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
- Headaches
- Hyperesthesia
- Paresthesia
- Dysesthesia
- Muscular atrophy of part supplied by affected nerve
- Paralysis
- Lack of reflexes
Symptoms of neuritis
Hypersensitivity
Hyperesthesia
Numbness, tingling
Paresthesia
Painful sensation
Dysesthesia
Mass of immune cells, pus, and other material draining into deeper brain tissue.
- Results in necrosis of healthy brain tissue
- encephalomalacia (brain softening)
Cerebral (brain) Abscess
Necrosis of brain tissue
Encephalomalacia (brain softening)
- Usually from bacterial (staph, strep, pesudomonas)
- Bacteria can get to the brain from an injury, respiratory tract, ear or eye infection.
Cause of cerebral (brain) abscess
Inflammation of the spinal cord.
- Highly infectious, mainly affects children under 5
- Spread through oral or fecal-oral route
Poliomyelitis
Infantile paralysis
Polio
- Fever, headache, sore throat, abdominal pain
- Stiffness of neck, trunk, extremities
- Atrophy of a group of muscle => contraction => permanent deformity
- Paralysis in hours (e.g. respiratory, GI tract or leg)
Results of Poliomyelitis
Acute viral infection of the central nervous system of warm-blooded animals (wolves, cats, dogs).
- transmitted by bite of rabid animal (madness, rage, fury)
- If left untreated => 100% fatal in animals
Rabies
- Hydrophobia
- Increase in saliva production
- Abnormal behavior
- Paralysis => respiratory failure => coma => death
Results of Rabies
Fear of water, attempts to drink water trigger laryngeal spasm.
Hydrophobia
Acute, infectious, life-threatening bacterial disease that affects the nervous system.
Tetanus
Toxin produced by Clostridium tetani => toxin attaches to motor neurons.
- Found in animal feces, spores in soil
Cause of tetanus
Leads to painful muscle contractions, particularly of the jaw (lockjaw) and the neck muscles.
Result of tetanus
- Painful, uncontrolled contractions of skeletal muscles => gradually affects muscles of the esophagus, neck, back, arms, legs
- High fever
- Tachycardia
- Dysphagia
- Intense pain
Symptoms of tetanus
Faster heartbeat.
Tachycardia
Difficulty swallowing.
Dysphagia
Chronic neurogenic disease marked by sudden alterations in consciousness and convulsions.
- A temporary lack of oxygen to vital brain centers
- Recurrent seizures of unknown origin
Epilepsy
- Congenital abnormality of blood vessels in the brain.
- Some disorders which block blood flow to the brain.
Predisposing factors for epilepsy
- Petit mal seizure
- Grand mal seizure
Types of epilepsy
- Loss of consciousness, usually for a few seconds
- No memory of the seizure, no complications
Petit mal seizure
- Loss of consciousness, muscle rigidity, spasms of face, neck, arms, legs, person will thrash about.
- Generally lasts fir a few minutes
- No memory of the seizure
- May results in cyanosis, breathing difficulty, bitten tongue, excessive salivation, bloody froth or saliva
Grand mal seizure
- Alzheimer’s disease
- Amyotrophic lateral sclerosis
- Parkinson’s disease
- Multiple sclerosis
- Creutzfeldt-Jakob disease
Degenerative Diseases of the CNS
Progressive and fatal brain disease due to the formation of protein plaques, or tangles of nerve fibers that interfere with communication between nerve cells in the brain.
- Named for German physician Alois Alzheimer
- Most common type of dementia
Alzheimer’s Disease
- Amnesia, impaired recognition, forgetfulness
- Emotional upsets, confusion, mood changes
- Inability to concentrate => inability to complete simple tasks
- Irritability, agitation, restlessness, depression, hostility
- Motor disturbances, muscle rigidity, paralysis, apraxia
Symptom’s of Alzheimer’s Disease
Loss of short term memory.
Amnesia
Skilled movements.
Apraxia
In Alzheimer’s Disease, external surface of the brain with widened sulci and narrowed gyri mostly over frontal and parietal regions.
Cerebral atrophy
Lou Gehrig’s Disease
- Caused by destruction of both upper and lower motor neurons (brain and spinal cord).
- More often affects middle-aged men, fatal within 5 years.
Amyotrophic Lateral Sclerosis
- Cramps
- Muscle weakness and atrophy
- Uncontrollable twitching
Symptoms of Amyotrophic Lateral Sclerosis
Degenerative disorder of the central nervous system basal ganglia (nuclei) causing faulty nerve signal transmission.
