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n 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 ligrees 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 nd 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
erce 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
aect 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, rie 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