<unk>  can be divided into 2 major subgroups: acute (delirium or acute confusional state) and chronic (dementia). A third entity, encephalopathy (amnestic), denotes a gray zone between delirium and dementia. The Diagnostic and Statistical Manual of Mental Disorders has broken up the diagnoses that once fell under the diagnostic category<unk>  mental disorder into three categories: delirium, dementia, and amnestic. Delirium Delirium or Acute<unk>  is a recently appearing state of mental impairment, as a result of intoxication, drug overdose, infection, pain, and many other physical problems affecting mental status. In medical contexts, "acute" means "of recent onset". As is the case with most acute disease problems, acute<unk>  is often temporary, although this does not guarantee that it will not recur or progress to become chronic, that is, long-term. A more specific medical term for the acute subset of<unk> s is delirium. Thinking, remembering, sleeping, and paying attention can become difficult during alcohol withdrawal, after surgery, or with dementia. Dementia Dementia or chronic<unk>  is long-term. For example, some forms of chronic drug or alcohol dependence can cause<unk>  due to their long-lasting or permanent toxic effects on brain function. Other common causes of chronic<unk>  sometimes listed are the various types of dementia, which result from permanent brain damage due to strokes, Alzheimer's disease, or other damaging causes which are irreversible. Amnestic pertains to amnesia and is the impairment in ability to learn or recall new information, or recall previously learned information. Although similar, it is not coupled with dementia or delirium. Amnestic Amnestic conditions denotes a gray zone between delirium and dementia; its early course may fluctuate, but it is often persistent and progressive. Damage to brain functioning could be due not only to<unk>  (physical) injury (a severe blow to the head, stroke, chemical and toxic exposures,<unk>  brain disease, substance use, etc.) and also to non-organic means such as severe deprivation, abuse, neglect, and severe psychological trauma.
Organic brain syndrome
Diencephalic syndrome
Acquired brain injury
Otodental syndrome
Chiasmal syndrome
Traumatic brain injury
Pediatric concussion
Autoimmune encephalitis