skills

Digital and ancillary tools are advancing the assessment of chorea, offering promising but evolving solutions to complement traditional clinical methods. These innovative technologies provide objective, continuous, long‐term, and sensitive measurements of chorea, enabling more accurate and comprehensive evaluations. By leveraging wearable sensors and smartphone applications, clinicians can monitor chorea in real‐time, both within clinical environments and at patients’ homes. ²⁶ This capability facilitates a more comprehensive understanding of the variable and evolving characteristics of chorea, including data on movement patterns, “soft signs,” frequency, amplitude, and velocity of choreiform movements. ¹³

Wearable sensors equipped with accelerometers are particularly effective in quantifying chorea by measuring jerky movements. This technology provides a precise assessment of symptom severity and variability, which is especially beneficial in conditions like HD, where chorea can significantly fluctuate throughout the day. For instance, studies have demonstrated that wearable sensors can capture the variability of motor symptoms in HD patients, offering valuable insights into how chorea impacts daily life and responds to treatment. ^{14 , 19} Platforms like the Roche HD Digital Monitoring Platform have demonstrated the feasibility of remotely monitoring HD symptoms using smartwatches and smartphones. ²¹ These tools capture motor and cognitive changes, track symptom fluctuations over time and in real‐world settings, and support more accurate assessments and personalized treatment plans.

Digital tools enable remote monitoring, thereby reducing the need for frequent clinic visits and enhancing patient engagement in their care. A study using wearable sensors in HD patients successfully captured motor symptoms in daily life, providing insights into symptom variability and response to treatment. ²¹ Furthermore, another study utilizing a smartphone and smartwatch‐based digital monitoring platform found that digital outcomes correlated well with in‐clinic tests, supporting the validity of these tools for remote monitoring. ¹⁹ The ability of smartphones or wearable devices to assess patients’ symptoms in their natural environment also reduces the potential bias of clinical settings. ^{13 , 27} This advantage was also valuable when patients were unable to visit the clinics, such as during the COVID‐19 pandemic. ^{13 , 28} This alignment between digital and traditional assessments underscores the potential of digital tools to revolutionize the management of chorea, offering a more patient‐centered and efficient approach to care. Indeed, incorporating digital tools into clinical practice enhances the precision of chorea assessments and improves patient outcomes by facilitating more personalized and timely interventions (Supplementary Fig. S1).

Limitations of Digital Sensors for Evaluating Chorea

While digital sensors offer a more comprehensive evaluation of symptom progression in HD, their integration for evaluating chorea faces several limitations that impede widespread adoption and effectiveness. A key challenge is the variability in sensor data quality, influenced by factors such as sensor placement, calibration, and user compliance. Consistent data quality is essential for accurate assessments and informed treatment decisions. ¹¹ Additionally, rigorous validation of devices and data analysis methodologies is also vital. International collaborations and harmonizing standardized protocols are essential for ensuring the effective and broad implementation of these technologies. ²⁹

Another limitation is the need for advanced algorithms to distinguish between voluntary movements and involuntary chorea, as well as to analyze the collected data for relevant disease‐related insights in real‐world settings. This distinction is crucial for accurately quantifying chorea and necessitates sophisticated signal processing techniques. ²¹ Developing reliable algorithms demands not only advanced machine learning models capable of distinguishing different types of movements but also large, high‐quality ground‐truth datasets, a challenge compounded by the variability of chorea patterns across patients. ^{21 , 30}

Furthermore, incorporating digital tools into clinical workflows can be challenging. The integration of these technologies necessitates substantial investment in both infrastructure and the training of healthcare professionals. This encompasses both the technical aspects and the necessity for healthcare providers to adapt to new methods of data analysis and interpretation. ¹¹ It is also important to consider selection bias. Socio‐cultural factors, such as age and enthusiasm for technology, may influence recruitment. However, there is a scarcity of studies addressing the impact of factors like relatives, gender, education, and working conditions on the use of wearable or portable technologies. Additionally, the patient's disease stage and functional status can affect the applicability and tolerability of these devices across different stages of illness.

Lastly, ethical considerations such as data privacy and security are paramount when using digital tools for remote monitoring and data collection. Protecting patient data while enabling smooth data exchange between healthcare providers is a key challenge. ^{31 , 32} Ensuring data privacy involves protecting health information from unauthorized access, misuse, or breaches, which can compromise patient trust in the healthcare system. ³³ Implementing comprehensive data security measures, including encryption and access controls, is crucial for protecting patient privacy and ensuring compliance with data protection regulations. ^{31 , 32} While digital sensors show great promise for evaluating chorea in HD, overcoming these limitations is crucial for the effective clinical integration of this technology. This includes enhancing data quality, advancing algorithms, and investing in infrastructure and training for healthcare professionals.

