Brain, Spinal Cord, and Nerves

The brain is the control centre for the rest of the body. All parts of the brain, spinal cord, and nerves pass messages using electrical current. Most automatic actions like breathing are controlled in the lower brain at the back and bottom of the skull. Decision making, movement, sensation, and many other functions are controlled by different parts in the larger, upper part of the brain.

There are spaces called ventricles in the middle of the brain that hold cerebral spinal fluid (CSF) that acts as a cushion for the brain. There are also important nerves called cranial nerves that link directly from the brain to specific areas of the body.

The spinal cord is the main link connecting the brain and the body. It is protected inside a series of spinal bones called vertebrae. The vertebrae are stacked on top of each other with padding in between. Each pad is called a ‘disc.’

Nerves to and from the rest of the body branch off of the spinal cord all the way down the back. These nerves branch off further, providing the signals needed to make muscles move and feel sensations like pressure, heat, and pain.

Potential Problems:

Any issues with the brain, spine, or nerves can cause a number of problems. The nervous system is complex, and not all damage is reversible. Below are some of the difficulties with the brain, spine and nerves that are seen in the MSICU.


Everyone has had a fever at some point in their lives. Normally, a fever is the body trying to fight off an infection by a bacteria or virus. Body temperature is regulated by an area of the brain called the hypothalamus. If this area of the brain is injured, inflamed or infected, fevers can become difficult to control. A fever that is too high for too long can cause further damage.


A seizure happens when brain cells misfire and send chaotic signals to the rest of the body. Sometimes there are too many signals all at once, sending conflicting messages to the cells. Seizures have many forms, but all involve a change in the level of consciousness. The area of seizure activity can be located using an EEG to map the electric signals in the brain. Seizures can also cause damage in the brain if they are frequent and severe. There are a number of medications and procedures that can be used to treat them, depending on the underlying cause.

Cerebral edema

Edema is the collecting of fluid, in this case fluid in and around the brain. Cerebral edema can happen in response to injury or infection. The brain only has so much room, so an excess of fluid can put pressure on it and impair its function. Excess fluid can be drawn away from the brain with medications like mannitol, or directly using a drain.


A hematoma is a collection of blood at a site of injury. The most common hematoma is a bruise. Hematomas in and around the brain can cause a problem because of the limited space for the brain to swell, or for blood to pool. A hematoma can put pressure on the brain and affect function. Hematomas can sometimes be drained if they are on top of or in between the layers that surround the brain.


Hydrocephalus is the collection of fluid in the ventricles of the brain. There are cells lining the ventricles where cerebral spinal fluid (CSF) is made. If the route for CSF circulation or drainage is blocked, hydrocephalus can result. This condition can lead to brain compression and increased pressure in the skull. Hydrocephalus can happen as a birth defect, injury, or disease. In the MSICU, new onset hydrocephalus is treated with an intraventricular drain placed into the ventricle. If the hydrocephalus becomes a chronic problem, the neurosurgeons will assess the need for a permanent drain called at VP Shunt.


An intracranial hemorrhage is a medical emergency. If a patient hemorrhages into the brain, a lot of damage can occur due to blood loss and increased pressure within the brain.

Subarachnoid hemorrhages

The brain and spinal cord are both surround by protective layers: the dura, arachnoid, and pia layers. The space between the arachnoid and pia layers is the largest, and it is filled with fluid and arteries that supply the brain. Bleeding in this subarachnoid (below the arachnoid) space can be very dangerous because of all the arteries. Bleeding happens faster from arteries because they move blood at a higher pressure. Subarachnoid hemorrhages can be caused by head trauma, stroke, or an aneurysm that has burst.


Aneurysms are arteries with weak walls. Arteries carry blood at high pressure. If they break open a lot of blood can escape very quickly. If they burst, they cause bleeding into the brain or the space around the brain. Subarachnoid hemorrhages are sometimes caused by ‘berry aneurysms’ that burst in the artery-rich subarachnoid space. Another common place for aneurysms is a circle of arteries around the bottom of the brain called the Circle of Willis. Aneurysms can indirectly cause a stroke if the artery that burst is the only one bringing blood to a certain part of the brain.


A stroke is damage to part of the brain cause by a loss of blood supply. The blood supply may be cut off by a narrowed blood vessel or clot blocking the way, this is called an ischemic (is-keem-ic) stroke. When the blood supply is diminished by bleeding from another area of the brain, this is called a hemorrhagic stroke.

