12.5 - Health Issues Related to the Human Nervous System

Nervous System Diseases

Progressive disease caused by an immune-system abnormality that attacks the myelin sheath in the brain and spinal cord.
The damaged myelin sheath prevents impulse transmission from and to the brain.

Causes loss of the ability to reason and care for oneself.
The patient becomes confused, forgetful and disoriented, even in familiar places.
Continued brain deterioration causes loss of the ability to read, write, eat, walk and talk.

Shrinkage of the nervous system causes tremors in the limbs, jaw, feet and face.
The patient has difficulty maintaining posture and balance.

Caused by deterioration and death of motor neurones that control muscles used in chewing, walking and talking.

Occurs because of brain damage before or after birth; may also occur in children aged three to five years.
Causes failure of muscles and the ability of motor neurones to function properly.

Abnormal activity in parts of the brain causes nerve cells to produce unusual signals.
The patient may become unconscious and experience muscle spasms.

Drug abuse can cause addiction and withdrawal symptoms such as shivering, sweating and vomiting.
Stimulants: Increase central nervous system activity; excessive use causes temporary euphoria followed by depression.
Sedatives (depressants): Delay nerve impulse transmission and calm the mind.
Hallucinogenic drugs: Cause hallucinations.
Narcotic drugs: Relieve pain and anxiety and delay normal brain functions.
Alcohol: Disrupts coordination and thinking and delays nerve impulse transmission.