Disease: End to Parkinson's

Neurologists David C. Poskanzer and Robert S. Schwab of Massachusetts General Hospital predicted in 1961 that Parkinson's disease would all but dis appear by 1980. Some medical authorities were skeptical, for they had seen no change in the number of Parkinson's cases over the years. Poskanzer and Schwab have now reiterated their earlier conclusion, and cite new evidence to support it.

Basis of the Poskanzer-Schwab prediction was an intensive study that convinced the two researchers that a majority of Parkinsonism victims developed the disease as a result of the worldwide epidemic of encephalitis lethargica that lasted from 1915 to 1926. By 1931, the virus that caused the epidemic had inexplicably died out, apparently completely. Many of the epidemic's victims who were mildly infected suffered delayed nerve damage, the two doctors believe. In some cases the damage has taken three or four decades to manifest itself as Parkinson's disease. If sufferers from the disease were indeed restricted to victims of the 1915-26 epidemic, the doctors postulated, their numbers would continue to increase for some 40 years, then dwindle as the victims died. The average age would rise as surviving patients grew older.

In 1961 Poskanzer and Schwab noted that the mean age of persons newly afflicted with Parkinsonism was 60.6, compared with 34.7 in 1922 in the midst of the epidemic. Now, after studying 421 additional patients, Poskanzer and Schwab have found even more important evidence to support their theory: none of the Parkinson's victims they have studied thus far were born after 1931.