In 1985, science journalist Jon Palfreman investigated a group of drug addicts who were struck with Parkinson’s-like symptoms after taking tainted heroin. Thirty years later, Palfreman was diagnosed with Parkinson’s disease. In his book Brain Storms, he describes having Parkinson’s as “going on vacation in another country and having to drive on the ‘wrong’ side of the road.” Palfreman describes his own journey with the disease and discusses new treatments for Parkinson’s patients. Read an excerpt here.

*This copy was updated on September 17, 2015, to reflect the following correction: An earlier version stated that Jon Palfreman investigated the group of drug addicts with Parkinson’s-like symptoms in 1982. While cases started occurring that year, the date he documented them was 1985.