Premium
Subtle involvement of the sympathetic nervous system in amyotrophic lateral sclerosis
Author(s) -
Oey P. Liam,
Vos Pieter E.,
Wieneke George H.,
Wokke John H.J.,
Blankestijn Peter J.,
Karemaker John M.
Publication year - 2002
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.10049
Subject(s) - baroreflex , amyotrophic lateral sclerosis , medicine , autonomic nervous system , microneurography , sympathetic nervous system , cold pressor test , heart rate , orthostatic intolerance , blood pressure , orthostatic vital signs , cardiology , anesthesia , disease
The literature on the involvement of the autonomic nervous system (ANS) in amyotrophic lateral sclerosis (ALS) is conflicting. We therefore investigated several aspects of autonomic function, namely muscle sympathetic nerve activity (MSNA), blood pressure, cardiac function (electrocardiogram; ECG), and respiration in 16 patients with sporadic ALS and in 12 age‐matched healthy volunteers, both at rest and during sympathoexcitatory stimulation. We measured MSNA by provoking venous pooling during short‐lasting lower body negative pressure (LBNP) and during the cold pressor test (CPT). To assess the vagal (baroreflex) control of heart rate (HR), we measured spontaneous baroreflex sensitivity (BRS). To assess the involvement of the ANS beyond the cardiovascular system, we measured the sympathetic skin response (SSR). The stand‐up test showed that none of the subjects had orthostatic intolerance. In comparison with the control group, the ALS patients had an increased HR and a decreased BRS at rest, and a reduced MSNA response to LBNP. The CPT response was normal and the total MSNA at rest did not differ significantly from that of controls. The latencies of the palmar and plantar SSR were prolonged, and in 3 ALS patients there was no plantar SSR. The results indicate that the sympathetic nervous system shows subtle abnormalities in ALS, predominantly sympathetic overactivity. They also point to the involvement of the preganglionic sympathetic column as the cause of the higher sympathetic activity and the absence of SSR. The higher sympathetic activity is postulated to be due to changes in modulation of the sympathetic system, whereas the absence of the SSR is probably caused by disruption of the reflex pathway. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002