Neurologic complications of renal disease.

Renal failure and its treatment are associated with a number of neurologic complications that must be differentiated from the nervous system complications of the disease leading to renal failure. Uremic encephalopathy is characterized by clinical signs of depressed brain function coexisting with excitation, often in the form of generalized epileptic seizures. Peripheral neuropathy, due to axonal involvement, is common and is characterized by ascending sensory and motor dysfunction. The treatment of renal failure also may lead to the development of neurologic abnormalities in the form of dialysis disequilibrium characterized by headache, nausea, irritability that may progress to seizures, coma, and death, which is caused by the entry of free water into the brain and swelling. Dialysis dementia, caused by the toxic effects of aluminum, is now rare. Renal transplant recipients may develop cerebrovascular disease, infections by opportunistic organisms, or malignant neoplasms, particularly primary lymphoma of the brain. As transplant recipients live longer and more operations are performed, additional complications may be seen in the future.