Neurological Deterioration in Wilson's Disease-Types, Etiology, Course, and Management.

Wilson's disease (WD) is an inherited disorder of copper metabolism in which pathological copper accumulation, mainly in the liver and the brain, leads to hepatic and/or neuropsychiatric signs and symptoms. Chelators and zinc salts can successfully induce negative copper balance in many patients; however, neurological deterioration may still be observed. This phenomenon can be divided into: (1) early 'paradoxical' neurological deterioration, which usually develops in the first 6 months of anti-copper treatment and may be commonly related to drug type, or (2) late neurological deterioration, which mostly occurs after 6 months of treatment and is often related either to non-compliance with treatment, overtreatment resulting in copper deficiency, or adverse drug reactions. Another explanation, especially for early neurological deterioration, is natural WD progression, which can be difficult to differentiate from drug-related deterioration, but usually leads to a worse outcome. There is still no consensus on how to define neurological deterioration in WD using scales or biomarkers, how to distinguish it from the natural disease progression, its risk factors, and optimal management. This narrative review, based on the current literature, aims to provide definitions, prevalence, pathological mechanisms and factors related to neurological deterioration, and also proposes schemes for diagnosis and treatment.