ABSTRACT
OBJECTIVE: To relate clinical severity of idiopathic carpal tunnel syndrome (CTS) to current perception threshold (CPT). METHODS: Subjects were 51 patients with CTS (involving 51 hands), and 50 healthy control subjects (50 hands). Involved hands were grouped into three clinical grades (mild, moderate, severe). Using a neurometer (Neurotron, Baltimore, MD), we investigated the relationship between clinical grade and CPT abnormalities. RESULTS: In the mild CTS group, most hands showed CPT abnormalities only at 2000 Hz stimulation. The moderate group included a higher percentage of hands showing abnormalities at both 2000 and 250 Hz stimulation increased. The severe group included the highest percentage of hands with abnormal values at all frequencies tested. CONCLUSIONS: CPT showed abnormalities appear progressively from 'higher to lower' frequency stimulations relative to the increasing severity of CTS. SIGNIFICANCE: Sensory nerve fiber dysfunction apparently begins in larger fibers, extending stepwise to smaller fibers as the clinical grade of CTS progresses.
Subject(s)
Carpal Tunnel Syndrome/physiopathology , Nerve Fibers/physiology , Sensory Thresholds/physiology , Adult , Aged , Cross-Sectional Studies , Electric Stimulation/methods , Electrophysiology/methods , Female , Humans , Male , Middle Aged , Neural Conduction/physiologyABSTRACT
The purpose of this study was to determine the sensitivity and specificity for the current perception threshold (CPT) test during clinical examination of idiopathic carpal tunnel syndrome (CTS). We studied 71 patients (102 hands) with CTS; 50 healthy individuals (100 hands) served as a control group. Using a neurometer, we investigated standard CPT values to obtain the sensitivity and specificity of the CPT test in the clinical examination of CTS. In the CTS group, cases that had abnormal values in the range analysis, the ratio analysis, or both were called "true-positive CPTs"; in the control group cases that had normal values in the range and ratio analyses were called "true-negative CPTs." We defined the sensitivity as the percentage of true-positive CPTs in the CTS group and the specificity as the percentage of true-negative CPTs in the control group. The sensitivity of the CPT test using both range and ratio analyses was 73%, and its specificity was 74%. Based on these results we concluded that the CPT test is a reliable quantitative sensory function test.
Subject(s)
Carpal Tunnel Syndrome/physiopathology , Sensory Thresholds , Aged , Female , Humans , Male , Middle Aged , Neural Conduction , Retrospective Studies , Sensitivity and SpecificityABSTRACT
The recovery level for sensory function after carpal tunnel release for the treatment of idiopathic carpal tunnel syndrome (CTS) was assessed with the current perception threshold (CPT) test. Seventeen CTS patients (21 hands) were followed, and the CPTs at the index finger of each patient was measured preoperatively and at 1, 3, and 6 months postoperatively. After carpal tunnel release, there was significant recovery of CPT at all stimulation frequencies, indicating improvement of all sensory functions including sensations of temperature, pain, touch, and vibration.