Some ASPECTS OF DESEASES OF THE NERVOUS SYSTEM
DESEASES
OF THE NERVOUS SYSTEM
In our consideration of principles of structure and function in the nervous system, we have laid the groundwork for the study of diseases of the nervous system. In this section, we will discuss the causes of damage to the nervous system, the way that damage expresses itself as a symptom, the broad range of diseases of the nervous system, and the neurological diagnosis.
AGENTS OF DAMAGE TO THE NERVOUS SYSTEM
The agents of damage to the nervous system may produce acute or chronic
symptoms. They may act locally, or throughout the body and nervous system.
They may produce behavioral symptoms suddenly or gradually. We
briefly review here the agents of disease.
Widespread disorders often result from deficiencies in nutrients (minerals
like calcium, vitamins, amino acids) or oxygen (e.g., resulting from reduced
blood supply caused by narrowing of the arteries, or atherosclerosis), ingested
toxins, infections, trauma to the head, and general degeneration of
neurons. In all of these cases, the agent of disease may pervade the nervous
system. Because of differing vulnerabilities, however, symptoms may appear
only, or at first, in specific systems. Many general disorders of this type
affect level of consciousness and memory. A clearly localized site of damage
may also produce widespread symptoms. For example, a tumor may cause a
build-up in pressure of cerebrospinal fluid, thus affecting the whole brain
and causing symptoms like headache and drowsiness.
More localized symptoms are often produced by tumors, disorders in
blood supply (produced by either stroke [occlusion of blood vessels] or
hemorrhage [ruptured arteries that leak blood], localized infections, specific
genetic malformations, or degeneration of cells in a specific area.
THE EXPRESSION OF DAMAGE IN THE NERVOUS SYSTEM
The kinds of symptoms that may appear after nervous system damage can
be positive or negative. Common sense suggests that damage should result
in negative symptoms-loss or deficiency in the function that the damaged
area serves. This is true much, but not all of the time. Sometimes, there are
positive symptoms which may occur for two reasons. First, damage can cause
irritation and can increase the activity of an area that is injured.
Second, if damage decreases the activity of an area that inhibits another
area, there will be an increase of activity due to release from inhibition in the
inhibited area. In either case, the symptoms are positive in the sense that
there is more activity in the nervous system and more behavior in the organism.
Epilepsy is the best example of a disorder whose primary symptoms are
"positive." Epilepsy is a common disorder that affects over one million
Americans. Damage to neural tissue produced by any of a number of different
agents of disease may leave the tissue irritable and may lead to increased
activity, because of damage to inhibitory systems or because the
residue of the damage (e.g., scar tissue) excites neighboring neurons. The
excessive activity (seizures) that is produced leads to an exaggerated (rather
than deficient) expression of the function of the area. Seizures occur intermittently,
with sudden discharge of neurons. These may be widespread,
leading to muscle contraction throughout the body and loss of consciousness,
or they may be much more localized. The part of the brain or type of
mental event that appears first in the seizure is an indicator of the location of
the primary damage in the brain. Depending on the location of the irritable
tissue, the primary symptom may be sensory (e.g., an hallucination), motor
(e.g., twitches or larger muscle contractions), or emotional (e.g., fear or
laughing). Sometimes, the initial events of the seizure produce mild symptoms
(an aura) related to the site of damage (e.g., unusual sensations or feelings).
Some seizures spread progressively from the original site to other parts
of the brain. Epilepsy can be treated by controlling the agent of disease that
caused it, or by use of drugs that reduce the irritability of neurons (Adams
and Victor, 1981).
Disorders of feeding illustrate the relations between neural damage and
symptoms. In animals and humans, the lateral (side), as opposed to the medial
(midline), part of the hypothalamus produces eating when
activated. Damage to this area may lead to the negative symptoms of cessation
of eating arid loss of appetite (Teitelbaum, 1967). The positive symptom
of increased eating can occur for two reasons. One, as we have
discussed, is that damage can cause irritation and increased activity in the
injured area. There is some evidence that damage to the lateral hypothalamic
area can produce occasional seizures, and that these seizures produce
periods of excessive (binge) eating (Green and Rau, 1994). (Only a very
small minority of "binge eaters," however, are suspected to have such seizures.)
A second source of increased eating is release from inhibition. Damage
to a part of the brain (the medial hypothalamus) that inhibits the lateral
hypothalamus, releases the lateral hypothalamus from inhibition. The result
is increased eating and obesity in animals and humans (Teitelbaum,
1997).
