Mechanisms Of Brainstem Dysfunction
Neuroimaging and neuropathological studies show that the brainstem is prone to vascular, inflammatory, and excitotoxic insults . For instance, sepsis can be associated with impaired autoregulation of cerebral blood flow and microcirculatory dysfunction, which may compromise the brainstem perfusion. Second, a multifocal necrotizing leukoencephalopathy involving the brainstem can be secondary to an intense systemic inflammatory response . Finally, the neuro-inflammatory process can culminate in neuronal apoptosis, which is evidenced in brainstem autonomic nuclei in patients who died from septic shock or in experimental sepsis . Interestingly, it has been shown that apoptosis of autonomic nuclei can induce hypotension in septic rat .
Both humoral and neural pathways can induce a neuro-inflammatory process. The former involves the area postrema , which allows the diffusion of circulating inflammatory mediators into the brainstem the latter involves mainly the vagal nerve, which mediates the transmission of peripheral inflammatory signals to the brainstem . Autonomic brainstem nuclei are regulated by these two pathways, which then play a major role in the control of systemic inflammatory response.
Finally, metabolic processes can be involved. It is well known that electrolyte disturbances but also renal and liver failure impair brainstem responses, as illustrated by centro-pontine myelinolysis or by usefulness of FOUR score in hepatic encephalopathy .
What Conditions And Disorders Affect Your Brainstem
A wide range of injuries or conditions can damage your brainstem. Some of these include:
- Blood clots: When a clump of blood forms where it shouldnt, sometimes blocking blood flow.
- Brain tumors: A mass of irregular cells in the brain.
- Encephalitis: Inflammation in your brain tissue.
- Heart attack : A sudden blockage in one or more of your coronary arteries that stops blood flow to the heart.
- Stroke: Interruption of the blood supply in your brain.
- Sudden cardiac death: An abrupt loss of your heart function.
- Traumatic brain injury : A sudden injury, often from a severe jolt or blow to the head, that affects your brain functions.
How A Stroke Affects The Brain Stem
When a stroke occurs in the brain stem, the supply of blood becomes compromised by a clogged artery or burst artery . This is a medical emergency because brain cells begin to die from a lack of oxygen-rich blood.
A stroke can occur in any of the three major areas of the brain stem: the midbrain, pons, and medulla. Furthermore, some strokes that injure the brain stem also affect the cerebellum or other surrounding areas.
When a brain stem stroke occurs, it can cause atypical symptoms like vertigo and nausea. These are much different than the hallmark symptoms of a stroke, such as slurred speech and arm weakness. As a result, brain stem strokes can be difficult to diagnose.
As with all strokes, the event is a medical emergency that requires swift treatment to save the persons life.
After a stroke has been treated, the patient must work to overcome the secondary effects that occur. These effects vary greatly among survivors, which we will discuss next.
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Organ Function And Clinical Significance
The brainstem serves as a conduit from the brain to the cranial nerves and spinal cord. As a result, the brainstem is involved with motor, sensory, and special sensory function, as well as regulation of temperature, cardiac function, respiratory function, and consciousness. It is well accepted that the entire brainstem may be treated to 54Gy using conventional fractionation with minimal risk of late brainstem toxicity. Small volumes of brainstem may tolerate higher doses. Similar to the brain, the brainstem is heterogeneous, and it is not well known which regions are most susceptible to radiation-induced damage.
Stephanie Willerth, in, 2017
Is Damage To The Brain Stem Fatal
Brain stem injury is a very fatal health condition that can change ones memory, paralyze or change ones personality. The treatment required for brain stem injury is very expensive and causes serious life-long hardship to the family of the affected person along with emotional and psychological problems.
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Brain Stem Keeps You Breathing And More
Another brain part that’s small but mighty is the brain stem. The brain stem sits beneath the cerebrum and in front of the cerebellum. It connects the rest of the brain to the spinal cord, which runs down your neck and back. The brain stem is in charge of all the functions your body needs to stay alive, like breathing air, digesting food, and circulating blood.
Part of the brain stem’s job is to control your involuntary muscles the ones that work automatically, without you even thinking about it. There are involuntary muscles in the heart and stomach, and it’s the brain stem that tells your heart to pump more blood when you’re biking or your stomach to start digesting your lunch. The brain stem also sorts through the millions of messages that the brain and the rest of the body send back and forth. Whew! It’s a big job being the brain’s secretary!
Right Brain Left Brain
The cerebrum is divided into two halves: the right and left hemispheres They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.