Decreased level of consciousness
  • The patient’s level of consciousness can provide a lot of clues to how a person is doing. Consciousness can range from alert to comatose, but there are a lot of steps in between. If a patient’s level of consciousness starts to change, the team will assess the changes and implement a plan accordingly.
  • Changes in level of consciousness can be related to recent drugs administered, electrolyte imbalances, oxygen delivery and carbon dioxide exchange, etc. For example, a person may be given medications to reduce pain, limit anxiety, or help them sleep and these medications could make the patient sleepier. Taking this into account, the level of consciousness is assessed regularly in the MSICU using the Glasgow Coma Scale and a Motor Activity Scale called VAMASS.
  • Delirium is an altered level of consciousness that occurs frequently in intensive care. The MSICU is a very stressful environment, and the patient is experiencing a number of challenges to their body and mind. These stresses can cause a person to confuse reality and experience imagined events, have memory problems, and have problems paying attention or being aware of their surroundings. ICU delirium is caused by many factors, but factors common to intensive care are infection, sleep deprivation, disruption of the day and night cycles, the use of multiple medications, and stress to the body.
  • Delirium is managed by orienting the person to reality, helping them understand what is happening to them, and the use of specific drugs. At times, the use of sedatives and painkillers to help a patient rest can aggravate a patient’s delirium and the use of these drugs must be balanced with the need to prevent delirium.

Paralysis is the inability to feel or move certain parts of the body. Paralysis can be a result of an infection or injury. A person with a spinal cord injury may be paralyzed from the point of injury down. If they were hurt at the neck, they may not be able to move or feel anything below that point. Paralysis can also be induced with medications on purpose to allow for a procedure or operation. In these cases, the paralysis is temporary.


Extensive injuries are referred to as trauma. Any head or spinal injury that causes a change in the level of consciousness or affects body function is a medical emergency. Head trauma may include a fractured skull, a broken neck, or crushing injuries. Although broken bones are a problem, the biggest concern with head trauma is the prevention, detection, and treatment of swelling that can compress the brain. The swelling from trauma may be blood (hematoma), fluid (cerebral edema), or tissues that have been pressed into the brain from injury.


Tumours can affect the function of the brain in a couple of different ways. If the tumour is large enough, it can compress brain tissue and increase cranial pressure much like blood or fluid can. Certain kinds of tumours also prevent cells in the brain from doing what they are supposed to, disrupting thought, feeling, actions, and body functions.

Guillain-Barré syndrome (GBS)

This syndrome involves paralysis that starts in the legs and spreads up the body. Sometimes the paralysis goes high enough to affect a person’s breathing, making a ventilator necessary. After going so far up, the paralysis from GBS reverses itself from the top of the body back to the legs. Not all patients will recover back to their previous level of functioning prior to the onset of GBS. If your loved one has been diagnosed with GBS and is in the MSICU, please see the social worker for support with long term planning.


A coma is a level of consciousness reduced to the point that a person is not aware of his or her surroundings. A person in a coma will not open their eyes to command, respond to pain, or speak. They cannot be awoken. Most often, though, a coma is a result of brain injury or disease. Sometime the physician will use certain drugs to put a person in a coma if the body needs a rest and time to heal. These induced comas can be reversed when needed.

Prevention and Therapies:


Evacuation is the draining of blood or fluid from around the brain to relieve pressure. This therapy is used if the pressure from the fluid is affecting brain function.

ICP drain

An intracranial pressure (ICP) drain is used to drain just enough fluid to bring the pressure inside the brain to a safe level. The pressure is monitored, and the drain adjusted frequently.

Cerebral shunt

A shunt is a kind of tube or drain that can be installed to drain fluid one way. Cerebral shunts are sometimes installed to drain CSF out of the ventricles and into the abdominal cavity. The fluid can then be reabsorbed by the body. Shunts are more commonly used to help children but are occasionally used for adults.

Spinal Precautions

A person at risk of having a head or spinal injury will be treated with spinal precautions. A collar is used to prevent the neck from moving in case there may be damage. The patient will be transferred and repositioned by ‘log roll’ to keep the spine in a straight line. If tests confirm there has been no damage to the spine, precautions can be discontinued.


The MSICU has a policy of least restraint. However, some patients, such as those suffering from delirium, may need to have their hands controlled with soft, wide cuffs to prevent them from pulling out their breathing tubes and other lines. 

