Copper deficiency in Wilson's disease: an avoidable complication of treatment

Neurological complications due to copper deficiency in the context of Wilson disease treatment: a case report with long-term follow-up and review of the literature

The objective is to investigate the presentation, complications, management, and outcomes of copper deficiency-induced neurological pathologies due to Wilson disease (WD) overtreatment. We examined the case of a WD patient who developed a low thoracic dorsal myelopathy due to chronic hypocupremia from excessive zinc therapy. A comprehensive literature review was conducted to identify similar cases. Ten additional cases of neurological pathology resulting from copper deficiency in the context of WD over-treatment were identified, all occurring during therapy with zinc salts. Myelopathy and peripheral neuropathy were the most common complications, while two additional groups reported leukoencephalopathy. Early cytopenia was often associated with copper deficiency-related neurological pathology appearing early in the context of copper deficiency. WD patients undergoing treatment, especially with zinc salts, should be closely monitored to prevent over-treatment and the consequent copper deficiency. Regular complete blood counts could provide early detection of copper deficiency, avoiding irreversible neurological damage. Swift recognition of new neurological signs not consistent with WD and timely discontinuation of the decoppering therapy are critical for improving outcomes. The optimal management, including the potential benefit of copper supplementation in patients with WD and subsequent therapy adjustments, remains unclear and necessitates further investigation. Despite the general poor functional neurological outcomes, there were some exceptions that warrant further exploration.

Neurological presentations revealing acquired copper deficiency: diagnosis features, aetiologies and evolution in seven patients

BACKGROUND

Acquired copper deficiency (ACD) is a rare condition usually diagnosed from haematological changes.

AIMS

To characterise the diagnosis features and the evolution of patients with ACD revealed by neurological symptoms.

METHODS

Clinical, biological and magnetic resonance imaging (MRI) data were prospectively analysed at diagnosis and during follow up under copper supplementation.

RESULTS

Seven patients were studied over a 5-year period. Time to diagnosis ranged from 2.5 to 15 months. Subacute ascending paraesthesias and gait disorder were the first symptoms. All patients had a posterior cord syndrome (PCS) with sensory ataxic gait associated with superficial hypoesthesia of the feet; 50% had also lateral cord signs. Electrodiagnostic tests diagnosed a lower limb sensory neuropathy in four patients. Spinal cord MRI was normal in three of seven patients. Anaemia and lymphopenia were diagnosed in six of seven patients. Serum copper was always low, and urinary copper was low or normal. Serum and urinary zinc were high in four patients. Decreased copper intake (stoma/parenteral nutrition, malnutrition, malabsorption with lack of vitamin supplementation after bariatric or other digestive surgeries) was found in four patients, and the chronic use of denture adhesive paste containing zinc was discovered in four patients. One patient had both the causes recorded. After copper supplementation, copper balance and then haematological disturbances were the first features to normalise gradually in 2 months. Radiological myelitis disappeared in 10 months, whereas neurological symptoms improved in six of seven patients after a mean follow up of 2 years.

CONCLUSIONS

Progressive PCS with anaemia and lymphopenia must raise the possibility of an ACD. Early copper supplementation could increase the neurological prognosis.

Update on the clinical management of Wilson's disease

Wilson's disease (WD), albeit relatively rare, is an important genetic metabolic disease because of highly effective therapies that can be lifesaving. It is a great imitator and requires a high index of suspicion for correct and timely diagnosis. Neurologic, psychiatric and hepatologic problems in WD are very nonspecific, and we discuss the most common clinical phenotypes. The diagnosis remains laboratory based, and here we review the most important challenges and pitfalls in laboratory evaluation of WD, including the emerging role of genetic testing in WD diagnosis. WD is a monogenic disorder but has very high allelic heterogeneity with >500 disease-causing mutations identified, and new insights into phenotype-genotype correlations are also reviewed. The gold standard of therapy is chelation of excessive copper, but many unmet needs exist because of possible clinical deterioration in treated patients and potential adverse effects associated with currently available chelating medications. We also review the most promising novel therapeutic approaches, including chelators targeting specific cell types, cell transplantation and gene therapy.