Elevated pain threshold in patients with asymptomatic diabetic neuropathy: an intraepidermal electrical stimulation study.
The loss of epidermal nerve fibers is regarded as an early pathological change in human diabetes. We investigated epidermal Aδ nerve fiber function by examining pain threshold by means of intraepidermal electrical stimulation (IES) in early diabetic neuropathy.



We recruited 20 asymptomatic diabetic patients. Eighteen age-matched, healthy subjects served as controls. We placed the IES electrode onto the skin of the foot dorsum and delivered weak electrical stimulation. We defined pain threshold as the minimum electrical intensity at which a subject felt a pricking sensation.



The mean pain thresholds in the patient group were significantly higher (0.053 ± 0.036 mA; P < 0.01) than in the control group (0.027 ± 0.006 mA).



We confirmed that the pain threshold was elevated in early diabetic neuropathy. We conclude that the IES electrode is a useful tool to evaluate early diabetic polyneuropathy. Muscle Nerve 54: 146-149, 2016.
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Chieko
C
Suzuki
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Tomoya
T
Kon
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Yukihisa
Y
Funamizu
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Tatsuya
T
Ueno
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Rie
R
Haga
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Haruo
H
Nishijima
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Akira
A
Arai
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Masahiko
M
Tomiyama
Department of Neurology, Aomori Prefectual Central Hospital, 2-1-1, Higashi-Tsukurimichi, Aomori, 030-8553, Japan.
Masayuki
M
Baba
D000368:Aged; D016022:Case-Control Studies; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D004558:Electric Stimulation; D004817:Epidermis / Q000294:innervation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology*
diabetic polyneuropathy; electrical stimulation; epidermal nerve fibers; intraepidermal; pain; pain threshold