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

Tolerability of electrodiagnostic studies in patients: a prospective study

Introduction

Nerve conduction study (NCS) and electromyography (EMG) are electrodiagnostic studies that are highly tolerated by patients despite their nature of causing pain and discomfort. However, few studies have focused on the true tolerability of these procedures in patients. This study aimed to determine the true tolerance rate of NCS and EMG in patient populations and the factors that might be associated with them.

Methods

Participants scheduled for electrodiagnostic studies were prospectively recruited between March 2023 and September 2023. After completion of the study, the physicians completed a questionnaire on each patient's tolerance of the studies.

Results

Of the 103 patients enrolled in the study, 98 were able to tolerate both tests, and 5 patients were intolerant to 1 or both tests. The overall tolerance rate of NCS and EMG was 95.1% (0.951, 95% CI 0.897 to 0.981). Age, sex, ethnicity, the type of NCS performed and the type of EMG performed were not associated with NCS or EMG intolerance.

Conclusion

Most patients tolerated the NCS and EMG; however, a small percentage of patients were intolerant. Clinicians should recognise the intolerance of certain patients when introducing and performing electrodiagnostic tests.

A simple test to assist with the diagnosis of common fibular nerve entrapment and predict outcomes of surgical decompression

BACKGROUND

Common fibular (peroneal) nerve (CFN) entrapment is the most frequent nerve entrapment in the lower extremity. It can cause pain, sensory abnormalities, and reduced ability to dorsiflex the foot or a drop foot. A simple test to assist with diagnosis of CFN entrapment is described as an adjunctive clinical tool for the diagnosis of CFN entrapment and also as a predictor of successful surgical decompression of a CFN entrapment.

METHODS

The test, a lidocaine injection into the peroneus longus muscle at the site of a common fibular nerve entrapment, was studied retrospectively in 21 patients who presented with a clinical suspicion of CFN entrapment. Patients ages ranged from 17 to 71 (mean 48.5).

RESULTS

The lidocaine injection test (LIT) was positive in 19 patients, and of these, 17 underwent surgical decompression and subsequently experienced improved ability to dorsiflex their foot and reduced sensory abnormalities.

CONCLUSION

The LIT is a simple, safe adjunctive test to help diagnose and also predict a successful outcome of surgical decompression of a CFN entrapment. The proposed mechanism of action of the LIT could lead to new, non-surgical treatments for CFN entrapment.

Motor amplitudes may predict electromyography-confirmed radiculopathy in patients referred for radiating limb pain

INTRODUCTION

Radiculopathy is diagnosed by needle electromyography, with nerve conduction studies excluding alternative diagnoses.

METHODS

In patients referred for electrodiagnostic evaluation of radiating limb pain, we compared ulnar motor amplitudes between those with and without electromyographically confirmed C8 radiculopathy, as well as fibular motor amplitudes between those with and without electromyographically confirmed L5 radiculopathy.

RESULTS

Patients with electromyographically confirmed C8 or L5 radiculopathy demonstrated decreased ulnar or fibular motor amplitudes, respectively, as compared to patients without radiculopathy. Receiver operating characteristic curves demonstrated good diagnostic accuracy, with areas under the curve of 0.85 and 0.82, respectively. Optimal cut-offs for electromyographically confirmed C8 and L5 radiculopathies were 10.2 mV and 3.6 mV, respectively, with associated sensitivities/specificities of 0.86/0.74 and 0.92/0.60.

DISCUSSION

Ulnar and fibular motor amplitudes may have clinical utility in assessing the likelihood of patients demonstrating electromyographically confirmed C8 and L5 radiculopathies with active denervation. The findings may be particularly useful in patients intolerant of needle electromyography. Muscle Nerve 59:561-561, 2019.

Do Physicians Underestimate Pain in Terminal Cancer Patients? A Prospective Study in a Hospice Setting

OBJECTIVES

Unrelieved pain is present in a majority of terminal cancer patients. However, the treatment of pain in palliative and hospice care is affected by the lack of validated pain assessment. The goal of this study was to evaluate differences in pain evaluation between terminal cancer patients and physicians and evaluate the pain levels as a survival biomarker.

MATERIALS AND METHODS

Patients were evaluated every 7 days for a total of 4 assessments. Physicians evaluated patients' pain on an numeric rating scale (NRS) scale after clinical examination, after which the patients completed NRS, Quality of Life Questionnaire Core 15 Pal (QLQ-C15-PAL), and Edmonton Symptom Assessment System (ESAS) questionnaires.

RESULTS

On average, physicians minimally underestimated the pain level in patients (3.47 vs. 3.94 on an NRS scale). Pain was overestimated in 28% and underestimated in 46% of the patients. However, half of all underestimation was clinically meaningful, compared with 28% of the overestimation. For patients with an NRS score of ≥7, pain underestimation was both clinically and statistically significant (5.56 vs. 8.17). Pain ratings exhibited a very small correlation to survival (up to r=-0.22), limiting their use as a survival biomarker.

DISCUSSION

Although physicians can accurately assess mild pain in terminal cancer patients in the hospice setting, the underestimation of pain is still clinically significant in almost a quarter of patients, and especially pronounced in patients with higher levels of pain and in female patients. Hence, validated pain assessment is a necessity in hospice care, with the choice of pain evaluation tool dependent on patient and physician preference.