Reduced baroreflex sensitivity and cardiorespiratory transfer in amyotrophic lateral sclerosis

Sympathetic disturbances increase risk of sudden cardiac arrest in sporadic ALS

“…In contrast to our results and the findings of several previous studies [4,5,31], ALS has been associated with subclinical sympathetic hyperactivity rather than hypoactivity [10,[27][28][29][30]. For example, one previous report described increased heart rate and baroreflex sensitivity, suggesting sympathetic hyperactivity.…”

Autonomic impairment in amyotrophic lateral sclerosis

“…These frequently occur during sleep [6,7]. Elevated resting heart rate and blood pressure have been reported in ALS, although not consistently (Table 1) [8][9][10][11][12][13][14][15][16][17]. Elevated plasma noradrenaline (norepinephrine) were also noted [11,17].…”

“…Normal sympathetic responses to the tilt test [8][9][10]13] and the cold pressure test [12] were reported in patients with mild disease. On the other hand, respirator dependent patients exhibited exaggerated increased reflex hypertension and tachycardia in response to cold pressor test [19].…”

Chronological changes of sympathetic outflow to muscles in amyotrophic lateral sclerosis

“…The need for further studies was emphasized, considering that sympathetic hyperactivity resembled the excessive excitability of motor neurons at the anterior horn of the spinal cord. While various subsequent studies of autonomic function have been reported [8][9][10][11], chronological changes in sympathetic nervous function over the course of ALS have not been evaluated.…”