Parkinson’s disease is one of the most common neurological disorders to affect older people. In patients with Parkinson’s, the nerve cells, or neurons, that produce the neurotransmitter called dopamine are destroyed, causing many different symptoms.

Twelve- and 20-gauge shotguns are popular choices among hunters and sport shooters alike. Both gauges are effective at hunting birds and small game, and both feature prominently in competitions such as trap shooting and sporting clays.

Parkinson's disease is a devastating diagnosis, because while the illness is treatable, it is not curable. Parkinson's disease is marked by progressive degradation of the nervous system, which results in symptoms including tremors, muscle stiffness, slow movements, impaired balance and changes in speech.

Alzheimer disease is a chronic, incurable brain disorder characterized by progressive loss of brain tissue and function. The early stages of Alzheimer disease primarily affect intellectual functions. Late-stage Alzheimer disease directly or indirectly affects other body systems. The condition is ultimately fatal.

Prednisone, or Deltasone, is a corticosteroid utilized as a headache preventative. HeadacheMigraineRelease.com suggests that Prednisone is ideal to relieve the acute pain associated with status migraines, which are migraines with an extended headache phase lasting more than 5 hours.

A dopamine antagonist is a chemical, medication or drug that prevents the actions stimulated by dopamine. Dopamine is a naturally produced chemical in the body that binds to regions in the brain to help regulate emotions and movement.

A seizure is a characteristic symptom of epilepsy and may be caused by birth defects, problems during pregnancy or delivery, illness, fevers, infections and poisons in the body.

Classic migraines start with a warning sign, called an aura. A migraine aura occurs before the actual migraine attack. Most often, a migraine aura is characterized by visual disturbances, according to MayoClinic.com.

Multiple sclerosis is a physically debilitating disease that is still not fully understood by doctors. The most likely cause is the accidental destruction of nerves in the brain and spinal cord by the patient's own immune system.

Passing hard stools is usually as a result of constipation or the infrequent movement of the bowels. Most healthy people have at least three bowel movements per week, according to MedlinePlus. If you are unable to have a bowel movement or are having difficulty passing stool, contact your doctor.

A stroke is an interruption of the blood supply to your brain that results in the death of brain cells. You may experience symptoms like difficulty walking and speaking, numbness on one side of your body, headache and blurred vision.

Essential tremor is also called benign essential tremor and is, among the 20 different types, the most common. This type of tremor is an unintentional, rhythmic, back and forth muscle movement of one or more parts of your body, but most commonly affects one or both hands.