Delirium: diagnosis

The diagnosis of delirium is based on the patient's examination data for a certain period of time, sufficient to detect changes in the level of consciousness and cognitive disorders. For a quick assessment of cognitive functions, a Short orientation-memory-concentration test (Short Orientation-Memory-Concentration Test of Cognitive Impairment) is applied directly to the patient's bedside. To assess the orientation of the patient is asked to name his name, location, date, time of day. To assess the patient's short-term memory, ask to remember the name and address, which is repeated until the patient can name them. Concentration is checked by checking the countdown from 20 to 1, and then transferring in the reverse order of the months of the year. Finally, the patient is asked to repeat the name and address they remember. The estimate is based on the number of errors. The test can be fully or partially repeated several times a day or for several days to detect fluctuations in its performance. A brief study of the mental status (The Mini-Mental State Examination - MMSE) can also be used to assess orientation, concentration, memorization and reproduction, praxis, ability to naming, repeating and executing commands. For the screening diagnosis of delirium, various techniques have been proposed, but they are not reliable enough, valid and easy to use. Many of them focus on the state of cognitive functions, while the non-indicative manifestations of delirium are ignored.

Since patients with delirium can not provide the physician with reliable information, they should try to obtain the necessary information regarding the premorbid state and previous symptoms from relatives and friends of the patient, as well as from medical personnel. Medical records may contain useful information about sleep duration and quality, confusion and perception disorders.

In patients with delirium, sleep disorders are common, primarily disturbances in the sleep and wake cycle. Patients are often frightened on awakening and often report bright dreams and nightmares. Twilight syndrome (sundowing) - the increase in behavioral disorders at night is another frequent manifestation of delirium. Although the prevalence of twilight syndrome was not studied in hospitalized patients, it was noted that it was detected in every eight patients placed in care institutions.

Perceptual disorders can be assessed by asking the patient open questions, for example, about how he was treated earlier and whether any unusual events happened to him. Following this, you can ask more focused questions about the presence of hallucinations, for example: "Sometimes a special state of consciousness arises when a person hears voices (or sees objects) that he usually does not hear (or does not see). Did this happen to you? ". Patients with hallucinations or illusions can hide under a blanket or pull on a sheet. Sometimes they talk to themselves or turn their heads or eyes to the side under the influence of some internal stimuli.

Affective disorders, in particular depression, can be assessed using the Hamilton Depression Scale or the Geriatric Depression Scale. The scale of depression of Hamilton is based on a scoring of depression symptoms by a doctor. The Geriatric Depression Scale provides for the assessment of symptoms by the patient himself. However, she does not evaluate the symptoms, which can be associated not only with depression, but also with a somatic or neurological disease, such as a dream or an appetite disorder. To assess manic symptoms, the Young Mania Scale can be used. The use of standardized scales in the examination process allows obtaining more reliable and reliable data than a routine clinical examination. In addition, these scales provide a more objective quantification of existing disorders. As a supplement to clinical examination, scales can be used in dynamics to assess the effectiveness of treatment.

[1], [2], [3], [4]

Criteria for diagnosis of delirium

• A. Consciousness disorder (eg, incomplete awareness of the environment) with a limited ability to focus, maintain and switch attention
• B. Violation of cognitive functions (memory loss, disorientation, speech disorder) or a perception disorder that can not be better explained by the presence of previous, established or developing dementia
• C. Disorders develop over a short period of time (usually hours or days) and are prone to fluctuations throughout the day
• D. Data of anamnesis, fiscal examination or additional research methods confirm that the disorders are a direct physiological consequence of the general disease

[5], [6], [7], [8], [9]

Criteria for diagnosis of intoxication delirium

• A. Consciousness disorders (eg, incomplete awareness of the environment) with a limited ability to focus, maintain and switch attention
• B. Violation of cognitive functions (memory loss, disorientation, speech disorder) or a perception disorder that can not be better explained by the presence of previous, established or developing dementia
• C. Disorders develop over a short period of time (usually hours or days) and are prone to fluctuations throughout the day
• D. Anamnesis, physical examination or additional research methods are supported by (1) or (2):
  • Symptoms indicated in criteria A and B develop during intoxication
  • The violations are etiologically related to the use of medicines

