Strength-duration properties in diabetic polyneuropathy.
We sought to examine the changes in the strength-duration time constant (SDTC) of the median nerve in diabetic polyneuropathy. The SDTC is a measure of axonal excitability and depends on the biophysical properties of the axonal membrane. It may provide some information about Na(+) channel functioning. Forty-nine diabetic patients (30 men, 19 women; mean age, 54.6+/-9.4 years) and 15 age-matched healthy subjects (11 men, 4 women; mean age, 53.1+/-7.6 years) participated in the study. SDTC and rheobase values were 384.5+/-97.9 micros and 4.6+/-2.4 mA in patients and 313.8+/-46.7 micros and 6.0+/-2.6 mA in controls. The SDTC was found to be significantly different between the two groups (P=.009 for SDTC and P=.066 for rheobase). Fasting glucose and HbA1c levels of patients were 206.6+/-88.7 mg/dL and 8.8+/-2.4%, and these were not correlated with SDTC or rheobase (P<.05). We suggest that longer SDTC, indicating increased axonal excitability may develop in patients with polyneuropathy associated with uncontrolled diabetes.
Yerdelen
Deniz
D
Department of Neurology, Cukurova University Faculty of Medicine, Adana, Turkey. yerdelend@gmail.com
Koç
Filiz
F
Uysal
Hilmi
H
Sarica
Yakup
Y
D003929:Diabetic Neuropathies / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology*; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D011115:Polyneuropathies / Q000503:physiopathology*; D012016:Reference Values; D015222:Sodium Channels / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013497:Sural Nerve / Q000503:physiopathology
D015222:Sodium Channels; D000254:Sodium-Potassium-Exchanging ATPase