DISORDERS OF THE NERVOUS SYSTEM

Bell Work What’s your reaction time?

Go to this website and check it out:

https://www.justpark.com/creative/reaction-time-test/

Read the following brief article and summarize what “reaction time” is and define any key words

http://www.nsta.org/publications/news/story.aspx?id=48510

Standards 20) Differentiate between the central nervous system

and the peripheral nervous system, detailing the anatomy of each system, important functions, differences between afferent, efferent, and associative neurons, and the different categories of nervous cells and tissue.

21) Explain the process of action potentials of the nervous system and name the factors that affect the speed at which a nerve impulse travels. Include in the explanation the all-or-none law and substances that can change the transmission such as amino acids, monoamines, acetylcholine, etc.

Ischemic Trauma

(stroke=lack of oxygen to brain) Cerebral Vascular Accidents (CVA)

Transient Ischemia Attacks (TIA)

Cerebral Vascular Accident (CVA)

Major stroke

Brain tissue dies due to insufficient blood supply

Symptoms largely permanent

Third leading cause of death in USA

Risk Factors

Smoking

Hypertension

Heart disease

Family History

Cerebral Vascular Accident CVA Etiology

90% blood clots lodges in carotid arteries, blocking

flow of blood to the brain

10% ruptured blood vessels in the brain

Symptoms

Hemiplegia- paralysis on one side of the body

Sudden, severe headache

dizziness

CVA Sudden loss of vision in one eye

Aphasia (difficulty with speech)

Dysphasia (difficulty swallowing)

Coma

Possible death

Cerebral Vascular Accident CVA Treatment

Immediate care

CT to determine etiology

If clot, treatment to dissolve clot

Prevention

Transient Ischemia Attacks (TIA) mini-stroke

Stop smoking, exercise, lose weight, control

hypertension

Physical Trauma Cerebral Palsy

Hydrocephalus

Cerebral Palsy Permanent, non-progressive brain defect reflected

in voluntary muscular movement

May be due to birth injury or abnormal brain development from infection prenatal

Spastic hemi- or quadriplegia –spastic paralysis of limbs

No impairment in intellect

Symptoms- head rolling, grimacing, difficult speech and swallowing

Hydrocephalus Increased volume of cerebrospinal fluid within the

ventricles

Usually blockage in 3rd or 4th ventricle

Enlargement of head (infants)

Brain damage possible

Treatment – surgery -bypass or shunt performed to

relieve pressure

Infections of the Nervous System

Encephalitis

Meningitis

Polio ---- Post polio syndrome (degenerative)

Neuritis

Bell’s Palsy

Encephalitis

Inflammation of the brain

Cause- usually viral (chemical)

Symptoms- severe headache, fever, lethargy,

extreme weakness, visual disturbances

Diagnosis – LP, EEG,

Treatment- some difficult to treat, antiviral

medications, e.g. acyclovir

Meningitis

Inflammation of the meninges

Cause viral or bacterial

Symptoms – fever and stiff neck, headaches,

In severe form, may lead to paralysis, coma and

death

Lumbar puncture used for diagnosis

If bacterial cause, treated with antibiotics

Poliomyelitis Disease of the motor neurons of the spinal cord

Almost eliminated in USA by vaccinations

Sudden onset of paralysis after flu-like symptoms

Treatment –supportive care until virus runs its

course, then treatment to recover strength to

damaged muscles

Post-Polio Syndrome Etiology- late onset fatigue of motor neurons

originally affected by polio virus

Symptoms – muscle weakness (atrophy)

Treatment – no treatment, exercise may help

Bell’s Palsy

Facial Nerve -7th cranial nerve affected

Appears as a stroke on one side of the face, eye does not close properly, the mouth droops, numbness on the effected side

Cause – nerve becomes swollen, is inflamed- usually due to infection with virus

Symptoms usually disappear within a few weeks

If total paralysis, total recovery may not be possible

Epilepsy

Seizure disorder

Characterized by recurring and excessive discharge

from the neurons

Seizures thought to be result of spontaneous,

uncontrolled electrical activity

Cause – uncertain, many variables

Spinal Cord Injuries Paralysis -loss of power of motion or sensation

Paraplegia – paralysis of the lower limbs

Hemiplegia – paralysis on one side of the body

Quadriplegia- paralysis of all four extremities

Diagnostic TestsLumbar Puncture- removal of CSF from spinal canal,

needle puncture between the 3rd and 4th lumbar vertebrae the spinal cord ends at second L 2 level.

Electroencephalogram (EEG)- recording of the electrical activity of the brain

CAT Scan – Computerized Axial Tomography- combines x-ray emission with nuclear medicine – produces cross-sectional images

MRI- Magnetic Resonance Imaging- uses a magnetic field along with radio frequency to produce cross-section images of the body

Activity: Degenerative Nervous System Disorders

Research one of the following and create a PPT (6-10 slides):

Alzheimer's Disease

Parkinson’s Disease

Multiple Sclerosis

Use pictures/graphics and briefly explain:

Description of the disease

Is it genetic or not?

How is this diagnosed?

Possible treatments/management

What is the prognosis?

Activity: What is a stroke?

Click on the tab on the class website.

Follow the directions to the KHAN Academy link and answer the questions concerning strokes.