Mirror movements in amyotrophic lateral sclerosis.

Area of Science:

• Neuroscience
• Neurology
• Motor Neuron Diseases

Background:

• Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons.
• Mirror movements (MM) have been observed in ALS and linked to disrupted transcallosal inhibition (TI).

Purpose of the Study:

• To investigate the occurrence of MM in ALS patients.
• To assess the relationship between MM and TI.
• To explore the potential of MM as an early diagnostic biomarker for ALS.

Main Methods:

• Clinical assessment of MM in 26 ALS patients.
• Transcranial magnetic stimulation (TMS) to evaluate TI using the ipsilateral silent period.

Main Results:

• Mirror movements were present in 39% of ALS patients.
• A significant negative correlation was found between MM occurrence and the ALS Functional Rating Scale-Revised (ALSFRS-R).
• All patients with MM exhibited pathological TI in at least one hemisphere.

Conclusions:

• The presence of MM in ALS patients is associated with impaired transcallosal inhibition.
• MM may reflect the involvement of transcallosally projecting neurons in the ALS disease process.
• Mirror movements could represent an early diagnostic biomarker for amyotrophic lateral sclerosis.