Ulnar F-wave Study in the Detection of Subclinical Diabetic Neuropathy

Abstract

Background:    Diabetic peripheral neuropathy (DPN) brought on by damage to the peripheral sensory and motor nerves. Since the F-wave passes through both the afferent and efferent pathways in the motor nerve, alterations in the F response parameters may indicate injury to either of these pathways.
Objective:    To explore the effectiveness of ulnar F-wave parameters in diagnosing subclinical neuropathy in patients with type 2 diabetes mellitus (T2DM).
Methods:    The study examined F-wave, glycated hemoglobin (HbA1c), and modified Toronto clinical neuropathy score (mTCNS), in addition to sural to radial amplitude ratio, sensory and motor conduction of upper and lower limb nerves, in 116 T2DM patients and 121 control participants.
Results:    In comparison to controls, DPN patients exhibit longer F-minimum (Fmin), F-maximum (Fmax), F-ratio (Fr), and modified F-ratio (mFr). Along with higher F-chronodispersion (Fc) and F-estimate (Fe), they also show lower F-persistence (Fp), F-wave conduction velocity (FWCV), and F-index (Fi). Patients with DPN have higher F-estimate (Fe) values than the controls, whereas patients without DPN have lower Fi. There was a strong correlation observed between several F-wave parameters and the mTCNS, disease duration, and HbA1c.
Conclusion:    Increased mFr value, longer Fm latency, and higher Fi value were useful in the early identification of subclinical DPN, while higher Fi value, FWCV slowing, and prolonged Fmin and Fmax latencies helped identify patients with clinical DPN. When separating diabetics with T2DM from those without DPN, the Fi value has the highest sensitivity and specificity.
Keywords:    DM, subclinical neuropathy, ulnar nerve, F-wave.
Citation:    Abdul Qader AA, Hamdan FB, Khudhair MS. Ulnar F-wave study in the detection of subclinical diabetic neuropathy. Iraqi JMS. 2025; 23(2): 282-296. doi: 10.22578/IJMS.23.2.11