3-Hz postural tremor in multiple system atrophy cerebellar type (MSA-C)-a static posturography study

Area of Science:

• Neurology
• Biomedical Engineering
• Clinical Diagnostics

Background:

• Multiple System Atrophy (MSA) is a neurodegenerative disorder with parkinsonian (MSA-P) and cerebellar (MSA-C) subtypes.
• Postural instability is a key symptom in MSA, impacting patient mobility and quality of life.
• Objective assessment of postural control is crucial for understanding disease progression and differentiating subtypes.

Purpose of the Study:

• To evaluate and compare static postural dysfunction in patients with MSA-P and MSA-C using static posturography.
• To identify specific posturographic markers that can aid in differentiating between MSA-P and MSA-C.

Main Methods:

• Recruited 29 MSA-P patients, 40 MSA-C patients, and 23 healthy controls (HC).
• Utilized the Sensory Organization Test (SOT) on a static posturography platform.
• Measured postural sway amplitude, transformed it into energy value using Fourier analysis, and recorded SOT scores, falls, and 3-Hz tremors.

Main Results:

• Both MSA-P and MSA-C groups showed significantly lower SOT scores compared to HC (P < 0.01).
• MSA-C patients had further reduced vestibular scores compared to MSA-P (P < 0.05).
• A typical 3-Hz postural tremor was observed in 97.5% of MSA-C patients versus 24.1% of MSA-P patients (P < 0.05).
• MSA groups consumed significantly more energy for postural control across all tasks and frequencies compared to HC.
• MSA-C showed higher energy consumption than MSA-P, particularly in higher frequency bands and more challenging tasks (P < 0.05).

Conclusions:

• Both MSA-P and MSA-C present with severe static postural dysfunction.
• The presence of a typical 3-Hz postural tremor is highly characteristic of MSA-C and valuable for differentiating it from MSA-P.