HICU - EEG Monitoring in the Medical ICU

A common cause of altered mental status in the ICU, often due to infections leading to inflammation in the body.

A condition where the brain's function is impaired due to metabolic abnormalities, such as problems with the liver or kidneys, or imbalances in blood sugar or electrolytes.

A condition characterized by reversible brain swelling that can be caused by high blood pressure, certain medications, pregnancy complications, or imbalances in calcium or other minerals in the blood.

Blood clots or infections within blood vessels in the brain, often caused by conditions like heart valve infections (endocarditis) or immune system disorders.

Inflammation of blood vessels in the central nervous system, often linked to autoimmune diseases like lupus or Sjogren's syndrome.

Seizures that are a common symptom in patients with altered mental status in the ICU.

Seizures that do not cause visible movements or other outward signs, making them difficult to detect without continuous brain monitoring.

A type of EEG pattern often associated with brain dysfunction, occurring in cycles rather than being sustained.

The presence of a coma, meaning a state of profound unconsciousness.

The primary area of a hospital focused on providing critical care for acutely ill patients.

A continuous electroencephalogram (EEG) used to monitor brain activity in real-time.

The presence of NCS or PDs as detected by cEEG in patients admitted to the MICU.

The probability of experiencing seizures in the MICU, often influenced by factors like sepsis.

A negative outcome in patients with ESZs or PDs, potentially including death or significant disability.

A specialized form of EEG monitoring that continuously records brain activity, providing a comprehensive view of brain function over time.

A crucial measure reflecting blood flow to the brain. It's the difference between blood pressure and intracranial pressure.

A condition where blood vessels in the brain narrow, reducing blood flow and potentially leading to brain damage.

A ratio often used in quantitative EEG analysis. It's calculated as the power of the alpha brainwaves divided by the power of delta brainwaves, reflecting brain activity and potentially ischemia.

An indicator used in quantitative EEG to assess intracranial pressure. It's calculated as the inverse of median frequency multiplied by delta ratio.

A condition characterized by altered mental status, confusion, and disorientation, often caused by underlying medical conditions.

A state in which brain activity becomes extremely slow and sluggish, often seen during profound disturbances in brain function.

The analysis of EEG waveforms that helps quantify brain activity and identify patterns that are not easily observable by the naked eye.

The pressure within the skull, which can be influenced by factors like brain swelling, bleeding, or tumors.

A technique that allows for measurement of ICP without surgically implanting a device in the skull.

Generalized periodic discharges (GPDs) are a type of abnormal brain activity seen on an EEG. They're characterized by repeating patterns of electrical activity, often occurring at a certain frequency.

Triphasic waves (TWs) are a specific type of GPDs, where each wave has three distinct phases: a sharp negative, a positive, and another negative deflection.

Triphasic waves were once thought to always indicate toxic or metabolic encephalopathy, especially in cases of liver failure. However, recent research suggests they can also be associated with seizures.

Antibiotic-associated encephalopathy (AAE) is a condition that can occur after taking certain antibiotics, particularly cephalosporins and penicillins. It can cause altered brain function, sometimes accompanied by seizures or muscle spasms (myoclonus).

A study found that some patients with triphasic waves improved after receiving IV benzodiazepines (BZDs) or non-sedating anti-seizure drugs (ASDs). This suggests that some instances of TWs may be linked to seizures and respond to anti-seizure treatment.

In a study, IV benzodiazepines effectively reduced symptoms in about 19% of patients with triphasic waves, while non-sedating anti-seizure drugs showed a higher response rate (about 42%).

Even though triphasic waves were historically associated with liver failure, the study showed no differences in metabolic profiles between patients who responded to anti-seizure drugs and those who did not respond.

EEG findings should always be interpreted in the context of the patient's clinical condition. This means considering the patient's symptoms, medical history, and other laboratory tests.

EEG findings are often more meaningful when considered together with clinical symptoms. This approach helps to identify the underlying cause of the brain activity changes and guide treatment strategies.

The EEG is a valuable tool for diagnosing and monitoring brain activity in patients with altered mental status. However, it's important to interpret the EEG findings carefully in the context of the patient's clinical presentation.

EEG patterns in critically ill patients can mimic seizure activity even without a seizure, falling on a spectrum from normal to ictal.

EEG patterns showing repetitive, three-phase waves, often linked to cefepime antibiotic neurotoxicity.

A critical illness affecting the nerves and muscles, often causing weakness and inability to follow commands, despite a normal EEG.

The optimal length of time to continuously monitor brain activity in critically ill patients is not yet fully established.

The likelihood of a seizure decreases significantly if none have occurred within the first 16 hours for patients with irregular brain activity, and within 2 hours for those with normal brain activity.