Prospective double-blind crossover trial of ibuprofen in reducing EMG pain

Oral and topical analgesia in pediatric electrodiagnostic studies

INTRODUCTION/AIMS

Electrodiagnostic examinations, such as nerve conduction studies (NCS) and needle electromyography (EMG), are perceived as painful by children and their parents/guardians. Methods to reduce peri-procedural pain improve compliance and have neurocognitive and neuropsychiatric benefits. This study aimed to assess the efficacy of combined oral and topical analgesics (COTA), oral analgesics (OA), and placebo in reducing pain during NCS/EMG in children.

METHODS

We performed a double-blind, randomized, placebo-controlled trial on children presenting to our neurophysiology lab. Patients were stratified into two age groups (6M-6Y and 7Y-18Y) and randomized into three arms: COTA, OA, and placebo. Pain scores post-NCS/EMG were assessed using the Modified Behavioral Pain Scale (MBPS) and Faces Pain Scale-Revised (FPS-R).

RESULTS

One hundred thirteen participants were enrolled. A comparison of participants from both age groups combined revealed no significant differences in guardian FPS-R scores across all arms for NCS and EMG. A significant difference in the distribution of post-NCS FPS-R score severities in children aged 7Y-18Y was noted between OA and placebo (p = .007). EMG was more painful than NCS across all arms (p < .05). In children aged 6M-6Y undergoing at least 10 muscle samplings during EMG, those receiving COTA had significantly lower pain scores (p = .014).

DISCUSSION

This study reveals the complexity of pediatric pain perception during NCS/EMG and highlights that other methods to reduce experienced pain are required. Our findings suggest that procedural characteristics, such as number of muscles sampled, may influence the effectiveness of analgesia and serve as a foundation for future research aimed at optimizing pain management strategies.

Effect of 2% Topical Lidocaine Gel on Discomfort from Electrical Stimulation During Nerve Conduction Studies- A Prospective Double-Blind Placebo-Controlled Study

Purpose

Procedure discomfort can limit electrodiagnostic studies. Reducing discomfort can maximize the benefits of these diagnostic tools. This study targeted the discomfort associated with nerve conduction studies (NCS).

Patients and Methods

This was a prospective randomized double-blind placebo-controlled study comparing the effect of topical lidocaine gel (2%) versus analgesic-free lubricant gel (K-Y gel) on pain perception during NCS. Sequential patients (n=130) referred for routine NCS participated in the study. We applied 1 mL of lidocaine gel to one palm, and 1 mL of K-Y gel to the other as a control. After 20-45 min of application, graded increments of electrical stimulation intensity were delivered to record the median and ulnar mixed palmar nerve responses. Patients were then asked to score the degree of pain felt from electrical stimulation over each palm using the Wong-Baker Faces Pain Scale (WBFPS) and the Numeric Rating Scale (NRS), independent of baseline pain.

Results

Mean WBFPS and NRS scores for lidocaine-treated palms were significantly lower than those for controls using parametric paired t-test (3.79 vs 4.37 and 3.35 vs 3.78 respectively, all p-values<0.05). Subgroup analysis showed a significant decrease in mean scores in females, patients aged ≤50 years, patients without a history of previous NCS, and patients without comorbidities (all p-values<0.05). Median scores using nonparametric Wilcoxon ranked test also showed statistically significant differences (all p-values<0.05).

Conclusion

The results indicate that topical lidocaine 2% gel reduces discomfort associated with NCS. However, despite the statistical significance, clear clinical significance may be lacking. Clinical implementation may be considered for the subgroups that showed the greatest benefit. Further studies that incorporate more efficient drug delivery methods may yield better results.

The provision of written information and its effect on levels of pain and anxiety during electrodiagnostic studies: A randomised controlled trial

Objective

The provision of written information is a low-cost and readily available intervention that has been found to reduce pain and anxiety in a variety of clinical settings. The current study was undertaken to determine if information provision may improve patients’ experience during conventional electrodiagnostic studies.

Methods

128 participants were recruited from a tertiary teaching hospital who were referred for electrodiagnostic studies. They were randomized into 2 groups where the intervention group was provided with written information about the electrodiagnostic testing. Patients were invited to complete a questionnaire that included pain and anxiety using a visual analogue scale (VAS) following the testing. All participants underwent nerve conduction studies (NCS) whilst a subset also underwent subsequent needle electromyography (EMG).

