Case Report: Zinc containing dental fixative causing copper deficiency myelopathy

摘要

A 62-year-old male, previously well, was referred to neurology clinic following 6 months history of worsening lower limbs instability, paraesthesia, pain and weakness rendering him housebound. Examination revealed upper motor neuron pattern of weakness of the lower limbs and loss of proprioception. Serum analysis revealed reduced caeruloplasmin and copper levels with raised zinc. Spinal imaging revealed subtle dorsal column intensity changes in C2-C7, confirmed with 3T MRI. A copper deficiency myeloneuropathy was diagnosed secondary to chronic use of a zinc-containing dental fixative paste. The paste was discontinued and a copper supplementation was started. Resolution of symptoms was not achieved with intensive physiotherapy. The patient remains a wheelchair user though progression of symptoms has halted. Prompt recognition and treatment of hyperzincaemia-induced hypocupraemia earlier in the disease course may have prevented any irreversible neurological deficit.