meningioma | The brain and the spinal cord

The brain and the spinal cord



The brain, commonly referred to as brains, is a complex organ made up of nerve tissues and specialized supporting tissues, as it occupies most of the cerebrum. It is surrounded by many bones that form the skull. The part of the skull where the brain is located is called a cranial box. The lower part of the brain, the base, is linked to the spinal cord. Together, the brain and spinal cord form the central nervous system (CNS). Many nerves transmit electrical signals to and from the brain and spinal cord.

Structure and function of the brain
The brain is the control center of the body. He constantly receives and interprets the nerve signals of the body and sends new signals based on this information. Different parts of the brain control the movements, the language, the emotions and the consciousness, as well as the internal functions of the body including heart rate, respiration and body temperature.

The brain is made up of 3 main parts, the brains, the cerebellum and the brainstem.

Central nervous system scheme

Types of cells in the brain
The brain is composed of 2 main types of cells.

Nerve cells (neurons) transmit the electrical signals that make the nervous system work. They may not be replaced or repaired when damaged. These are the longest cells in the body.

Diagram of the structure of a neuron

Glial cells (neurogliales cells) support, feed and protect nerve cells. The different types of glial cells are as follows:

Astrocytes
Oligodendrocytes
Épendymocytes
Microglial cells
Brain
The brain is the most voluminous part of the cerebrum (which explains the frequent use of the word "brain" rather than "cerebral" in the current language). It is divided into 2 halves called left cerebral hemisphere and right cerebral hemisphere. These two hemispheres are connected by a nerve fiber bridge called the callus body.

The right half of the brain (right hemisphere) controls the left side of the body while the left half of the brain (left hemisphere) controls the right side of the body.

The cerebral cortex is the outer part of the brain that consists of folds. It is also called a grey substance. The cerebral cortex is mainly composed of cell bodies and dendrites of nerve cells (neurons). The cell bodies contain the nucleus and other essential parts of the cell. Dendrites are the short fibrous extensions that receive signals from other nerve cells. The inner part of the brain is called white substance. It is mainly composed of the long fibers of nerve cells called axons that circulate signals between the brain and the rest of the body. The fatty envelope of the axons, the myelin, gives this part of the brain a whitish hue.

Each hemisphere is divided into 4 sections called lobes that include the frontal, parietal, temporal, and occipital lobes.

Diagram of the lobes of the brain

Each lobe has different functions.

The frontal lobe controls movements, language, behavior, memory, emotions and intellectual functions such as reflection, reasoning, problem-solving, decision-making and planning.

The parietal lobe controls sensations such as touch, pressure, pain and temperature. It also controls the understanding of size, shape and direction, so-called spatial orientation.

The temporal lobe controls hearing, memory and emotions. The dominant temporal lobe, the left side in most right-handed, also commands language.

The occipital lobe controls the vision.

Cerebellum

The cerebellum is located under the brain, in the back part of the cerebrum. It is divided into 2 parts, or hemispheres, and also contains grey substance and white substance.

The cerebellum is responsible for:

of movements;

of posture;

of balance;

reflexes;

Complex actions such as walking and talking

The collection of sensory information from the body.

Brain stem

The brainstem is a bundle of nerve tissue located at the base of the brain. It connects the brain and the cerebellum to the spinal cord.

The brainstem is composed of the following three regions:

Midbrain

Bridge

Spinal Bulb

The brainstem circulates messages between the other parts of the brain and the rest of the body and controls the following functions:

Breathing

Body temperature

blood pressure

Heart rate

Hunger and thirst

Food digestion

Cerebrospinal liquid

Cerebrospinal fluid (CSF) is a clear, aqueous liquid that surrounds and protects the brain and spinal cord and serves as a cushion. The CSF also carries the nutrients from the blood to the brain and removes the waste. The CSF circulates in cavities called ventricles and on the surface of the brain and spinal cord.

Brain

The brain and spinal cord are covered with 3 layers of tissue (membranes) that protect them called brains:

Dura Mater – outer layer, thickest

arachnoid – thin, intermediate membrane

Mother Pie – inner membrane, thin

The LCR circulates in the space between the arachnoid and the mother-pie. This space is called subarachnoid.

Callus Body

The callus body is a bundle of nerve fibers that allows communication between the two cerebral hemispheres. It's the biggest fiber bundle in the brain.

Thalamus

The thalamus is a structure located in the center of the brain that is composed of 2 lobes, or sections. It serves as a relay to almost all the information circulating between the brain and the rest of the nervous system.

Hypothalamus

The hypothalamus is a small structure in the center of the brain under the thalamus. It plays a role in regulating body temperature, hormone secretion, blood pressure, emotions, appetite and sleep habits.

