"Some causes of Dementia or Dementia-like symptoms can be reversed. Your doctor may identify and treat these causes:
Infections and immune disorders. Dementia-like symptoms can result from fever or other side effects of your body's attempt to fight off an infection. People may develop thinking difficulties if they have infections like a urinary tract infection (UTI), meningitis and encephalitis, untreated syphilis, Lyme disease, or conditions that cause a completely compromised immune system, such as leukemia.
Metabolic problems and endocrine abnormalities. People with thyroid problems, too little sugar in the bloodstream (hypoglycemia), too low or too high amounts of sodium or calcium, or an impaired ability to absorb vitamin B-12 may develop Dementia-like symptoms or other personality changes.
Nutritional deficiencies. Dementia-like symptoms can occur as a result of not drinking enough liquids (dehydration); not having enough thiamin (vitamin B-1), a condition common in people with chronic alcoholism; and not having enough vitamins B-6 and B-12 in your diet.
Reactions to medications. Dementia-like symptoms may occur as a reaction to a single medication or because of an interaction of several medications.
Subdural hematomas. Subdural hematomas are caused by bleeding between the surface of the brain and the covering over the brain. They can cause symptoms similar to Dementia.
Poisoning. Dementia-like symptoms can occur as a result of exposure to heavy metals, such as lead, and other poisons, such as pesticides. Dementia-like symptoms may also occur in some people who have abused alcohol or recreational drugs [See also Wernicke-Korsakoff Syndrome (WKS)]. Symptoms may disappear after treatment, but in some cases symptoms may still be present after treatment.
Brain tumors. Dementia rarely can result from damage caused by a brain tumor.
Anoxia. This condition, also called hypoxia, occurs when organ tissues aren't getting enough oxygen. Anoxia may occur due to severe asthma, heart attack, carbon monoxide poisoning or other causes. If you've experienced a severe lack of oxygen, recovery may take longer. Symptoms, such as memory problems or confusion, may occur during recovery.
Normal-pressure hydrocephalus. Sometimes people have a condition caused by enlarged ventricles in the brain (normal-pressure hydrocephalus). This condition can cause walking problems, urinary difficulty and memory loss. Shunt surgery, which delivers cerebrospinal fluid from the head to the abdomen or heart, may help these symptoms."
Source: click here.