(Kiosk 1) Severe Copper Deficiency While Using Zinc-containing Dental Cream Results in Posterior Column Abnormalities and Myeloneuropathy: A Case Study

Case Diagnosis: Copper deficiency is commonly underdiagnosed. Common clinical findings include anemia, leukopenia, and neurological changes. The main causes of copper deficiency are bariatric surgery, increased zinc consumption, and malabsorption. Myeloneuropathy can be a rare presentation for copper deficiency. A diagnosis of myeloneuropathy requires a high level of clinical suspicion. MRI findings usually include hyperdensities in the spinal cord. EMG and NCS testing can also be helpful in guiding a diagnosis.

Case Description or Program Description: We present a case of a 62-year-old female with history of anemia who developed a severe copper deficiency after using zinc-containing dental cream leading to posterior column abnormalities and myeloneuropathy. The patient had progressively decreased sensation, ataxia, and unintentional weight loss. EMG results indicated an axonal sensorimotor neuropathy. MRI of the spine showed dorsal column abnormalities from C1-T9. The patient was started on copper replacement, discontinued zinc-containing dental cream, and completed physical therapy; symptoms improved with these interventions.

Setting: Outpatient Physical Medicine and Rehabilitation Clinic

Assessment/Results: MRI of the spine showed T2 hyperdensities in the dorsal column from C1-T9.
EMG results indicated an axonal sensorimotor neuropathy.

Discussion (relevance): The unique clinical course and presentation of this patient provides an opportunity to provide more timely care for patients with similar symptoms. There is limited data addressing zinc toxicity with copper deficiency and even more limited data regarding copper deficiency myeloneuropathy. Zinc toxicity is a rare and underdiagnosed cause of copper deficiency. This case represents the challenges associated with diagnosing and treating myeloneuropathies and may provide some clinical guidance when presented with a case of unique neurologic symptoms, weight loss, and blood dyscrasias.

Conclusions: Although the patient presented with symptoms of a distal-symmetric peripheral sensorimotor neuropathy, atypical symptoms raised concerns for further diagnosis. Although further diagnostic testing did confirm an axonal sensorimotor neuropathy and a copper deficiency, posterior cord abnormalities were also noted on spinal MRI. The patient’s response to copper replacement, discontinuation of zinc-containing cream and therapy reflects the importance of a timely diagnosis and treatment.