Organic brain syndrome, also known as organic brain disease, organic brain disorder, organic mental syndrome, or organic mental disorder, refers to any

syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek language, Greek σύνδρομον, meaning "concurrence". When a sy ...

disorder Disorder may refer to randomness, non-order, or no intelligible pattern. Disorder may also refer to: Healthcare * Disorder (medicine), a functional abnormality or disturbance * Mental disorder or psychological disorder, a psychological pattern ...

of mental function whose cause is alleged to be known as organic (

physiologic Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical a ...

) rather than purely of the mind. These names are older and nearly obsolete general terms from

psychiatry Psychiatry is the medical specialty devoted to the diagnosis, prevention, and treatment of mental disorders. These include various maladaptations related to mood, behaviour, cognition, and perceptions. See glossary of psychiatry. Initial p ...

, referring to many

physical disorder Physical disorder (as a medical term) is a poorly defined term typically used in contrast to a mental disorder or a genetic disorder. The term mental disorder is heavily used in psychiatric medicine, and is defined in some psychiatric medicine tex ...

s that cause impaired mental function. They are meant to exclude psychiatric disorders (

mental disorder A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitti ...

s). Originally, the term was created to distinguish physical (termed "organic") causes of mental impairment from psychiatric ( termed "functional") disorders, but during the era when this distinction was drawn, not enough was known about brain science (including

neuroscience Neuroscience is the science, scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a Multidisciplinary approach, multidisciplinary science that combines physiology, an ...

, cognitive science,

neuropsychology Neuropsychology is a branch of psychology concerned with how a person's cognition and behavior are related to the brain and the rest of the nervous system. Professionals in this branch of psychology often focus on how injuries or illnesses of t ...

, and mind-brain correlation) for this cause-based classification to be more than educated guesswork labeled with misplaced certainty, which is why it has been deemphasized in current medicine. While mental or behavioural abnormalities related to the dysfunction can be permanent, treating the disease early may prevent permanent damage in addition to fully restoring mental functions. An organic cause to brain dysfunction is suspected when there is no indication of a clearly defined psychiatric or "inorganic" cause, such as a mood disorder.

Types

Organic brain syndrome can be divided into 2 major subgroups: acute (

delirium Delirium (also known as acute confusional state) is an organically caused decline from a previous baseline of mental function that develops over a short period of time, typically hours to days. Delirium is a syndrome encompassing disturbances ...

or acute confusional state) and chronic (

dementia Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affe ...

). A third entity, encephalopathy ( amnestic), denotes a gray zone between delirium and dementia. The

Diagnostic and Statistical Manual of Mental Disorders The ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM; latest edition: DSM-5-TR, published in March 2022) is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common langu ...

has broken up the diagnoses that once fell under the diagnostic category organic mental disorder into three categories: delirium, dementia, and amnestic.

Delirium

''Delirium'' or ''Acute organic brain syndrome'' is a recently appearing state of mental impairment, as a result of intoxication, drug overdose,

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...

, pain, and many other physical problems affecting mental status. In medical contexts, "

acute Acute may refer to: Science and technology * Acute angle ** Acute triangle ** Acute, a leaf shape in the glossary of leaf morphology * Acute (medicine), a disease that it is of short duration and of recent onset. ** Acute toxicity, the adverse ef ...

" means "of recent onset". As is the case with most acute disease problems, acute organic brain syndrome is often temporary, although this does not guarantee that it will not recur or

progress Progress is the movement towards a refined, improved, or otherwise desired state. In the context of progressivism, it refers to the proposition that advancements in technology, science, and social organization have resulted, and by extension w ...

to become chronic, that is, long-term. A more specific medical term for the ''acute'' subset of organic brain syndromes is

. Thinking, remembering, sleeping, and paying attention can become difficult during alcohol withdrawal, after surgery, or with dementia.

Dementia

''Dementia'' or ''chronic organic brain syndrome'' is long-term. For example, some forms of chronic drug or

alcohol dependence Alcohol dependence is a previous (DSM-IV and ICD-10) psychiatric diagnosis in which an individual is physically or psychologically dependent upon alcohol (also chemically known as ethanol). In 2013, it was reclassified as alcohol use disorder ...

can cause organic brain syndrome due to their long-lasting or permanent toxic effects on brain function. Other common causes of chronic organic brain syndrome sometimes listed are the various types of

, 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 organic (physical) injury (a severe blow to the head, stroke, chemical and toxic exposures, organic brain disease, substance use, etc.) and also to non-organic means such as severe deprivation, abuse, neglect, and severe psychological trauma.

