The value of spontaneous electromyographic activity in differentiating ischemic myelopathies from inflammatory demyelinating diseases: A retrospective study.

Background: Differentiating ischemic myelopathies from inflammatory demyelinating diseases is challenging due to overlapping imaging and clinical manifestations. Needle electromyography (EMG) is highly sensitive to spinal anterior horn damage.

Objectives: This study investigates the diagnostic value of spontaneous EMG activity in distinguishing ischemic myelopathies from inflammatory demyelinating diseases.

Methods: We retrospectively analyzed medical records of patients diagnosed with ischemic myelopathies or inflammatory demyelinating diseases at the Neurology Department of Chinese PLA General Hospital from January 2019 to May 2024. All patients underwent needle EMG to evaluate abnormal spontaneous activities. Age- and sex-matched groups were created using 1:1 propensity score matching, and EMG findings were compared. Diagnostic efficacy was evaluated using ROC curve analysis.

Results: Among 119 patients (ischemic myelopathies, 44; inflammatory demyelinating disease, 75), significant differences in age, sex, and EMG spontaneous activity were observed (p < 0.001). After matching, the difference in EMG spontaneous activity remained statistically significant (56.3% vs. 9.4 %, p < 0.001). ROC analysis revealed that EMG spontaneous potential had an AUC of 0.734 (95 % CI 0.609-0.837), with 56.25 % sensitivity and 90.62 % specificity for identifying ischemic myelopathies.

Conclusions: EMG spontaneous potentials may aid in differentiating ischemic myelopathies from inflammatory demyelinating diseases. Their high specificity for ischemic myelopathies (90.62 %) suggests a potential role in improving diagnostic accuracy in spinal cord disorders.