Aims: To investigate the efficacy of the Neuropen, a new clinical device that assesses both pain and pressure perception, to evaluate peripheral nerve function in diabetic patients compared with standard clinical testing methods.
Methods: Peripheral nerve function was assessed in 124 diabetic patients attending a multidisciplinary diabetes clinic, using (i) the modified Neuropathy Disability Score (NDS), derived from assessment of vibration, pinprick (pain), temperature sensation plus ankle reflexes, and (ii) vibration perception threshold (VPT) measured at the hallux. Patients were stratified into various neuropathic groups according to their NDS score. In addition, nerve function was assessed using the Neuropen, a device combining a 10-g monofilament and a weighted Neurotip. Inability to feel sensation on either or both feet for each test of the Neuropen (i.e. the monofilament or the Neurotip) was defined as an abnormal response.
Results: The sensitivity of the Neuropen to detect neuropathy compared with the NDS (score > or = 6/10) was high using either an abnormal monofilament response (87.8%), an abnormal Neurotip response (91.8%) or a combination of the two (82.0%). Neuropen specificity improved, however, when the combination of abnormal monofilament and abnormal Neurotip responses was used (68%), rather than the individual tests (57% and 41%, respectively).
Conclusions: The Neuropen is a sensitive device for assessing nerve function and may provide an inexpensive alternative screening method to identify patients with moderate to severe neuropathy.