Contralateral R1 in Amyotrophic Lateral Sclerosis

Presence of a contralateral R1 component on blink reflex evaluation.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting both upper and
 lower motor neurons. Electroneuromyography is an important tool for the diagnosis. Previous
 studies have shown that different components of the blink reflex, such as the latencies of
 homo- and contralateral R2 responses can be affected. Studies have found that a contralateral
 R1 component can appear in neurological diseases with affection of the central nervous system
 especially upper motor neuron, such as HTLV1 infection. Thus, you aim to determine if a
 contralateral R1 component could be present in ALS.