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Copper deficiency myeloneuropathy is a debilitating disorder that causes widespread sensory loss, weakness, and severe gait impairment.  Risk factors include gastrointestinal surgery, malabsorptive syndromes, and chronic zinc supplementation.

A 59-year-old woman with Crohn’s disease s/p gastrojejunostomy presented with one year of progressive gait instability, bilateral hand and lower extremity weakness, and sensory loss that began in the hands before spreading to the feet and then ascending to the chest.  She was seen by an outside neurologist, who diagnosed CIDP and started monthly IVIG infusions, but she continued to decline.  On admission, her examination revealed weakness of hip and knee flexion, wrist flexion and extension, and finger extension and abduction; absent proprioception throughout the lower extremities with decreased proprioception to the metacarpophalangeal joints of both hands; decreased vibration and pinprick sensation to the knees and wrists; and diffuse hyperreflexia with bilateral ankle clonus and Babinski signs.  Laboratory studies showed WBC 3.5 (RR 4.6-10.2), ANC 840 (RR 1790-7850), copper 7 (RR 70-175 mcg/dL), ceruloplasmin 6 (RR 20-60 mg/dL), and zinc 63 (RR 60-130 mcg/dL).  CSF studies were normal.  EMG showed a severe length-dependent axonal sensorimotor polyneuropathy.  MRI of the cervical and thoracic spine demonstrated hyperintense signal in the dorsal columns. The patient endorsed taking a daily zinc supplement since 2021 to prevent infection with COVID-19.  Zinc was discontinued and she was treated with intravenous copper chloride for five days and discharged home on oral copper supplementation without clinical improvement at follow-up one month later.

Clinicians must be vigilant to screen for copper deficiency in patients with unexplained myelopathy,  polyneuropathy, or neutropenia, as delayed diagnosis can lead to irreversible neurological impairment.  Use of zinc supplements, which became popular during the COVID-19 pandemic, is an important risk factor for this condition.