Local heat effect on sympathetic skin responses after pain of electrical stimulus.
OBJECTIVE
To investigate the analgesic effort of local superficial heating by studying sympathetic skin responses.


METHODS
Randomized trial.


METHODS
Electromyography laboratory in the department of physical therapy and rehabilitation of a university hospital.


METHODS
Twenty healthy volunteers participated with informed consent.


METHODS
Sympathetic skin response (SSR) amplitudes following electrical stimulation of the right peroneal nerve and skin temperatures in both hands were recorded simultaneously. All of the recordings were repeated at 5-minute intervals during local heat application over the right palm and within 15 minutes after heat application was stopped.


RESULTS
SSR amplitudes in both hands decreased significantly during local heating (p < .05) and did not return to their initial levels within 15 minutes of the recovery period; the reductions remained statistically significant (p < .05). Amplitude reductions were statistically more significant on the heated hand compared with those on the contralateral hand (p < .05).


CONCLUSIONS
Therapeutic local heat application reduces the sudomotor response to a painful stimulus. This analgesic effect may be due to suppression of cortical pain sensation resulting from increased levels of endorphins, and may also be a result of local inhibition of both afferent and efferent C fibres.
On
A Y
AY
Department of Physical Therapy and Rehabilitation, Ege University Hospital, Izmir, Turkey.
Colakoglu
Z
Z
Hepguler
S
S
Aksit
R
R
D000328:Adult; D000698:Analgesia / Q000379:methods*; D001831:Body Temperature / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D009412:Nerve Fibers / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D010543:Peroneal Nerve / Q000502:physiology; D012016:Reference Values; D012867:Skin / Q000294:innervation*; D018709:Statistics, Nonparametric; D013564:Sympathetic Nervous System / Q000502:physiology*