Locomotor coordination in patients with Hereditary Spastic Paraplegia

Area of Science:

• Neuroscience
• Biomechanics
• Human Movement Science

Background:

• Hereditary Spastic Paraplegia (HSP) is a neurological disorder characterized by progressive lower limb weakness and spasticity.
• Locomotion in HSP patients is significantly affected, impacting daily life and mobility.
• Understanding the specific coordination deficits is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate the effects of weakness and spasticity in HSP on lower limb coordination during walking.
• To analyze kinematic and electromyographic (EMG) patterns to identify gait abnormalities in HSP.

Main Methods:

• Kinematic and EMG data were collected from 21 individuals with HSP and 20 controls during walking at matched speeds.
• Principal Component Analysis (PCA) was used to examine covariation between lower limb joint angles.
• Non-negative Matrix Factorization (NMF) analyzed the modular organization of EMG patterns from 12 leg muscles.

Main Results:

• HSP gait exhibited altered joint angle covariation, reduced distal segment range of motion, and significantly lower foot lift.
• EMG analysis showed a comparable motor output structure but wider temporal patterns in sacral-innervated muscles in HSP patients.
• These findings highlight specific coordination changes impacting distal limb movement and muscle activation.

Conclusions:

• Corticospinal degeneration and spasticity in HSP significantly impact the coordination of distal limb segments during walking.
• Basic muscle modules associated with distal spinal segments show altered temporal characteristics in HSP.
• The study provides insights into the neuromuscular basis of gait impairment in Hereditary Spastic Paraplegia.