Brain Monitoring: Hospital Techniques And Insights

Hospitals use a variety of tools to monitor brain activity, including electroencephalography (EEG), which involves attaching electrodes to a patient's scalp to detect electrical activity in the brain. This can be done on an outpatient basis or during a hospital stay and is used to evaluate brain disorders such as epilepsy, Alzheimer's disease, and sleep disorders. In addition to EEG, hospitals also employ other methods such as wearable devices and remote sensors to measure brain function, including sleep patterns, cognition, and gaze analysis. These technologies provide valuable insights into brain health and facilitate the development of innovative solutions for health monitoring. Continuous EEG monitoring, for example, helps detect unusual brain patterns in real time for neurocritical ICU patients, aiding in early diagnosis and treatment.

Electroencephalogram (EEG)

Electroencephalography (EEG) is a test that detects abnormalities in brain waves or the electrical activity of the brain. It is a safe, painless procedure that has been used for many years to evaluate several types of brain disorders. During an EEG, small metal disks with thin wires, called electrodes, are pasted onto the scalp. These electrodes detect tiny electrical charges that result from the activity of brain cells. The charges are then amplified and displayed as graphs on a computer screen or printed out on paper for a healthcare provider to interpret.

A routine EEG recording lasts for about 20 to 40 minutes, with the patient sitting or lying down and relaxing with their eyes closed. The patient may be asked to breathe deeply or be exposed to flashing lights to observe any effects on brain activity. In some cases, a sleep EEG may be carried out if a routine EEG does not provide sufficient information or to specifically test for sleep disorders. An ambulatory EEG involves recording brain activity throughout the day and night over an extended period.

EEG is particularly useful for diagnosing and monitoring epilepsy, as seizure activity shows up as rapid spiking waves on the recording. It can also be used to detect lesions in the brain, which may appear as slow EEG waves, and to evaluate disorders such as Alzheimer's disease, psychoses, and narcolepsy. Additionally, EEG can help determine the overall electrical activity of the brain, including in comatose patients, and monitor blood flow during surgery.

Before an EEG, patients are typically instructed to wash their hair with shampoo, avoiding conditioner and styling products. They may also be asked to refrain from consuming caffeine, as it can sometimes impact the results. Any medications or supplements being taken should be disclosed to the healthcare provider, who will explain the procedure and address any concerns.

Wearable devices

One example of a wearable brain-monitoring device is the EEG (electroencephalogram) headband or headset. These devices use electrodes placed on the scalp to detect small electric signals produced by the brain. The data collected by these devices can be stored and interpreted by both the patient and their healthcare provider. EEG technology has traditionally been limited to stationary devices in hospitals and labs, but wearable EEGs offer a more portable and accessible option for patients.

The BrainBit headband is one such wearable EEG device that is designed for comfortable daily use. It features dry electrodes and sensors that capture high-fidelity brain signals, which are then converted into digital data. This data can be transferred to a smartphone, tablet, or computer via Bluetooth, allowing for convenient monitoring and analysis.

Another type of wearable brain device is the tDCS (transcranial direct current stimulation) device, which is designed to electrically stimulate specific parts of the brain rather than solely monitor brain activity. These devices typically come in the form of a headset or headband and deliver a low-grade electrical current to the scalp. While some tDCS treatments have shown promise in treating depression, anxiety, and cognitive symptoms, further research is needed to fully understand their effectiveness.

The development of wearable brain-monitoring devices offers several advantages, including convenience, accessibility, and the ability to collect data in real-world settings. However, it is important to note that this technology is still relatively new and requires more extensive testing and validation. There are also varying costs associated with these devices, ranging from budget options to more expensive subscription-based models.

Brain injuries

There are various methods used to monitor brain activity in patients with brain injuries. One common method is the Electroencephalogram (EEG), which detects abnormalities in brain waves and electrical activity. During an EEG, electrodes are attached to the patient's scalp to record the electrical activity of the brain cells, which is then interpreted by a healthcare provider. EEGs can be used to evaluate trauma, drug intoxication, or the extent of brain damage, and can also monitor blood flow during surgery. Another method is functional Magnetic Resonance Imaging (fMRI), which measures brain activity based on blood flow. When conscious people are given a command, certain areas of their brain become more active, and blood flow to these areas increases. This can be useful in detecting covert awareness in unresponsive patients.

