Encephalopathy is a term that means brain disease, damage, or malfunction. Encephalopathy can present a very broad spectrum of symptoms that range from mild, such as some memory loss or subtle personality changes, to severe, such as dementia, seizures, coma, or death. In general, encephalopathy is manifested by an altered mental state that is sometimes accompanied by physical manifestations (for example, poor coordination of limb movements).

The term encephalopathy, in most cases, is preceded by various terms that describe the reason, cause, or special conditions of the patient that leads to brain malfunction. For example, anoxic encephalopathy means brain damage due to lack of oxygen, and hepatic encephalopathy means brain malfunction due to liver disease. Additionally, some other terms either describe body conditions or syndromes that lead to a specific set of brain malfunctions. Examples of these are metabolic encephalopathy and Wernicke's encephalopathy (Wernicke's syndrome). There are over 150 different terms that modify or precede "encephalopathy" in the medical literature; the purpose of this article is to introduce the reader to the main categories of conditions that fall under the broad term of encephalopathy.

Despite the numerous and varied causes of encephalopathy, at least one symptom present in all cases is an altered mental state. The altered mental state may be subtle and develop slowly over years (for example, in hepatitis the decreased ability to draw simple designs, termed apraxia) or be profoundly obvious and develop rapidly (for example, brain anoxia leading to coma or death in a few minutes). Often, symptoms of altered mental status can present as inattentiveness, poor judgment, or poor coordination of movements.

-- lethargy

-- Dementia

-- Seizures

-- tremors

-- muscle twitching and myalgia

-- Coma