Have never seen the movie but have read all about Oliver Sacks and his experiments with L-Dopa and his catatonic patients. L-Dopa increases neurotransmission which is what brought those patients out of their catatonic state but also causes inflammation. Now it's got me wondering if the increased inflammation is what caused those patients relapse.
Encephalitis lethargica which causes the catatonic state is considered an autoimmune disease, maybe leronlimab could help although with the small patient population it may never be studied.