%0 Journal Article %T The Demise of Poskanzer and Schwab¡¯s Influenza Theory on the Pathogenesis of Parkinson¡¯s Disease %A Danny Estupinan %A Sunina Nathoo %A Michael S. Okun %J Parkinson's Disease %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/167843 %X In 1961, David C. Poskanzer and Robert S. Schwab presented a paper, ¡°Studies in the epidemiology of Parkinson¡¯s disease predicting its disappearance as a major clinical entity by 1980.¡± This paper introduced the hypothesis that Parkinson¡¯s disease was derived from a single aetiology, the influenza virus. We review the original Poskanzer and Schwab hypothesis that Parkinson¡¯s disease was based on the association between the 1918-19 influenza epidemic and the later observation of Parkinsonism in some influenza sufferers. We also further explore the prediction that Parkinson¡¯s disease would totally disappear as an entity once original influenza victims were all deceased. Current research has revealed that there are many potential causes and factors important in the occurrence of Parkinson¡¯s disease, postencephalitic Parkinsonism, and encephalitis lethargica. Poskanzer and Schwab presented a novel hypothesis; however, it was proven false by a combination of research and time. 1. Introduction In 1817, James Parkinson, a London physician, wrote about six patients in An Essay on the Shaking Palsy and offered one of the first descriptions of Parkinson¡¯s disease. He described several symptoms of what he referred to as ¡°paralysis agitans¡± and ¡°involuntary tremulous motion¡­ in parts not in action and even when supported; with a propensity to bend the trunk forwards¡­ the senses and intellect being uninjured¡± [1]. During the mid-1800s, Jean-Martin Charcot also made several contributions to the early descriptions of Parkinson¡¯s disease including the addition of symptoms such as the masked facies, rigidity, bradykinesia, and postural as well as gait issues [2, 3]. In 1876, Charcot rejected the term ¡°paralysis agitans¡± since patients were not physically weak and did not always exhibit tremor. He suggested naming the entity after James Parkinson [2]. He described Parkinson¡¯s disease as ¡°n¨¦vrose¡± or a neurological disease without a known pathologic lesion [2]. Charcot also separated the entity from other tremulous diseases such as multiple sclerosis [3]. In 1917, one hundred years after Parkinson¡¯s first description, the Romanian born Greek neurologist Constantin von Economo observed a cluster of unusual symptoms such as high fever, pharyngitis, confusion, lethargy, ophthalmoplegia, somnolence, and mental status changes. This confluence of symptoms was referred to as encephalitis lethargica (EL), a clinical phenomenon occurring in Europe and North America between 1916 and 1926, that had a wide range of associated signs and symptoms [4¨C7]. As many as twenty-eight types of %U http://www.hindawi.com/journals/pd/2013/167843/