Treating hallucinations in Parkinson’s disease

ABSTRACT

Introduction

Hallucinations in Parkinson’s disease are common, can complicate medication management and significantly impact upon the quality of life of patients and their carers.

Areas covered

This review aims to examine current evidence for the management of hallucinations in Parkinson’s disease.

Expert opinion

Treatment of hallucinations in Parkinson’s disease should be both individualized and multifaceted. Screening, education, medication review and the avoidance of common triggers are important. For well-formed visual hallucinations, acetylcholinesterase inhibitors are recommended first-line. Refractory or severe symptoms may require the cautious use of atypical antipsychotics. Antidepressants may be beneficial in the appropriate setting. Unfortunately, current therapies for hallucinations offer only limited benefits and future research efforts are desperately required to improve the management of these challenging symptoms.

KEYWORDS:

• Hallucinations
• psychosis
• Parkinson’s disease
• treatment
• Lewy body disease

Article highlights

• Hallucinations, especially visual hallucinations, are common in Parkinson’s disease and impact upon quality of life for patients and carers.

• The development of visual hallucinations signals advancing disease and is often accompanied by cognitive impairment.

• When hallucinations develop acutely, triggers such as infections, dehydration and the effects of new medication should be systematically investigated and treated.

• Optimisation of vision and hearing impairment and education and support including the provision of respite care, are effective strategies for all patients.

• The efficacy of psychological therapies for these symptoms is under-researched.

• Rivastigmine has good evidence for reducing visual hallucinations and improving cognition and is available in capsule and transdermal patch forms.

• In more severe cases, an atypical antipsychotic may be required. Pimavanserin is the only FDA-approved drug for this indication but access is limited. Clozapine also has good evidence though is associated with rare but often predictable serious adverse effects. Quetiapine has a better safety profile but has less evidence for efficacy. All antipsychotics are associated with increased morbidity and mortality in PD which must be balanced with the quality of life implications of untreated psychosis for individual patients.

• Cholinesterase inhibitors and antipsychotics should be withdrawn slowly to reduce the risk of rebound symptoms and a withdrawal syndrome.

• Electroconvulsive therapy may be helpful in complex cases where other treatments have failed.

• This issue is relevant to a broad range of clinicians and a coordinated multidisciplinary approach is necessary for further research efforts and better treatment.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

ForeFront is a collaborative research group at the Brain and Mind Centre, University of Sydney supported by an NHMRC Dementia Team Grant [#1095127]. SJG Lewis is supported by an NHMRC Investigator Grant [#1195830]. E Matar is a recipient of the NHMRC Postgraduate Scholarship and the Australian and New Zealand Association of Neurologists Education and Research Foundation Scholarship.