(Kiosk 3) Segmental Demyelinating Polyneuropathy Contributing to Weakness in Spinal Cord Compression: A Case Report

Case Diagnosis: 64-year-old male with bilateral lower extremity weakness, urinary retention, and constipation

Case Description or Program Description: The patient is a 64-year-old male with hypertension and rheumatoid arthritis, and was previously independent for self-care, activities of daily living, and ambulation who presented with one week of bilateral lower extremity weakness, urinary retention, and constipation. Magnetic resonance imaging (MRI) of the thoracolumbar spine showed multiple osseous lesions in the thoracic spine with an associated large right posterior epidural mass resulting in severe central stenosis and cord compression at the T3 level. He was diagnosed with a T4 incomplete spinal cord injury. Bone marrow biopsy confirmed a diagnosis of multiple myeloma. Management included a steroid course and radiation therapy.
The lower extremity weakness was not improving at inpatient rehab as anticipated with high dose steroids. A magnetic resonance image of his spine was obtained which did not demonstrate a mechanical cause of compression to explain the symptoms.

Setting: Electrodiagnostic Laboratory

Assessment/Results: Electromyography and nerve conduction study (EMG/NCS) found temporal dispersion of the compound muscle action potentials with prolonged latencies indicative of a motor more than sensory demyelinating peripheral polyneuropathy.

Discussion (relevance): In denervated muscles, increased neuromuscular activity during the acute phase of sprouting compromises sprouting. It was recommended that he avoid strength exercises to the most severely denervated areas of his legs for the next three to four months to help with reinnervation, but to continue with activities of daily living and ambulation as this type of exercise would promote reinnervation and maintain the muscle architecture. This diagnosis altered treatment plan while in acute inpatient rehabilitation.

Conclusions: Physicians should have a low threshold to obtain further work up, including EMG/NCS, if a patient is not progressing as they should in acute inpatient rehab as it could reveal need for further medical intervention as well as affect therapy interventions.