Other methods of monitoring brain activity in brain-injured patients include the use of serum markers, cerebral microdialysis, brain tissue oxygenation, and pressure reactivity index. These methods can help determine the state of neurological injury and guide intensive care management. Additionally, eye-tracking technology has been proposed as an objective biomarker for brain injury and concussion, providing valuable insights into brain function and cognition.

The treatment and rehabilitation of brain injuries depend on their severity and location. In the case of severe traumatic brain injuries, surgery may be required to relieve pressure, remove debris, or repair skull fractures. Patients are also monitored for infections and blood clots that can form during long periods of inactivity. After stabilization, patients are often transferred to rehabilitation centers, where a multidisciplinary team helps with recovery. This team may include neurologists, nurses, psychologists, and therapists, who work to improve the patient's ability to perform daily activities and address cognitive, physical, and emotional difficulties.

Brain disorders

Hospitals use a variety of methods to monitor brain activity and diagnose brain disorders. One of the most common techniques is electroencephalography (EEG), which measures the brain's electrical activity via electrodes placed on the scalp. EEGs can detect abnormal electrical discharges and are often used to diagnose epilepsy, brain death, sleep disorders, encephalopathies, cerebral hypoxia after cardiac arrest, and other neurological disorders. They are also used to evaluate brain trauma, drug intoxication, and the extent of brain damage in comatose patients.

EEGs have been used for many years and are considered safe and painless. They can be performed as routine EEGs to detect abnormal brain waves or as ambulatory EEGs, where patients can go about their day while wearing a small EEG recorder. Video EEGs are used to record seizures, and sleep EEGs are used to obtain more information about sleep disorders.

Another technique used to study brain activity is functional magnetic resonance imaging (fMRI), which provides detailed images of brain activity by detecting blood flow in the brain. While fMRI doesn't directly record neuronal activity, it offers an unrivalled look at the localisation of different functions within the brain. It is particularly useful for mapping cognitive function.

Other methods for monitoring brain activity and diagnosing brain disorders include:

• Positron emission tomography: Imaging of the brain's glucose use, similar to a CT scan but using injected radioactive dye.
• Single-photon emission computed tomography (SPECT): Produces 3D images of brain activity and blood flow, providing a detailed "map" of brain function.
• Sleep studies: Used to diagnose sleep disorders and monitor the effect of treatment on sleep patterns.
• Eye-tracking: Used as an early diagnostic tool for autism and to discriminate between types of dementia.
• Gait mapping: Used to detect movement disorders by analysing a patient's walking pattern.
• Balance tests: Used to evaluate neurological function and brain health.
• Evoked-potential studies: Measure the brain's response to sight, hearing, and touch stimuli.

While these techniques provide valuable insights into brain activity and disorders, they also have limitations. For example, EEG data can be contaminated by artifacts, and current technologies cannot directly record detailed neuronal activity through the human skull. However, innovations in wearable and microsensor solutions show potential for directly measuring brain electrical activity and other aspects of brain function, such as sleep patterns, cognition, and gaze analysis.

Brain surgery

After brain surgery, patients typically remain in the hospital for observation, with the length of stay depending on the type of surgery. Less invasive procedures like endovascular surgery may only require a one-to-two-day hospital stay, while open craniotomies can necessitate up to ten days in the hospital, including intensive care and regular imaging tests to monitor healing. The recovery process can be tiring and uncomfortable, and patients may experience side effects like headaches. Follow-up appointments with the care team are essential for monitoring healing progress.

During brain surgery, it is crucial to monitor brain activity and map brain function to identify areas responsible for critical functions that must be avoided. Traditionally, this is done with the help of a team of electrophysiologists who are located separately from the surgeons and communicate their findings verbally or on paper. However, a new flexible microdisplay technology combines an electrode grid and LEDs to provide a real-time visual representation of brain activity during surgery. This device offers improved precision, allowing surgeons to more effectively identify areas to target and avoid, thereby enhancing the safety and effectiveness of brain surgery.

Awake brain surgery, also known as awake craniotomy or awake brain mapping, is performed when a tumour is located near regions controlling language, cognition, sensation, or body movement. This technique allows surgeons to precisely map out these critical areas to preserve essential functions. The patient remains conscious during the procedure and is asked to perform tasks or answer questions to help identify vital areas of the brain. While this approach carries similar risks to conventional brain surgery, it enables surgeons to remove tumours while minimising potential impacts on the patient's language, sensory, and motor abilities.

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