An abnormal relationship between blood pressure and pulse rate in amyotrophic ateral sclerosis

Objectives - To clarify the autonomic dysfunctions in amyotrophic lateral sclerosis (ALS) patients, we investigated the relationship between blood pressure (BP) and pulse rate (PR), QTc interval, and coefficient of variation in the R-R interval (CV R-R ) in ALS patients. Materials and methods - BP and PR were determined automatically every 30 min for 24 h in 6 patients with ALS and in 18 healthy age-matched volunteers. The QTc interval and CV R-R were also evaluated using an electrocardiogram. Results - The relationship between BP and PR was lost in the ALS group. There was no significant difference in the QTc interval or CV R-R between the ALS and control groups. Conclusion - We speculate that the imbalance between BP and PR observed in the ALS group reflects a disorder in the balance between the sympathetic and parasympathetic nervous systems.