Preoperative Prevalence of Ulnar Neuropathy and Changes in Ulnar Nerve Latency During Surgery

Study Overview
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Brief Summary
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This study is to investigate the incidence of undiagnosed ulnar neuropathy in patients undergoing surgery. The investigators hope to determine if patients with ulnar neuropathy have changes in nerve conduction latency during surgery.

Detailed Description
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After obtaining an informed consent, the participating subjects will be asked a few questions relating to ulnar nerve dysfunction. Following this the investigators will do a focused physical exam looking for decrement of sensation in the distribution of the ulnar nerve and muscle strength of the hand muscles supplied by the ulnar nerve. After this the subjects will undergo an EMG exam to measure the conduction velocity of the ulnar nerve. Basically the nerve will be stimulated with a small current and the resultant muscle activity of the hand muscle will be picked up using an EKG like patch applied to the skin over the hand. If a subject is diagnosed to have ulnar neuropathy preoperatively the investigators would study the EMG based nerve conduction during surgery at 30-60 minute intervals for the duration of surgery. For purposes of comparison the investigators would measure the ulnar nerve conduction during surgery in age and sex matched controls.

Official Title
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Preoperative Prevalence of Ulnar Neuropathy and Changes in Ulnar Nerve Latency During Surgery

Conditions
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Ulnar Neuropathy

Intervention / Treatment
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* Other: Electromyography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 50 yrs of age or older Scheduled to undergo a surgical procedure at UTMC with an anticipated length of 2hours or greater Exclusion Criteria: Less than 50yrs Not scheduled for a surgical procedure at UTMC or scheduled for a surgical procedure with an anticipated length of less than 2hours

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group Cohort<br>All subjects will have nerve conduction studies (Electromyography/EMG) pre-operatively, monitored intra-operatively and immediately post-operative. | Other: Electromyography<br>* All subjects will have an EMG before, during and immediately after surgery.<br>* Other names: EMG;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevalence of ulnar neuropathy in patients scheduled to undergo anesthesia and surgery as measured by electromyography | Prevalence of undiagnosed or subclinical ulnar neuropathy as determined by electromyography | Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amplitude (mV) | Compare preoperative, perioperative and postoperative amplitude changes from EMG | Day 1 | 
| Latency (ms) | Compare preoperative, perioperative and postoperative latency changes from EMG | Day 1 | 
| Velocity (m/s) | Compare preoperative, perioperative and postoperative velocity changes from EMG | Day 1 |