[Chorea in hemodialysis: Is chorea just a neurological syndrome or is it related to uremia or dialysis?].

Chronic renal failure and haemodialysis patients are prone to develop encephalopathy. The causes of encephalopathy are often unclear. Clinical signs of encephalopathy in the uraemic patient often overlap with several other affections causing neurological disorders. Whenever basal ganglia are anatomically involved, movement disorders arise, including chorea. Some acute and chronic neurological syndromes associated with chronic uraemia have consistently been reported (uraemic encephalopathy, dialysis disequilibrium syndrome, dialysis dementia, nephroangiosclerosis neuropathy and ageing neuropathy). Other clinical conditions in which neurological involvement exists are not so frequent in both haemodialysis patients and in the general population (Wernicke's encefalopathy, Creutzfeldt-Jacob disease). Because of the non specific symptoms and the very heterogeneous aetiology, a careful physical examination should be performed in haemodialysis patients with clinical signs of encephalopathy and the main metabolic alterations should be sought; moreover, central nervous system imaging examination is often appropriate. In case of basal ganglia anatomical involvement, supported by findings of imaging techniques, it is necessary to evaluate individual causes of encephalopathy by means of more accurate tests including analysis of cerebro-spinal fluid, measurement of plasma levels of vitamin B components and laboratory tests searching for more uncommon diseases such as Huntington's chorea and Wilson's disease.