Comparison of clinical evaluation and neurosensory testing in the early diagnosis of superimposed entrapment neuropathy in diabetic patients.

Diabetic patients are more susceptible to the development of entrapment neuropathy than nondiabetics. Since these patients suffer from a slowly progressing diabetic polyneuropathy, standard neurosensory and motor tests of nerve function are not sufficient in the diagnosis of superimposed nerve compression. This is most evident in the early stages of compression when quantitative diagnosis is important for making decisions on surgical decompression. We evaluated the validity of computer-assisted pressure-specified sensory device (PSSD) testing in the early detection of superimposed entrapment in diabetic neuropathy in comparison with standard clinical tests. Twenty-five diabetic patients with complaints of peripheral nerve dysfunction were evaluated by clinical tests and PSSD. Out of those, nerve entrapment was detected in 15 patients (60%) (9 in late and 6 in early stage) by neurosensory PSSD testing. Standard clinical tests were confirmative in 33.3% of these cases (44% of late and 16.7% of early stage). Out of 144 evaluated nerves, 50 were diagnosed with entrapment (24 in late and 26 in early stage) using PSSD. Clinically, diagnosis was confirmed in 16% of entrapped nerves (20.8% of late and 11.5% of early stage). Average diabetes duration in patients with entrapment diagnosed using PSSD was significantly shorter than for those diagnosed clinically (4.14 +/- 2.04 vs. 7.2 +/- 1.3, respectively; P = 0.005). Among evaluated factors, mean age and diabetes duration were found to be significantly shorter in patients with entrapment than in those with advanced diffused changes (54.47 +/- 13.07 vs. 67.10 +/- 14.2; P = 0.019 and 5.33 +/- 3.74 vs.14.22 +/- 8.17; P = 0.006; respectively). Our results revealed higher sensitivity of PSSD in comparison with standard clinical tests in the detection of early-stage entrapment in patients with diabetes. To assess accuracy of PSSD in the proper patients' qualification for surgery, further prospective, postoperative studies are needed.