SAN DIEGO — Use of alternative therapies in the management of Parkinson's disease is supported only by weak data, according to one of four new practice parameters issued by the American Academy of Neurology at its annual meeting.
Considering that 60%–70% of PD patients turn to alternative therapies, the parameter provides the evidence a clinician needs to answer patient inquiries about their use.
AAN's review also found only weak evidence that exercise or speech therapy improves motor function. There was insufficient evidence to show that patients with PD derive any benefit from acupuncture, biofeedback, chiropractic, Mucuna pruriens (a nutritional supplement derived from a tropical legume, also known as velvet bean, that contains levodopa), or the Alexander technique (a form of movement therapy emphasizing correct posture and the proper positioning of the head with regard to the spine), according to the parameters, the 100th set to be issued by the AAN, which is known for the rigor of its guidelines. An estimated 80% of the AAN membership uses the academy's various practice parameters in their clinical practice. The goals of the parameters are not to dictate decision making but rather to provide neurologists with the information they need to make evidence-based judgments.
The four new guidelines address the diagnosis and prognosis of new-onset PD, neuroprotective strategies and alternative therapies, treatment of PD with motor fluctuations and dyskinesia, and evaluation and treatment of depression, psychosis, and dementia in PD.
For each parameter, the Quality Standards Subcommittee selected a committee composed of movement disorder specialists, a general neurologist, and, in the case of the nonmotor-symptom parameter, psychiatrists. Each committee surveyed the literature published from 1996 to January 2005, and scientifically rigorous studies were selected. For the treatment of PD with motor fluctuations and dyskinesia parameter, 730 articles were initially identified but only 29 met criteria for inclusion, explained coauthor Dr. Rajesh Pahwa of the University of Kansas, Kansas City.
The use of selegiline, levodopa, or a dopamine agonist for the initiation of treatment for PD is supported by the highest level of data.
For neuroprotection, the panel found that levodopa may be considered for the initial treatment of PD because it does not accelerate disease progression and is safe. However, the neuroprotective value of other medications is unproven. Good evidence is available to discount any protective effects from vitamin E (2,000 U).
For motor fluctuations, the panel recommended that entacapone and rasagiline should be offered, while pergolide, pramipexole, ropinirole, and tolcapone may be considered to reduce “off time” in PD. Only weak evidence is available to support the use of subcutaneous apomorphine, cabergoline, or selegiline, and the panel disregarded the use of sustained-release carbidopa/levodopa or bromocriptine.
The panel also updated the evidence on deep brain stimulation (DBS) for motor fluctuations, a matter that it last addressed 7 years ago. Level C evidence was found for DBS of the subthalamic nucleus, while there is insufficient evidence to make any recommendations about DBS of the globus pallidus interna or ventral intermediate nucleus of the thalamus.
For the first time, the AAN established a practice parameter for nonmotor PD symptoms, reflecting current thought that almost all PD patients are affected with one or more of these problems and that they have serious consequences. For instance, psychosis is the strongest marker for placement of a PD patient in a nursing home and, if untreated, leads to 100% mortality within a year, said coauthor Dr. Jill M. Miyasaki of the University of Toronto. With treatment, mortality falls to 28%. The panel examined whether effective screening tools and treatments were available for these conditions. While these parameters looked only at depression, psychosis, and dementia, new guidelines in preparation will address other nonmotor features of PD, including other behavioral issues, constipation, lightheadedness, and bladder problems.
The guidelines also will help investigators identify gaps in knowledge that may guide future research. For instance, more evidence is needed to determine whether DBS of areas other than the subthalamic nucleus is effective for treating motor fluctuations. There is also a need for head-to-head comparisons of medications.
The parameters are available in the April 11 issue of Neurology (2006;66:968–1002) and on the AAN's Web site (www.aan.com/professionals/practice/guideline/index.cfm
The guidelines “scored an 'A,'” commented Robin A. Elliott, executive director of the Parkinson's Disease Foundation. Mr. Elliott was particularly appreciative of the patient summary sheets. Noting that only one-third of PD patients are treated by a movement disorders specialist, Mr. Elliott said the parameters “will empower larger groups of doctors to become expert in PD.”