The specific cause of Parkinsonâs is unknown; however, medical experts believe the symptoms are related to a chemical imbalance in the brain caused by brain-cell death. Parkinson's disease is chronic (persists over a long period of time), and progressive (symptoms grow worse over time).arkinson's disease (or, simply, Parkinson's or PD) is the most common form of parkinsonism, a group of motor system disorders.
Quick Answer. Non-mandatory ZIP codes were introduced to the United States in 1963. Robert Moon, a postal inspector with the United States Postal Service, proposed the ZIP code system as early as 1944. Continue Reading.
In 1983, the USPS changed its ZIP Code system to include the new ZIP+4. A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a small delivery segment such as a street, a city block, a group of apartments, or even an individual address that receives a high volume of mail.