This article on hallucinations and psychosis in PD is from the Spring 2010 APDA newsletter, which I received in June. http://www.apdaparkinson.org/data/NewsL ... -11-10.PDF
Hallucinations and Psychosis in Parkinsonâs Disease
By Dag Aarsland, MD
American Parkinson Disease Association (APDA) Newsletter
Psychotic symptoms in Parkinsonâs disease (PD) include visual-perceptual symptoms such as visual hallucinations (VH), illusions, passage and presence phenomena. Hallucinations may also occur from other modalities, mainly auditory, but usually in combination with VH. In addition, thought disorders, typically delusions may occur. Psychotic symptoms may be mild or severe, occur together or single, be accompanied by affective and behavior disturbances and require psychiatric hospitalization.
Psychotic symptoms are a frequent occurrence in PD. The frequencies vary according to the definition used. If mild forms are included, psychotic symptoms may affect up to 50 percent of patients. Studies on psychosis have mostly focused on visual hallucinations, the most common type of psychotic symptom in PD. Hallucinations, however, can occur in all sensory domains and delusions of various types are also relatively common. Relatively few longitudinal studies of the course of PD exist. Psychotic symptoms, however, once present, tend to be persistent and progressive.
The typical VHs consist of persons, who may or may not be familiar, and less often animals or objects. They may be numerous, but often single or few in numbers. They are usually complex, and stereotype in a given patient. They appear suddenly, often move, and usually seem very real. They usually vanish suddenly, sometimes when the patients try to ascertain their reality by approaching or touching them, or asking other people to confirm their presence. They often occur in dim light, often at night. Insight into the pathological nature of the phenomenon may or may not be present. Lack of insight is more common in subjects with cognitive impairment.
Capgras delusion (a friend, spouse, or close family member has been replaced by an identical-looking impostor) and similar misidentification phenomena may also occur. Typically, the patient thinks that a spouse is someone else which may create challenging situations with affective and behavioral changes. Other forms of delusions are relatively rare, but are often persecutory, or focus on infidelity.
The neuropsychiatric symptoms in PD tend to cluster into distinct syndromes. In a recent study, five clusters were identified. The largest groups showed symptoms of mild depression, followed by a group with hallucinations and mild other symptoms.
One group had sleep disturbances exclusively, and another showed apathy, anxiety and depression. A small group showed a variety of severe symptoms, including psychosis and agitation.
Assessment and diagnosis
Recently, consensus criteria for PD-associated psychosis were proposed after an NIH-sponsored workshop. Psychotic symptoms, however, are not always reported voluntarily, and the clinician should ask for these phenomena. Some patients may deny or refuse to report these symptoms, or, in dementia, may have forgotten, and thus a caregiver
should be questioned as well. The frequency, intensity and impact of the symptoms should be noted, as well as the situation and circumstances in which they occur, the detailed phenomenology, and any other accompanying symptoms such as cognitive impairment, depression, anxiety, and sleep disorders. There are several rating scales in use, although no generally accepted ones.
Psychotic symptoms develop from a complex interplay of extrinsic and intrinsic factors. It was previously considered that VHs in PD were caused by the dopaminergic medication. It is now generally accepted, however, that although dopaminergic drugs - in particular dopamine agonists - can contribute to the emergency of psychosis, other factors may be more important, such as dementia and visuospatial (thought process that involves visual and spatial awareness) impairment, as well as general factors such as old age and more advanced disease stage. Brain changes found to be associated with an increased risk for psychotic symptoms in PD include cholinergic deficiencies and Lewy bodies in the temporal lobe. Pathological excitation of the visual pathways caused by physical or chemical factors may contribute.
The impact of psychosis is substantial in that it is associated with dementia, depression, earlier mortality, greater caregiver strain, and nursing home placement. Thus, it is crucial to identify these symptoms in order to optimize the management of PD patients.
Psycho-educative approaches, such as information and guidance about the nature of the phenomena may help, as well as cognitive approaches such as distraction or redirecting attention. Environmental interventions such as improving light conditions and visual aids may also be useful. Searching for potential contributing medical factors is always important, such as pain, infection, dehydration, metabolic disturbances, sensory deficits, and recent changes in medication.
First line is always to attempt adjustment of the antiparkinsons treatment. Reduction of dose or number of drugs may reduce the symptoms, even without worsening of motor symptoms. According to expert opinion, anticholinergics should be withdrawn first. It is usually recommended to withdraw selegiline, amantadine and dopamine agonists before changing the levodopa dosage.
The only adequately tested drug to recommend is clozapine, which has been shown to improve VH without worsening motor symptoms. Randomized placebo-controlled trials, however, have been conducted in patients without dementia only. The risk of agranulocytosis necessitates regular blood tests. Other antipsychotic agents such as risperidone and olanzapine, are less useful, because they are less effective and have a higher risk for adverse events including motor worsening, cognitive decline, and drowsiness and confusion. Initial open-label reports on quetiapine were promising, although two placebo-controlled trials were negative. More novel antipsychotics, such as ziprasidone and aripiprazole, have not yet been tested systematically and preliminary reports are inconclusive. Careful monitoring is required, and dosing should be low with small increments. Recent reports have highlighted that antipsychotic agents have a risk of cerebrovascular incidents and increased mortality, as well as worsening cognition in elderly people with dementia.
Cholinergic agents may improve neuropsychiatry symptoms in PD, but there is yet no evidence to support their use for VH in PD. Rivastigmine, however, seems to be particularly useful for PD with VH, in that the rapid cognitive decline in this group can be reduced.
âNeuropsychiatry Symptoms in Parkinsonâs Disease,â Movement Disorders, 2009 Nov. 15;24(13): 2175-2186.
Dr. Aarsland is a professor of psychiatry at the Norwegian Center for Movement Disorders, Stavanger University Hospital, Stavanger, Norway.