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.
An extended ZIP+4 code, introduced in the 1980s, includes the five digits of the Dover ZIP code, a hyphen, and four more digits that determine a more specific location within a given ZIP code in Dover, Delaware. The Dover Zip Code is 19901, 19903, 19904, 19905, 19906.