Parkinson’s disease: a multi-faceted disease

Abstract

The content of this supplement of the Journal of Neurology is the essence of lectures and workshops which were presented during the 11th German Parkinson Expert Meeting in Dresden in October 2010. Cutting-edge information on many major developments in the field of Parkinson’s disease (PD) is provided. The etiopathogenesis of PD is still unknown, although we have unraveled interplay between oxidative stress, genetic abnormalities, mitochondrial dysfunction, inflammation and apoptosis. In spite of these findings, the initial step in the development of PD is unknown. More and more important information is being gained from the study of patients with familiar PD as their genetic abnormalities are elucidated, and, to a lesser degree, from non-familiar PD patients. A major focus of modern PD research is on the premotor phase of the disease. Many patients present first with hyposmia, REM sleep disorder, depression, constipation or other autonomic disturbances, before they develop motor signs. Thus, a better understanding of the pre-motor phase could lead to early treatment with potential neuroprotective agents. In the paper by Winkler et al., a Parkinson’s disease risk score is presented which aims for the early diagnosis of PD. The most recent findings in PD suggest that patients have a relatively bad drug adherence, maybe due to the complexity of the drug regimen or due to progressive cognitive impairment. For this reason, once daily formulations are preferable. In addition, long-lasting continuous dopamine replacement therapy prohibits the occurrence of dyskinesia. There is good evidence that extended release preparations such as ropinirole PR lead to equal efficacy with better tolerability when compared with immediate release preparations. Both de novo patients and those in advanced stages of the disease derive benefit from these preparations. It is of particular note that even advanced patients tolerate ropinirole PR and improve significantly with respect to motor function, especially with being ‘‘on’’. In a head to head comparison, the extended release preparation was even superior to the immediate release form. Non-motor symptoms are becoming of particular interest, since they lead to a major impairment of the quality of life of our patients. A whole variety of non-motor symptoms is discussed in detail in this supplement, and special focus is placed on sleep impairment in PD. REM sleep disbehavior is one of the early signs of PD and should give rise to careful clinical examination. The use of modern extended release preparations of dopamine agonists, has led to an improvement in sleep, especially sleep quality and early morning akinesia. Nonetheless, there are still many patients who wake up too early or wake up due to nocturia. A detailed description is given for different specific sleep disturbances such as restless legs syndrome, rapid eye movement sleep behaviour disorder, periodic limb movements in sleep and obstructive sleep apnea. Impulse control disorders have not previously played a major role in PD treatment. However, we now know that levodopa, and in particular, high doses of dopamine agonists, may cause hypersexuality, binge eating, gambling, This article is part of a supplement sponsored by GlaxoSmithKline.