<prompt> A symmetric high-voltage, triphasic slow wave pattern is seen on EEG in the following :Hepatic encephalopathyUremic encephalopathyHypoxic encephalopathyHypercarbic encephalopathy  <response>: Answer is A Hepatic encephalopathy Symmetric, high voltage, triphasic slow wave 2 - 5 second pattern on Electroencephalogram EEG is characteristic but non specific of Hepatic encephalopathy The diagnosis of hepatic encephalopathy should be considered when four major factors are present Acute or chronic hepatocellular disease and or extensive poal systemic collateral shunts. Disturbance of awareness and mentation which may progress from forgetfulness and confusion to stupor and finally coma. Shifting combinations of neurological signs including asterixis, rigidity, hyperreflexia, extensor plantar signs and rarely seizures. A characteristic but nonspecific, symmetric, high voltage, triphasic slow wave 2 to 5 second pattern on electroencephalogram. 