Future Perspectives

Integrating digital tools into multidisciplinary care for individuals with chorea is increasingly essential. These technologies support comprehensive management by addressing both motor symptoms of chorea and their impact on psychosocial well‐being. Future research in the context of HD should focus on developing advanced predictive models that can forecast chorea severity and progression. Such models enable early interventions, potentially improving patient outcomes by allowing healthcare providers to initiate treatments at optimal times. Moreover, extending the application of digital tools to other conditions associated with chorea, such as Sydenham's chorea, could provide valuable insights into their pathophysiology and treatment strategies. Digital tools may help elucidate choreic disorder pathophysiology through the following mechanisms: (1) kinematic distinctions (eg, Huntington's progressive amplitude escalation reflecting basal ganglia neurodegeneration vs. Sydenham's stress‐triggered variability linked to autoimmune striatal dysfunction); (2) mechanistic stimulus–response differentiation, such as HD worsening versus Sydenham's improving during balance tasks, exposing disease‐specific pathway disruptions. ^{34 , 35} These broader application approaches move beyond monitoring to directly link digital phenotypes to biological mechanisms.

In conclusion, integrating digital tools into modern chorea management marks a significant step toward more objective, continuous, patient‐centered care. While challenges remain, such as ensuring data quality and privacy, as well as developing sophisticated algorithms to differentiate chorea from voluntary and other involuntary movements, these technologies show substantial potential in improving early diagnosis, monitoring symptom severity, and treatment for individuals with chorea. As validation and refinement continue, digital solutions are poised to play a central role in the clinical management of chorea. Ultimately, modern phenomenology supported by digital and ancillary tools offers a promising way to overcome the limitations of traditional assessments through real‐time and continuous monitoring of chorea.

Authors’ Roles

(1) Research project: A. Conception, B. Organization, C. Execution. (2) Data curation and analysis: A. Design, B. Execution, C. Review and Critique. (3) Manuscript Preparation: A. Writing of the First Draft, B. Review and Critique.

G.S.: 1A, 1B, 1C, 2A, 2B, 2C, 3A, 3B.

C.H.L.: 1A, 1B, 1C, 2A, 2B, 2C, 3B.

Disclosures

Ethical Compliance Statement: The authors confirm that the approval of an institutional review board was not required for this work. Informed consent was not required, as this study did not involve any human participants. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. Declaration of patient consent: Not applicable. No patients or human participants were involved in this study.

Funding Sources and Conflict of Interest: No specific funding was received for this work. The authors declare no conflicts of interest relevant to this work.

Financial Disclosures for the previous 12 months: GS has received research and CME support from the Michael J. Fox Foundation through the Global Parkinson's Genetics Program (GP2) (MJFF‐026331), and speaker's honoraria and CME support from various pharmaceutical companies in the Philippines (in alphabetical order): AbbVie Inc., Bharat Serums And Vaccines Limited (BSV), Cathay Drug Company Inc., DKSH Philippines, E* Chimes Pharmaceutical Inc., Haleon Philippines (GlaxoSmithKline Consumer Healthcare Philippines), HI‐Eisai Pharmaceutical, Inc., Hizon Laboratories, Inc., InnoGen Pharmaceuticals Inc, LRI‐Therapharma, Lotus Pharmaceutical, Lundbeck Philippines, Inc., Medchoice Pharma Inc., Medichem Pharmaceutical Inc., Medtronic Philippines Inc., Menarini Philippines, Inc., Nestlé Philippines, Inc., One Pharma Marketing Inc., Pfizer Philippines Inc., Sandoz Philippines Corp., Sun Pharma Philippines, Torrent Pharma Philippines, Inc., Vexxa Lifesciences, and Zydus Healthcare Philippines Inc. received research support from the Michael J. Fox Foundation through the Global Parkinson's Genetics Program (GP2) and speaker's honoraria from various pharmaceutical companies in the Philippines. C‐HL has received research support from research funding from the National Health Research Institutes (NHRI‐EX114‐11407NI).

Supporting information

Figure S1. Modern phenomenology: a collaborative approach combining conventional clinical assessments and ancillary and digital tools. Conventional clinical methods (eg, clinical‐based assessments, rating scales) utilize human expertise and contextual judgment, offering holistic patient interaction, but are prone to subjective assessments and accessibility challenges. Artificial intelligence and digital tools enhance diagnostic accuracy and scalability yet face limitations such as data reliability and ethical concerns. Modern phenomenology integrates both approaches to provide more precise and personalized patient care.

Data Availability Statement

The data that supports the findings of this study are available in the supplementary material of this article.