Neurological complications in renal failure: a review

Abstract

Neurological complications whether due to the uremic state or its treatment, contribute largely to the morbidity and mortality in patients with renal failure. Despite continuous therapeutic advances, many neurological complications of uremia, like uremic encephalopathy, atherosclerosis, neuropathy and myopathy fail to fully respond to dialysis. Moreover, dialytic therapy or kidney transplantation may even induce neurological complications. Dialysis can directly or indirectly be associated with dialysis dementia, dysequilibrium syndrome, aggravation of atherosclerosis, cerebrovascular accidents due to ultrafiltration-related arterial hypotension, hypertensive encephalopathy, Wernicke's encephalopathy, hemorrhagic stroke, subdural hematoma, osmotic myelinolysis, opportunistic infections, intracranial hypertension and mononeuropathy. Renal transplantation itself can give rise to acute femoral neuropathy, rejection encephalopathy and neuropathy in graft versus host disease. The use of immunosuppressive drugs after renal transplantation can cause encephalopathy, movement disorders, opportunistic infections, neoplasms, myopathy and progression of atherosclerosis. We address the clinical, pathophysiological and therapeutical aspects of both central and peripheral nervous system complications in uremia.

Introduction

Patients with renal failure often have signs and symptoms related to fluid and electrolyte disturbances, anemia, malnutrition, bone disease and gastrointestinal problems. Vascular and neurologic impairment in particular remain an important source of morbidity and mortality in this vulnerable patient population.

In this paper, disease related and treatment related neurological complications in renal failure will be reviewed. With the introduction of dialysis and renal transplantation, the spectrum of neurological complications changed. The incidence and severity of uremic encephalopathy, atherosclerosis, neuropathy and myopathy have declined but many patients fail to fully respond to dialytic therapy.

Moreover, dialytic therapy or kidney transplantation may even induce neurological complications. Dialysis dementia, dialysis dysequilibrium syndrome, hypertensive encephalopathy and cerebrovascular accident due to ultrafiltration-related arterial hypotension can occur as a direct consequence of dialysis. Furthermore, dialysis is associated with aggravation of atherosclerosis and can contribute to the development of Wernicke's encephalopathy, hemorrhagic stroke, subdural hematoma, osmotic myelinolysis, opportunistic infections, intracranial hypertension and neuropathy. Patients with renal failure may benefit from kidney transplantation, but the use of immunosuppressive drugs can cause encephalopathy, movement disorders, opportunistic infections, neoplasms, myopathy and progression of atherosclerosis. Renal transplantation itself can give rise to acute femoral neuropathy, rejection encephalopathy and neuropathy in graft versus host disease (Table 1). In what follows, we will address both central and peripheral nervous system complications in patients with renal failure.