Cerebral angioplasty

Much like angioplasty in the heart, surgeons can insert a catheter through an artery into the brain to repair damage from the inside. This is often a treatment option for aneurysms. The surgeon can fill the aneurysm bubble in with very thin coils of metal to make it stronger and prevent it from bursting and causing a bleed.



Diuretics can be used to draw water away from the brain in cases of cerebral edema.  The amount of urine increases when diuretics are used.


Mannitol is a type of diuretic given by IV that draws fluid away from the organs and into the bloodstream to be eventually eliminated with the urine. It is commonly given to people with increasing intracranial pressure.


Anti-inflammatory group of drugs used to reduce swelling after an injury. The inflammation, swelling, and fluid accumulation around the site of injury can pinch the nerves and spinal cord. Reducing the swelling as quickly as possible increases the likelihood the nerve function can be restored.


These medications are used to lessen or prevent seizures. Many of these drugs can be used to reduce anxiety and provide sedation at different doses.

Diagonostic Tests and Monitoring:

Neurological Assessment

A doctor or a nurse can do a neurological assessment for a patient. The function of the brain, spine, and nerves is usually tested every twelve hours or more often if there are concerns. These tests can help keep track of changes in the health of the brain and nerves.

ICP monitor

An intracranial pressure (ICP) monitor is inserted by a neurosurgeon to monitor the pressure of the fluid (CSF) in and around the brain. It can also be used as a drain to remove extra CSF or blood and reduce the pressure on the brain.

Nuclear Medicine

Nuclear medicine involves using mildly radioactive substances, called isotopes, to identify injury or disease. It can be used to identify changes in blood vessels anywhere in the body. Certain radioactive substances will find and attach themselves to particular cell types or proteins. The person is then scanned with a special camera. The isotopes ‘light up’, telling the physicians where the cell or protein they are looking for has collected. This can be very helpful to identify areas that have been damaged by a stroke or hemorrhage. It can also be used to check if the treatment being given to open up blocked vessels has worked. Patients go to Nuclear Medicine with a nurse if they need this scan.

CT Scan
  • A CT or CAT Scan is a specialized kind of X-ray. A person is scanned and the pictures gathered are turned into a 3D image by the machine’s computer. CT scans are good at picking up collections of fluid.
  • Sometimes a patient is injected with an X-ray dye that will show up under the CT scan. This is called a CT with contrast. It can help narrow down where there may be problems with the vessels such as bleeding or blockages. A nurse goes with a patient to the Radiology department for CT scans.
  • MRIs are used to get a very detailed picture of the body tissues and organs, including the brain and spinal cord. MRIs use a strong electromagnetic field to make two and three dimensional images of the area scanned. The use of a strong magnet means it is important to remove all metal before an MRI. The scanner is loud, so patients and staff are given ear plugs.
  • Sometimes a patient will be given a substance to increase the contrast and sharpen the details of certain body parts, such as the blood vessels or spinal cord. Like a CT scan, an MRI is painless. Patients travel to radiology with a nurse to get an MRI.
EEG and Continuous EEG

EEG is the short form for electroencephalogram. An EEG is a painless way to measure the electrical activity of the brain and may be used as a tool to diagnose brain function. There are a number of small stickers with a metal base called electrodes that are placed on specific areas of the head to monitor brain activity. An EEG is the only way to find seizures if there is no muscle activity. A person may be put on a continuous EEG if the team suspects the patient is having ‘silent seizures.'

Lumbar puncture (LP, Spinal Tap)
  • A lumbar puncture is a way to look for infection or blood in the brain and spinal cord. The patient lays on their side with their legs and arms curled up. The doctor gives them a local painkiller if needed and cleans the area with a solution to prevent infection. A needle is inserted between the lower back bones into the space next to the spinal cord.
  • This space contains the same fluid that slowly circulates around the brain and ventricles. A small amount of this fluid is drawn out and tested. Pressure is applied to the area to stop up any bleeding and a sterile dressing is applied. The results of tests done on CSF from a lumbar puncture can be used to decide what treatments may help.
Peripheral Nerve Stimulator

A peripheral nerve stimulator is used to make sure a patient is getting the lowest effective doses of certain medications that affect the nerves. The team wants to make sure they are sedated and pain-free using the minimal amount of drugs. This can help limit the possibility of side effects.

Cerebral angiogram

Angiograms can be used to look at arteries anywhere in the body, such as the brain (cerebral angiogram) or heart (cardiac angiogram). Once the problem has been located, the physician may take steps to correct it all in one procedure. A cerebral angiogram can identify blockages that may have caused a stroke. They can also be used to find aneurysms.