In the human brain, there are about 100 billion neurons, or nerve cells, according to the University of Washington. These neurons send out messages through chemical and electrical signaling. Sensory neurons pick up sensations, such as the stove is hot, and relay it back to the brain. The brain then sends information to the motor neurons to carry out an action, such as moving the hand away from the stove.
But when there is a loss of function or structure of these neurons, it affects normal functioning. There are several different types of degenerative nerve diseases, which include Creutzfeldt-Jakob disease, Parkinson’s disease, Friedreich’s ataxia, Huntington’s disease, multiple sclerosis and Alzheimer’s disease.
Creutzfeldt-Jakob disease is a rare disorder that affects about one in one million people, according to MedlinePlus.
With classic Creutzfeldt-Jakob, the majority of cases are sporadic Creutzfeldt-Jakob disease, in which there no known cause. The other classic form is familial Creutzfeldt-Jakob disease. Variant Creutzfeldt-Jakob disease, which makes up less than 1 percent of cases, is related to mad cow disease, noted MedlinePlus.
With Parkinson’s disease, patients most commonly develop symptoms after age 50, though there are some patients who develop the disease in young adulthood. Parkinson’s disease results from the destruction of the nerve cells that produce the neurotransmitter dopamine. When the nerve cells do not have the dopamine they need, they cannot send motor messages properly, resulting in symptoms such as tremors, slowed movements and difficulty starting movement.