Symptoms

Many of the symptoms of Organic Mental Disorder depend on the cause of the disorder, but are similar and include physical or behavioral elements. Dementia and delirium are the cause of the confusion, orientation, cognition or alertness impairment. Therefore, these symptoms require more attention because hallucinations, delusions, amnesia, and personality changes are the result. These effects of the dementia and delirium are not joined with the changes of sensory or perception abilities. Memory impairment, judgment, logical function and agitation are also some extremely common symptoms. The more common symptoms of OBS are

confusion In medicine, confusion is the quality or state of being bewildered or unclear. The term "acute mental confusion"

; impairment of

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remember ...

, judgment, and intellectual function; and agitation. Often these symptoms are attributed to

psychiatric illness A mental disorder, also referred to as a mental illness or psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. Such features may be persistent, relapsing and remitti ...

, which causes a difficulty in

diagnosis Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine "cause and effect". In systems engin ...

Associated conditions

Disorders that are related to injury or damage to the

brain A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...

and contribute to OBS include, but are not limited to: *

Alcoholism Alcoholism is, broadly, any drinking of alcohol that results in significant mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognized diagnostic entity. Predomi ...

Alzheimer's disease Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As ...

Attention deficit/hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inappr ...

Autism The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...

Concussion A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include loss of consciousness (LOC); memory loss; headaches; difficulty with thinking, concentration ...

Encephalitis Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations ...

Epilepsy Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...

* Fetal alcohol syndrome * Hypoxia *

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms beco ...

Intoxication Intoxication — or poisoning, especially by an alcoholic or narcotic substance — may refer to: * Substance intoxication: ** Alcohol intoxication ** LSD intoxication ** Toxidrome ** Tobacco intoxication ** Cannabis intoxication ** Cocaine in ...

overdose A drug overdose (overdose or OD) is the ingestion or application of a drug or other substance in quantities much greater than are recommended.

caused by substance use disorders including

alcohol use disorder Alcoholism is, broadly, any drinking of alcohol that results in significant mental or physical health problems. Because there is disagreement on the definition of the word ''alcoholism'', it is not a recognized diagnostic entity. Predomin ...

* Non-medical use of

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but ...

hypnotic Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia ...

s * Intracranial

hemorrhage Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, v ...

trauma Trauma most often refers to: *Major trauma, in physical medicine, severe physical injury caused by an external source *Psychological trauma, a type of damage to the psyche that occurs as a result of a severely distressing event *Traumatic inju ...

* Korsakoff syndrome *

Mastocytosis Mastocytosis, a type of mast cell disease, is a rare disorder affecting both children and adults caused by the accumulation of functionally defective mast cells (also called ''mastocytes'') and CD34+ mast cell precursors. People affected by mas ...

Meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or ...

Psychoorganic syndrome Psychoorganic syndrome (POS), also known as organic psychosyndrome, is a progressive disease comparable to presenile dementia. It consists of psychopathological complex of symptoms that are caused by organic brain disorders that involve a reductio ...

Stroke A stroke is a disease, medical condition in which poor cerebral circulation, blood flow to the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemorr ...

transient ischemic attack A transient ischemic attack (TIA), commonly known as a mini-stroke, is a minor stroke whose noticeable symptoms usually end in less than an hour. TIA causes the same symptoms associated with strokes, such as weakness or numbness on one side of ...

(TIA) * Withdrawal from drugs, especially

hypnotics, e.g.

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

benzodiazepines Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...

Other conditions that may be related to organic brain syndrome include:

clinical depression Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Intro ...

neuroses Neurosis is a class of functional mental disorders involving chronic distress, but neither delusions nor hallucinations. The term is no longer used by the professional psychiatric community in the United States, having been eliminated from t ...

, and

psychoses Psychosis is a condition of the mind that results in difficulties determining what is Reality, real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are thought disorder, incohe ...

, which may occur simultaneously with the OBS.

