Movement-related cortical potentials in ALS increase at lower and decrease at higher upper motor neuron burden...

Area of Science:

• Neuroscience
• Neurology
• Electrophysiology

Background:

• Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease primarily affecting motor neurons.
• Respiratory failure is the leading cause of mortality in ALS patients.
• Movement-related cortical potentials (MRCPs) reflect cortical activity preceding voluntary movements and can be altered in neurological conditions.

Purpose of the Study:

• To investigate alterations in MRCPs, including finger-flexion and inspiratory potentials, in ALS patients with varying degrees of upper motor neuron (UMN) involvement.
• To explore the relationship between UMN burden and MRCP characteristics in ALS.
• To understand the dynamic changes in MRCPs during disease progression.

Main Methods:

• Electroencephalography (EEG) was recorded from 21 ALS patients and 19 healthy controls during self-paced finger-flexion and nasal inspiration tasks.
• Analysis focused on early (BP1), late (BP2), and motor potential (MP) components of MRCPs.
• Patients were categorized into low UMN burden (LUB) and high UMN burden (HUB) subgroups.

Main Results:

• ALS patients exhibited higher overall MRCP amplitudes compared to controls.
• The LUB subgroup showed significantly higher MRCP amplitudes than controls and the HUB subgroup.
• The HUB subgroup displayed significantly lower motor potential (MP) amplitudes than the LUB subgroup, suggesting a decrease with progressive UMN deterioration.

Conclusions:

• Increased MRCPs in LUB patients compared to HUB patients suggest divergent pathophysiological mechanisms in ALS.
• The findings indicate that MRCPs can reflect different stages and severities of UMN involvement in ALS.
• Progressive UMN deterioration is associated with an initial increase followed by a decrease in MP amplitudes in ALS.