CH. 14 DISEASES OF THE
NERVOUS SYSTEM
Human Diseases, Injuries and
Conditions
Ms. Monroe
Part 2:
Degenerative
Neural Diseases
SWCTA
Dr. Michael J. Georges
Central Nervous System
The Brain
• From a top view,
notice how the brain is
divided into two halves,
called hemispheres.
– Each hemisphere
communicates with
the other through
the corpus
callosum, a bundle
of nerve fibers.
Cerebral Cortex
• The cortex is a sheet
of tissue that makes
up the outer layer of
the brain.
– The thickness of
the cerebral cortex
varies from 2 to 6
mm.
Cerebral Cortex
• Functions:
 Thought
 Voluntary
movement
 Language
 Reasoning
 Perception
Conditions of the Cerebral Cortex
• Huntington’s Disease (Chorea) – an inherited
•
•
•
•
disease but sx’s may not appear until middle age.
If either parent has the disease, ALL their children will
have a 50% chance of inheriting it.
A progressive degenerative disease of the brain that
results in loss of muscle control & causes certain brain
cells to waste away, affecting mental status.
Chorea means ceaseless, rapid, jerky movements, which
are involuntary – distinctive of this disease.
Affects both the mind & body which leads to
personality changes, carelessness, poor judgment, and
impaired memory, ultimately deteriorating to total
mental incompetence, dementia.
• ALZHEIMERS DISEASE – genetic based disease.
• Occurs from a loss of the chemical signal acetylcholine
and the dysfunction of synaptic junctions necessary to
carry out the message designated by the nerve(s).
• Currently, 4 million elderly Americans are afflicted. Of
people ages 75-84 yrs, 19% have Alzheimer’s and age
85 and beyond it rises to more than 40%.
• Individuals with one afflicted parent is 3 times as likely
to develop this disease.
• Sx’s may start as early as the 40’s to 50’s and
include forgetfulness, confusion, emotional
outbursts & personality changes. Confirmation of
this disease is subject only to autopsy.
• CONVULSION – a sudden, intense series of
involuntary contractions and relaxations by
muscles. Not to be confused with a seizure !
• Primary cause is abnormal electrical discharges spread
over the brain. Hyper-excitation of nerves abnormally
stimulate muscles to conract.
• Other factors – chemical imbalance, an accumulation of
waste products in the blood (toxemia, drug poisoning,
and withdrawal from alochol), irritations to nerve cells,
infectious diseases such as meningitis & encephalitis, &
occurs in infants and young children with high fevers.
EPILEPSY
• A group of uncontrolled cerebral discharges that
recurs at random intervals. Seizures associated
with epilepsy are a form of convulsions.
• Can be acquired as a result of a brain injury, a
penetrating wound, skull fx, tumor and alcoholism.
Most cases are idiopathic (unknown) but may also be
inherited. Petit Mal seizure – may be mild or severe
with loss of conscious for a few seconds, appearing
absent-minded. Some muscular twitching around eyes,
mouth, & head swaying. Seen mostly in children and
usually disappears in late teens or early 20’s.
• Major seizures of epilepsy involve a loss of
consciousness and person falls to the floor.
• General convulsions are mild to severe with violent
shaking & thrashing movements. Hyper-salivation
causes foaming at the mouth. Loses control of urine
& sometimes feces. This is characteristic of grand
mal epilepsy.
• Aura – warning of an approaching grand mal
seizure which allows person to lie down or reach for
support. Felt as a ringing in the ears, tingling in fingers,
seeing spots or various odors.
• After a seizure, the person is groggy and unaware of
what happened. Length of seizures vary and may recur
at varied frequencies.
• Diagnosis is made by an electroencephalogram
(EEG), a recording of brain waves.
• Tx – anticonvulsant medication (Dilantin) is very
effective.
Developmental Errors
(Formed during fetal development)
• SPINA BIFIDA – a
condition when one or more
vertebrae fail to fuse, leaving an
opening in the vertebral column.
• Results in muscular abnormalities,
incorrect posture, inability to walk,
lack of bladder &/or bowel control.
• Strabismus (crossed eyes) may
point to this disorder.
• Dietary supplements of folic acid
(folate) at a dose of 0.4 mg/day, in
addition to no smoking or alcohol
consumption by pregnant woman
will assure a baby born with normal
spinal cord and cranial
development.
Other Forms of Spina Bifida
• MENINGOCELE –
meninges protrude
through the opening in
the vertebra as a sac
filled with CSF.
• MENINGOMYELOCELE-
serious defect where
nerve elements protrude
into the sac and are
trapped, preventing
proper placement. Thus,
child may be mentally
retarded.
• Surgical correction
effective.
HYDROCEPHALUS
(Water/Fluid in the Brain)
• HYDROCEPHALUS –
abnormal accumulation of
cerebrospinal fluid,
causing the ventricles of
the brain to enlarge and
push the brain against the
skull. Usually caused by
an obstruction or a
congenital defect (stenosis
of an opening in the
ventricles).
• TX – a shunt is inserted to
relieve the excess fluid by
diverting in via catheter
into the peritoneal cavity
and enter general
circulation.
Cerebellum
• The word "cerebellum"
comes from the Latin
word for "little brain."
The cerebellum is located
behind the brain stem.
