Session Information
Session Title: AA 2021 Virtual Posters - Neurological Rehabilitation
Session Time: None. Available on demand.
Disclosures: Eric Kessler, MD: No financial relationships or conflicts of interest
Case Diagnosis: 51-year-old woman with a history of chronic neck pain, found to have myotonic discharges on EMG
Case Description: A 51-year-old woman with history of anterior cervical discectomy and fusion (C4-C6) and bilateral carpal tunnel syndrome (CTS) presented with neck pain and right arm weakness that initially resolved after her surgery in 2018 but returned eight months after surgery. She endorsed heaviness, fatigue and stiffness in her right arm and hand, and left leg paresthesias. Her exam showed normal strength and positive Hoffman’s sign bilaterally. Magnetic resonance imaging (MRI) of her cervical spine showed post-procedural changes and progression of degenerative changes. Lyrica, injections (cervical epidural, trigger point, facet) and physical therapy provided limited benefit. Initial electromyography (EMG) and nerve conduction study (NCS) done in 2020 showed bilateral CTS. Patient was referred for repeat EMG/NCS in January 2021, which showed diffuse myotonic discharges throughout the upper extremities and left lower extremity, suggesting a generalized myotonia. Clinically, she had no dystrophic features or proximal weakness.
Setting: Outpatient specialty clinicsAssessment/
Results: The patient was referred to a neuromuscular specialist for genetic testing for myotonia. She was also instructed to stop taking fenofibrate given the possibility of drug induced myotonia.
Discussion: Myotonic disorders are characterized by impaired muscle relaxation following voluntary contraction. EMG shows repetitive discharges with waxing and waning amplitude and frequency. Presentations range from asymptomatic electrical myotonia to weakness, stiffness and pain. Certain medications (for example, cholesterol lowering agents) can cause electrical myotonia. This case report presents diffuse myotonia in a patient with chronic neck pain. EMG findings may be incidental versus a potential cause of chronic neck pain and bilateral CTS.
Conclusion: Due to clinical overlap with other conditions, myotonic disorders may be missed as a potential cause of chronic neck pain associated with bilateral CTS. Evaluation with EMG and early diagnosis can prevent unnecessary surgeries and treatment.
Level of Evidence: Level V
To cite this abstract in AMA style:
Kessler E, Portugal SE, Lin J. Myotonic Discharges on Electromyography in a Patient with Chronic Neck Pain [abstract]. PM R. 2021; 13(S1)(suppl 1). https://pmrjabstracts.org/abstract/myotonic-discharges-on-electromyography-in-a-patient-with-chronic-neck-pain/. Accessed May 31, 2025.« Back to AAPM&R Annual Assembly 2021
PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/myotonic-discharges-on-electromyography-in-a-patient-with-chronic-neck-pain/