High resting level and weak response of baroreflex-governed sympathetic outflow in amyotrophic lateral sclerosis
2011 (English)In: Muscle and Nerve, ISSN 0148-639X, E-ISSN 1097-4598, Vol. 43, no 3, 432-440 p.Article in journal (Refereed) Published
Both altered sympathetic function and insulin resistance have been observed in amyotrophic lateral sclerosis (ALS). Insulin is a sympathetic stimulator. We recorded muscle sympathetic nerve activity (MSNA) by microneurography in 9 patients with ALS and 9 healthy controls during rest. We also initiated a number of sympathoexcitatory maneuvers, including intake of 100 g of glucose. Patients showed reduced glucose tolerance and a higher heart rate and higher level of MSNA at rest than controls (61.0 ± 15.2 vs. 41.2 ± 5.8 bursts/min, P = 0.006); baroreflex inhibitory influence was present. In contrast, MSNA in ALS patients responded more weakly to maneuvers. This inverse relationship is interpreted as a "ceiling effect," as ALS patients use nearly maximal MSNA capacity already at rest and do not have sympathetic failure. The increased level of MSNA may be a primary feature of ALS, but insulin stimulation may also contribute. Our findings are assessed in relation to previous, sometimes seemingly contradictory observations.
Place, publisher, year, edition, pages
2011. Vol. 43, no 3, 432-440 p.
Amyotrophic lateral sclerosis, Autonomic dysfunction, Blood pressure regulation, Insulin, Sympathetic nervous system
Medical and Health Sciences
Research subject Neurology
IdentifiersURN: urn:nbn:se:uu:diva-148270DOI: 10.1002/mus.21894ISI: 000287785600017PubMedID: 21305564OAI: oai:DiVA.org:uu-148270DiVA: diva2:401737