Brain Damage

The basic definition of brain damage is an injury to the brain caused by various conditions such as head
trauma, inadequate oxygen supply, infections, or intracranial hemorrhage. This damage may be
associated with a behavioral or functional abnormality. The brain can be damaged in many ways and
severity. Depending upon the type, location, and severity of any damage to the brain, the outcome can
range from a complete recovery to some amount of disability or even death.

Some causes of brain damage can be:

Genetics - where a gene passed down to a child may prevent proper development of the brain

Trauma - where a physical blow from an object or fall causes physical damage to the brain

Loss of Blood Flow - where a blood clot from a stroke or loss of flow from a heart attack stops the
flow of blood. Damage begins 4 minutes without oxygen

Tumors - where any abnormal growth invaded the brain causing pressure and pushing it aside, as
well as taking needed oxygen away from it

All traumatic brain injuries are head injuries, but a head injury isn't necessarily brain injury. There are
two types of brain injury that both the brain’s normal functioning:

Traumatic brain injury (TBI)

Typically caused by an external force, such as a blow to the head, that causes the brain to move inside
the skull or damages the skull. This in turn damages the brain.
Causes of traumatic brain injury include:
• blows to the head
• car accidents
• sports injuries
• falls or accidents
• physical violence

Acquired brain injury (ABI)

Typically occurs at the cellular level. It's most often associated with pressure on the brain such as from
a tumor. It may also result from neurological illness such as multiple sclerosis (MS).
Causes of acquired brain injury include:
• poisoning or exposure to toxic substances
• infection
• strangulation, choking, or drowning
• stroke
• heart attacks
• tumors
 • aneurysms
• neurological illnesses
• abuse of illegal drugs

Both traumatic brain injury and acquired brain injury occur after birth. Neither is degenerative and
sometimes the two terms are used interchangeably.

There are numerous symptoms of brain damage, whether traumatic or acquired. They fall into
four major categories: Cognitive, perceptual, physical, and behavioral/emotional.

Cognitive symptoms of brain damage include: Physical symptoms of brain damage include:
• difficulty processing information • persistent headaches
• difficulty in expressing thoughts • extreme mental fatigue
• difficulty understanding others • extreme physical fatigue
• shortened attention span • paralysis
• inability to understand abstract concepts • tremors
• impaired decision-making ability • seizures
• memory loss • sensitivity to light
Perceptual symptoms of brain damage • sleep disorders
include: • slurred speech
• loss of consciousness
• change in vision, hearing, or sense of
Behavioral/emotional symptoms of brain
touch
damage include:
• spatial disorientation
• inability to sense time • irritability and impatience
• disorders of smell and taste • reduced tolerance for stress
• balance issues • sluggishness
• heightened sensitivity to pain • flattened or heightened emotions or reactions
• denial of disability
• increased aggressiveness

Types of Brain Damage

1. Cerebrovascular Accident

Cerebrovascular accident (CVA) is the medical term for a stroke. A stroke is when blood flow to a part
of your brain is stopped either by a blockage or the rupture of a blood vessel. There are important signs
of a stroke that you should be aware of and watch out for.

Seek medical attention immediately if you think that you or someone around you might be having a
stroke. The more quickly you receive treatment, the better the prognosis, as a stroke left untreated for
too long can result in permanent brain damage.

Types of cerebrovascular accident

There are two main types of cerebrovascular accident, or stroke: an ischemic stroke is caused by a
blockage; a hemorrhagic stroke is caused by the rupture of a blood vessel. Both types of stroke
deprive part of the brain of blood and oxygen, causing brain cells to die.

Symptoms of a cerebrovascular accident

The quicker you can get a diagnosis and treatment for a stroke, the better your prognosis will be. For
this reason, it’s important to understand and recognize the symptoms of a stroke.

Stroke symptoms include:

 difficulty walking
 dizziness
 loss of balance and coordination
 difficulty speaking or understanding others who are speaking
 numbness or paralysis in the face, leg, or arm, most likely on just one side of the body
 blurred or darkened vision
 a sudden headache, especially when accompanied by nausea, vomiting, or dizziness

The symptoms of a stroke can vary depending on the individual and where in the brain it has happened.
Symptoms usually appear suddenly, even if they’re not very severe, and they may become worse over
time.

2. Brain Tumor

A brain tumor is a collection, or mass, of abnormal cells in your brain. Your skull, which encloses your
brain, is very rigid. Any growth inside such a restricted space can cause problems.

Brain tumors can be cancerous (malignant) or noncancerous (benign). When benign or malignant
tumors grow, they can cause the pressure inside your skull to increase. This can cause brain damage,
and it can be life-threatening.