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What Does The Brain Do
Different parts of the brain receive and understand different messages from different parts of your body. The Brain is divided into two halves called Hemispheres. The Right Hemisphere works the left side of the body and the Left Hemisphere works the right side of the body. These two Hemispheres are joined together by a thick grouping of more than 200 million nerve fibres called the Corpus Callosum . These nerve fibres let messages pass from one side of the brain to the other.
Each Hemisphere of your brain has parts called Lobes. Each Lobe has different jobs that it does. The part of the Brain that makes our body parts move is called The Motor Cortex. It is found towards the back of the Frontal Lobe which is located at the front of your head. Different parts of the Motor Cortex of your Frontal Lobe move different parts of your body. Researchers have been able to map exactly which part of your brain moves each part of your body. They created a picture or a “Motor Map” of this which is called The Motor Cortex Homunculus to show us which part of our brain in the Motor Cortex is responsible for moving each part of our body.
Go to the ABIOS website Brain Map for more information about the what the Brain does.
How Is The Brain Supplied With Blood
The brain needs a steady flow of enough oxygen, glucose, and other nutrients. For that reason, it has a particularly good blood supply. Each side of the brain receives blood through three arteries:
- In the front, the anterior cerebral artery supplies the tissue behind the forehead and under the crown .
- The middle cerebral artery is important for the sides and areas that are further inside the brain. The anterior and middle cerebral artery split off from the internal carotid artery, a major blood vessel in the neck.
- The posterior cerebral artery supplies the back of the head, the lower part of the brain, and the cerebellum. It is supplied with blood from the vertebral arteries, which are also major arteries of the neck.
Before the three arteries reach their brain region, where they split into smaller branches, they are close together below the brain. In this area, they are connected to each other by smaller blood vessels forming a structure similar to a traffic circle. The arteries are connected to each other in other areas as well. The advantage of these connections is that blood supply problems in the brain can be compensated for to some extent: For example, if a branch of an artery gradually becomes narrower, blood can still flow to the part of the brain it supplies through these alternative routes .
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About Brain Stem Death
Brain stem death is when a person no longer has any brain stem functions, and has permanently lost the potential for consciousness and the capacity to breathe.
When this happens, a ventilator keeps the person’s heart beating and oxygen circulating through their bloodstream.
A person is confirmed as being dead when their brain stem function is permanently lost.
How Brain Death Occurs
Brain death can occur when the blood and/or oxygen supply to the brain is stopped. This can be caused by:
- cardiac arrest when the heart stops beating and the brain is starved of oxygen
- heart attack a serious medical emergency that occurs when the blood supply to the heart is suddenly blocked
- stroke a serious medical emergency that occurs when the blood supply to the brain is blocked or interrupted
- blood clot a blockage in a blood vessel that disturbs or blocks the flow of blood around your body
Brain death can also occur as a result of:
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How Do You Treat Lesions
If needed, benign skin lesions can get local treatment with topical medications, such as retinoids, corticosteroids, or antimicrobial agents, as well as laser therapy, cryotherapy, phototherapy, or surgical removal. If the skin lesion is caused by a systemic disease, treatment may also address the underlying cause.
What Is The Brainstem And What Does It Do
In addition to connecting the brain to the rest of the nervous system, the brainstem has a number of essential functions. To simplify things, I’ll discuss some of the functions associated with each of the three major regions of the brainstem. It should be noted, however, that the organization of the brainstem is very complex and this is just an overview.
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Tests To Confirm Brain Death
Although rare, a few things can make it appear as though someone is brain dead.
These include drug overdoses and severe hypothermia, where body temperature drops below 32C.
A number of tests are carried out to check for brain death, such as shining a torch into both eyes to see if they react to the light.
Functional Neuroanatomy Of The Brainstem
The brainstem can be categorized into three major parts: midbrain, pons, and medulla oblongata . The brainstem contains both gray and white matter, with the basilar artery representing the vascular supply. The gray matter includes the nuclei of the cranial nerves , the ARAS , the extrapyramidal and the central autonomic nervous system . This gray matter controls brainstem reflexes, arousal, automatic movements, and homeostasis, respectively. The white matter is composed of ascending sensory pathways and descending pyramidal and extrapyramidal pathways .
General anatomy of the brainstem and oculocephalic circuit. A Anatomical sagittal sections. B Representation of the sagittal section plans and of the oculocephalic circuit
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Anatomy Of The Brain And Spine
Learn more about the anatomy and the functions of the brain and spine
- Information and support
- Anatomy of the brain and spine
The brain and spine are vital to keep the body alive and functioning. Everything we do depends on the messages that are sent from the brain, along the spinal cord and on to the rest of the body.
