Neurological manifestations of uraemia and chronic dialysis.

BACKGROUND

The management of uraemic neurological manifestations is a major target of the treatment of the uraemic syndrome. Chronic dialysis is associated with novel neurological manifestations.

OBJECTIVE

To describe the clinical characteristics, pathogenesis and management of the main neurological syndromes encountered in uraemia and chronic dialysis.

METHODS

Review of the pertinent literature. Selected references, which have been critical in the understanding of the topic, were included in this review.

RESULTS

The main neurological manifestations of uraemia include encephalopathy, neuropathy that can affect cranial, peripheral and autonomic nerves, and proximal myopathy. Retention of uraemic toxins is the main putative cause of uraemic encephalopathy and neuropathy. Arrest or prevention of uraemic encephalopathy and neuropathy are main targets of the dialytic treatment and constitute major criteria of its adequacy. The main cause of uraemic myopathy is secondary hyperparathyroidism and parathyroidectomy is its main treatment. Chronic dialysis is associated with three main neurological syndromes, the disequilibrium syndrome, seen usually in the first few haemodialysis sessions and prevented by starting dialysis with a low dose and progressively increasing the dialysis dose in subsequent dialysis sessions, dialysis dementia, which results from aluminium overloading and is prevented by reducing exposure of the dialysis patients to aluminium, and nerve entrapment, particularly carpal tunnel syndrome, which is caused by beta2-microglobulin amyloidosis and may be prevented by the use of high-flux dialysers which provide relatively high clearance for beta2-microglobulin or by daily haemodialysis.

CONCLUSIONS

Specific neurological manifestations are part of the uraemic syndrome and may complicate chronic dialysis. The diagnosis of these manifestations, their differentiation from other neurological syndromes that can complicate the course of renal failure or dialysis, and their specific treatment require clinical acumen and represent a major challenge for physicians treating patients with chronic renal failure or undergoing chronic dialysis.