Brain tumors are categorized as primary or secondary:

 A primary brain tumor originates in your brain. Many primary brain tumors are benign.
 A secondary brain tumor, also known as a metastatic brain tumor, occurs when cancer
 cells spread to your brain from another organ, such as your lung or breast.

Benign vs. malignant brain tumors

Though benign brain tumors can cause many serious issues, they are not cancerous, meaning that they
grow slowly and don’t typically spread to other tissues.

They also usually have more clearly defined borders, making them easier to remove surgically, and they
don’t usually come back after removal.

On the other hand, malignant brain tumors are cancerous, grow rapidly, and can spread to other parts of
your brain or central nervous system, which can cause life-threatening complications.

Types of brain tumors

Primary brain tumors

Primary brain tumors originate in your brain. They can develop from your:

 brain cells
 the membranes that surround your brain, which are called meninges
 nerve cells
 glands, such as the pituitary of pineal

Primary tumors can be benign or cancerous. In adults, the most common types of brain tumors are
gliomas and meningiomas.

Other primary brain tumors

Other primary brain tumors include:

 pituitary tumors, which are usually benign

 pineal gland tumors, which can be benign or malignant
 ependymomas, which are usually benign
 craniopharyngiomas, which occur mostly in children and are benign but can have clinical
symptoms like changes in vision and premature puberty
 primary central nervous system (CNS) lymphomas, which are malignant
 primary germ cell tumors of the brain, which can be benign or malignant
 meningiomas, which originate in the meninges
  schwannomas, which originate in cells that produce the protective cover of your nerves (myelin
sheath) called Schwann cells

Secondary brain tumors

Secondary brain tumors make up the majority of brain cancers. They start in one part of the body and
spread, or metastasize, to the brain. The following can metastasizeTrusted Source to the brain:

 lung cancer
 breast cancer
 kidney cancer
 skin cancer

Secondary brain tumors are always malignant. Benign tumors don’t spread from one part of your body
to another.

What are the symptoms of a brain tumor?

Symptoms of brain tumors depend on the location and size of the tumor. Some tumors cause direct
damage by invading brain tissue and some tumors cause pressure on the surrounding brain.

Headaches are a common symptom of a brain tumor. You may experience headaches that:

 are worse in the morning when waking up

 occur while you’re sleeping
 are made worse by coughing, sneezing, or exercise

You may also experience:

 vomiting
 blurred vision or double vision
 confusion
 seizures (especially in adults)
 weakness of a limb or part of the face
 a change in mental functioning

Other common symptoms include:

 clumsiness
 memory loss
  confusion
 difficulty writing or reading
 changes in the ability to hear, taste, or smell
 decreased alertness, which may include drowsiness and loss of consciousness
 difficulty swallowing
 dizziness or vertigo
 eye problems, such as drooping eyelids and unequal pupils
 uncontrollable movements
 hand tremors
 loss of balance
 loss of bladder or bowel control
 numbness or tingling on one side of the body
 trouble speaking or understanding what others are saying
 changes in mood, personality, emotions, and behavior
 difficulty walking
 muscle weakness in the face, arm, or leg
3. Seizures

A seizure is a sudden, uncontrolled burst of electrical activity in the brain. It can cause changes in
behavior, movements, feelings and levels of consciousness. Having two or more seizures at least 24
hours apart that don't have a known cause is considered to be epilepsy.

There are many types of seizures, and they have a range of symptoms and severity. Seizure types vary
by where they begin in the brain and how far they spread. Most seizures last from 30 seconds to two
minutes. A seizure that lasts longer than five minutes is a medical emergency.

Seizures can happen after a stroke or a head injury. They also may be caused by an infection such as
meningitis or another illness. Many times, though, the cause is unknown.

Most seizure disorders can be controlled with medicine. However, managing seizures can affect your
daily life. You can work with your health care provider to balance seizure control and medicine side
effects.

Symptoms

Symptoms vary based on the type of seizure. They also can range from mild to severe. Seizure
symptoms may include:

 Temporary confusion.
 A staring spell.
  Jerking movements of the arms and legs that can't be controlled.
 Loss of consciousness or awareness.
 Cognitive or emotional changes. They may include fear, anxiety or a feeling that you've already
lived this moment, known as deja vu.
Health care providers typically classify seizures as focal or generalized. Seizures are classified based on
how and where the brain activity causing the seizure began. If providers don't know how the seizures
began, they may classify the seizures as unknown onset.