Results

Those who received information had a statistically significant lower perception of anxiety during NCS, whilst only females who received information had a statistically significant lower perception of pain to both NCS and EMG.

Conclusions

The provision of written information can reduce the degree of pain and anxiety experienced during electrodiagnostic testing.

Significance

Improving patient comfort and tolerability during electrodiagnostic testing may have practical implications towards more reliable and accurate results obtained from such investigations that may in turn improve patient diagnosis and management.

Paracetamol 325 mg/tramadol 37.5 mg effect on pain during needle electromyography: a double-blind crossover clinical trial

Needle insertion during electromyography (EMG) may cause varying levels of pain that could lead to inaccurate assessment and premature termination of the procedure. The aim of this study is to compare paracetamol 325 mg/tramadol 37.5 mg with placebo in relieving pain before EMG. This is a randomized, crossover, placebo-controlled, double-blind clinical trial; forty-four healthy individuals, including 27 males with a mean age of 35.3 years (range 18-59 years), entered this study. The needles were inserted unilaterally 2 h after administration of two analgesic tablets of paracetamol 325 mg/tramadol 37.5 mg or two placebo tablets. The pain was scored through a 100-mm visual analog scale (VAS) immediately and 2 h after the procedure. The side effects were also recorded. Within a week, the procedure was repeated on the other upper limb, changing the treatment and placebo. The immediate and 2-h VAS scores were notably lower after administration of treatment compared to placebo (immediate pain: 17.5 ± 12.8 vs. 32.1 ± 16.0, P < 0.001; and 2-h pain: 1.6 ± 5.6 vs. 5.8 ± 7.9, P = 0. 002). There was a higher prevalence of side effects when treatment was used (48 vs. 9 %, P < 0.001). Although most symptoms were mild, transient and resolved without medical interventions, on one occasion a volunteer experienced brief loss of consciousness and one subject had severe vertigo that required hospitalization and fluid therapy. Paracetamol 325 mg/tramadol 37.5 mg administration prior to EMG could effectively alleviate pain. Further application of this medication in patients with neuromuscular disorders would warrant additional clinical trials, particularly considering the adverse events.

Patient perception of pain versus observed pain behavior during a standardized electrodiagnostic test

INTRODUCTION

Clinicians often assume that observations of pain behavior are adequate for assessment of patient pain perception during procedures. This has not been tested during a standardized electrodiagnostic experience.

METHODS

During a prospective trial including extensive, standardized electrodiagnostic testing on persons with lumbar stenosis, vascular claudication, and asymptomatic volunteers, the subjects and an observer rated levels of pain.

RESULTS

In 60 subjects, observers significantly under-rated pain (Visual Analog Scale 3.17 ± 2.23 vs. 4.38 ± 2.01, t = -4.577, df = 59, P < 0.001). Perceived pain during testing related to bodily pain as measured by the visual analog, McGill, Pain Disability, and Quebec scales, but not age, duration of symptoms, Tampa kinesiphobia, Center for Epidemiological Studies Depression scale, or SF-36 health quality of life.

CONCLUSIONS

Persons with worse pain syndromes may perceive more pain during testing than others. Clinicians and researchers should understand that patients may have more pain than they recognize.

Factors influencing aversion to specific electrodiagnostic studies

OBJECTIVE

To compare the degree of discomfort caused by nerve conduction studies (NCS) versus needle electromyography (EMG), and to determine what factors predict aversion to one test or the other.

METHODS

Two hundred patients underwent both EMG and NCS, and were asked to indicate which test was more uncomfortable. Responses were then correlated with demographic information, testing characteristics, and medical histories to identify any notable associations.

RESULTS

Of the 200 patients, 58.5% (117) of the patients found the NCS more uncomfortable than EMG. Sixty-one percent (11/18) of the younger patients (18-29 years old) found EMG more uncomfortable (P = 0.08), whereas 68% (40/59) of the older patients (age greater than 60 years old) found NCS more uncomfortable (P = 0.05). Sixty-seven percent (14/21) of the patients whose BMI was less than 22 kg/m(2) rated EMG as more uncomfortable (P = 0.01). Sixty-nine percent (27/39) of the patients whose BMI was greater than or equal to 38 found the NCS more uncomfortable (P = 0.02). A positive correlation existed between NCS discomfort and number of nerves tested. 67% (35/52) of the patients with polyneuropathy found NCS more uncomfortable.

