Actor Michael Fox has Parkinson's disease, a chronic and progressive illness in which certain nerve cells, or neurons, die or become impaired. Early symptoms are subtle and occur gradually. More than 1 million Americans have Parkinson's, and many wind up unable to walk, talk or care for themselves.

The brain is an important organ that controls thought, memory, emotion, touch, motor skills, vision, respiration, temperature, hunger, and every process that regulates your body.

Disorders of the nervous system include stroke, infections such as meningitis, carpal tunnel syndrome, and functional disorders such as headache and epilepsy.

Neurology is the branch of medicine that is concerned with the study and treatment of disorders of the nervous system.

Neurological surgery is used to treat disorders of the brain, spine, and nerves. The doctor who specializes in neurological surgery is called a neurosurgeon or neurological surgeon.

Evaluating and diagnosing damage to the nervous system is complicated and complex. Many of the same symptoms occur in different combinations among the different disorders.

A neurological exam may be performed with instruments, such as lights and reflex hammers, and usually does not cause any pain to the patient.

The goals of a neurological rehab program include helping the patient return to the highest level of function and independence, and improving the overall quality of life—physically, emotionally, and socially.

Parkinson's disease is the most common form of parkinsonism, a group of motor system disorders. PD is slowly progressing and degenerative.