[10], [11], [12], [13], [14],

Criteria for the diagnosis of withdrawal symptoms

• A. Consciousness disorders (eg, incomplete awareness of the environment) with a limited ability to focus, maintain and switch attention
• B. Violation of cognitive functions (memory loss, disorientation, speech disorder) or a perception disorder that can not be better explained by the presence of previous, established or developing dementia
• C. Disorders develop over a short period of time (usually hours or days) and are prone to fluctuations throughout the day
• D. Anamnesis, physical examination or additional research methods confirm that the symptoms identified in criteria A and B developed during or shortly after the withdrawal syndrome

[15], [16],

Criteria for diagnosis of delirium of multiple etiology

• A. Consciousness disorders (eg, incomplete awareness of the environment) with a limited ability to focus, maintain and switch attention
• B. Violation of cognitive functions (memory loss, disorientation, speech disorder) or perception disorder, which can not be better explained by the presence of a previous, established or developing dementia
• C. Disorders develop over a short period of time (usually hours or days) and are prone to fluctuations throughout the day
• D. The history, physical examination or additional research methods confirm that delirium develops under the influence of more than one cause (for example, with a combination of several common diseases or a combination of one of the diseases with the action of a toxic substance or a side effect of the drug)

[17], [18], [19]

Additional research methods

Laboratory data help in determining the etiology of delirium. After careful collection of anamnesis and physical examination, a serum test is performed, including a general blood test, determination of the electrolyte level (including calcium and magnesium), glucose, folic acid, vitamin B 12, tests for kidney, liver, thyroid, serological reactions to syphilis and HIV infection, ESR. In the complex of examination, it is advisable to include a general urine test, tests for the content of toxic substances in the urine, determination of blood gases, as well as chest X-ray and ECG. In addition, in some cases, EEG, lumbar puncture, sowings of body fluids, neuroimaging may be necessary. There is no standard set of tests that would be used continuously to establish the etiology of delirium. The wider the survey, the more information it gives, but at the same time it requires more significant costs. A general practitioner can recruit a consultant to help determine the required scope of the examination and the optimal treatment.

• Clinical blood test with determination of the formula and ESR
• Electrolytes
• Kidney function
• Liver function
• Glucose
• Thyroid function
• Serological tests for syphilis
• HIV test
• Calcium
• Magnesium
• Folic acid
• General urine analysis
• Toxicological examination of urine
• Gases of arterial blood
• Chest X-ray
• ECG
• EEG
• Lumbar puncture
• Neuroviualization

[20], [21], [22], [23],

Instrumental methods of delirium diagnosis

Electroencephalusia. EEG can be useful in diagnosing delirium. About 50 years ago, Romano ourtk correlation between lowering the level of wakefulness, background frequency and disorganization of the EEG. Later they proposed the term "acute cerebral insufficiency" to determine the state, which we now call delirium. EEG with quantitative analysis can be used in differential diagnosis of delirium and dementia in elderly patients with an unclear diagnosis. An increase in the representation of the theta-activity in 89% of cases allows to correctly diagnose delirium and only in 6% gives a false negative result, consisting in the erroneous diagnosis of dementia.

Neuroimaging

In patients taking antidepressants, which have a higher risk of delirium, MRI reveals structural changes in the basal ganglia. Moderate or severe white matter damage increases the likelihood of delirium developing during electroconvulsive therapy. In patients who underwent delirium, CT revealed more frequent focal changes in the associative zones of the right hemisphere, cortical atrophy, ventricular expansion than in the control group.

Differential diagnosis of delirium

DSM-IV distinguishes variants of delirium depending on its etiology. The differential diagnosis of delirium coincides with the differential diagnosis of psychotic disorders. The cause of delirium may be dementia, schizophrenia, affective disorders with psychotic manifestations, common diseases, intoxications and withdrawal symptoms. Often the development of delirium is caused by several reasons.