CONCLUSION

Nerve conduction studies are more uncomfortable than needle EMG in the majority of patients, and predictions regarding which test will be more uncomfortable for a given patient are possible.

Electrical impedance myography in the diagnosis of radiculopathy

INTRODUCTION

We sought to determine whether electrical impedance myography (EIM) could serve as a diagnostic procedure for evaluation of radiculopathy.

METHODS

Twenty-seven patients with clinically and radiologically diagnosed cervical or lumbosacral radiculopathy who met a "gold standard" definition underwent EIM and standard needle electromyography (EMG) of multiple upper or lower extremity muscles.

RESULTS

EIM reactance values revealed consistent reductions in the radiculopathy-affected myotomal muscles as compared with those on the unaffected side; the degree of asymmetry was associated strongly with the degree of EMG abnormality (P < 0.001). EIM had a sensitivity of 64.5% and a specificity of 77.0%; in comparison, EMG had a sensitivity of 79.7% but a specificity of 69.7%.

CONCLUSIONS

These findings support the potential for EIM to serve as a new non-invasive tool to assist in diagnosis of radiculopathy; however, further refinement of the technique is needed for this specific application.

Comparison of the effects of vapocoolant spray and topical anesthetic cream on pain during needle electromyography in the medial gastrocnemius

OBJECTIVE

To compare the effects of a vapocoolant spray and an eutectic mixture of local anesthetics (EMLA) cream in reducing pain during needle electromyography examination.

DESIGN

Randomized controlled trial.

SETTING

Physical medicine and rehabilitation department of a university hospital.

PARTICIPANTS

Adults who underwent needle electromyography (N=99) were randomized to 1 of 2 experimental groups or the control group. Two patients dropped out during the study.

INTERVENTIONS

In the experimental groups, vapocoolant spray or EMLA cream were applied before needle electromyography. In the control group, needle electromyography was performed without pretreatment.

MAIN OUTCOME MEASURES

Intensity of pain associated with needle electromyography was assessed using a 100-mm visual analog scale (VAS). Patient satisfaction and preference for repeated use were measured using a 5-point Likert scale.

RESULTS

VAS score for pain intensity was significantly lower in the spray group (31.9; 95% confidence interval [CI], 22.0-41.7) compared with the control group (52.9; 95% CI, 45.9-60.0; P=.002), whereas there was no significant difference between the EMLA cream group (42.4; 95% CI, 34.2-50.7) and the control group. Patient satisfaction and preference for repeated use were higher in the spray group than the EMLA group.

CONCLUSIONS

Vapocoolant spray was more effective than EMLA cream in reducing pain during needle electromyography.

Effect of lidocaine iontophoresis on pain during needle electromyography

OBJECTIVE

Pain during needle electrode examination (NEE) is often poorly tolerated. No previous studies have evaluated the effect of lidocaine iontophoresis on pain reduction during NEE. Our objective was to determine whether pretreatment with lidocaine iontophoresis mitigates the pain felt during NEE.

DESIGN

In this prospective randomized, placebo-controlled, double-blinded study, the subjects were recruited from among patients scheduled for electromyographic evaluation of the bilateral upper limbs in a hospital-based clinic; they were randomized to receive either lidocaine (4%) or placebo (normal saline) administered through iontophoresis (40 mA/min) to the left opponens pollicis. The right opponens pollicis was untreated. A bilateral opponens pollicis NEE was then performed in standard fashion using a monopolar needle electrode, immediately after which the subjects rated their pain using a 10-cm Visual Analog Scale.

RESULTS

Fourteen subjects were studied. Paired t tests revealed that iontophoresis significantly decreased pain (untreated side: 6.61 ± 1.96, n = 7; treated side: 4.63 ± 2.90, n = 7; P < 0.05). However, there were no significant side-to-side differences in either group (lidocaine: 7.29 ± 1.56 vs. 5.63 ± 3.12; P = 0.19 and placebo: 5.93 ± 2.19 vs. 3.63 ± 2.48; P = 0.1).

CONCLUSIONS

Pretreatment with iontophoresis significantly reduced pain during NEE. However, the lack of group differences between lidocaine and saline iontophoresis suggested that the analgesic effect may have been attributable primarily to the iontophoresis modality itself rather than to the medication administered with iontophoresis.