Focal seizures

Focal seizures result from electrical activity in one area of the brain. This type of seizure can occur with
or without loss of consciousness:

 Focal seizures with impaired awareness. These seizures involve a change or loss of
consciousness or awareness that feels like being in a dream. People having these types of seizures
may seem awake but they stare into space and don't respond to their environment. They may
perform repetitive movements such as hand rubbing, mouth movements, repeating certain words
or walking in circles. They may not remember the seizure or even know that it occurred.
 Focal seizures without impaired awareness. These seizures may alter emotions. They also may
change the way things look, smell, feel, taste or sound. But the seizures don't cause a loss of
consciousness.
During these types of seizures, people may suddenly feel angry, joyful or sad. Some people have
nausea or unusual feelings that are hard to describe. These seizures may result in trouble speaking
and involuntary jerking of a body part such as an arm or a leg. They also may cause sudden
sensory symptoms such as tingling, dizziness and seeing flashing lights.
Symptoms of focal seizures may be confused with other disorders of the brain or nervous system. They
include migraine, narcolepsy or mental illness.

Generalized seizures

Seizures that appear to involve all areas of the brain from the time they start are called generalized
seizures. Different types of generalized seizures include:

 Absence seizures. Absence seizures, formerly known as petit mal seizures, often occur in
children. Absence seizures typically cause a person to stare into space or make subtle body
movements such as eye blinking or lip smacking. They usually last for 5 to 10 seconds. These
seizures may happen up to hundreds of times a day. They may occur in clusters and can cause a
brief loss of awareness.
 Tonic seizures. Tonic seizures cause stiffening of the muscles. These seizures usually affect
muscles in the back, arms and legs. People who experience these seizures may lose consciousness
and fall to the ground.
 Atonic seizures. Atonic seizures, also known as drop seizures, cause a loss of muscle control.
 People having this type of seizure may suddenly fall down or drop their head.
 Clonic seizures. Clonic seizures are associated with repeated jerking muscle movements. These
seizures usually affect the neck, face and arms on both sides of the body.
 Myoclonic seizures. Myoclonic seizures usually appear as sudden brief jerks or twitches of the
arms and legs. There is often no loss of consciousness.
 Tonic-clonic seizures. Tonic-clonic seizures, previously known as grand mal seizures, are the
most dramatic type of epileptic seizure. They can cause a sudden loss of consciousness, body
stiffening and shaking. They sometimes cause people to lose control of their bladder or to bite
their tongue. They may last for several minutes. Tonic-clonic seizures also may start as focal
seizures that then spread to involve most or all of the brain.
Causes

Nerve cells in the brain, known as neurons, create, send and receive electrical impulses. This allows the
cells to communicate. Anything that disrupts the communication pathways can lead to a seizure. Some
types of seizure disorders may be caused by genetic changes.

The most common cause of seizures is epilepsy. But not every person who has a seizure has epilepsy.
Sometimes seizures may be caused or triggered by:

 A high fever. When this happens, the seizure is known as a febrile seizure.
 An infection of the brain. This may include meningitis or encephalitis.
 Severe general illness, including a severe infection of COVID-19.
 Lack of sleep.
 Low blood sodium. This can happen with medicine that makes you urinate.
 Certain medicines that treat pain, depression or help people stop smoking . They can make it easier
for seizures to happen.
 A new, active brain injury, such as head trauma. It can cause bleeding in an area of the brain or a
new stroke.
 The use of legal or illegal drugs that may be sold on the streets, such as amphetamines or cocaine.
 Alcohol misuse, including during times of withdrawal or extreme intoxication.

4. Epilepsy

Epilepsy is a neurological condition that causes unprovoked, recurrent seizures. A seizure is a sudden
rush of abnormal electrical activity in your brain. Doctors diagnose epilepsy when you have two or
more seizures with no other identifiable cause.

Epilepsy affects 50 million people around the world, according to the World Health Organization
(WHO) and nearly 3.5 million people in the United States, per the Centers for Disease Control and
Prevention (CDC).

Anyone can develop epilepsy, but it most commonly onsets in young children and older adults.
According to research published in 2021, men develop epilepsy more often than women, possibly
because of higher exposure to risk factors like alcohol use and head trauma.

The two main types of seizures are:

 generalized seizures
 focal seizures

5. Genetic Neurological Abnormalities

A genetic brain disorder is caused by a variation or a mutation in a gene. A variation is a different form
of a gene. A mutation is a change in a gene. Genetic brain disorders affect the development and
function of the brain.

Some genetic brain disorders are due to random gene mutations or mutations caused by environmental
exposure, such as cigarette smoke. Other disorders are inherited, which means that a mutated gene or
group of genes is passed down through a family. They can also be due to a combination of both genetic
changes and other outside factors.

