ABSTRACT
To evaluate the role of different neurophysiological tests in the differential diagnosis of diabetic axonal neuropathy [DAN] and lumbosacral radiculopathy [LSR]. This study was conducted at Al-Kadhimiya Teaching Hospital, Baghdad, Iraq, from July 2006 to February 2007. Twenty-seven healthy subjects, 44 type 2 diabetics, and 36 LSR patients were studied. The HbA1c level, plain x-ray, and MRI of the lumbosacral region and different electrophysiological tests were assessed. The sural sensory nerve action potential [SNAP] amplitude values were reduced in 56.3%, and the sural/radial amplitude ratio [SRAR] values were reduced in 71.8% in the diabetic patients, but not in the LSR group. The peroneal compound muscle action potential [CMAP] amplitude was low in 70.45% DAN patients versus 35.5% LSR patients. Peroneal F-minimum [Fmin] values were prolonged in 56.8% DAN versus 32.25% LSR patients. The Fpersistence [Fp] values were low in 72.7% of DAN, versus 45.2% of LSR patients. However, the Fchronodispersion [Fc] was abnormal in 71% of LSR versus 11.4% of DAN patients. The SRAR was found to be more significant than the sural SNAP amplitude alone in the differential diagnosis of the 2 groups. Abnormal peroneal Fc and Fp seems to be valuable tests in the detection of LSR and DAN patients