We all get headaches. Headaches are a relatively minor problem associated with the nervous system. But what about more serious issues of the nervous system? As you can probably imagine, these can be extremely serious.
Disorders of the Nervous System
There are several different types of problems that can affect the nervous system.
Vascular disorders involve problems with blood flow. For example, a stroke occurs when a blood clot blocks blood flow to part of the brain. Brain cells die quickly if their oxygen supply is cut off. This may cause paralysis and loss of other normal functions, depending on the part of the brain that is damaged.
Nervous tissue may become infected by microorganisms. Meningitis, for example, can be caused by a viral or bacterial infection of the membranes that cover the brain and spinal cord. This may cause the brain to swell and lead to brain damage and death.
Encephalitis is inflammation of the brain with swelling, most often caused by viral infections. When the immune system tries to fight off a brain infection, just as it tries to fight off other infections, it can sometimes do more harm than good. The infection and the immune system’s response may cause swelling in the brain. With no room to expand, the brain pushes against the skull, possibly injuring the brain and even causing death. Medicines may help support the body in fighting off the infection and help relieve some symptoms.
Brain or spinal cord injuries may cause paralysis and other disabilities. Injuries to peripheral nerves can cause localized pain or numbness.
Abnormal brain functions can occur for a variety of reasons. Examples include headaches, such as migraine headaches, and epilepsy, in which seizures occur.
Nervous tissue may degenerate, or break down. Alzheimer’s disease is an example of this type of disorder, as is Amyotrophic Lateral Sclerosis, or ALS. ALS is also known as Lou Gehrig’s disease. It leads to a gradual loss of higher brain functions.
In addition to ALS and Alzheimer’s disease, other serious nervous system diseases include multiple sclerosis, Huntington’s disease, and Parkinson’s disease. These diseases rarely, if ever, occur in young people. Their causes and symptoms are listed below (Table below). The diseases have no known cure, but medicines may help control their symptoms.
Disease
Cause
Symptoms
Multiple Sclerosis
The immune system attacks and damages the central nervous system so neurons cannot function properly.
muscle weakness, difficulty moving, problems with coordination, difficulty maintaining balance
Huntington’s Disease
An inherited gene codes for an abnormal protein that causes the death of neurons.
uncontrolled jerky movements, loss of muscle control, issues with memory and learning
Parkinson’s Disease
An abnormally low level of a neurotransmitter affects the part of the brain that controls movement.
uncontrolled shaking, slowed movements, issues associated with speaking
Alzheimer’s Disease
Abnormal changes in the brain cause the gradual loss of most normal brain activity.
memory loss, confusion, mood swings, gradual loss of control over mental and physical abilities
Alzheimer’s Disease: Is the Cure in the Genes?
According to the Alzheimer’s Association, more than 6 million Americans live with Alzheimer’s. It is estimated that, by 2050, this number will rise to almost 13 million. In April 2011, an international analysis of the genes of more than 50,000 people led to the discovery of new genes that make Alzheimer’s disease more likely in older people, providing clues about how it starts and then progresses in a person’s brain. Research on Alzheimer’s has come a long way since then. Check out the short video below to learn more about genetics and Alzheimer’s disease.
Summary
Disorders of the nervous system include blood flow problems such as stroke, inflammatory conditions such as meningitis, brain injuries, and degeneration of nervous tissue, as in Alzheimer’s disease.
Review
Identify three nervous system disorders.
Multiple sclerosis is a disease in which the myelin sheaths of neurons in the central nervous system break down. What symptoms might this cause? Why?
