Delirium

deliriousconfusionAcute confusional stateacute confusionchange in mental statusimpaired cognitionA temporary state of confusion (delirium)acute deliriumdelirious statedelirious syndrome
Delirium, also known as acute confusional state, is an organically caused decline from a previous baseline mental functioning that develops over a short period of time, typically hours to days.wikipedia
439 Related Articles

Bipolar disorder

bipolarmanic depressionmanic depressive
schizophrenia, bipolar disorder) do not, by definition, meet the criteria for 'delirium.'
Mania is a distinct period of at least one week of elevated or irritable mood, which can range from euphoria to delirium, and those experiencing hypomania or mania generally exhibit several of the following behaviors: speaking in a rapid, uninterruptible manner, decreased need for sleep, short attention span, racing thoughts, increased goal-oriented activities, agitation, or exhibition of behaviors characterized as impulsive or high-risk, such as hypersexuality or excessive spending.

Organic brain syndrome

organic brain diseaseorganic brain damageorganic brain disorder
Delirium is caused by an acute organic process, which is a physically identifiable structural, functional, or chemical problem in the brain that may arise from a disease process outside the brain that nonetheless affects the brain. Without careful assessment and history, delirium can easily be confused with a number of psychiatric disorders or chronic organic brain syndromes because of many overlapping signs and symptoms in common with dementia, depression, psychosis, etc. Delirium may manifest from a baseline of existing mental illness, baseline intellectual disability, or dementia, without being due to any of these problems.
A more specific medical term for the acute subset of organic brain syndromes is delirium.

Psychosis

psychoticpsychosespsychotic break
Without careful assessment and history, delirium can easily be confused with a number of psychiatric disorders or chronic organic brain syndromes because of many overlapping signs and symptoms in common with dementia, depression, psychosis, etc. Delirium may manifest from a baseline of existing mental illness, baseline intellectual disability, or dementia, without being due to any of these problems.

Mental disorder

mental illnessnervous breakdownmentally ill
Without careful assessment and history, delirium can easily be confused with a number of psychiatric disorders or chronic organic brain syndromes because of many overlapping signs and symptoms in common with dementia, depression, psychosis, etc. Delirium may manifest from a baseline of existing mental illness, baseline intellectual disability, or dementia, without being due to any of these problems.
This category includes delirium and mild and major neurocognitive disorder (previously termed dementia).

Dementia

senilesenilitysenile dementia
Without careful assessment and history, delirium can easily be confused with a number of psychiatric disorders or chronic organic brain syndromes because of many overlapping signs and symptoms in common with dementia, depression, psychosis, etc. Delirium may manifest from a baseline of existing mental illness, baseline intellectual disability, or dementia, without being due to any of these problems.
Encephalopathy or delirium may develop relatively slowly and resemble dementia.

Consciousness

consciousconsciouslyhuman consciousness
While requiring an acute disturbance in consciousness/attention and cognition, delirium is a syndrome encompassing an array of neuropsychiatric symptoms.
In medicine, consciousness is assessed by observing a patient's arousal and responsiveness, and can be seen as a continuum of states ranging from full alertness and comprehension, through disorientation, delirium, loss of meaningful communication, and finally loss of movement in response to painful stimuli.

Syndrome

syndromesgenetic syndromessyndromic
Delirium is a syndrome encompassing disturbances in attention, consciousness, and cognition.
In Russia those psychopathological syndromes are used in modern clinical practice and described in psychiatric literature in the details: asthenic syndrome, obsessive syndrome, emotional syndromes (for example, manic syndrome, depressive syndrome), Cotard's syndrome, catatonic syndrome, hebephrenic syndrome, delusional and hallucinatory syndromes (for example, paranoid syndrome, paranoid-hallucinatory syndrome, Kandinsky-Clérambault's syndrome also known as syndrome of psychic automatism, hallucinosis), paraphrenic syndrome, psychopathic syndromes (includes all personality disorders), clouding of consciousness syndromes (for example, twilight clouding of consciousness, amential syndrome also known as amentia, delirious syndrome, stunned consciousness syndrome, oneiroid syndrome), hysteric syndrome, neurotic syndrome, Korsakoff's syndrome, hypochondriacal syndrome, paranoiac syndrome, senestopathic syndrome, encephalopathic syndrome.

Benzodiazepine

benzodiazepinesbenzodiazapinesbenzo
When delirium is caused by alcohol or sedative hypnotic withdrawal, benzodiazepines are typically used.
Benzodiazepines are the preferred choice in the management of alcohol withdrawal syndrome, in particular, for the prevention and treatment of the dangerous complication of seizures and in subduing severe delirium.

Orientation (mental)

disorientationorientationdisoriented
Problems with orientation lead to disorientation, and can be due to various conditions, from delirium to intoxication.

Orthostatic hypotension

postural hypotensionlow blood pressure with standingfeeling lightheaded with standing
Moderate drops in blood pressure can cause confusion/inattention, delirium, and episodes of ataxia.

Tangential speech

tangentialitytangentialtangentialiry
It tends to occur in situations where a person is experiencing high anxiety, as a manifestation of the psychosis known as schizophrenia, in dementia or in states of delirium.

