Tardive Dyskinesia

Continuous measurement of involuntary movement beside AIMS

Tardive dyskinesia trials use the Abnormal Involuntary Movement Scale (AIMS) as the regulatory anchor. NeuroQuantix adds continuous kinematic measurement of involuntary movement affecting fine motor control, so that VMAT2 inhibitor efficacy studies and antipsychotic safety monitoring can measure change beyond ordinal AIMS items.

Published evidence on digitized spiral analysis supports continuous, rater-independent motor measurement; the strength of that evidence for this condition is stated on this page. NeuroQuantix standardizes this evidence into a pre-specified endpoint for your program. Learn more about tardive dyskinesia from the NINDS/NIH overview.

Discuss Your Program View Technical Data

Continuous

Involuntary Movement

Velocity irregularity, trajectory deviation, pressure variability

None

Rater Dependence

Computed metrics

Isolated

Fine-Motor Impact

Upper-limb task rather than body-region rating

Limited

Evidence Status

Scoping review, Wang et al., 2025

Limitations of AIMS

The The Abnormal Involuntary Movement Scale (AIMS) is the current gold standard for tardive dyskinesia assessment in clinical trials. These are its documented limitations.

AIMS provides the regulatory precedent used in VMAT2 inhibitor approvals and remains the anchor for TD trials

AIMS items are 0 to 4 ordinal ratings assigned by an observer during a brief examination, so they carry inter-rater variability and compress small changes

A single observation window can miss fluctuating involuntary movement that continuous measurement captures

Fine-motor consequences of dyskinesia, which matter to patients, are not isolated by the body-region items

Published spiral evidence in tardive dyskinesia is limited; the platform is positioned for exploratory endpoint use while evidence accumulates

The TD Measurement Challenge

Tardive dyskinesia fluctuates within a visit and between visits, and the observer-rated AIMS samples one moment on an ordinal scale. VMAT2 inhibitor programs and antipsychotic safety studies need a measure that captures the fine-motor consequences of involuntary movement continuously and without a rater. NeuroQuantix provides that measure as a pre-specified exploratory endpoint beside AIMS, with the evidence status stated plainly.

Clinical Applications

VMAT2 inhibitor efficacy trials as an exploratory endpoint beside AIMS

Antipsychotic safety monitoring for drug-induced movement disorders

Long-term extension studies tracking involuntary movement over time

Published Evidence

Evidence from peer-reviewed publications supporting digital kinematic endpoints for tardive dyskinesia assessment. View the full evidence base.

Kinematic Signatures of Hyperkinetic Movement

Spiral drawing kinematics resolve irregular, involuntary movement components by frequency and amplitude, separating them from voluntary drawing motion.

Scoping review: Wang S, et al. Movement Disorders Clinical Practice, 2025

Statistical Power Advantage

Higher measurement precision translates directly into smaller enrollment requirements. See the full interactive power curve comparison on the NeuroQuantix platform page.

View Power Visualization

Frequently Asked Questions

What are the limitations of AIMS in tardive dyskinesia trials?

AIMS is an observer-rated ordinal scale scored during a short examination. It carries inter-rater variability, compresses small changes into whole-number steps, samples a single moment, and does not isolate the fine-motor consequences of dyskinesia. It remains the regulatory anchor; a continuous kinematic measure beside it adds sensitivity.

How does NeuroQuantix measure tardive dyskinesia objectively?

The platform captures involuntary movement as irregular velocity, pressure, and trajectory deviations during a brief spiral drawing at 240 Hz, and decomposes them by frequency. The result is a continuous, rater-independent measure of the fine-motor impact of dyskinesia that can be pre-specified as an exploratory endpoint beside AIMS.

Is there published evidence for spiral analysis in tardive dyskinesia?

Limited. The scoping review found extensive evidence in Parkinson disease and essential tremor and thinner evidence elsewhere. In tardive dyskinesia the appropriate use today is an exploratory endpoint that generates within-program evidence, with AIMS as the primary measure.