336 - The Significance of Electrodiagnostic Evaluation to Establish a Prognosis and Treatment Plan for Chronic Inflammatory Demyelinating Polyneuropathy

Friday, February 23, 2024

5:00 PM – 6:30 PM EDT

Presenting Author(s)

EB

Emily Baysden, MPH

Medical Student
Texas Tech University Health Sciences Center School of Medicine
Amarillo, Texas, United States

Co-Author(s)

NK

Nedha Kinnare, BA

Medical Student
Texas Tech University Health Sciences Center School of Medicine
Amarillo, Texas, United States
DN

Devi S. Nair, BS

Medical Student
Texas Tech University Health Sciences Center School of Medicine
Lubbock, Texas, United States
BZ

Bei Zhang, MD

Assistant Professor
Texas Tech University Health Sciences Center
Lubbock, Texas, United States
John W. Norbury, MD

Division Chief and Residency Program Director
TTUHSC
Lubbock, Texas, United States

Case Diagnosis: Chronic Inflammatory Demyelinating Polyneuropathy

Case Description: A 75-year-old male developed numbness in his left hand and was diagnosed with a C6 radiculopathy based on an electrodiagnostic (EDX) evaluation. He became progressively weak, was diagnosed with acute inflammatory demyelinating polyneuropathy (AIDP), and began IVIG treatment. Over 3 months, he relapsed in quick succession despite IVIG, shifting his diagnosis to chronic inflammatory demyelinating polyneuropathy (CIDP). A second EDX study was performed in the hospital and showed a demyelinating process with a preserved median nerve compound muscle action potential (CMAP). He progressed to a near-locked-in state. Conversations to transition to hospice had begun, however, based on the presence of the CMAP on the second EDX study, ongoing plasmapheresis was initiated. He began to improve; months later, outpatient neuromuscular ultrasound (NMUS) showed slight coalescing of fascicles and an increase in cross-sectional area at the right forearm. He regained his strength and walking ability and eventually returned to his functional baseline.

Discussions: CIDP is an immune-mediated nerve disorder that follows a slowly progressive course. Current protocol recommends EDX only for diagnosis without follow-up studies unless severe complications arise. IVIG and plasmapheresis (+/- glucocorticoids) are standard of care for CIDP. The switch from IVIG to plasmapheresis is indicated in CIDP refractory to IVIG. Repeated high-quality EDX studies could provide a standard measurement tool to assess treatment progress. The line between AIDP and CIDP can be difficult to distinguish. Flexibility in diagnostic decision-making and treatment protocols is necessary to achieve the best possible functional outcome.

Conclusions: EDX evaluations in the acute care hospital can be helpful prognostic tools for patients with CIDP since CMAP amplitude at the time of diagnosis corresponds with the eventual functional outcome. Future research is needed to understand how neuromuscular ultrasound may provide an additional tool to clarify the diagnosis, prognosticate, and possibly monitor response to treatment.