In contrast to these postencephalitic patients, people with ordinary Parkinson’s disease do not usually experience visual hallucinations until they have been on medication for many months or years. By the 1970s, I had several such patients who had started to get hallucinations, which were predominantly (though not exclusively) visual. Sometimes these began as webs and filigrees or other geometrical patterns; other patients experienced complex hallucinations, usually of animals and people, from the start. Such visions might seem quite real (one patient had a nasty fall while chasing a hallucinatory mouse), but the patients soon learned to distinguish them from reality and ignore them. At the time I could find almost nothing in the medical literature about such hallucinations, although it was sometimes said that L-dopa might make patients “psychotic.” But by 1975, more than a quarter of my patients with ordinary Parkinson’s disease, while otherwise doing well on L-dopa and dopamine agonists, had found themselves living with hallucinations.
Ed W., a designer, started to get visual hallucinations after he had been on L-dopa and dopamine agonists for several years. He realized that they were hallucinations and regarded them largely with curiosity and amusement; nevertheless, one of his physicians declared him “psychotic” — an upsetting misdiagnosis.
He often feels himself “on the verge” of hallucination, and he may be pushed over the threshold at night, or if he is tired or bored. When we had lunch one day, he was having all sorts of what he calls “illusions.” My blue pullover, draped over a chair, became a fierce chimerical animal with an elephant-like head, long blue teeth, and a hint of wings. A bowl of noodles on the table became “a human brain” (though this did not affect his appetite for them). He saw “letters, like teletype” on my lips; they formed “words” — words he could not read. They did not coincide with the words I was speaking. He says that such illusions are “made up” on the spot, instantaneously and without conscious volition. He cannot control or stop them, short of closing his eyes. They are sometimes friendly, sometimes frightening. For the most part, he ignores them.
Sometimes he moves from “illusions” to frank hallucinations. One such was a hallucination of his cat, which had gone to the vet for a few days. Ed continued to “see” her at home, several times a day, emerging from the shadows at one end of the room. She would walk across the room, paying no attention to him, and then disappear into the shadows again. Ed realized at once that this was a hallucination, and had no desire to interact with it (though it aroused his curiosity and interest). When the real cat came back, the phantom cat disappeared.1
In addition to such isolated or occasional hallucinations, people with Parkinson’s may develop elaborate and frightening hallucinations, often of a paranoid sort. Such a psychosis took hold of Ed toward the end of 2011. He started to have hallucinations of people who entered his apartment, emerging from “a secret chamber” behind the kitchen. “They invade my privacy,” Ed said. “They occupy my space.… They are very interested in me — they take notes, take photos, rifle through my papers.” Sometimes they had sex — one of the intruders was a very beautiful woman, and sometimes three or four of them would occupy Ed’s bed when he was not using it. These apparitions never appeared if he had real visitors or when he was listening to music or watching a favorite TV show; nor would they follow him when he left his apartment. He often regarded these persecutors as real and might say to his wife, “Take a cup of coffee to the man in my office.” She always knew when he was hallucinating — he would stare fixedly at one point or follow an invisible presence with his eyes. Increasingly, he started to talk with them — or
Ed’s neurologist, on hearing this, advised him to have “a drug holiday,” to stop all his anti-Parkinson’s medications for two or three weeks, but this left Ed so incapacitated he could hardly move or speak. He then planned a gradual reduction of medication, and, two months later, on half his previous dose of L-dopa, Ed’s hallucinations, his fears, and his psychosis have cleared completely.
