There is a form of Alcohol related dementia called Korsakoff's Syndrome that can result from alcohol misuse. It is generally caused by severe lack of Thiamine (vitamin B-1), which is a result of alcohol abuse. There are other conditions that can cause Korsakoff's as well but long term alcohol abuse is the most common. Wernicke's Encephalopathy can also develop causing gait problems. Once the nutrient deficiencies are corrected and the alcohol is cleared from the system the Wernicke's will reverse itself but memory problems will remain unfortunately. Obviously only a neurologist can make a definitive diagnosis, but where long term alcoholism is concerned, Korsakoff's is a more likely suspect than Alzheimer's or other forms of dementia. Hope that info helps, I just happened across it when I was studying up on Alzheimer's to learn more about my dad's condition...