Early Parkinson's disease: what is the best approach to treatment.
Early and correct diagnosis and treatment of Parkinson's disease (PD) are crucial for the patient's well being. At the first visit, it is important to deal with the patient's misconceptions of the disease and its course, to offer sources of information and to suggest exercises. To make a correct initial diagnosis of PD we need to assess the course of the initial levodopa responsiveness. The most frequent challenges in diagnosing PD are the conditions of essential tremor and multiple system atrophy. PD has 3 stages of development: (i) early--from the onset of symptoms to the appearance of motor fluctuations; (ii) middle--from motor fluctuations to the appearance of moderate-to-severe disability; and (iii) advanced--when moderate-to-severe disability is present. The medical treatment of early PD should be started when functional disability appears, which is a different threshold for each patient. For patients below 65 years old, or above 65 years old but with preserved mental function and with no severe comorbidity, initial monotherapy with a dopamine agonist is advisable. This approach appears to delay the appearance and reduce the amount of late motor complications with subsequent levodopa treatment. All dopamine agonists have similar efficacy, which is less than that of levodopa. It is important to consider the adverse effect profile when a choice for initial or adjunctive therapy is made. When levodopa therapy is started as an adjunct in younger patients or as initial monotherapy in older patients, sustained-release levodopa preparations are preferred. They have a longer half-life and possibly stimulate the dopamine receptors more continuously. Anticholinergic drugs are appropriate for younger patients with tremor-dominant PD. Amantadine is mainly used for dyskinesia control. Catechol-O-methyl-transferase inhibitors and neurosurgery are not treatments of choice for early PD but can be very effective for more advanced disease. The presence of presymptomatic markers of PD, such as changes in odour detection, handwriting, speech, movement time of self-initiated motor acts, personality traits, presence of antibodies against dopaminergic neurons, pattern of positron emission tomography results, appearance of mitochondrial DNA mutation profiles, etc., appear to be very important in the light of the emerging neuroprotective therapies. Neuroprotection is aimed at slowing the rate of disease progression. Selegiline has been shown to cause a mild delay in the need for levodopa, possibly suggesting some protection. However, this initial benefit was not sustained in long term studies. Currently, there is no neuroprotective drug for PD.