Thought disorder

formal thought disorderdisorganized thinkingabnormal thinking
Patients with a clouded consciousness, like that found in delirium, also have a formal thought disorder.

Schizophrenia

schizophrenicschizophrenicspositive symptoms
schizophrenia, bipolar disorder) do not, by definition, meet the criteria for 'delirium.'
It may be necessary to rule out a delirium, which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness, and indicates an underlying medical illness.

Opioid

opioidsopioid-induced constipationopioid analgesic
Infrequent adverse reactions in patients taking opioids for pain relief include: dose-related respiratory depression (especially with more potent opioids), confusion, hallucinations, delirium, urticaria, hypothermia, bradycardia/tachycardia, orthostatic hypotension, dizziness, headache, urinary retention, ureteric or biliary spasm, muscle rigidity, myoclonus (with high doses), and flushing (due to histamine release, except fentanyl and remifentanil).

Hyperthyroidism

thyrotoxicosishyperthyroidoveractive thyroid
Major clinical signs include weight loss (often accompanied by an increased appetite), anxiety, heat intolerance, hair loss (especially of the outer third of the eyebrows), muscle aches, weakness, fatigue, hyperactivity, irritability, high blood sugar, excessive urination, excessive thirst, delirium, tremor, pretibial myxedema (in Graves' disease), emotional lability, and sweating.

Anticholinergic

anticholinergicsanticholinergic druganticholinergic syndrome
Earliest rodent models of delirium used atropine (a muscarinic acetylcholine receptor blocker) to induce cognitive and electroencephalography (EEG) changes similar to delirium, and other anticholinergic drugs, such as biperiden and hyoscine, have produced similar effects.
Possible effects in the central nervous system resemble those associated with delirium, and may include:

Electroencephalography

EEGelectroencephalogramelectroencephalograph
Electroencephalography (EEG) allows for continuous capture of global brain function and brain connectivity, and is useful in understanding real-time physiologic changes during delirium.

Haloperidol

HaldolHaloparidolhaloperidol decanoate
Low-dose haloperidol when used short term (one week or less) is the most studied and standard drug for delirium.
Haloperidol is used in the treatment of schizophrenia, tics in Tourette syndrome, mania in bipolar disorder, nausea and vomiting, delirium, agitation, acute psychosis, and hallucinations in alcohol withdrawal.

Syndrome of inappropriate antidiuretic hormone secretion

SIADHsyndrome of inappropriate antidiuretic hormoneSyndrome of inappropriate secretion of antidiuretic hormone

Biperiden

Akineton
Earliest rodent models of delirium used atropine (a muscarinic acetylcholine receptor blocker) to induce cognitive and electroencephalography (EEG) changes similar to delirium, and other anticholinergic drugs, such as biperiden and hyoscine, have produced similar effects.
Particularly geriatric patients may react with confusional states or develop delirium.

Dementia with Lewy bodies

Lewy body diseaseLewy body dementiaDLB
Evidence for efficacy of atypical antipsychotics (i.e. risperidone, olanzapine, ziprasidone, and quetiapine) is emerging, with the benefit for fewer side effects Use antipsychotic drugs with caution or not at all for people with conditions such as Parkinson's disease or dementia with Lewy bodies.
Other conditions that share some symptoms of DLB include Alzheimer's disease (AD), Parkinson's disease, delirium, and rarely, psychosis.

Antipsychotic

antipsychoticsneurolepticneuroleptics
Antipsychotics are not supported for the treatment or prevention of delirium among those who are in hospital.
They have not been found to be useful for the prevention of delirium among those admitted to hospital.

Parkinson's disease

ParkinsonParkinson’s diseaseParkinson disease
Evidence for efficacy of atypical antipsychotics (i.e. risperidone, olanzapine, ziprasidone, and quetiapine) is emerging, with the benefit for fewer side effects Use antipsychotic drugs with caution or not at all for people with conditions such as Parkinson's disease or dementia with Lewy bodies. If the delirium involves alcohol withdrawal, benzodiazepine withdrawal, or contraindications to antipsychotics (e.g. in Parkinson's disease or neuroleptic malignant syndrome), then benzodiazepines are recommended.
A psychosis with delusions and associated delirium is a recognized complication of anti-Parkinson drug treatment and may also be caused by urinary tract infections (as frequently occurs in the fragile elderly), but drugs and infection are not the only factors, and underlying brain pathology or changes in neurotransmitters or their receptors (e.g., acetylcholine, serotonin) are also thought to play a role in psychosis in PD.

Neuroleptic malignant syndrome

Malignant neuroleptic syndrome
If the delirium involves alcohol withdrawal, benzodiazepine withdrawal, or contraindications to antipsychotics (e.g. in Parkinson's disease or neuroleptic malignant syndrome), then benzodiazepines are recommended.
The first symptoms of neuroleptic malignant syndrome are usually muscle cramps and tremors, fever, symptoms of autonomic nervous system instability such as unstable blood pressure, and sudden changes in mental status (agitation, delirium, or coma).