N.M. was a 54-year-old man with an 8-year history of PD. At the time of the evaluation he was in Hoehn and Yahr stage IV and on 1 g l-dopa, 3 mg pergolide, and intermittent subcutaneous injections of apomorphine due to severe motor fluctuations. This drug combination produced an acceptable amount of On time during the day but with severe dyskinesias. The patient was started on amantadine with the aim of reducing dyskinesias. Several days later, N.M.'s wife found the patient standing naked in front of the window in the middle of the night. He was shouting at an imaginary group of young people who, according to him, were making unpleasant noises. N.M.'s wife turned on the lights and was able to convince him about the unreality of his perceptions. This event is an example of visual and auditory hallucinations with preserved insight, also known as “hallucinosis.” […]