Multichannel EMG-based estimation of fiber conduction velocity during isometric contraction of patients with different stages of diabetic neuropathy.
This study compares muscle fiber conduction velocities estimated using surface electromyography during isometric maximal voluntary contraction in different stages of diabetic neuropathy. Eighty-five adults were studied: 16 non-diabetic individuals and 69 diabetic patients classified into four neuropathy stages, defined by a fuzzy expert system: absent (n=26), mild (n=21), moderate (n=11) and severe (n=11). Average muscle fiber conduction velocities of gastrocnemius medialis, tibialis anterior, vastus lateralis and biceps femoris were assessed using linear array electrodes, and were compared by ANOVA. Conduction velocities were significantly decreased in the moderate neuropathy group for the vastus lateralis compared to other groups (from 18% to 21% decrease), and were also decreased in all diabetic groups for the tibialis anterior (from 15% to 20% from control group). Not only the distal anatomical localization of the muscle affects the conduction velocity, but also the proportion of muscle fiber type, where the tibialis anterior with greater type I fiber proportion is affected earlier while the vastus lateralis with greater type II fiber proportion is affected in later stages of the disease. Generally, the muscles of the lower limb have different responsiveness to the effects of diabetes mellitus and show a reduction in the conduction velocity as neuropathy progresses.
University of Sao Paulo, School of Medicine, Physical Therapy, Speech and Occupational Therapy Dept., Sao Paulo, SP, Brazil.
Marco K
MK
Butugan
University of Sao Paulo, School of Medicine, Physical Therapy, Speech and Occupational Therapy Dept., Sao Paulo, SP, Brazil.
Cristina D
CD
Sartor
University of Sao Paulo, School of Medicine, Physical Therapy, Speech and Occupational Therapy Dept., Sao Paulo, SP, Brazil.
Ricky
R
Watari
University of Sao Paulo, School of Medicine, Physical Therapy, Speech and Occupational Therapy Dept., Sao Paulo, SP, Brazil.
Maria Cecília S
MC
Martins
University of Sao Paulo, School of Medicine, Center of Fuzzy Systems in Health, Sao Paulo, SP, Brazil.
Neli R S
NR
Ortega
University of Evry, Electrical Engineering Department, Evry, France.
Vincent A M
VA
Vigneron
University of Sao Paulo, School of Medicine, Physical Therapy, Speech and Occupational Therapy Dept., Sao Paulo, SP, Brazil. Electronic address: icnsacco@usp.br.
Isabel C N
IC
Sacco
D000368:Aged; D016022:Case-Control Studies; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D018450:Disease Progression; D004566:Electrodes; D004576:Electromyography / Q000379:methods*; D005260:Female; D017143:Fuzzy Logic; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D035002:Lower Extremity / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology; D052097:Quadriceps Muscle / Q000503:physiopathology; D013848:Thigh / Q000502:physiology
Diabetic polyneuropathies; Electromyography; Isometric contraction; Muscle fiber; Neural conduction