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OF THE NERVOUS SYSTEM
In our consideration of principles of structure and function in the nervous system, we have laid the groundwork for the study of diseases of the nervous system. In this section, we will discuss the causes of damage to the nervous system, the way that damage expresses itself as a symptom, the broad range of diseases of the nervous system, and the neurological diagnosis.
AGENTS OF DAMAGE TO THE NERVOUS SYSTEM
The agents of damage to the nervous system may produce acute or chronic
symptoms. They may act locally, or throughout the body and nervous system.
They may produce behavioral symptoms suddenly or gradually. We
briefly review here the agents of disease.
Widespread disorders often result from deficiencies in nutrients (minerals
like calcium, vitamins, amino acids) or oxygen (e.g., resulting from reduced
blood supply caused by narrowing of the arteries, or atherosclerosis), ingested
toxins, infections, trauma to the head, and general degeneration of
neurons. In all of these cases, the agent of disease may pervade the nervous
system. Because of differing vulnerabilities, however, symptoms may appear
only, or at first, in specific systems. Many general disorders of this type
affect level of consciousness and memory. A clearly localized site of damage
may also produce widespread symptoms. For example, a tumor may cause a
build-up in pressure of cerebrospinal fluid, thus affecting the whole brain
and causing symptoms like headache and drowsiness.
More localized symptoms are often produced by tumors, disorders in
blood supply (produced by either stroke [occlusion of blood vessels] or
hemorrhage [ruptured arteries that leak blood], localized infections, specific
genetic malformations, or degeneration of cells in a specific area.
THE EXPRESSION OF DAMAGE IN THE NERVOUS SYSTEM
The kinds of symptoms that may appear after nervous system damage can
be positive or negative. Common sense suggests that damage should result
in negative symptoms-loss or deficiency in the function that the damaged
area serves. This is true much, but not all of the time. Sometimes, there are
positive symptoms which may occur for two reasons. First, damage can cause
irritation and can increase the activity of an area that is injured.
Second, if damage decreases the activity of an area that inhibits another
area, there will be an increase of activity due to release from inhibition in the
inhibited area. In either case, the symptoms are positive in the sense that
there is more activity in the nervous system and more behavior in the organism.
Epilepsy is the best example of a disorder whose primary symptoms are
"positive." Epilepsy is a common disorder that affects over one million
Americans. Damage to neural tissue produced by any of a number of different
agents of disease may leave the tissue irritable and may lead to increased
activity, because of damage to inhibitory systems or because the
residue of the damage (e.g., scar tissue) excites neighboring neurons. The
excessive activity (seizures) that is produced leads to an exaggerated (rather
than deficient) expression of the function of the area. Seizures occur intermittently,
with sudden discharge of neurons. These may be widespread,
leading to muscle contraction throughout the body and loss of consciousness,
or they may be much more localized. The part of the brain or type of
mental event that appears first in the seizure is an indicator of the location of
the primary damage in the brain. Depending on the location of the irritable
tissue, the primary symptom may be sensory (e.g., an hallucination), motor
(e.g., twitches or larger muscle contractions), or emotional (e.g., fear or
laughing). Sometimes, the initial events of the seizure produce mild symptoms
(an aura) related to the site of damage (e.g., unusual sensations or feelings).
Some seizures spread progressively from the original site to other parts
of the brain. Epilepsy can be treated by controlling the agent of disease that
caused it, or by use of drugs that reduce the irritability of neurons (Adams
and Victor, 1981).
Disorders of feeding illustrate the relations between neural damage and
symptoms. In animals and humans, the lateral (side), as opposed to the medial
(midline), part of the hypothalamus produces eating when
activated. Damage to this area may lead to the negative symptoms of cessation
of eating arid loss of appetite (Teitelbaum, 1967). The positive symptom
of increased eating can occur for two reasons. One, as we have
discussed, is that damage can cause irritation and increased activity in the
injured area. There is some evidence that damage to the lateral hypothalamic
area can produce occasional seizures, and that these seizures produce
periods of excessive (binge) eating (Green and Rau, 1994). (Only a very
small minority of "binge eaters," however, are suspected to have such seizures.)
A second source of increased eating is release from inhibition. Damage
to a part of the brain (the medial hypothalamus) that inhibits the lateral
hypothalamus, releases the lateral hypothalamus from inhibition. The result
is increased eating and obesity in animals and humans (Teitelbaum,
1997).
For the Disorder Treatment I recommend click this link:
http://theliberatormethod.com