Pituitary gland

The pituitary gland is a small organ of the size of a pea, which is located in the center of the brain. It is attached to the hypothalamus and produces a number of different hormones that affect other endocrine glands. She receives messages from the hypothalamus and releases hormones that control the thyroid gland, adrenal gland, growth and physical development as well as sexual development.

Pineal body

The pineal body is a very small gland located in the third ventricle of the brain. It produces the hormone called melatonin, which affects the sleep-awake rhythms and sexual development.

Choroid Plexus

The choroid plexus is a small organ located in the ventricles that manufactures the CSF.

Cranial nerves

There are 12 pairs of cranial nerves that perform specific functions in the head and neck, which provide us with a sense of smell, vision, hearing, taste and language, sensations in the face and movements of facial muscles , eyes and tongue. A pair of nerves originates in specialized cells of the roof of the nose and another in the retina of the eye. The other 10 pairs of cranial nerves originate in the brainstem.

Blood-brain barrier

The blood-brain barrier (BBB) is a specialized system of cells that line the blood vessels of the brain. BBB prevents most of the substances in the blood from entering the brain and helps maintain a stable environment so that the brain's nerve cells can function properly.

BBB is made up of very small blood vessels (capillaries) that are covered with thin, flat endothelial cells. In other parts of the body, endothelial cells are separated from each other by small spaces that allow substances to enter and remove capillaries and go to other cells and tissues. In the brain, endothelial cells are very tight against each other so as to prevent any substance from getting out of the bloodstream to go into the brain.

Structure and function of the spine

Spine diagram

The spine is composed of 26 bones divided into 5 sections. These bones surround and protect the spinal cord and include 24 vertebrae (divided in cervical, thoracic and lumbar regions), sacrum and bone marrow.

Cervical region – It comprises 7 vertebrae at the top of the spine that depart from the base of the skull and descend to the lower part of the neck.

Thoracic region – It includes 12 vertebrae from the shoulders and down to the middle of the back.

Lumbar region – It includes 5 vertebrae from the middle of the back and down to the hips.

Sacrum – It is a large section of welded vertebrae located at the base of the spine.

Tail Bone – This is a small thin section of welded vertebrae located at the lower end of the spine.

Between the vertebrae are the disks (intervertebral disks).

Disc – It is a layer of cartilage located between each vertebra that serves as a pad to the vertebrae and spinal cord and protects them.

Spinal cord

The spinal cord is a thick column of nerves surrounded by the vertebrae that extends from the brainstem to the lumbar region of the spine. Just like the brain, the spinal cord contains gray substance and white substance. The spinal cord circulates information between the brain and a large part of the body through the spinal nerves.

Spinal nerves

Pairs of spinal nerves emerge between the vertebrae along the spinal cord. In the lumbar region, the spinal cord is branches into a group of spinal nerves that emerge from the lumbar vertebrae and sacrum. Spinal nerves control bodily functions such as movements, bladder and bowel control and respiration. The spinal nerves are numbered according to the neighbouring vertebrae.

Meningioma
Meningioma originates in cells of membranes that cover the brain and spinal cord (brains). The meningioma can be low grade or high grade (grades 1 to 3).

Meningioma is a common type of primitive brain tumor in adults. Sometimes the meningioma affects several members of the same family, especially people with neurofibromatosis. Meningioma appears most often in women.

Meningioma Benin
Meningioma Benin is a low grade tumor (Grade 1) that represents about 70 to 80% of all meningiomas. Meningioma Benin is the most common non-cancerous (benign) brain tumor and is most commonly observed in elderly people between 50 and 80 years of age.

The following treatments may be used for meningioma Benin.

We're doing surgery to remove the whole tumor or as much of the tumor as possible.

Radiation therapy can be administered after surgery if the tumor is not completely removed or as a primary treatment if surgery is not possible. Stereotactic radiosurgery may be performed after surgery for a small tumor that remains.

Active surveillance can be done with regular MRI tests to see if the tumor is developing in people who do not have symptoms and cannot undergo surgery.

Atypical meningioma
Atypical, or invasive, meningioma is a low-grade tumor (Grade 2), but it grows faster than benign meningioma and can spread to nearby tissue. It often reappears after being treated (relapse).

The following treatments may be used for atypical meningioma.

We're doing surgery to remove the whole tumor or as much of the tumor as possible.

Radiotherapy can be administered after surgery, especially if the tumor cannot be removed completely.

Meningioma anaplastic or malignant
Meningioma anaplastic, or malignant, is a high grade tumor (Grade 3). It's the least common type of meningioma. It often spreads to nearby brain and bone tissues and can spread to other parts of the body.

The following treatments may be used for meningioma anaplastic.

We're doing surgery to remove the whole tumor or as much of the tumor as possible.

We administer radiation therapy after surgery.

Clinical trials
A few clinical trials on the meningioma are underway in Canada and accept participants. The aim of the clinical trials is to find new methods for the prevention, detection and treatment of cancer. Learn more about clinical trials