The value of F waves of the upper and lower limbs in the diagnosis of diabetic peripheral neuropathy.

Objective: To explore the value of F waves of the upper and lower limbs in the diagnosis of diabetic peripheral neuropathy (DPN) .Methods: The F waves of the median and tibial nerves of lower limbs and upper limbs of 82 cases with diabetes(D group) and 22 healthy volunteers with age-and height-matched (Control group) were detected.The data of the appearance rate (F present) ， conduction velocity(Fcv) ，mean latency(Flme) of F waves were analyzed.The cases of group D were divided into symptom group and nosymptom according to the peripheral neuropathy symptoms， and normal and abnormal group according to nerve conduction detection (NCD) .Results: Compared with the control group， group D with symptoms had less Fpresent and slower Fcv in upper limbs and less Fpresent and longer Flme in lower limbs(P0.05 toP0.01) ， less Fpresent was only detected in nosymptoms.Compared with group D with nosymptoms， slower Fcv in the upper， and less Fpresent and longer Flme in the lower limbs were detected in symptoms group(P0.05 toP0.01) ， the differences of Fpresent of two groups were not statistical significant(P0.05) .Compared with the control group， the slower Fcv in upper limbs， slower Fcv of upper limbs and the less Fpresent and longer Flme of lower limbs were detected in diabetes with abnormal NCD，while for diabetes with normal NCD， the less Fpresent and slower Fcv in upper limbs and no obvious difference in lower limbs were detected.Compared with diabetes with normal NCD， slower Fcv in upper limbs and slower Fcv and longer Flme of lower limbs were detected in diabetes with abnormal NCD， and no obvious difference in upper limbs were detected(P0.05) .Conclusions: F wave(especially Fpresent) of upper limbs can be used as a sensitive diagnostic means for earlier DPN，and discover subclinical lesions.The proximal nerve damage of the upper limbs occurs sooner than the distal end.The parameter variation of the F waves are consistent to the clinical symptoms and NCD.Both proximal and distal nerves of the lower limbs can be involved synchronally in the DPN.