•
Functions:
 Movement
 Balance
 Posture
Degenerative Neural Diseases
Conditions of the Cerebellum
• MULTIPLE SCLEROSIS (MS) – a major disorder of the
CNS. Chronic & progressive disease of unknown origin.
• Usually affects young adults between 20-40 yrs.
• Possible causes include an immunologic reaction to a virus,
bacteria, trauma, or hereditary.
• Initial sx’s are muscular with loss of balance & poor circulation.
Tingling & numbness progress to a shaking tremor and muscular
weakness. Difficulty speaking clearly and bladder dysfunction
often develops.
• Vision may suddenly be impaired & double vision occurs often;
and blindness may develop. Nystagmus (involuntary rapid
eye movements) can occur.
• There is no effective TX for MS. Physical therapy helps the
muscular system, muscle relaxants are helpful psychological
counseling to help deal with the affects of the disease.
• Amyotrophic Lateral Sclerosis (ALS) – AKA
Lou Gehrigs disease.
• Is a chronic, terminal disease in which there’s a
progressive loss of motor neurons.
• Cause is unknown.
• ALS is characterized by disturbances in movement and
atrophy of muscles of the hands, forearms, and legs.
• Also affected are certain cranial nerves which impair
the muscles of the mouth & throat, thus swallowing &
tongue movements are affected, causing speech to be
difficult or impossible.
• ALS occurs later in life, most commonly 50 -60
years old and slightly more common in women.
• Death usually occurs within 3-4 years from
pulmonary failure.
Who was Lou?
• Lou Gehrig
• Diagnosed with ALS in
the 1930’s
• Famous New York
Yankee from (19231939)
• Babe Ruth was
teammate
• MVP & Hall of Famer
• Died at age 38 in 1941
Parkinson’s Disease – Overview
(Shaking Palsy)
• Parkinson's disease is a disorder that affects nerve
cells (neurons) in the part of the brain controlling
muscle movement (cerebellum).
• People with Parkinson's often experience trembling,
muscle rigidity, difficulty walking, and problems
with balance and coordination.
• These symptoms generally develop after age 50,
although the disease affects a small percentage of
younger people as well.
• Parkinson's disease is progressive, meaning the signs
and symptoms become worse over time.
• The cause is unknown, but may be hereditary.
• Parkinson's disease is treatable with physical therapy,
medications, and surgery.
Michael J. Fox
(Actor)
• Michael J. Fox was (born
1961) diagnosed with
young-onset Parkinson's
disease in 1991.
• Disclosed his diagnosis to
the public in 1998.
• Retired from acting in
2000.
• The Michael J. Fox
Foundation for
Parkinson's Research,
launched in year 2000, to
increase awareness &
funding about Parkinson's
disease.
• SIGNS AND SYMPTOMS
• The earliest symptom of Parkinson's disease can be as
subtle as an arm that doesn't swing when walking, a
mild tremor in the fingers of one hand or soft,
mumbling speech that's difficult to understand.
• Other signs and symptoms of Parkinson's disease may
include:
• Tremors – often start with slight shaking in one
finger and may spread to whole arm.
• Characteristic tremors of the fingers resemble “pillrolling”
• Slowed motion (bradykinesia). Shuffling walk, slow,
unsteady gait, stooped posture.
• Muscle (rigidity) stiffness in limbs, neck and face.
• Loss of automatic movements.
• Impaired Speech
• Dementia – diminished ability to think and remember
SUMMARY
• HUNTINGTON’S (Chorea) DISEASE – an inherited
disease that leads to loss of muscular function, affects both the
mind & body
• ALZHEIMER’S DISEASE - genetic based disease. Currently,
4 million elderly Americans are afflicted. Sx’s may start as early
as the 40’s to 50’s and include forgetfulness, confusion,
emotional outbursts & personality changes. Confirmation of this
disease is subject only to autopsy.
• CONVULSION – a sudden, intense series of involuntary
contractions and relaxations by muscles. Not to be confused
with a seizure !
SUMMARY
• EPILEPSY - A group of uncontrolled cerebral discharges that
recurs at random intervals. Seizures associated with epilepsy are
a form of convulsions. Two types - petit mal & major
seizures.
• Can be acquired as a result of a brain injury, a penetrating
wound, skull fx, tumor and alcoholism. Most cases are
idiopathic (unknown) but may also be inherited.
• SPINA BIFIDA – a condition when one or more vertebrae fail
to fuse, leaving an opening in the vertebral column thereby
allowing contents to protrude.
• Results in muscular abnormalities, incorrect posture, inability to
walk, lack of bladder &/or bowel control.
• MULTIPLE SCLEROSIS (MS) – a major disorder of the
CNS. Chronic & progressive disease of unknown origin.
• Usually affects young adults between 20-40 yrs. Does not affect
mental ability.
SUMMARY
• AMYOTROPHIC LATERAL SCLEROSIS (ALS)
– AKA Lou Gehrig’s disease.
• Is a chronic, terminal disease in which there’s a
progressive loss of motor neurons. Cause is unknown.
• ALS is characterized by disturbances in movement and
atrophy of muscles of the hands, forearms, and legs.
– Death usually occurs within 3-4 years from pulmonary
failure.
• PARKINSON’S DISEASEis a disorder that affects
nerve cells in the part of the brain controlling muscle
movement (cerebellum).
– The three obvious signs are trembling, muscle rigidity,
slowness of movement, difficulty walking, and problems
with balance and coordination.