Is there an aftermath of encephalopathy?

Maybe: Depends on the cause of the encephalopathy. If it was due to changes in metabolism (like cirrhosis, diabetes, etc.) then it may be quite reversible but there are some causes which may produce permanent and perhaps progressive damages.

Depends on the cause: Most patients will recover from metabolic causes once they are reversed, , this is the most common scenario. So if someone is confused from a bad reaction to a drug they will get better once the drug is stopped, or if from kidney failure they get better once the kidney's recover or with dialysis. If the brain itself is directly injured ( stroke, head injury etc..) the recovery can be variable.

Possibly: In many cases there can be fatigue, difficulty concentrating, and excessive sleepiness. Impaired calculating ability, handling stressful situations and labile emotions can all occur. Many of these symptoms tend to improve with time.