A comparison of electrophysiological tests for the early diagnosis of diabetic neuropathy

Subclinical diabetic neuropathy with normal conventional electrophysiological study

“…It is not uncommon to encounter the diabetic patients with normal clinical but abnormal electrophysiological features or with abnormal clinical and normal electrophysiological features. The former was previously designated as ''subclinical neuropathy'' [1] and the latter, as ''early DPN'' or as ''clinically defined DPN'', respectively [20]. Unlike diabetes mellitus type1(DM1), it is known that DPN starts at the initial stage of diabetes mellitus type 2 (DM2).…”

“…Unlike diabetes mellitus type1(DM1), it is known that DPN starts at the initial stage of diabetes mellitus type 2 (DM2). Even it is claimed that when DM2 is diagnosed, DPN may already be present [20]. Considering this argument of the possible underestimation of early DPN, especially in the case of DM2, early diabetic patients showing the above mentioned features of ''clinico-electrophysiological dissociation'' should be evaluated for whether they have a neuropathy.…”

The realistic yield of lower leg SNAP amplitudes and SRAR in the routine evaluation of chronic axonal polyneuropathies

“…In diabetic neuropathy abnormal late responses can be a sensitive early indicator of the neuropathy, but they can also be found in demyelinating polyneuropathies, proximal nerve and plexus lesions, radiculopathies, motor neuron disease, or spinal cord lesions. Late responses, though valuable, are not as specific as sensory conduction studies in the evaluation of distal axonal polyneuropathies [10,11,44,45].…”

“…The sural SNAP cannot always confirm the polyneuropathy, but experienced investigators have reported improved yield of the sural/radial nerve amplitude ratio (SRAR), the superficial peroneal and dorsal sural SNAP [9][10][11][12][13][14][15]. Most previous studies recruited asymptomatic healthy controls to determine SNAP reference values, whereas in routine clinical practice persons not suspected of polyneuropathy but with other diagnoses actually constitute the referent population.…”

A Study of Distal Sensory Nerves in Patients with Newly Diagnosed Asymptomatic Type 2 DM

“…The signs of diabetic neuropathy may not be evident on routine electrophysiological studies performed early in the course of the disorder and electrophysiological diagnosis becomes difficult in patients who are either asymptomatic or newly and slightly symptomatic [4]. The PNP has been reported to have a prevalence of 7% in the first year after the diagnosis of DM and 50% in a 25-year follow-up.…”