Some examples of genetic brain disorders include:

 Down Syndrome
 Phenylketonuria
 Tay-Sachs disease

Down Syndrome

Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small
“packages” of genes in the body. They determine how a baby’s body forms and functions as it grows
during pregnancy and after birth. Typically, a baby is born with 46 chromosomes. Babies with Down
syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having
an extra copy of a chromosome is ‘trisomy.’ Down syndrome is also referred to as Trisomy 21. This
extra copy changes how the baby’s body and brain develop, which can cause both mental and physical
challenges for the baby.

Even though people with Down syndrome might act and look similar, each person has different
abilities. People with Down syndrome usually have an IQ (a measure of intelligence) in the mildly-to-
moderately low range and are slower to speak than other children.

Some common physical features of Down syndrome include:

 A flattened face, especially the bridge of the nose

  Almond-shaped eyes that slant up
 A short neck
 Small ears
 A tongue that tends to stick out of the mouth
 Tiny white spots on the iris (colored part) of the eye
 Small hands and feet
 A single line across the palm of the hand (palmar crease)
 Small pinky fingers that sometimes curve toward the thumb
 Poor muscle tone or loose joints
 Shorter in height as children and adults

Causes and Risk Factors

 The extra chromosome 21 leads to the physical features and developmental challenges that can
occur among people with Down syndrome. Researchers know that Down syndrome is caused by
an extra chromosome, but no one knows for sure why Down syndrome occurs or how many
different factors play a role.
 One factor that increases the risk for having a baby with Down syndrome is the mother’s age.
Women who are 35 years or older when they become pregnant are more likely to have a
pregnancy affected by Down syndrome than women who become pregnant at a younger age.3-
5
However, the majority of babies with Down syndrome are born to mothers less than 35 years
old, because there are many more births among younger women.6,7

Phenylketonuria

Phenylketonuria (fen-ul-key-toe-NU-ree-uh), also called PKU, is a rare inherited disorder that causes an
amino acid called phenylalanine to build up in the body. PKU is caused by a change in the
phenylalanine hydroxylase (PAH) gene. This gene helps create the enzyme needed to break down
phenylalanine.

Without the enzyme necessary to break down phenylalanine, a dangerous buildup can develop when a
person with PKU eats foods that contain protein or eats aspartame, an artificial sweetener. This can
eventually lead to serious health problems.

For the rest of their lives, people with PKU — babies, children and adults — need to follow a diet that
limits phenylalanine, which is found mostly in foods that contain protein. Newer medications may
allow some people with PKU to eat a diet that has a higher or an unrestricted amount of phenylalanine.

Babies in the United States and many other countries are screened for PKU soon after birth. Although
there is no cure for PKU, recognizing PKU and starting treatment right away can help prevent
limitations in areas of thinking, understanding and communicating (intellectual disability) and major
health problems.

Symptoms

Newborns with PKU initially don't have any symptoms. However, without treatment, babies usually
develop signs of PKU within a few months.

Signs and symptoms of untreated PKU can be mild or severe and may include:

 A musty odor in the breath, skin or urine, caused by too much phenylalanine in the body
 Nervous system (neurological) problems that may include seizures
 Skin rashes, such as eczema
 Lighter skin, hair and eye color than family members, because phenylalanine can't transform into
melanin — the pigment responsible for hair and skin tone
 Unusually small head size (microcephaly)
 Hyperactivity
 Intellectual disability
 Delayed development
 Behavioral, emotional and social problems
 Mental health disorders

Tay-Sachs disease

Tay-Sachs disease is a rare genetic disorder passed from parents to child. It's caused by the absence of
an enzyme that helps break down fatty substances. These fatty substances, called gangliosides, build up
to toxic levels in the brain and spinal cord and affect the function of the nerve cells.

In the most common and severe form of Tay-Sachs disease, signs and symptoms start to show up at
about 3 to 6 months of age. As the disease progresses, development slows and muscles begin to
weaken. Over time, this leads to seizures, vision and hearing loss, paralysis, and other major issues.
Children with this form of Tay-Sachs disease typically live only a few years.

Less commonly, some children have the juvenile form of Tay-Sachs disease and may live into their teen
years. Rarely, some adults have a late-onset form of Tay-Sachs disease which is often less severe than
forms that begin in childhood.

Symptoms

There are three forms of Tay-Sachs disease: infantile, juvenile and late onset/adult.

