Confusion overview

# Overview
Confusion refers to mental dysfunction in which a lack of attention and disorientation occurs with the inability to think with normal speed or clarity. It is the inability to maintain a coherent stream of thought or action.

# Pathophysiology
Confusion results from global impairment of brain functions. Some areas of the brain are identified for various presentations of confusion. Drugs, poisons, and chemicals interact with the neurotransmitters and can cause confusion. Inflammatory agents are involved in conditions such as a fever.

# Causes
Confusion is a common symptom associated with various diseases and metabolic disorders.  Common causes of confusion include insults to the central nervous system (CNS), metabolic disorders, and side effects of medications or illicit drugs.

# Differentiating Confusion from other Diseases
Various conditions such as dementia, depression and amnesia involve confusion as part of their presentation. Obtaining a clear history about the onset of symptoms, and the onset of confusion in association with other symptoms, helps in differentiating confusion from other conditions.

# Epidemiology and Demographics
Nearly about 30% of older patients admitted for medical conditions are confused at some point of time during their admission. In surgical wards the chances of confusion ranges from 10-50%. Increasing rates are seen in patients admitted to intensive care units and in hospice care. There is no significant difference in the distribution based upon gender or race.

# Risk Factors
Increasing age, admission to the hospital, post-surgical status, alcoholism, and underlying brain lesions are a few important risk factors for confusion. Special care is required for elderly patients who are hospitalized.

# Natural History, Complications and Prognosis
Confusion is a disturbance in mental status which develops rapidly. If untreated it develops into a stupor / coma. Confusion caused by metabolic changes can be rapidly corrected and have good prognosis compared to the one caused by underlying structural abnormalities of the brain. The mortality rate for those who developed confusion at a hospital is nearly 39% in the first year which is nearly twice compared to age matched controls.

# Diagnosis

## History and Symptoms
Confused patients will not be able to provide a coherent history. Confirming the history with a patients caregiver is the key to obtaining an accurate history about the patient. Determining the patients drug history and co morbid conditions is very important. In young patients drug abuse and withdrawal should be evaluated. Some assessment scales are used to identify and diagnose confusion, and they include the Confusion Assessment Method, Mini Mental Status Examination, and The Neelon and Champagne (NEECHAM) Confusion Scale.

## Physical Examination
In cases of confusion, a physical examination  helps in localizing the lesion if the cause is from the brain. It also gives clues to the underlying cause of the disease. A complete neurological examination may not be done due to a limitation of the patient's condition.

## Laboratory Findings
Several laboratory tests are available for evaluating confusion. It is a physician's role to choose the most useful test based upon the history of the person. For example, a patient presenting with confusion, severe neck stiffness, headaches, and fever should be evaluated for infective foci.

## Electrocardiogram
Various heart conditions can cause hypoperfusion of the brain. This hypoperfusion can be a cause of confusion. An electrocardiogram can help to identify any associated heart conduction problems, which helps in the diagnosis.

## Chest X Ray
Lung pathologies usually cause hypoxia and confusion if left untreated. A chest x ray is the most important tool to evaluate such conditions. It can be very helpful in identifying various lung lesions and infections.

## CT
A CT scan of the head is an important diagnostic tool in cases of confusion where a cause couldn't be established. Before a lumbar puncture is done, a CT scan is the first test used in cases of suspected infections such as meningitis.

## MRI
An MRI scan is more sensitive in identifying intra cranial lesions than a CT scan. It can be used in cases with a high index of suspicion and a negative report on a CT scan.

## Echocardiogram or Ultrasound
An echocardiogram is a valuable tool in assessing the cardiac output. It also helps in determining the perfusion. An ultrasound is used for determining the cause of confusion in certain abdominal conditions such as any liver injuries, abdominal bleeds, and injuries to the major abdominal vessels.

## Other Imaging Findings
There are several other imaging studies that are not used as often for diagnosis. They are mostly used in cases of an unconfirmed diagnosis. Examples of these tests include CT angiography and FLAIR (Fluid attenuated inversion recovery images).

## Other Diagnostic Studies
Certain studies, such as electroencephalography (EEG), are of noticeable importance. These tests are done to exclude other diseases and aid in the diagnosis of certain conditions.

# Treatment

## Medical Therapy
Complete evaluation of the patient in an emergency department has to be done, which is followed by the administration of appropriate treatment. Every  confused individual should be administered with glucose and thiamine, followed by naloxone and flumazenil. Treatment must be started while waiting for the results. Early treatment can save the individual from long term effects.

## Surgery
Surgical options are limited for confusion because it all depends on the cause of confusion. Some conditions, such as a subdural hematoma that can be drained, are surgically evacuated. In such cases, a consultation with a neurosurgeon may be needed. In cases of traffic accidents, a person may be bleeding severely due to fractures and visceral injury. In such cases, an orthopedic surgeon would most likely be needed.