Professor R. is a very good musician; he started to play the piano when he was five and still plays for many hours a day. He is curious about his illusions, and he has done his best to transcribe or play the illusory music. (His best chance of “catching” this phantom music, he has found, is to set up a newspaper on the music stand and play it as soon as the newsprint turns into music.) But the “music” is scarcely playable, because it is always very highly ornamented, with innumerable crescendo and decrescendo markings, while the melody line is three or more octaves above middle C, and so may have half a dozen or more ledger lines above the treble staff.
Seeing music has been described to me by others (see this page). Esther B., a composer and music teacher, wrote to me that, twelve years after being diagnosed with Parkinson’s, she started to have “a rather peculiar visual phenomenon.” She described this in detail:
When I look at a surface — like a wall, or a floor, or a garment someone is wearing, or a curved surface like a tub or sink, or other surfaces too numerous to mention — I see a sort of collage of music scores superimposed upon the surface, especially with my peripheral vision. When I try to focus on any one image, it dims out or disappears elusively. These images of music scores come unbidden and are especially vivid after I’ve been working with any written music. The images always appear more or less horizontal, and if I tilt my head one way or the other, the horizontal images will tilt accordingly.
Howard H., a psychotherapist, began to notice tactile hallucinations soon after being diagnosed with Parkinson’s, as he wrote:
I would feel that the surfaces of various objects were covered by a film of fuzz, like peach fuzz, or the down in a pillow. It could also be described as cotton candy or spider webs. Sometimes the webs and fuzz can get very “lush,” as when I reach down to pick up something that has fallen under my desk and my hand feels as if it has become submerged in a huge pile of this “stuff.” But when I try to scoop up that pile, I see nothing and yet feel that I have a large amount of this “stuff” in my hands.
Is the use of L-dopa wholly responsible for such effects? Can L-dopa be regarded as a hallucinogenic drug? This seems unlikely in view of the fact that it is used in treating other conditions (such as dystonias) without provoking any hallucinations. Is there then something in the parkinsonian brain, or at least in some parkinsonian brains, which may predispose to visual hallucinations?2
Too often, parkinsonism is seen as no more than a movement disorder, but it may also involve a number of other aspects, including sleep disturbances of various sorts. People with Parkinson’s may sleep poorly at night and often have chronic sleep deprivation. Their sleep may be marked by vivid and sometimes bizarre dreams, or nightmares in which they are awake but paralyzed, helpless to combat dream images being superimposed on their waking consciousness. All of these factors additionally predispose to hallucination.
In 1922 the French neurologist Jean Lhermitte described the sudden onset of visual hallucinations in an elderly patient — people in costume, children playing, animals around her (she would sometimes try to touch them). The patient had insomnia at night and drowsiness in the daytime, and her hallucinations tended to come at dusk.
Though this lady had dramatic visual hallucinations, she had no visual impairments and no lesions in the visual cortex. But she had neurological signs suggesting an unusual pattern of damage in parts of the brain stem, the midbrain, and the pons. It was well known at this point that lesions in the visual pathway could cause hallucinations, but it was not clear how damage in the midbrain — not a visual area — could do so. Lhermitte thought such hallucinations might go with a derangement of the sleep-wake cycle, that they were essentially dreams or dream fragments invading daytime consciousness.
Five years later, the Belgian neurologist Ludo van Bogaert reported a somewhat similar case — his patient suddenly started seeing the heads of animals projected on the walls of his house at dusk. There were neurological signs similar to those of Lhermitte’s patient, and van Bogaert also surmised midbrain damage. When his patient died, a year later, an autopsy revealed a large midbrain infarction involving (among other structures) the cerebral peduncles (hence his coinage of the term “peduncular hallucinations”).
