A drug to combat Parkinson's disease is being developed which could halt the cognitive impairment of the disease

The investigators are searching for a drug that will halt the advance of Parkinson’s disease: the second most common neurodegenerative disease after Alzheimer’s disease, with over 300,000 suffers in Spain. To coincide with World Parkinson’s Day, on 11 April, experts point out that improving the quality of life of sufferers requires early diagnosis: “by the time the disease appears with the initial manifestations of tremors or memory loss –points out UOC Faculty of Health Sciences professor, Jaime Kulisevsky – half of the affected neurons have already been eliminated”.

The UOC team of researchers, led by Kulisevsky himself and integrated within a group of scientists at Hospital de la Santa Creu i Sant Pau, has two lines of research focused on improving the quality of life of sufferers by reducing the cognitive disorders caused by the disease. On the one hand, they are developing a new drug and, on the other, promoting a trial with patients using transcranial magnetic stimulation to obtain significant improvements in cognitive aspects such as memory.

Parkinson’s is a neurodegenerative disease principally related to age. In its process, it progressively eliminates a series of neuronal populations. When these neurons die, they generate tremors, slowness and rigidity and this also affects memory and other aspects, such as reasoning. It is not a fatal disease but one with a high incidence: every year, 18 cases are diagnosed per 100,000 people and this rate increases exponentially from the age of 40 to the point where 30% of the population aged over 80 have Parkinson’s disease.

Between 5% and 10% of cases are genetic in origin

The most common situation is for the disease to start from the age of 55–60, although there are cases of it affecting younger people. “We have detected patients aged under 40; the possibility of the disease being caused genetically is increasing. There is a gene responsible for ‘familial Parkinson’s disease’,” says the UOC researcher, who also emphasizes how advances in genetic studies have helped establish this correlation. According to Kulisevsky, between 5% and 10% of cases are genetic in origin.

However, it should also be borne in mind that there are risk factors which precipitate the development of the disease (for example, pesticides) and protective factors (consuming coffee and fruit or having a healthy lifestyle). “Nowadays we consider that it has different causes: genetic predisposition and environmental factors. Without doubt, Parkinson’s disease is an illness of the brain produced by different causes, but which express themselves in a single way,” Kulisevsky points out.

Research to improve the quality of life

The cognitive impairment of Parkinson’s disease, which covers learning, reasoning and memory, is as grave if not more so than those of Alzheimer’s disease. The UOC, in collaboration with CIBERNED of Madrid's Hospital Carlos III, is developing a drug that could halt these symptoms which “are what cause the most stress to carers and sufferers”. The drug could be ready to begin the experimental phase by the end of 2017.

Furthermore, researchers from the UOC and Hospital de la Santa Creu i Sant Pau are evaluating whether transcranial magnetic stimulation improves the motor abilities and cognitive and neuropsychiatric symptoms associated with the disease. To date, this technique has been applied mostly to patients suffering from depression. However, the UOC has decided to use it in a pioneering way in diseases such as Alzheimer’s and Parkinson’s disease, in the hope that sufferers will be able to improve their quality of life and live longer under better conditions. The trial phase of the study is forecast to begin in the final quarter of this year. For the time being, the research team has defined the scale that will make it possible to measure the impact of the disease on the cognitive ability of the sufferer. Various international laboratories use this as a guide.

These studies are in addition to other international lines of research. In the absence of a definitive treatment formula, several studies are looking at how to prevent the death of the neurons or, at least, reduce the toxicity of the protein (alpha-synuclein) which manifests itself in an abnormal way and causes neuronal death. Work is being carried out in this field to develop a vaccine that will protect the neuron from the impact of the diseased protein. Studies are also being conducted to reduce the side effects of some commonly-used drugs such as levodopa.

According to Kulisevsky, the research is evolving considerably. “Nowadays there are people who are active for many years and with a good quality of social and working life,” he says.

The importance of early detection

The researchers point out that the leap in improving the quality of life of sufferers will occur when they manage to detect the disease at an early stage. At the moment, the diagnosis is “clinical, based on suspicion”; “instead of waiting for the symptoms to appear, we need to work on the risk factors”. “New advances in the treatment to control the disease will come from clinical trials with this risk population”, Kulisevsky concludes.