In 1970, Oliver Sacks wrote five letters to various medical journals in the U.S. expressing his concern about the prescription drug levodopa, which had been developed just a year earlier. As a practicing neurologist, he had used levodopa (L-Dopa) to treat Parkinson’s and encephalitis lethargica (or “sleepy-sickness”) in his patients—both neurological disorders that arise from a deficiency of dopamine—and found it to have serious adverse effects. As he described in his 1985 book The Man Who Mistook His Wife for a Hat, treating people with sleepy-sickness with L-Dopa resulted in an over-correction of motor function: “First they were ‘awakened’ from stupor to health: then they were driven towards the other pole—of tics and frenzy.”
This phenomenon would come to be known as levodopa-induced dyskinesia—an increase in involuntary muscle movements or spasms that results from too much dopamine flooding your brain. It’s one of the most common side effects of conventional treatment of Parkinson’s Disease (PD) and one of the most devastating: some PD patients describe their dyskinesia as worse than the disease itself, causing many to decrease or put off treatment altogether to stave off the inevitable side effects.