What Happens When You Damage Your Brain Stem
When an accident causes brain stem damage, the affects can be devastating. In fact, destruction of the midbrain, pons, or medulla oblongata causes brain death, and the unfortunate victim of the injury cannot survive. And while damage to brain stem can cause death, even an injury that does not cause death, can cause significant brain stem injury symptoms. Because so many functions that are essential to survival are located in and pass through the brain stem, an injury to a persons brain stem is often the most devasting injury a person can suffer short of death.
For example, one injury a person can suffer after damage to their brain stem is locked-in syndrome, which is a condition in which a person is fully conscious, but the person cannot move or communicate, except through eye movements or blinking. Despite the devasting effects of the condition, a person suffering from locked-in syndrome can survive for decades in the vegetative state that the syndrome causes.
Brain stem injuries are often severe, even resulting in death, but a lower brain stem injury, while potentially not as serious, can also cause a variety of problems. For instance, a lower brain stem injury can cause loss of consciousness for a few seconds to a few minutes. The injury can cause a person to be dazed, confused, and disoriented. The injury can also cause severe headaches, nausea or vomiting, fatigue or drowsiness, problems with speech, difficulty sleeping, or sleeping more than usual.
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Brainstem Dysfunction In Critically Ill Patients
The leading causes of primary brainstem dysfunction are summarized in Table and major differential diagnosis of brainstem dysfunction in Table . In the following section, we will discuss evidence for brainstem dysfunction encountered in critically ill patients beyond primary brainstem dysfunction.
Table 7 Differential diagnosis of brainstem dysfunction
Diagnosing Brain Stem Death
There are a number of criteria for diagnosing brain stem death.
For a diagnosis of brain stem death to be made:
- a person must be unconscious and fail to respond to outside stimulation
- a person’s heartbeat and breathing can only be maintained using a ventilator
- there must be clear evidence that serious brain damage has occurred and it can’t be cured
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Brain Stem Injury Symptoms
The brain stem plays an important role in how messages are transmitted from the brain to the rest of the body. The most common signs of a brain stem injury often involve a person not being able to function as they should. Symptoms of a brain stem injury include:
- Abnormal sleeping patterns
If you have suffered a head injury, it is critical to seek medical attention as soon as possible. You will want to be certain that a physician has ordered the necessary tests to diagnose a brain stem injury so you can receive the proper treatment and have the best chance at recovery.
S Of The Brain And Spinal Cord
The main areas of the brain include the cerebrum, cerebellum, and brain stem. Each part has a special function.
Cerebrum: The cerebrum is the large, outer part of the brain. It is divided into left and right hemispheres and controls reasoning, thought, emotion, and language. It is also responsible for planned muscle movements and for taking in and interpreting sensory information such as vision, hearing, smell, touch, and pain.
Cerebellum: The cerebellum lies under the cerebrum at the back part of the brain. It helps coordinate movement.
Brain stem: The brain stem is the lower part of the brain that connects to the spinal cord. It contains bundles of very long nerve fibers that carry signals controlling muscles and sensation or feeling between the cerebrum and the rest the body. Special centers in the brain stem also help control breathing and the beating of the heart. Also, most cranial nerves start in the brain stem.
The brain stem is divided into 3 main parts: the midbrain, pons, and medulla oblongata.
Because the brain stem is a small area that is so essential for life, it might not be possible to surgically remove tumors in this area.
Cranial nerves: The cranial nerves extend directly out of the base of the brain . These nerves carry signals directly between the brain and the face, eyes, ears, tongue, mouth, and some other areas.
Choroid plexus: The choroid plexus is the area of the brain within the ventricles that makes CSF, which nourishes and protects the brain.
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Unique Status Of Cerebral Cortex And The Concept Of The Reptilian Brain
The idea that evolution affects only the cerebral cortex, with brainstem and cerebellum essentially unchanged entered the popular culture of neuroscience through the writings of Paul Maclean, The Triune Brain and Carl Sagans reptilian brain . The concept of the reptilian brain maintains that the brainstem and cerebellum are old structures that have not changed over evolution. That perspective still colors the understanding of students and the general public today. As shown in this review, it clearly does not reflect the dramatic changes in cerebellar and brainstem structures and their contribution to uniquely human capabilities.
Why Is Damage To The Brain Stem Life Threatening
Heartbeat and breathing can cease, causing death. The brain stem can become compressed due to swelling, leading to hemorrhaging and stroke. This may result in speech impairment, breathing difficulties, including sleep apnea and difficulty swallowing. In acute cases, there may be personality changes and memory loss.
Persevering On The Road To Recovery
The road to recovery looks different for everyone. Fortunately, survivors can regain lost function, at least partially, through intensive rehabilitation.
With enough hard work, patients can often make remarkable recoveries, like Becky and Luke.
We hope this article helped illustrate how a stroke affects the brain stem, and what to expect on the road to recovery.