- Insufficient dopamine (neurotransmitter)
Parkinson’s Disease
- Environmental toxins, no hereditary basis
- Trauma (often affect boxers)
- Tumors
- Prior infections
- Drugs
- Atherosclerosis (more common)
Causes of Parkinson’s Disease
- “Tremors at rest”, rigidity of muscles, weakness of muscles, a forward lean
- Slurred speech
- Digestive and urinary difficulty
- Hypotension
- In late stages: depression and dementia
Symptoms of Parkinson’s disease
Low blood pressure.
Hypotension
A chronic disease of the nervous system characterized by remissions and relapses and by the presence of patches of demyelination associated with sclerosis or hardening, scattered diffusely throughout the gray and white matter o the brain stem and spinal cord.
Multiple Sclerosis
T-lymphocytes and macrophages attach its own myelin
- Causes softening of the spinal cord
Multiple sclerosis : autoimmune disease
Protective sheath composed of lipids and proteins, around axons of some neurons.
Myelin
- Loss of coordination (1st symptom)
- Optic disturbances
- Tremors
- Disturbance in neural pathways
- local anesthesia and paralysis
- Respiratory problems
- Loss of bowel and bladder control
- Paralysis to the limbs
Symptoms of Multiple Sclerosis
A rare, degenerative brain disorder.
- Rapid development (6-12 months); incurable, ultimately fatal within 1 year.
Creutzfeldt-Jakob Disease
- Probably due to a protein called a prion that folds abnormally => which affects it’s function.
- Possibly from eating infected beef
Possible causes for Creutzfeldt-Jakob Disease
- Personality changes
- Hallucinations
- Muscle twitching and stiffness
- Lack of coordination
- Speech impairment
- Blindness, come
Symptoms of Creutzfeldt-Jakob Disease
- Cerebral palsy
- Microcephaly
- Anencephaly
- Hydrocephalus
- Spina bifida
CNS: Congenital Disorders
Motor disturbance present at birth, usually due to a congenital birth defect or birth trauma.
- Non-progressive, little or no mental change
- Life-long condition that affects communication between brain and muscles => motor disturbance => uncoordinated movement.
Cerebral Palsy
- Limited motor skills
- Speech difficulties
- Learning disabilities
Symptoms of cerebral palsy
Small brain, occurs with Down’s syndrome. Abnormally small head and brain, usually results in mental retardation, probably genetic.
Microcephaly
No brain, congenital absence of the brain, absence of major portions of the brain.
Anencephaly
Neural tube defect, one or more vertebrae fail to fuse (usually at the lumbar area) => Leaving an opening or weakness in the vertebral column.
- Possible causes: radiation, virus, genetic factors, folic acid deficiency.
Spina Bifida
Excessive accumulation of CSF in the ventricles of the brain.
Hydrocephalus
- Usually due to obstruction of the flow of CSF out of the brain.
- congenital defect
- In newborns: toxoplasmosis (parasite in cat litter)
- Infection (encephalitis), brain tumor
Causes of hydrocephalus
- Brain damage
- Mental changes
- Bulging eyes
- Tight scalp
- Prominent head vein
Results of hydrocephalus
Brain and spinal cord tumor
- Most of benign
- May cause hemorrhage in brain and spinal cord
- Often destructive due to increased intracranial pressure => headache, vomiting, walking and coordination problems, double vision.
Neoplasms of the Brain and Spinal cord
Tumors originating in neuroglia (glial cells = supportive cells) of the brain or spinal cord.
- Most common type of brain tumor
- Categorized by location and type of cells that originated the tumor.
Gliomas
- Astrocytomas
- Meningioma
- Retinoblastoma
Types of Gliomas
Astrocytes, in brain or spinal cords.
- Most common type of childhood brain tumor
- In cerebellum
Astrocytomas
Tumor of the meninges (dura mater)
- Slow growing, most common in 40 and 50 year old people.
- In cerebral hemispheres, under the skull
- Usually are separate from the brain and can be removed entirely during surgery
- Can recur and certain types can be malignant
Meningioma
Malignant tumor of one or both eyes.
- Retinal cells
- Develops during infancy or early childhood
- Usually diagnosed by two years of age
- Probably hereditary
Retinoblastoma
Primitive neuroepithelial cells = retinoblasts
Retinal cells
- Brain purge
- Hemorrhage
- Atrophy
- Diminished circulation
- Discoloration
Postmortem Conditions
