central nervous system

The central nervous system (CNS) consists of the brain and spinal cord. They are protected by three membranes: dura (outer membrane), arachnoid (middle), pia (inner membrane) generally called meninges. In addition, the brain and spinal cord are protected by bony shells, which are the skull and spine respectively. This is a very complex system, because it is responsible to perceive stimuli from the outside world and transmit nerve impulses to muscles and instinctively. The cavities of these organs (ventricles in the case of the brain and ependymal canal in the case of the spinal cord) are filled with a clear, colorless liquid, which is called cerebrospinal fluid. Their functions are varied: it serves as a means of exchange of certain substances, as a system of removal of waste products and to maintain the proper ionic balance, transports oxygen and glucose from blood to neurons and is also very important as a buffer system mechanic.

The cells forming the central nervous system are arranged so as to give rise to two very characteristic formations: the gray matter, consisting of the soma of neurons and their dendrites as well as unmyelinated fibers., And white matter, consisting mainly by nerve extensions (dendrites and axons), whose function is to conduct information, in addition to myelinated fibers which are what give it that color in them. In short, all the animals whose body has a central nervous system are endowed with neural mechanisms responsible for receiving and processing the sensations gathered by the different senses and transmit orders to respond accurately to different effectors.

poliomyelitis

It is a viral disease that can affect nerves and lead to total or partial paralysis.

causes

Polio is a disease caused by infection with poliovirus. The virus is spread by:

Direct contact from person to person

Contact with infected mucus or phlegm from the nose or mouth

Contact with infected feces

The virus enters through the mouth and nose, multiplies in the throat and digestive tract before being absorbed and spread through blood and lymph system. The time that elapses from the moment of being infected with the virus to developing symptoms of the disease (incubation) ranges between 5 and 35 days (an average of 7 to 14 days).

The risks include:

Lack of immunization against polio

Traveling to an area that has experienced a polio outbreak

In areas where there is an outbreak, those most likely to get the disease include children, pregnant women and the elderly. This disease is more common in the summer and fall.

symptoms

There are three basic patterns of polio infection: subclinical infections, non-paralytic and paralytic. Approximately 95% are subclinical infections that may have no symptoms.

Symptoms of subclinical infection

General discomfort or uneasiness (malaise)

Headache

red throat

mild fever

Sore throat

vomiting

People with subclinical polio infection might not have symptoms or your symptoms may last 72 hours or less.

People with subclinical polio infection might not have symptoms or your symptoms may last 72 hours or less.

Clinical poliomyelitis affects the central nervous system (brain and spinal cord) and is divided into the non-paralytic and paralytic forms. It may occur after recovery from a subclinical infection.

NO POLIO PARALYTIC

Back pain or lumbago

diarrhea

Excessive tiredness, fatigue

Headache

irritability

Leg pain (calf muscles)

moderate fever

muscle stiffness

Muscle tenderness and spasm in any area of ​​the body

Pain and stiffness in the neck

Pain in the anterior neck

Pain or stiffness in the back, arms, legs and abdomen

Rash or skin lesion with pain

vomiting

Symptoms usually last 1 to 2 weeks.

paralytic poliomyelitis

Fever 5 to 7 days before other symptoms

Abnormal sensations (but not loss of sensation) in an area

abdominal distension

Shortness of breath

constipation

Difficulty starting to urinate

drooling

Headache

Irritability or poor temper control

Muscle contractions or spasms, particularly in the calf, neck or back

muscle pain

Muscle weakness, asymmetrical (only on one side or worse on one side)

appears rapidly

Location depends on where the spinal cord is affected

Worsening paralysis

Sensitivity to touch, mild touch may be painful

Stiff neck and back

Difficulty swallowing

Sclerosis

Sclerosis (Greek Skleros, in Spanish, "hard")  is a hardening of the organ or tissue due to increased connective tissue. Sclerosis is, therefore, a disease which derives from another, is an autonomous disease.

The disease usually occurs due to tissue damage as a result of inflammation, poor perfusion or also aging processes. Similarly, an autoimmune disease can also lead to a sclerosis. The result is an uncontrolled production of connective tissue, which leads to a hardening. Affected organs harden and lose elasticity.

Meningitis

It is a bacterial infection of the membranes covering the brain and spinal cord (meninges).

aseptic meningitis

Gram-negative meningitis

Meningitis caused by H. influenzae

meningococcal meningitis

pneumococcal meningitis

staphylococcal meningitis

tuberculous meningitis

Causes, incidence, and risk factors

The most common causes of meningitis are viral infections that usually get better without treatment. However, bacterial meningitis infections are extremely serious and can result in death or brain damage even if treated.

Meningitis can also be caused by:

chemical irritation

Allergies to medications

mushrooms

tumors

Types include:

aseptic meningitis

cryptococcal meningitis

Gram-negative meningitis

Meningitis caused by H. influenzae

Meningitis due to cancer (carcinomatous meningitis)

meningococcal meningitis

pneumococcal meningitis

staphylococcal meningitis

Syphilitic aseptic meningitis

tuberculous meningitis

Acute bacterial meningitis is a true medical emergency and requires immediate treatment in a hospital.