Memory disorders are often observed in both dementia and delirium. However, a patient with an initial stage of dementia usually retains a clear consciousness without fluctuations in the level of wakefulness. Since patients with dementia are predisposed to the development of delirium, it should be borne in mind that aggravation of impaired attention and other cognitive disorders may be associated not only with the disease itself, which causes dementia. In this case, the condition of the patient with dementia should be analyzed for possible delirium development. Often, these patients are unable to report on the acute development of discomfort, which may occur due to exacerbation of a chronic medical condition or infection. In a patient with dementia, the cause of behavioral disorders may be delirium. With the development of delirium, the patient should undergo a physical examination, it is necessary to carry out an examination of blood serum and urine, chest X-ray, ECG, as it can be caused by a severe intercurrent disease. In addition, it is necessary to carefully collect the medical history, since the medications that the patient takes to treat co-morbidities or behavioral disorders associated with dementia, can cause delirium.

In some cases, delirium acts as a kind of forerunner of dementia or draws attention to developing cognitive impairments that previously remained unnoticed. Short-term period, during which delirium develops, distinguishes it from dementia.

[24], [25], [26], [27], [28]

Schizophrenia

A well-collected medical history often helps in differential diagnosis of delirium with schizophrenia or schizophreniform psychosis. For example, a violation of the ability to concentrate and switch attention distinguishes delirium from schizophrenia. In addition, schizophrenia is not characterized by memory and orientation disorders. Sometimes dementia develops in a patient with schizophrenia. In the diagnosis of such situations, the points indicated earlier are taken into account. In the differential diagnosis between delirium and schizophrenia, it is important to consider the relationship of delirium to the intake of certain medications, concomitant diseases, intoxications or withdrawal symptoms. Delirium delusions usually do not have such a bizarre and systematized character as in schizophrenia. In addition, schizophrenia and delirium do not exclude each other, since a patient with schizophrenia may develop delirium.

Neuroleptics used to treat schizophrenia can cause delirium. Side effects of neuroleptics associated with delirium include malignant neuroleptic syndrome, which is an emergency, and akathisia, a subjective anxiety, usually accompanied by psychomotor agitation. Signs of a malignant neuroleptic syndrome are fever, rigidity, hyperactivity of the autonomic nervous system, elevation of the level of CK, leukocytosis. In addition, many antipsychotics have anticholinergic activity, which can contribute to the development of delirium.

Affective disorders with psychotic manifestations

Affective disorders, such as depression or mania, accompanied by psychotic manifestations (affective psychoses), can be mistaken for delirium, and vice versa. These states are important to correctly differentiate, because their prognosis and treatment are very different. Unrecognized and untreated depression is associated with increased morbidity, disability, increased healthcare costs, increased mortality. Mania is also associated with disability and increased morbidity. Changing the mood background for delirium is not as pronounced as in affective disorders, although patients with delirium may experience dysphoria, expansive mood, or affective lability. In patients with affective disorders, a history of mood changes is more frequent. The content of psychotic disorders in patients with affective disorders is often depressive or manic, including delusions of self-incrimination, suicidal and derogatory ideas in depression or delusion of grandeur in mania. At the same time, delirium delirium has a more fragmented character. Permanently persistent mood changes are more characteristic of affective disorders than of delirium. Detection of neuropsychological examination of attention impairment and other cognitive functions also helps in differential diagnosis of delirium and affective disorder with psychotic manifestations. Depression with psychotic disorders is usually well treated with antidepressants and neuroleptics or electroconvulsive therapy. In patients with bipolar disorder, the manic phase with psychotic manifestations can be treated with normotimic agents, neuroleptics or electroconvulsive therapy. At the same time, delirium, mistakenly diagnosed as affective psychosis, will deteriorate against the background of the use of these drugs - because they are capable of increasing confusion, and the cause of delirium, which remains unrecognized, is not properly corrected.

[29], [30], [31], [32], [33]