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Neurology

Electrodiagnostic Testing for Diagnosing Polyneuropathy

Educational Objective
To understand how to interpret the results of diagnostic tests and apply them clinically.

1 Credit CME

JAMA

Published Online: November 16, 2021

JAMA Diagnostic Test Interpretation

Article Information and Disclosures

Ryan D. Jacobson, MD¹;

Michelle Glantz, DO¹

Author Affiliations

¹Department of Neurological Sciences, Rush University, Chicago, Illinois

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A 50-year-old woman with a history of seizures presented to the electromyography laboratory with progressive lower extremity pain and gait imbalance for approximately 5 years. A neurological examination demonstrated reduced pinprick sensation in both feet and absent vibratory sensation at the first toes. Mild weakness of ankle dorsiflexion and absent ankle jerk reflexes were noted bilaterally. She had a slightly wide-based gait, high-arched feet, and hammer toes. She had no known family history of polyneuropathy and no history of diabetes, alcohol misuse, known vitamin deficiency, hypothyroidism, or HIV. Nerve conduction studies (NCS) and needle electromyography (EMG) were performed. The results are shown in Table 1 and Table 2.

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A 50-year-old woman with a history of seizures presented to the electromyography laboratory with progressive lower extremity pain and gait imbalance for approximately 5 years. A neurological examination demonstrated reduced pinprick sensation in both feet and absent vibratory sensation at the first toes. Mild weakness of ankle dorsiflexion and absent ankle jerk reflexes were noted bilaterally. She had a slightly wide-based gait, high-arched feet, and hammer toes. She had no known family history of polyneuropathy and no history of diabetes, alcohol misuse, known vitamin deficiency, hypothyroidism, or HIV. Nerve conduction studies (NCS) and needle electromyography (EMG) were performed. The results are shown in Table 1 and Table 2.

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Article Information

Corresponding Author: Ryan D. Jacobson, MD, Department of Neurological Sciences, Rush University, 1725 W Harrison St, Ste 1118, Chicago, IL 60612 (ryan_jacobson@rush.edu).

Conflict of Interest Disclosures: None reported.

References

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Centers for Medicare and Medicaid Services. Physician fee schedule look-up tool. Accessed August 19, 2021. https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/PFSlookup

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Stuppia G , Rizzo F , Riboldi G , et al. MFN2-related neuropathies: clinical features, molecular pathogenesis and therapeutic perspectives. J Neurol Sci. 2015;356(1-2):7-18. doi:10.1016/j.jns.2015.05.033 PubMed Google Scholar Crossref

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AMA CME Accreditation Information

Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00  AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:

1.00 Medical Knowledge MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program;;
1.00 Self-Assessment points in the American Board of Otolaryngology – Head and Neck Surgery’s (ABOHNS) Continuing Certification program;
1.00 MOC points in the American Board of Pediatrics’ (ABP) Maintenance of Certification (MOC) program;
1.00 Lifelong Learning points in the American Board of Pathology’s (ABPath) Continuing Certification program; and
1.00 credit toward the CME [and Self-Assessment requirements] of the American Board of Surgery’s Continuous Certification program

It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.