Delirium vs Encephalopathy – Differences


Delirium, also known as an acute confusional state, is an abrupt change in the brain which causes emotional disruption and mental confusion. It is more common in the very young and seniors. For instance, at least 10 percent of elderly patients who are admitted to the hospital have the condition.


Healthcare professionals have identified 3 types of delirium:

  • mixed delirium – the affected individual may quickly switch back and forth from hyperactive to hypoactive states;
  • hyperactive delirium – it is the most easily recognized type and is described as being uncooperative and highly alert. Other symptoms include – hallucinations, rapid mood changes, agitation, and restlessness;
  • hypoactive delirium – it may include sluggishness, inactivity or reduced motor activity, seeming to be in a daze, or abnormal drowsiness.


Common symptoms of delirium include:

  • hallucinations (visual, but not auditory);
  • talking which doesn’t make sense;
  • signs of medical illness (like fever, pain, chills, etc.) or medication side effects;
  • slurred speech and language difficulties;
  • incontinence;
  • personality or emotional changes, with frequent changes in moods, including anger, anxiety, apathy, agitation, euphoria, depression, fear, suspicion, or irritability;
  • disorganized thinking;
  • sudden onset over hours to days;
  • memory loss, including decreased recall and short-term memory;
  • disorientation and confusion, not aware of the correct place or time;
  • changes in sleep patterns, like – reversed sleep-wake cycles;
  • changes in movement (for instance, may be very restless or slow-moving);
  • decreased concentration, attention, and environmental awareness;
  • easily distracted;
  • changes in perception and feeling.


Problems that may result from the condition include:

  • side effects of drugs used to treat delirium;
  • progression to coma or stupor (the lack of critical mental function);
  • loss of ability to interact;
  • loss of ability to care for self or function.


The most common causes of the disorder are an infection, dehydration, and the use of drugs, particularly anticholinergics, psychoactive drugs (chemical substances which change brain function), and opioids.

Risk Factors

Certain underlying conditions increase the risk of the disorder:

  • organ failure, eg, chronic lung disease, kidney, heart, or liver failure;
  • advanced age;
  • sleep deprivation;
  • poor hearing or eyesight;
  • interventions, including diagnostic tests;
  • limb fractures;
  • use of bladder catheters;
  • immobilization, including physical restraints;
  • undertreated pain;
  • advanced cancer;
  • malnutrition, frailty, immobility;
  • sudden cessation of regular alcohol use;
  • sudden withdrawal of a regular medication;
  • multiple medical problems;
  • use of multiple medications;
  • underlying brain diseases, like dementia, Parkinson’s disease, or stroke.


The diagnosis of the disorder is clinical and no laboratory test can diagnose it.


Common treatments include:

  • certain drugs, like haloperidol, can be used to help control the sufferer’s agitation. Other medications like olanzapine (an atypical antipsychotic medication) can be an effective alternative to haloperidol;
  • all current drug therapy should be reviewed;
  • temperature is reduced with fanning techniques and paracetamol;
  • the affected individual should be carefully nursed and rehydrated.


It is a term for any diffuse disease of the brain which alters brain structure or function. The main symptom of the disease is an altered mental state.


There are several types of encephalopathy, including:

  • Hashimoto’s encephalopathy – it is characterized by good clinical response to steroids and thyroid autoimmunity. This type is thought to be caused by a person’s immune system attacking the brain.
  • hypoxic-ischaemic encephalopathy – it can be caused by near-drowning, heavy bleeding, or near-suffocation. It is a dangerous medical condition that needs immediate medical intervention.
  • chronic traumatic encephalopathy – it is associated with contact sports like football or boxing. In addition, it is associated with the development of dementia.
  • hepatic encephalopathy (also known as portosystemic encephalopathy) – it can be caused by a chronic liver condition, an inflammatory condition of the liver in which the histopathological and biochemical abnormalities are present over a long period of time.


Common symptoms include:

  • difficulty swallowing;
  • loss of memory;
  • seizures;
  • reduced ability to concentrate or think clearly;
  • dementia;
  • muscle weakness;
  • tremor;
  • unusual eye movements;
  • difficulty speaking;
  • involuntary muscle twitching;
  • changes in personality, like those involving aggression, irritability, having suicidal thoughts, or impulsive behavior.


Complications can include:

  • speech impairments;
  • persistent fatigue;
  • hearing or vision defects;
  • paralysis;
  • memory problems;
  • personality changes;
  • lack of muscle coordination;
  • weakness.


The three main causes of the disorder are kidney disease, liver disease, and lack of oxygen in the brain. Other causes of encephalopathy include:

  • poor nutrition (inadequate vitamin B1 intake);
  • infectious (viruses, bacteria, prions, or parasites);
  • alterations in pressure within the brain;
  • alcohol abuse (alcohol toxicity);
  • a variety of toxic chemicals (lead, mercury, or ammonia);
  • brain tumors;
  • metabolic diseases (hypo- or hypernatremia, hyper- or hypocalcemia, or hypo- or hyperglycemia).


Tests may include:

  • electroencephalogram (EEG) – this test is used to measure the electrical activity in the brain;
  • CT or MRI scan of the brain – it is done to detect damage or abnormalities;
  • spinal tap – during this test, your healthcare provider will take a sample of the spinal fluid to look for pathogenic bacteria, diseases, toxins, viruses, or prions;
  • blood test – it is done to detect pathogenic bacteria, diseases, prions, toxins, viruses,  chemical or hormonal imbalance.


Treatment focuses on improving the signs and symptoms and can include:

  • using nutritional supplements;
  • making dietary changes;
  • medication to reduce seizures or reduce ammonia (a chemical made by bacteria in the intestines) levels in patients with a hepatic encephalopathy.


The disorder may cause irreversible damage and permanent structural changes to the brain. But, treating the underlying cause of encephalopathy may improve symptoms.

Bottom Line – Delirium vs Encephalopathy

Delirium is a serious disturbance in mental abilities which results in reduced awareness of the environment and confused thinking. It can be triggered by certain medications, an infection, intoxication, or drug withdrawal. The disorder is mistaken for depression or dementia, particularly when sufferers are withdrawn or quiet.

Encephalopathy is a general term describing a disease that affects the structure or function of the brain. It may be caused by mitochondrial or metabolic dysfunction, infectious agents (virus, bacteria, or prion), lack of blood flow or oxygen to the brain, poor nutrition, chronic progressive trauma, prolonged exposure to toxic elements (including drugs, solvents, paints, radiation, certain metals, and industrial chemicals), increased pressure in the skull, or brain tumor.