Hepatic Encephalopathy Grade IV EEG

A 58-year-old male with Child-Pugh Class C cirrhosis from chronic hepatitis C and alcohol use presents with progressive confusion, disorientation, and unresponsiveness over 48 hours. He is now comatose with a Glasgow Coma Scale of 6. Laboratory investigations show serum ammonia of 285 μmol/L, INR 3.8, and total bilirubin 18.2 mg/dL. Bedside EEG is performed to assess the severity of metabolic encephalopathy. The pattern marked **A** in the diagram—generalized high-amplitude triphasic waves at 1.5–2 Hz with frontal predominance—is observed. Which of the following best describes the clinical significance of this EEG finding?