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Causes of Central nervous system

Trauma

Any type of traumatic brain injury (TBI) or injury done to the spinal cord can result in a wide spectrum of disabilities in a person. Depending on the section of the brain or spinal cord that suffers the trauma the outcome may be anticipated.

Infections

Infectious diseases are transmitted in several ways. Some of these infections may affect the brain or spinal cord directly. Generally, an infection is a disease that is caused by the invasion of a micro-organism or virus.

Degeneration

Degenerative spinal disorders involve a loss of function in the spine. Pressure on the spinal cord and nerves may be associated with herniation or disc displacement. Brain degeneration also causes central nervous system diseases. Studies have shown that obese people may have severe degeneration in the brain due to loss of tissue affecting cognition.

Structural defects

Common structural defects include: birth defects,^[7] anencephaly, hypospadias, and spina bifida. Children born with structural defects may have malformed limbs, heart problems, and facial abnormalities.

Tumors

A tumor is an abnormal growth of body tissue. If benign, tumors can be non-cancerous, but if they are malignant, they are cancerous. In general, they appear when there is a problem with cellular division. Problems with the body’s immune system can lead to tumors.

Autoimmune disorders

An autoimmune disorder is a condition where the immune system attacks and destroys healthy body tissue. This is caused by harmful substances, called antigens.

Stroke

A stroke is an interruption of the blood supply to the brain. Approximately every 40 seconds, someone in the US has a stroke.^[8] This can happen when a blood vessel is blocked by a blood clot or when a blood vessel ruptures, causing blood to leak to the brain. If the brain cannot get enough oxygen and blood, brain cells can die, leading to permanent damage.

Disease of Central nervous system

Encephalitis

  Encephalitis is an inflammation of the brain. It is usually caused by a foreign substance or a viral infection. Symptoms for this disease include: headache, neck pain, drowsiness, nausea, and fever. If caused by the West Nile virus,^[3] it may be lethal to humans, as well as birds and horses.

Meningitis

Meningitis is an inflammation of the meninges (membranes) of the brain and spinal cord. It is most often caused by a bacterial or viral infection. Fever, vomiting, and a stiff neck are all symptoms of meningitis.

Tropical spastic paraparesis

Troby a virus that can also cause leukemia, a disease of the bone marrow.

Arachnoid cysts

Arachnoid cysts are cerebrospinal fluid covered by arachnoidal cells that may develop on the brain or spinal cord.^[4] They are a congenital disorder and in some cases may not show symptoms. However, if there is a large cyst, symptoms may include headache, seizures, ataxia (lack of muscle control),hemiparesis, and several others. Macrocephaly and ADHD are common among children, while pre-senile dementia, hydrocephalus (an abnormality of the dynamics of the cerebrospinal fluid), and urinary incontinence are symptoms for elderly patients (65 and older).

Huntington's

Huntington's disease is a rare neurological disorder that is inherited. Degeneration of neuronal cells in the frontal lobe of the brain occurs. There is a progressive decline which results in abnormal movements.^[5] Statistics show that Huntington’s disease may affect 10 per 100,000 people of Western European descent.

Alzheimer’s

Alzheimer’s is a neurodegenerative disease typically found in people over the age of 65 years. Worldwide, approximately 24 million people have dementia; 60% of these cases are due to Alzheimer’s. The ultimate cause is unknown. The clinical sign of Alzheimer’s is progressive cognition deterioration.

Locked-in syndrome

Locked-in syndrome is due to a lesion on the brain stem, damaging the pons. It is a condition where the patient is awake, but suffers from paralysis^[6] of all or nearly all voluntary muscles of the body and cannot communicate or move. Causes of locked-in syndrome may be: traumatic brain injury,circulatory system disease, nerve cell damage, and overdose of medication.

Central nervous system Functions

Spinal Cord

 The spinal cord transmits sensory reception from the peripheral nervous system. It also conducts motor information to the body's skeletal muscles, cardiac muscles, smooth muscles, and glands. There are 31 pairs of spinal nerves along the spinal cord. These nerves each contain both sensory and motor axons. The spinal cord is protected by vertebrae, and connects the peripheral nervous system to the brain, and it acts as a "minor" coordinating center.