Viral meningitis is milder and occurs more often than bacterial meningitis. It usually develops in late summer and early fall and often affects children and adults under 30. Most infections occur in children under 5 years. Most cases of viral meningitis due to enteroviruses, which are viruses that also cause intestinal illness.

Many other viruses can cause meningitis. For example, viral meningitis can be caused by the herpes virus, the same virus that can cause cold sores and genital herpes (although people with cold sores or genital are not at increased risk of developing herpes meningitis).

Recently, West Nile virus, spread by mosquito bites, has become a cause of viral meningitis in most of the United States.

symptoms

Symptoms usually appear quickly and may include:

Fever and chills

Changes in mental status

Nausea and vomiting

Sensitivity to light (photophobia)

Severe headache

Stiff neck (meningismus)

Additional symptoms that may occur include:

agitation

bulging fontanelles

Decreased consciousness

Poor feeding or irritability in children

rapid breathing

Unusual posture with the head and neck arched backwards (opisthotonos)

Meningitis is an important cause of fever in children and newborns.

People can not differentiate whether bacterial or viral meningitis are the way they feel, so they should seek prompt medical attention.

Encephalitis

Is irritation and swelling (inflammation) of the brain, usually due to infections.

Causes, incidence, and risk factors

Encephalitis is a rare disease. It occurs mostly in the first year of life and decreases with age. The very young and the elderly are more likely to have a severe case.

The most common cause of encephalitis is a viral infection and many types of viruses may cause. Exposure to viruses can occur through:

Inhalation of respiratory droplets from an infected person

Contaminated food or drink

Bites of mosquitoes, ticks and other insects

Contact with skin

Different viruses are present in different places and often tend to cluster in a certain season.

Encephalitis caused by herpes simplex virus is the leading cause of severe cases in all ages, including newborns.

Many of the viruses for which there is now a vaccine can also cause encephalitis, such as:

measles

mumps

polio

rage

rubella

chickenpox

Other viruses that can cause encephalitis include:

adenovirus

Coxsackie virus

cytomegalovirus

Virus of eastern equine encephalitis

echovirus

West Nile Virus

The virus causes inflammation of brain tissue. This tissue swells (cerebral edema), which can destroy brain cells, cause bleeding in the brain (intracerebral hemorrhage) and brain damage.

Other causes of encephalitis may include:

An allergic reaction to vaccines

Autoimmune disease

Bacteria such as Lyme disease, syphilis and tuberculosis

Parasites such as nematodes, cysticercosis and toxoplasmosis in AIDS patients and others with weakened immune systems

cerebral trauma

Types of head injuries

• A concussion is a jarring injury to the brain. Most of the time it doesn't involve a loss of consciousness. A person who has a concussion may feel dazed and may lose vision or balance for a while after the injury. 
• A brain contusion is a bruise of the brain. This means there is some bleeding in the brain, causing swelling.
• A skull fracture is when the skull cracks. Sometimes the edges of broken skull bones cut into the brain and cause bleeding or other injury.
• A hematoma is bleeding in the brain that collects and clots, forming a bump. A hematoma may not be apparent for a day or even as long as several weeks. So it's important to tell your doctor if someone with a head injury feels or acts oddly. Watch out for headaches, listlessness, balance problems or throwing up.

Symptoms

It's normal to have a headache and nausea, and feel dizzy right after a head injury. Other symptoms include ringing in the ears, neck pain, and feeling anxious, upset, irritable, depressed or tired.

The person who has had a head injury may also have problems concentrating, remembering things, putting thoughts together or doing more than one thing at a time.

These symptoms usually go away in a few weeks, but may go on for more than a year if the injury was severe.

Get help if you notice the following symptoms:

• Any symptom that is getting worse, such as headaches, nausea or sleepiness
• Nausea that doesn't go away
• Changes in behavior, such as irritability or confusion
• Dilated pupils (pupils that are bigger than normal) or pupils of different sizes
• Trouble walking or speaking
• Drainage of bloody or clear fluids from ears or nose
• Vomiting
• Seizures
• Weakness or numbness in the arms or legs

A TBI can cause problems with the ability to awaken the consciousness, vigilance and responsiveness. Generally, there are five abnormal states of consciousness that can result from brain trauma. Stupor, coma, persistent vegetative state, locked-in syndrome and brain death.

Stupor is a state in which the patient is unresponsive but can wake up briefly by a strong stimulus, such as a throbbing pain. Coma is a state in which the patient is completely unconscious, not responsive and impossible to wake up. Patients who are comatose unresponsive to external stimuli such as pain or light, and have no cycles in sleeping and waking. Coma is the result of a widespread and diffuse trauma of the brain and brain lobes comprising top, bottom or brainstem. Coma is generally short duration, lasting for a period of a few days to several weeks. After this period, some patients gradually emerge from his coma, some progress to a vegetative state and others die.

Patients in a vegetative state are oblivious to their surroundings, but still have a normal sleep-wake cycle and periods seem to be aware. Unlike the point where the patient's eyes remain closed, patients in a vegetative state often open their eyes and can move, emit moans or react to tests to measure reflexes. A vegetative state can result from trauma diffuse the hemispheres of the brain without damage to the lower brain and brainstem. Anoxia or lack of oxygen to the brain, which is a common complication of cardiac arrest, can also lead to a vegetative state.