Infantile form

In the most common and severe form, called infantile form, an infant typically begins showing signs
and symptoms by about 3 to 6 months of age. Survival is usually only a few years. Signs and symptoms
can include:

 Exaggerated startle response when the baby hears loud noises

 "Cherry-red" spots in the eyes
 Loss of motor skills, including turning over, crawling and sitting up
 Muscle weakness, progressing to paralysis
 Movement problems
 Seizures
 Vision loss and blindness
 Hearing loss and deafness
 Problems swallowing
 Loss of mental functions and a lack of response to surroundings
 Growth in head size (progressive macrocephaly)
Juvenile form

The juvenile form of Tay-Sachs disease is less common. Signs and symptoms vary in severity and
begin in childhood. Survival is typically into the teen years. Signs and symptoms can include:

 Behavior problems
 Gradual loss of skills and movement control
 Frequent respiratory infections
 Slow loss of vision and speech
 Decline in mental function and responsiveness
 Seizures
Last onset/adult form

This is a rare and less severe form with signs and symptoms beginning in late childhood to adulthood.
Severity of symptoms varies greatly, and this form does not always impact life expectancy. Signs and
symptoms progress slowly and can include:

 Muscle weakness
 Clumsiness and loss of coordination
 Tremors and muscle spasms
 Loss of the ability to walk
  Problems speaking and swallowing
 Psychiatric disorders
 Sometimes loss of mental function
Causes

Tay-Sachs disease is a genetic disorder that is passed from parents to their children. It occurs when a
child inherits a flaw (mutation) in the HEXA gene from both parents.

Risk factors

Because the gene change that causes Tay-Sachs disease is found more often in certain populations, risk
factors for Tay-Sachs disease include having ancestors from:

 Eastern and Central European Jewish communities (Ashkenazi Jews)

 Certain French Canadian communities in Quebec
 Cajun community of Louisiana
 Old Order Amish community in Pennsylvania
6. Degenerative Nerve Diseases

Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking,
breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical
condition such as alcoholism, a tumor, or a stroke. Other causes may include toxins, chemicals, and
viruses. Sometimes the cause is not known.

Degenerative nerve diseases include:

A. Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia among older people. Dementia is a
brain disorder that seriously affects a person's ability to carry out daily activities.

AD begins slowly. It first involves the parts of the brain that control thought, memory and language.
People with AD may have trouble remembering things that happened recently or names of people they
know. A related problem, mild cognitive impairment (MCI), causes more memory problems than
normal for people of the same age. Many, but not all, people with MCI will develop AD.

In AD, over time, symptoms get worse. People may not recognize family members. They may have
trouble speaking, reading or writing. They may forget how to brush their teeth or comb their hair. Later
on, they may become anxious or aggressive, or wander away from home. Eventually, they need total
care. This can cause great stress for family members who must care for them.

AD usually begins after age 60. The risk goes up as you get older. Your risk is also higher if a family
member has had the disease.

No treatment can stop the disease. However, some drugs may help keep symptoms from getting worse
for a limited time.

b. Parkinson's Disease

Parkinson's disease (PD) is a type of movement disorder. It happens when nerve cells in the brain don't
produce enough of a brain chemical called dopamine. Sometimes it is genetic, but most cases do not
seem to run in families. Exposure to chemicals in the environment might play a role.

Symptoms begin gradually, often on one side of the body. Later they affect both sides. They include

 Trembling of hands, arms, legs, jaw and face

 Stiffness of the arms, legs and trunk
 Slowness of movement
 Poor balance and coordination

As symptoms get worse, people with the disease may have trouble walking, talking, or doing simple
tasks. They may also have problems such as depression, sleep problems, or trouble chewing,
swallowing, or speaking.

There is no lab test for PD, so it can be difficult to diagnose. Doctors use a medical history and a
neurological examination to diagnose it.

PD usually begins around age 60, but it can start earlier. It is more common in men than in women.
There is no cure for PD. A variety of medicines sometimes help symptoms dramatically. Surgery and
deep brain stimulation (DBS) can help severe cases. With DBS, electrodes are surgically implanted in
the brain. They send electrical pulses to stimulate the parts of the brain that control movement.

c. Huntington's Disease

Huntington's disease (HD) is an inherited disease that causes certain nerve cells in the brain to waste
away. People are born with the defective gene, but symptoms usually don't appear until middle age.
Early symptoms of HD may include uncontrolled movements, clumsiness, and balance problems. Later,
HD can take away the ability to walk, talk, and swallow. Some people stop recognizing family
members. Others are aware of their environment and are able to express emotions.

If one of your parents has Huntington's disease, you have a 50 percent chance of getting it. A blood test
can tell you if have the HD gene and will develop the disease. Genetic counseling can help you weigh
the risks and benefits of taking the test.

There is no cure. Medicines can help manage some of the symptoms, but cannot slow down or stop the
disease.