Practice Parameter: neuroprotective strategies and alternative therapies for Parkinson disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: To define key issues in the management of Parkinson disease (PD) relating to neuroprotective strategies and alternative treatments, and to make evidence-based treatment recommendations. METHODS: Two clinical questions were identified. 1) In a patient diagnosed with PD, are there any therapies that can slow disease progression? 2) Are there any nonstandard pharmacologic or nonpharmacologic therapies that have been shown to improve motor function in PD? Articles were classified according to a four-tiered level of evidence scheme. Recommendations were based on the evidence. RESULTS AND CONCLUSIONS: 1. Levodopa does not appear to accelerate disease progression. 2. No treatment has been shown to be neuroprotective. 3. There is no evidence that vitamin or food additives can improve motor function in PD. 4. Exercise may be helpful in improving motor function. 5. Speech therapy may be helpful in improving speech volume. 6. No manual therapy has been shown to be helpful in the treatment of motor symptoms, although studies in this area are limited. Further studies using a rigorous scientific method are needed to determine efficacy of alternative therapies.

Practice parameter: therapies for essential tremor: report of the Quality Standards Subcommittee of the American Academy of Neurology.

BACKGROUND: Essential tremor (ET) is one of the most common tremor disorders in adults and is characterized by kinetic and postural tremor. To develop this practice parameter, the authors reviewed available evidence regarding initiation of pharmacologic and surgical therapies, duration of their effect, their relative benefits and risks, and the strength of evidence supporting their use. METHODS: A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 1966 and August 2004. Articles were classified according to a four-tiered level of evidence scheme and recommendations were based on the level of evidence. RESULTS AND CONCLUSIONS: Propranolol and primidone reduce limb tremor (Level A). Alprazolam, atenolol, gabapentin (monotherapy), sotalol, and topiramate are probably effective in reducing limb tremor (Level B). Limited studies suggest that propranolol reduces head tremor (Level B). Clonazepam, clozapine, nadolol, and nimodipine possibly reduce limb tremor (Level C). Botulinum toxin A may reduce hand tremor but is associated with dose-dependent hand weakness (Level C). Botulinum toxin A may reduce head tremor (Level C) and voice tremor (Level C), but breathiness, hoarseness, and swallowing difficulties may occur in the treatment of voice tremor. Chronic deep brain stimulation (DBS) (Level C) and thalamotomy (Level C) are highly efficacious in reducing tremor. Each procedure carries a small risk of major complications. Some adverse events from DBS may resolve with time or with adjustment of stimulator settings. There is insufficient evidence regarding the surgical treatment of head and voice tremor and the use of gamma knife thalamotomy (Level U). Additional prospective, double-blind, placebo-controlled trials are needed to better determine the efficacy and side effects of pharmacologic and surgical treatments of ET.

Localization of nerve growth factor receptors in cholinergic neurons of the human basal forebrain.

Nerve growth factor (NGF) receptors were visualized in the basal human forebrain using an immunohistochemical procedure with a monoclonal antibody previously shown to recognize human melanoma cell NGF receptors. The receptors were found to be exclusively located in the medical septal nucleus, the diagonal band of Broca, and the nucleus basalis. This location coincided with that of cell bodies of ascending cholinergic neurons of the basal forebrain. In addition, NGF receptor-positive cells were costained for acetylcholinesterase. These findings indicate that cholinergic neurons of the basal forebrain but none of the other neurons located in this area express receptors for NGF. Results suggest that NGF acts as a trophic factor for cholinergic neurons in the human brain in a similar way as has been established in recent years for the rat brain.