Sensitivity to ischaemia of single sympathetic nerve fibres innervating the dorsum of the human foot.

Z'Graggen, Werner Josef; Solà, R; Graf, N E; Serra, J; Bostock, H (2017). Sensitivity to ischaemia of single sympathetic nerve fibres innervating the dorsum of the human foot. Journal of physiology, 595(13), pp. 4467-4473. Wiley-Blackwell 10.1113/JP274324

[img] Text
Z'Graggen_et_al-2017-The_Journal_of_Physiology.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (647kB) | Request a copy

KEY POINTS Changes in nerve conduction velocity following an impulse (i.e. velocity recovery cycles) reflect after-potentials, and can provide an indication of altered nerve membrane properties. This study used microneurography to assess the effects of ischaemia on single human sympathetic fibres innervating the dorsum of the foot. It was found that velocity recovery cycles can distinguish whether a sympathetic nerve fibre is depolarized or not. The method may be used to detect membrane depolarization of sympathetic nerve fibres in human patients when autonomic neuropathy is suspected. ABSTRACT The aim of this study was to determine whether velocity recovery cycles (VRCs) could detect the effects of ischaemia on sympathetic nerve fibres. VRCs of human sympathetic nerve fibres of the superficial peroneal nerve innervating the dorsum of the foot were recorded by microneurography in seven healthy volunteers. Sympathetic nerve fibres were identified by studying their response to manoeuvres increasing sympathetic outflow and by measuring activity-dependent slowing at 2 Hz stimulation. VRCs were assessed at rest, during 30 min of induced limb ischaemia and during 20 min of recovery after ischaemia. From each VRC was measured the relative refractory period (RRP), the supernormality and the time to peak supernormality (SN@). During ischaemia, RRP increased from the baseline value of 37.4 ± 8.7 ms (mean ± SEM) to 67.1 ± 12.1 ms (P < 0.01) and SN@ increased from 68.6 ± 9.8 ms to 133.8 ± 11.0 ms (P < 0.005). The difference between SN@ and RRP separated ischaemic from non-ischaemic sympathetic nerve fibres. It is concluded that these sympathetic nerve fibres are sensitive to ischaemia, and that VRCs provide a method to study changes of axonal membrane potential of human sympathetic nerve fibres in vivo.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Neurosurgery

UniBE Contributor:

Z'Graggen, Werner Josef

Subjects:

600 Technology > 610 Medicine & health

ISSN:

0022-3751

Publisher:

Wiley-Blackwell

Language:

English

Submitter:

Nicole Söll

Date Deposited:

26 Feb 2018 08:53

Last Modified:

27 Oct 2019 02:35

Publisher DOI:

10.1113/JP274324

PubMed ID:

28378458

Uncontrolled Keywords:

ischaemia supernormality sympathetic nerve fibre

BORIS DOI:

10.7892/boris.107942

URI:

https://boris.unibe.ch/id/eprint/107942

Actions (login required)

Edit item Edit item
Provide Feedback