Around 1% of adults have Parkinson’s disease, with a median time of 9 years between diagnosis and death.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments in people with early-stage Parkinson’s disease? What are the effects of adding other treatments in people with Parkinson’s disease who have motor complications from levodopa? What are the effects of surgery in people with later Parkinson’s disease? What are the effects of nursing and rehabilitation treatments in people with Parkinson’s disease? We searched: Medline, Embase, The Cochrane Library and other important databases up to November 2006 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
We found 59 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: adding a catechol-methyl transferase inhibitor, or dopamine agonist to levodopa; amantadine; dopamine agonists; levodopa (immediate-release, modified-release); monoamine oxidase B inhibitors; occupational therapy; pallidal deep brain stimulation; pallidotomy; Parkinson’s disease nurse specialist interventions; physiotherapy; speech and language therapy; subthalamic nucleus deep brain stimulation; subthalamotomy; swallowing therapy; thalamic deep brain stimulation; and thalamotomy.
Around 1% of adults have Parkinson's disease, with a median time of 9 years between diagnosis and death.
Levodopa is considered effective at reducing symptoms in early Parkinson's disease, but can cause irreversible dyskinesias and motor fluctuation in the long term. We don't know whether levodopa, or any other treatment, improves survival.
Modified-release levodopa seems no more effective than immediate-release levodopa at improving symptoms, and delaying motor complications.
Monoamine oxidase B inhibitors (MAOBIs) may improve symptoms, reduce motor fluctuations, and delay the need for levodopa, but can cause adverse effects.
We don't know whether amantadine is beneficial for people with early Parkinson's disease, although it is currently used to treat dyskinesia. People taking amantadine for dyskinesia in early Parkinson's may have a higher risk of psychiatric adverse effects in the later stages of the disease.
Adding a catechol-O-methyl transferase (COMT) inhibitor or dopamine agonist to levodopa, or using dopamine agonists as monotherapy, may reduce ‘off' time and improve symptoms compared with levodopa alone, but can cause adverse effects.
The COMT inhibitor tolcapone can cause fatal hepatic toxicity.
Surgery may be considered in people with later Parkinson's disease, but can cause fatalities. Post-operative complications include speech problems and apraxia.
Although evidence is lacking, many clinicians feel that both pallidal deep brain stimulation and subthalamic nucleus deep brain stimulation improve symptoms of advanced Parkinson's disease.Bilateral subthalamic nucleus deep brain stimulation may lead to greater improvement in motor symptoms, but more cognitive impairment, than pallidal deep brain stimulation. Pallidal deep brain stimulation is associated with severe intraoperative complications.Adding subthalamic nucleus deep brain stimulation to medical treatment may improve quality of life and motor symptoms compared with medical treatment alone or other forms of surgery. It can, however, cause neurological complications, neuropsychological adverse effects, and fatal surgical complications.Unilateral pallidotomy may improve symptoms and function more than medical treatment, but may be less effective than bilateral subthalamic stimulation.We don't know whether subthalamotomy or thalamotomy are effective.
Nurse specialist interventions, occupational therapy, physiotherapy, speech and language therapy and swallowing therapy are generally considered effective and safe in people with Parkinson's disease, although few studies have been found.