Measuring vibration sensations with graduated tuning fork. Simple and reliable means to detect diabetic patients at risk of neuropathic foot ulceration.
To find a simple and reliable means to measure vibration sensations, 189 diabetic patients and 88 control subjects were tested at different sites with a graduated tuning fork. Within-test variation at big toes reached 8.4% in diabetic patients vs. 2.2% in control subjects. Mean contralateral variation was 7.5% in diabetic patients vs. 2.5% in control subjects. Tuning-fork sensations were inversely correlated with duration of diabetes, whereas no correlation was found with HBA1c levels or the severity of retinopathy. Ninety-nine (52%) patients had vibratory sensation at big toes of less than 99th percentile of normal values for age. In addition, 51% of the patients with clinical symptoms at extremities (n = 67), 70% of the patients without tendon reflexes (n = 50), and 75% of the patients with abnormal nerve conduction velocities (n = 60) also had low vibration sensations. All patients with lower-limb injuries (n = 7) had values at big toes of less than 2. Altogether, the graduated tuning fork represents a simple and reliable alternative to quantitate vibration sensations. Long-term follow-up of asymptomatic patients will indicate whether these abnormalities reflect underlying neuropathy. Patients with abnormal values at screening will necessitate additional investigations and special foot-care education programs.
Endocrinology Branch, Antiquaille Hospital, Lyon, France.
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C
Thivolet
J
J
el Farkh
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A
Petiot
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C
Simonet
J
J
Tourniaire
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000150:complications / Q000503:physiopathology*; D005069:Evaluation Studies as Topic; D005534:Foot Diseases / Q000209:etiology*; D006801:Humans; D008307:Malleus; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D009460:Neurologic Examination / Q000295:instrumentation*; D012044:Regression Analysis; D012684:Sensory Thresholds / Q000502:physiology; D012883:Skin Ulcer / Q000209:etiology*; D013933:Thumb; D013997:Time Factors; D014034:Toes; D014732:Vibration