Axonal excitability during ischemia in MELAS
Article first published online: 28 MAR 2013
Copyright © 2012 Wiley Periodicals, Inc.
Muscle & Nerve
Volume 47, Issue 5, pages 762–765, May 2013
How to Cite
Ng, K., Kumar, K. R., Sue, C. and Burke, D. (2013), Axonal excitability during ischemia in MELAS. Muscle Nerve, 47: 762–765. doi: 10.1002/mus.23733
- Issue published online: 22 APR 2013
- Article first published online: 28 MAR 2013
- Accepted manuscript online: 25 NOV 2012 11:10PM EST
- Manuscript Accepted: 16 NOV 2012
- NHMRC of Australia. Grant Number: 512316
- axonal excitability;
- mitochondrial disease;
- peripheral nerves
In mitochondrial disease, it is likely that energy substrate depletion leads to paralysis of ATPase-dependent pumps, resulting in membrane depolarization. Axonal depolarization has been demonstrated in a crisis, but not in the resting state. We, therefore, stressed axons using ischemia to see if this would reveal abnormal responses, as occurs in diabetes mellitus.
Excitability of median nerve axons at the wrist was studied in 13 patients with MELAS (6 with glucose intolerance) and 17 control subjects in response to ischemia due to inflation of a cuff around the arm for 10 min.
There were no significant differences in preischemic measures of axonal excitability or in the intra- and postischemic responses.
Although depolarization has been noted to occur spontaneously during a crisis, we could not demonstrate a defect of axonal ATP-dependent mechanisms. The mechanisms underlying axonal excitability and neuropathy in diabetes may not apply to MELAS. Muscle Nerve 47: 762–765, 2013