Vibration Perception Threshold Values and Clinical Symptoms of Diabetic Peripheral Neuropathy LC20-LC23
Prof. Sheela Pavithran,
Professor Cum Vice Principal, Department of Medical Surgical Nursing, Amrita College of Nursing, Amrita Vishwa Vidyapeetham,
Health Sciences Campus, Kohci-682041, Ernakulam District, Kerala, India.
Introduction: Diabetic Peripheral Neuropathy (DPN) causes damage to the peripheral nerves. Vibration Perception Threshold (VPT) helps to test the loss of protective sensation of the nerves.
Aim: To find the association between VPT values and clinical symptoms of DPN.
Materials and Methods: The descriptive study assessed association between the VPT values and clinical symptoms of 220 diabetic patients selected by purposive sampling. The VPT was measured by a sensitometer. A metal probe was placed under the toes of the patient and the voltage was increased gradually from zero and the transition from no vibration to the point of vibration is marked as VPT. Average of three measurements were taken to calculate the VPT value of the given patient. The VPT values were graded as ‘normal’ (<15v), ‘mild’ (15-20v), ‘moderate’ (20-25v) and >25 as ‘severe’ neuropathy. Data were collected using S-LANSS pain score and questionnaire on clinical symptoms of DPN. Frequency and percentage were used to analyse the sample characteristics and Fishers exact to find the association between VPT values and the clinical symptoms. Pearson’s correlation was computed between the VPT value and number of neuropathic symptoms.
Results: Almost all 219 (99.5%) the patients were symptomatic and a moderate positive correlation (r=+0.59) was found between VPT values and clinical symptoms of DPN. Sensory symptoms were observed in 96.5% of patients. Clinical symptoms of diabetic peripheral neuropathy such as unsteadiness, slipping of foot from chappal, tingling, callus, dry skin, cut/ulcer, hyper pigmentation, black discolouration, oedema, pin and needle sensation (plantar), muscle cramps, night symptoms, osteomyelitis were significantly associated with VPT value. There was a positive correlation between VPT values and the number of symptoms of DPN (r=0.590).
Conclusion: Diabetic patients are at risk for DPN and proper foot care is mandatory to prevent foot complications and probable amputation. So, VPT score can be considered an indicator of DPN and be used to identify high-risk patients.