Brain

  The brain apprehends signals from the spinal cord as well as the olfactory nerves (or the first cranial nerve) and optic nerves. It allows the body to function. The brain is protected by the skull; however, if the brain is damaged, the results to the human body can be very consequential.

Central nervous system

The central nervous system (CNS) is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish. It contains the majority of the nervous system and consists of the brain and the spinal cord. Some classifications also include the retina and the cranial nerves in the CNS. Together with the peripheral nervous system, it has a fundamental role in the control of behavior. The CNS is contained within thedorsal cavity, with the brain in the cranial cavity and the spinal cord in the spinal cavity. In vertebrates, the brain is protected by the skull, while the spinal cord is protected by the vertebrae, and both are enclosed in the meninges.

Neural and mental dysfunction

Mental disorders, learning disabilities and mental retardation are not usually classed as primarily neurological. However the distinction can be a matter of some debate, either in regard to specific facts about the cause of a condition or in regard to the general understanding of brain and mind. Furthermore the definition of disorder can be contested in regard to what is considered abnormal, dysfunctional, harmful or unnatural in neurological, evolutionary, psychometric or social terms.

While certain types of mental condition are not usually classified primarily as neurological disorders, and certain types of brain disorder are not usually classified primarily as mental conditions, there are now an array of basic sciences that deal with the continuum between the neural and the mental, including subspecialities of psychology and neuroscience such as neuropsychology, cognitive neuropsychology or cognitive (thought) neuroscience, affective (emotion) neuroscience, behavior neuroscience (also known as biopsychology), social neuroscience, and neurophenomenology(subjective experience and consciousness).

These basic fields inform the applied medical and clinical disciplines of neurology,psychiatry and clinical psychology, whose theories and treatments now routinely encompass a biopsychosocial model. These disciplines in turn comprise subspecialities such as behavioral neurology,neuropsychiatry and clinical neuropsychologythat deal with cases where a connection between mental/behavioral problems and brain dysfunction is particularly called for.Biopsychiatry is the general term for the approach in psychiatry that seeks to explain all mental disorders primarily in terms of the biological functioning of the nervous system.

The conventional distinctions drawn between mind, brain and nervous system are to some extent mirrored by the various overlapping categories of clinical examination, namelymental state examination, neuropsychological assessment and neurological examination. At the present time a brain scan alone cannot accurately diagnose a mental disorder or tell the risk of developing one, but can be used to rule out other medical conditions such as a brain tumor.^[5]

Classification of Neurological disorder

Neurological disorders can be categorized according to the primary location affected, the primary type of dysfunction involved, or the primary type of cause. The broadest division is between central nervous system (CNS) disorders andperipheral nervous system (PNS) disorders. The Merck Manual lists brain, spinal cord and nerve disorders in the following overlapping categories:^[2]

• Brain:
  • Brain damage according to cerebral lobe (see also lower brain areas such as basal ganglia, cerebellum,brainstem):
    • Frontal lobe damage
    • Parietal lobe damage
    • Temporal lobe damage
    • Occipital lobe damage
  • Brain dysfunction according to type:
    • Aphasia (language)
    • Dysarthria (speech)
    • Apraxia (patterns or sequences of movements)
    • Agnosia (identifying things/people)
    • Amnesia (memory)
• Spinal cord disorders (see spinal pathology, injury,inflammation)
• Peripheral nervous system disorders
• Cranial nerve disorders
• Autonomic nervous system disorders
• Seizure disorders such as epilepsy
• Movement disorders such as Parkinson's disease
• Sleep disorders
• Headaches (including migraine)
• Lower back and neck pain (see Back pain)
• Other pain (see Neuropathic pain)
• Delirium and dementia such as Alzheimer's disease
• Dizziness and vertigo
• Stupor and coma
• Head injury
• Stroke (CVA, cerebrovascular attack)
• Tumors of the nervous system (e.g. cancer)
• Multiple sclerosis (MS) and other demyelinating diseases
• Infections of the brain or spinal cord (including meningitis)
• Prion diseases (a type of infectious agent)
• Complex regional pain syndrome (CRPS) (a chronic pain condition.)