Diseases of The Nervous System (unit 12) Flashcards
Cavities in the brain with cells that produce cerebral spinal fluid (CSF).
Ventricles
Starts from two lateral ventricles through interventricular foramina into:
- 3rd ventricle- through cerebral aqueduct into
- 4th ventricle- Through lateral and medial apertures into
- Subarachnoid space of the brain and spinal cord.
CSF circulation
After starting at the two lateral ventricles through the interventricular foramina, the CSF goes here.
The third ventricle
From the third ventricle, the CSF goes through the cerebral aqueduct into the:
The 4th ventricle
From the 4th ventricle, the CSF goes through the lateral and medial apertures into:
The subarachnoid space of the brain and spinal cord
Injury to the brain.
- Concussion
- Contusion
- Laceration
- Intracranial (brain) hemorrhage
Brain trauma
Loss of cerebral control following injury (fracture, laceration, cutting, wound, hemorrhage)
- Immediate and temporary disturbance of brain function, disruption of normal electrical activity.
Concussion
- Blood leaking from the brain
- Injection of spinal fluid into the brain => molecular (chemical) disturbance
Results of concussions
- Drowsiness, loss of coordination, slow pulse, convulsions, projectile vomiting, stupor, comatose.
Symptoms of concussions
A bruise- crushing (compression) of the brain.
- Leads of hemorrhage
- Often accompanied by swelling
- Caused by fracture or trauma to the skull
Contusion
A cutting wound that penetrates the skull.
- Results in hemorrhage, bleeding.
Laceration
- Extradural (epidural) hemorrhage
- Subdural hemorrhage
- Subarachnoid hemorrhage
Types of Intracranial (brain) Hemorrhage
Intracranial hemorrhage due to a fracture or trauma to the head.
- Bleeding => blood collects and proceeds down to the brain
- If unrelieved => death can occur in days or weeks.
Extradural (epidural) Hemorrhage
Intracranial hemorrhage caused my a more severe fracture or injury.
- More rapid bleeding
- If unrelieved => death within a few days.
Subdural Hemorrhage
Most severe intracranial hemorrhage, due to a laceration.
- Very rapid bleeding into the brain
- Death occurs within hours
Subarachnoid Hemorrhage
Inflammation of the membranes (meninges) of the brain and spinal cord.
- May affect any age group: newborn => elderly
Meningitis
- Microorganisms that spread into blood and cerebral spinal fluid (CSF) into meninges => muscle paralysis => respiratory failure (diaphragm) within 12-24 hours.
- Viruses (most cases), fungi, protozoans, and cancers
Causes of meningitis
A life threatening meningitis that may cause epidemic meningitis.
- Spread by respiratory secretions
Bacterial Meningitis (Neisseria meningitides)
A type of meningitis that is common in people with impaired immune system (AIDS).
Fungal Meningitis
- Headaches
- Stiff neck*
- Fever
- Photophobia
- Vomiting
Symptoms of meningitis
Temporary lack of circulation to a part of the brain; may lead to ischemia.
- Mini-stroke (lasting minutes- hours).
- Warning sign for a stroke
Transient Ischemic Attack (TIA)
- Clot
- Narrowing (atherosclerosis)
- Blockage in carotid artery
Causes of Transient Ischemic Attack (TIA)
- Loss of sensation
- Loss of movement
- Loss of speech
- Loss of mental function or vision
- Generally disappear completely within 24 hours (after resumption of blood flow).
Symptoms of Transient Ischemic Attack (TIA)
Sudden death of some brain cells due to lack of oxygen caused by blockage or rupture of an artery in the brain => hemorrhage => softening of the brain => ischemia and infarction.
- Effect depends on the size of the hemorrhage
- 3rd leading cause of death
Cerebrovascular Accident (CVA)
- Arteriosclerosis
- High blood pressure
- Thrombus or embolus in cerebral blood vessel
- Aneurysm
Predisposing factors of cerebrovascular accident (CVA)
- Most common is weakness or paralysis of one side of the body with partial or complete loss of voluntary movement or sensation in a leg or arm.
Symptom of cerebral vascular accident (CVA)
Inflammation of the brain
Encephalitis
- Bacteria (staph, strep)
- Viruses (Herpes, encephalitis virus)
- Complication of measles or chickenpox.
- Infections usually spread from upper respiratory tract, sinuses, ears, or eyes.
Cause of encephalitis
Horse => mosquito => human
- West nile virus
Equine encephalitis
- Swelling of the brain
- Fever, headache, body aches, skin rash and swollen lymph nodes
- Severe infections - high fever, stiff neck, stupor (sleepiness), disorientation, coma, tremors, occasional convulsions, paralysis, and rarely death
- Death rates 3% to 15% (higher in elderly than in younger)
Symptoms of encephalitis
Acute inflammation of the brain (encephalo-) and the spinal cord (myelo-).
- Can be caused by viruses which infect the nervous system.
Encephalomyelitis
Occurs most commonly after acute viral infection such as measles (rubeola) => autoimmune attack on the nervous system.
Acute disseminated encephalomyelitis
Late stages of syphilis; often affect the brain and spinal cord.
Neurosyphilis
- Include general paresis (incomplete paralysis)
- Can result in dementia, deafness, blindness, paralysis, insanity
Damage to the brain by neurosyphilis
Tabes Dorsalis
Spinal cord damage by neurosyphilis
Slowly progressive, degeneration of the spinal cord, results in locomotive ataxia.
Tabes Dorsalis
Wobbliness
Ataxia
Inflammation of a nerve or nerves.
Neuritis
- Injury- compression, contusion
- Infection (tetanus, tuberculosis), inflammation
- Chemical poisoning (arsenic, lead), medication
- Neoplasm or stress
Etiology of neuritis