The blink reflex and recovery of blink reflex in amyotrophic lateral sclerosis: impact for early diagnosis

Introduction: In this study the blink reflex (BR) and the recovery of blink reflex (RBR) was performed at patients with Amyotrophic Lateral Sclerosis (ALS) at different stages of the disease. Patients with polyneuropathy, Parkinson's disease (PD), muscle disease and spinal muscular atrophy, and healthy volunteers were examined. Methods: The BR was evoked by stimulating the supraorbital nerve via surface electrodes using rectangular stimuli of 0.2 ms duration and 15 to 40 mA intensity. Five successive trials were averaged and the mean latencies for the R1 and R2 components were calculated. The RBR was tested by d…