What tests are used to assess bradykinesia?

Tests to Assess Bradykinesia

The most effective tests for assessing bradykinesia include the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III), finger tapping tests, hand movement assessments, and specialized motion analysis using wearable sensors. 1

Clinical Assessment Tests

UPDRS Part III (Motor Examination)

• UPDRS-III is the gold standard clinical tool for assessing bradykinesia, containing 14 items designed to evaluate cardinal motor findings in Parkinson's disease including tremor, rigidity, bradykinesia, and postural instability 2, 3
• The motor component specifically evaluates bradykinesia through multiple tasks that assess movement speed, amplitude, and rhythm 4
• This scale has a maximum (worst) score of 108 points and serves as the primary outcome assessment measure in clinical trials 3, 4

Specific Motor Tasks for Bradykinesia Assessment

• Finger tapping test: Patient taps thumb and index finger together in rapid succession to assess speed, amplitude, and rhythm 1, 5
• Hand movements test: Opening and closing hands repeatedly in rapid succession 1, 5
• Pronation-supination movements: Alternating palm up/down movements of the hands 1
• Toe tapping: Rapid tapping of the foot on the floor 1
• Leg agility: Raising and tapping the foot on the ground 1
• Arising from chair: Assessment of ability to stand from a seated position without using arms 1, 6

Enhanced Testing Methods

Activation Maneuvers

• To enhance detection of subtle bradykinesia, have the patient perform a contralateral activation maneuver (e.g., opening and closing the opposite hand) while testing movement speed in the primary limb 1
• This technique often reveals bradykinesia that might otherwise be difficult to detect 1

Objective Measurement Technologies

• Wearable inertial measurement units (IMUs) can quantify whole-body bradykinesia by measuring joint angles at both upper and lower limbs and trunk motion 6
• These technologies provide bradykinesia indices for walking (WBI) and standing up from a chair (sit-to-stand; SBI) 6
• Automated video analysis using deep learning algorithms can detect and measure movement parameters consistent with MDS-UPDRS III scoring 5
• The Parkinson's KinetiGraph (PKG) system calculates bradykinesia scores every two minutes over extended periods, recognizing bradykinesia as movements with lower acceleration, reduced amplitude, and longer intervals between movements 7

Distinguishing Features from Other Conditions

• Bradykinesia must be differentiated from hypokinesia (reduced amount of movement) as they represent different aspects of motor impairment 8
• When assessing bradykinesia, it's important to rule out other parkinsonian syndromes such as progressive supranuclear palsy (PSP), which may present with vertical gaze palsy alongside bradykinesia 2, 1
• Corticobasal syndrome should be considered when asymmetric bradykinesia is accompanied by alien hand phenomenon 2, 1

Common Pitfalls to Avoid

• Failure to distinguish between bradykinesia (slowness of movement) and hypokinesia (reduced amount of movement) can lead to diagnostic confusion 8
• Not using activation maneuvers may cause clinicians to miss subtle bradykinesia 1
• Confusing drug-induced parkinsonism with idiopathic Parkinson's disease - both can present with bradykinesia but have different treatments 1
• Failing to consider that bradykinesia can affect cognitive response time tests, potentially confounding neuropsychological assessments 2
• Not accounting for the impact of fluctuations in cognition or alertness on bradykinesia assessment in patients with conditions like Dementia with Lewy Bodies 2

Specialized Testing for Research and Advanced Assessment

• 3D automated analysis tools using deep learning can study the evolution of movement parameters during protocol repetitions of the MDS-UPDRS III 5
• Temporal Self-Attention (TSA) mechanisms in video analysis can help focus on subtle temporal visual cues like the frequency of movements 9
• Multi-domain learning methods can predict patient-level severity through task-assembling of various bradykinesia assessments 9