Download Diseases and Disorders of the Nervous System

Diseases and
Disorders of the
Nervous System
• Characterized by psychotic episodes involving
hallucinations & delusions
• Genetic & environmental components
• Treatments: focus on drugs that block dopamine
receptors, although evidence indicates that the
neurotransmitters serotonin, norepinephrine &
glutamate are also involved
• Drugs that reduce symptoms often have negative
side effects
schizophrenia
http://www.youtube.com/watch?v=ZB28gfSmz1Y&edufilte
r=qHa9aXpFjKo0Ws2ZYlmAoQ&safe=active
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2.
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Bipolar disorder
swings of mood from high to low
Major depression
involves persistent low mood
 both illnesses have genetic and environmental
component
 drug treatments against depression often increase the
activity of biogenic amines
Depressive illness
• Dementia characterized by confusion, memory loss, and
personality changes
• Age related, progressive
• Involves the death of neurons in large areas of the brain
• Post- mortem diagnosis: neurofibrillary tangles (bundles of
degenerated processes) and senile plaques (aggregates of beta
amyloid)
• Membrane secretases cleave a protein into this insoluble peptide
that accumulate outside neurons and appear to trigger death of
neighboring neurons
• PIB: chemical that accumulates in regions of amyloid deposits;
may help in early detection/ identifying treatments for AD
Alzheimer's disease
http://www.youtube.com/watch?v=SFDHTjxphD0&edufilte
r=qHa9aXpFjKo0Ws2ZYlmAoQ&safe=active
• Progressive, age related motor disorder characterized by
difficulty in movements, rigidity, & muscle tremors
• Death of neurons in the substantia nigra, which normally
release dopamine in the basal nuclei, lead to the motor
symptoms of the disease
• Protein accumulation is associated with neuron
degeneration
• Possibly result of genetic and environmental factors
• Management of symptoms: drugs such as L-dopa, brain
surgery, deep brain stimulation
• Potential cure: implanting dopamine-secreting neurons in
the substantia nigra or basal ganglia
Parkinson’s disease
http://www.healthline.com/health-slideshow/famous-facesparkinsons#promoSlide
http://www.youtube.com/watch?v=dGeMX_h67mI&edufilt
er=qHa9aXpFjKo0Ws2ZYlmAoQ&safe=active
• Chronic condition characterized by abnormal & excessive
discharge of neurons resulting in a clinical event (seizure)
• Affects approx. 2-3% of population
• Incidence greatest in children and elderly
• Classifications (based on clinical presentations &
electroencephalographic (EEG) findings):
1. Generalized seizures: abnormal EEG originating from
both brain hemispheres
2. Partial seizures: abnormal EEG originating from one
brain hemisphere (most cases have no know etiology)
Epilepsy
• Treatments (depending on type)
1. Surgery- removal of the focus: (ex. Temporal lobectomy)
2. Corpus Callosotomy (to prevent the spread between
hemispheres)
3. Vagus nerve stimulation (device implanted into
subcutaneous tissue; attaches to vagus nerve, impulses
may be increased with the use of a magnet)
4. Medication
Epilepsy (cont.)
http://www.youtube.com/watch?v=7zG_ljMU7A&edufilter=qHa9aXpFjKo0Ws2ZYlmAoQ&s
afe=active
• 3rd leading cause of death after heart disease & malignancy;
estimated that average of 500,000 new strokes per year will occur in
the U.S.
• Most disabling of neurologic diseases- approx. 50% of survivors
have residual neurological deficit & > 25% require chronic care
• Includes all disorders in which an area of the brain is transiently or
permanently affected by ischemia or bleeding and one or more of the
cerebral blood vessels are involved in the pathological process
• Ischemic stroke: accounts for 85% of strokes
• Hemorrhagic stroke: accounts for 15% of strokes
• Some causes of ischemic stroke: atherosclerosis, artery disease, drug
abuse, migraine, arthritis
Cerebrovascular
disease
• TIA (transient ischemic attack): temporary reduction in
perfusion to a focal region of the brain. Patient
experiences focal neurological deficits such as slurred
speech, aphasia, monocular blindness, weakness or
paralysis of limb. Duration: 2-15 minutes. May be the
only warning of impending stroke
Cerebrovascular
disease (cont.)
• Some risk factors (ischemic stroke):
Non modifiable
1. Age: stroke rate doubles each decade after age 55
2. Heart disease: CHF, CAD, AF
3. Male gender, African American or Hispanic race, family
history of stroke
4. Prior stroke or TIA; migraine
Modifiable
Hypertension, hyperlipidemia, alcohol abuse, cigarette smoking,
oral contraceptive use, diabetes
Cerebrovascular
disease (cont.)
http://www.youtube.com/watch?v=VrHtVdYaWwM&edufil
ter=qHa9aXpFjKo0Ws2ZYlmAoQ&safe=active