Uremic encephalopathy is a complication of renal failure leading to cerebral dysfunction. It is characterized by nausea, vomiting, lethargy and disorientation in the initial stages progressing to delirium, seizures and later coma, if untreated. Diagnosis is based on clinical signs, cognitive tests, renal function tests, serum biochemistry, and imaging studies of the brain.
Uremic encephalopathy (UE) is an acquired metabolic complication of renal failure with accumulation of toxic metabolites which cross the blood brain barrier to cause cerebral dysfunction. It manifests in the form of acute or subacute neurological features which are usually reversible    . Initial symptoms of UE are nausea, vomiting, loss of appetite, drowsiness, inability to concentrate emotional lability, irritability, confusion progressing, if untreated, to seizures, delirium, myoclonus, asterixis and coma .
Once treatment of renal dysfunction is instituted patients may present with impaired cognition, generalized asthenia, and peripheral neuropathy . Renal dialysis in chronic renal failure or end-stage renal disease is associated with dysequilibrium and dementia. Dialysis-associated disequilibrium is characterized by nausea, muscle cramps, altered sensorium, and seizures while dialysis-associated dementia is a progressive condition with increased incidence of mortality seen in patients on long-term hemodialysis. Dialysis encephalopathy can be either sporadic, epidemic or associated with pediatric renal disease .
Workup in a patient presenting with confusion, nystagmus, hyperreflexia, clonus, asterixis and coma should include a thorough history and neurological examination. An ophthalmic examination may reveal papilledema. UE can be evaluated with many cognitive tests to measure psychomotor speed, short-term recognition and ability to make simple decisions. Laboratory tests are likely to show anemia (due to chronic renal disease), leukocytosis (if there is an underlying infection), with renal function tests  showing severely elevated blood urea nitrogen and serum creatinine levels. Serum electrolyte and glucose levels should be ordered to evaluate sodium and blood glucose levels to exclude electrolyte abnormalities, hyperglycemia, and hyperosmolar syndromes. Serum calcium, magnesium, phosphate and parathyroid hormone levels should be checked to exclude other causes of encephalopathy. A toxicology screen should also be performed. An electroencephalogram (EEG) obtained in UE is likely to show a disorganized pattern with absent alpha waves and occasional theta and delta waves.
Imaging studies like magnetic resonance imaging (MRI) or computed tomography (CT) scan of the head are only indicated to exclude intracranial tumors and hematoma or hemorrhage. CT scan findings are not specific for UE but MRI will reveal an increase in signal intensity either in the cerebral cortex or in the basal ganglia.  . This is also called the lentiform fork sign. Based on the MRI findings, UE has been classified into two varieties :