Two Measures of Tactile Acuity in CRPS Type I Patients

Study Overview
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Brief Summary
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This study aims to investigate whether two different measures of tactile acuity lead to comparable results in patients diagnosed with CRPS Type I of the upper extremity. Additionally patients with a neuropathy of the median nerve and healthy controls are included.

Official Title
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Comparison of Two Measures of Tactile Acuity in CRPS Type I Patients , Patients With a Neuropathy of the Median Nerve and Healthy Controls.

Conditions
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CRPS Type I of the Upper Extremity, Neuropathy of the Median Nerve, Healthy Controls

Intervention / Treatment
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* Other: Tactile acuity measured by 2PD and the GOT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients diagnosed with CRPS Type I according to the Budapest Criteria Patients diagnosed with a neuropathy of the median nerve Healthy Controls,matched in age and gender to both patient cohorts Exclusion Criteria: intolerable hyperalgesia lesions at the fingertips high grade digit contracture central neurologic disorders psychiatric disorders

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CRPS Type I<br>Patients diagnosed with complex regional pain syndrome type I of the upper limb | Other: Tactile acuity measured by 2PD and the GOT<br>* For a detailed description of the methods see outcome measures<br>* Other names: Grating Orientation Task (GOT);|
| Active Comparator: Median Nerve Neuropathy<br>Patients diagnosed with a neuropathy of the median nerve of the upper limb. | Other: Tactile acuity measured by 2PD and the GOT<br>* For a detailed description of the methods see outcome measures<br>* Other names: Grating Orientation Task (GOT);|
| Active Comparator: Healthy Controls<br>Healthy adult persons. | Other: Tactile acuity measured by 2PD and the GOT<br>* For a detailed description of the methods see outcome measures<br>* Other names: Grating Orientation Task (GOT);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| tactile acuity as measured by 2-point-discrimination | Thresholds on the tip of the index finger of boths hands are assessed using the method of constant stimuli. One single needle and seven pairs of needles with different spacings are tested in randomized order. After each presentation, the subject has to report the sensation of one or two needles by answering immediately one or two. Each distance is presented eight times resulting in 64 single decisions. The summed responses are plotted against distance as a psychometric function for absolute threshold and get fitted by a binary logistic regression. Thresholds are taken from the fit at the distance at which 50% correct answers are given | unique measurement of maximal one hour duration | 
| tactile acuity as measured by the Grating Orientation Task (GOT) | Stimuli are taken from a set of dome-shaped plastic gratings with equal groove and ridge widths. Gratings are applied to the immobilized distal fingerpad of the index finger of boths hand with the ridges oriented either along or across the long axis of the finger in randomized sequences of the two alternatives. Subjects have to report the orientation of the gratings as along or across. The largest groove widths in the set is 6mm, the minimal width is 0.5mm. Thresholds were taken from the groove width at which the performance was 75% correct. Unless the performance is exactly 75% for a particular grating, interpolation between gratings spanning the 75% correct responses ared used | unique measurement of maximal half an hour duration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CRPS Type I, tactile acuity, 2-point-discrimination, Grating Orientation Task, sensory signs