Treatment

While the treatment depends on which particular disorder is involved in Organic Mental Disorder, a few that are possible. Treatments can include, but are not limited to, rehabilitation therapy such as physical or occupational, pharmacological modification of the neurotransmitter function, or medication. The affected parts of the brain can recover some function with the help of different types of therapy. Online therapy can be just as intense and helpful as rehabilitation therapy, in person, and can help those affected regain function in daily life.

Prognosis

Some disorders are short-term and treatable, and their prognosis is not as lengthy. Rest and medication are the most common courses of action for these treatable cases to help the patient return to proper health. Many of the cases are long-term, and there is not as much of a set and defined prognosis. The course of action can include extensive counseling and therapy. There are many reasons that the long-term cases are harder to treat and these include these cases normally get worse over time, and medication or therapy could not work. In this case, many of the prognosis tracks are to help the patient and their family become more comfortable and understand what will happen.

Associated conditions

* Brain injury caused by trauma ** Bleeding into the brain (intracerebral hemorrhage) ** Bleeding into the space around the brain (subarachnoid hemorrhage) ** Blood clot inside the skull causing pressure on brain (subdural hematoma) **

* Breathing conditions ** Low oxygen in the body ( hypoxia) ** High carbon dioxide levels in the body (

hypercapnia Hypercapnia (from the Greek ''hyper'' = "above" or "too much" and ''kapnos'' = "smoke"), also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Carbon dioxide is a gaseous p ...

) * Cardiovascular disorders ** Abnormal heart rhythm ( arrhythmias) ** Brain injury due to high blood pressure ( hypertensive brain injury) ** Dementia due to many

strokes A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop funct ...

(multi-infarct dementia) ** Heart infections (

endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...

myocarditis Myocarditis, also known as inflammatory cardiomyopathy, is an acquired cardiomyopathy due to inflammation of the heart muscle. Symptoms can include shortness of breath, chest pain, decreased ability to exercise, and an irregular heartbeat. Th ...

) ** Stroke ** Transient ischemic attack ( TIA) * Degenerative disorders **

(also called senile dementia, Alzheimer's type) **

Creutzfeldt–Jakob disease Creutzfeldt–Jakob disease (CJD), also known as subacute spongiform encephalopathy or neurocognitive disorder due to prion disease, is an invariably fatal degenerative brain disorder. Early symptoms include memory problems, behavioral changes ...

** Diffuse Lewy Body disease **

Huntington's disease Huntington's disease (HD), also known as Huntington's chorea, is a neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an uns ...

Multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This ...

** Normal pressure

hydrocephalus Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain. This typically causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary i ...

Pick's disease Frontotemporal dementia (FTD), or frontotemporal degeneration disease, or frontotemporal neurocognitive disorder, encompasses several types of dementia involving the progressive degeneration of frontal and temporal lobes. FTDs broadly present a ...

* Dementia due to metabolic causes * Drug and alcohol-related conditions ** Alcohol withdrawal state ** Intoxication from drug or alcohol use **

Wernicke–Korsakoff syndrome Wernicke–Korsakoff syndrome (WKS) is the combined presence of Wernicke encephalopathy (WE) and Korsakoff syndrome. Due to the close relationship between these two disorders, people with either are usually diagnosed with WKS as a single syndrom ...

(a long-term effect of excessive alcohol consumption or malnutrition) ** Withdrawal from drugs (especially sedative-hypnotics and

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are inv ...

s) * Infections ** Any sudden onset (acute) or long-term (chronic) infection ** Blood poisoning (

sepsis Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

) ** Brain infection (

encephalitis Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations ...

) **

(infection of the lining of the brain and spinal cord) ** Prion infections such as mad cow disease ** Late-stage syphilis ( general paresis) * Other medical disorders ** Cancer ** Kidney disease ** Liver disease ** Thyroid disease (high or low) ** Vitamin deficiency (B1, B12, or folate) *

Lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense soli ...

toxicity can cause permanent organic brain damage * Accumulation of metals in the brains ** Aluminum **

Mercury poisoning Mercury poisoning is a type of metal poisoning due to exposure to mercury. Symptoms depend upon the type, dose, method, and duration of exposure. They may include muscle weakness, poor coordination, numbness in the hands and feet, skin rashes ...

References

External links

AllRefer Health.com. 13 December 2006.
{{Mental and behavioral disorders, selected = neurological Mental disorders due to brain damage Syndromes