SAN DIEGO — So-called benign hallucinations associated with dopaminergic treatment for Parkinson's disease rarely remain “benign,” calling into question the accuracy of the term.
Researchers at Rush University in Chicago studied the clinical progression of 48 patients with Parkinson's disease who were diagnosed with hallucinations characterized by the patient's retention of the insight that the hallucinations are unreal.
These hallucinations have been called benign, and traditionally have been associated with a score on the Unified Parkinson Disease Rating Scale (UPDRS) of 2.
In 2 years, just 2 of the 48 patients at Rush continued to have benign hallucinations without requiring either a decrease in their dose of dopaminergic medications or an addition of neuroleptic agents to counteract the hallucinations or progressing to more serious hallucinations with loss of insight (UPDRS Thought Disorder score of 3) or to delusions (UPDRS Thought Disorder score of 4).
Most patients, 39 of 48, progressed to scores of 3 or 4.
Among nine patients who remained at a score of 2, seven required reduced dopaminergic medication doses in response to worsening hallucinations, and three required neuroleptics to control the hallucinations.
Although the median time to progression of hallucinations to the point where patients were frankly delusional was less than 2 years after the onset of the study, the total length of time that patients were suffering from hallucinations prior to enrollment in the study was not certain, reported Dr. Christopher G. Goetz, director of the Rush movement disorders center, in a poster presentation at the annual meeting of the American Neurological Association.
However, the study made clear that even if hallucinations seem “benign … at the moment,” they “portend serious consequences” and should not be given a label that suggests they are unimportant clinical developments, he said.
“Because hallucinations progress, the concept of benign hallucinations is prognostically misleading,” Dr. Goetz and his associates said.
“The term benign hallucinations should be considered generally unsound and dropped from the operative vocabulary,” Dr. Goetz and associates concluded.