How to identify Parkinson’s disease as early as possible? Answering this question as well as possible could improve the medical management of this neurodegenerative pathology which causes slowing of movements, general stiffness, difficulty in locomotion and tremors. Among the avenues considered to date: the appearance of fairly common gastrointestinal disorders (constipation, irritable bowel, etc.), which could prove to be potential warning signs. Recent research suggests that these same symptoms may precede the development of neurovascular disease, brain aneurysm or stroke, or even Alzheimer’s disease. Would it be the same for Parkinson’s?
It is this hypothesis that an American-Belgian team wanted to explore. The results of their research, detailed in a study published this Friday, August 25 by the scientific journal Gut, from the British Society of Gastroenterology, seem to confirm this lead. “Our study is the first to establish substantial evidence that the clinical diagnosis of constipation, but also of dysphagia – difficulty in swallowing -, gastroparesis – a condition in which the stomach empties too slowly – and of irritable bowel syndrome without diarrhea, could predict the development of Parkinson’s disease”, they underline in a press release accompanying their work.
Tens of thousands of medical records peeled
In order to demonstrate this, the scientists decided to use data from the American national network TriNetX, which brings together thousands of medical records. They selected those from 24,624 people who had been diagnosed with Parkinson’s disease. Then they compared them with 19,046 patients suffering from Alzheimer’s disease, 23,942 diagnosed with a neurovascular disease, and also with a “control group” of 24,624 patients free of these pathologies. They then sorted people with Parkinson’s by age, gender, ethnicity and time since diagnosis and compared them with equivalent people from other groups. Finally, they studied the frequency of intestinal disorders appearing in their medical records six years before the onset of Parkinson’s.
To support their findings, the researchers performed a second comparison process. They first divided into 18 groups all the patients who had been diagnosed with one of the 18 intestinal diseases they had identified. They then compared, one by one, each group suffering from one of the 18 conditions with a group not suffering from the same disease. Through the study of medical records, the researchers followed all these groups for five years, which allowed them to determine how many patients had developed Parkinson’s or other neurological disorders.
Four Disorders Clearly Linked to Parkinson’s
The authors explain that the two analyzes show that four bowel disorders are associated with a higher risk of being diagnosed with Parkinson’s disease. Thus, the risk of developing this neurodegenerative disease is more than doubled in the five years following the diagnosis of gastroparesis, dysphagia, as well as constipation. Irritable bowel syndrome without diarrhea is associated with a 17% increased risk. On the other hand, the researchers discovered that the removal of the appendix could have a protective effect, since it seems associated with a lower risk, which leads them to question the role of this organ in the development of Parkinson’s. . Finally, neither inflammatory bowel conditions nor vagotomy – the partial or total removal of the vagus nerve in order to treat an ulcer – have been associated with an increased risk.
The study also points out that other intestinal problems, such as functional dyspepsia – the burning or “full belly” feeling without an obvious cause -, irritable bowel syndrome with diarrhea and diarrhea accompanied by fecal incontinence, are more common in people who have developed Parkinson’s. But these diseases were also more common before the onset of Alzheimer’s or neurovascular disease, which rules out their direct link with Parkinson’s.
Obvious limits, but interesting leads
As the authors point out, their study is observational, which means that it is content to collect statistics in order to analyze them. It cannot therefore, as such, establish a certain cause. The researchers point to other limitations to their findings, including the fact that the follow-up period could have been longer to strengthen their hypothesis, or that the information entered into the electronic medical records was not always 100% complete. .
Their study nevertheless remains the first to shed light on this hypothesis. The scientists also point out that their findings “warrant vigilance for gastrointestinal syndromes in patients at high risk for Parkinson’s disease and underscore the need for further study of gastrointestinal precedents in Parkinson’s disease.” ‘Alzheimer’s and Neurovascular Diseases’. If new research is therefore needed to confirm this lead, this work could constitute a first step towards a better understanding of this disease, against which drugs remain ineffective. Indeed, current treatments limit the manifestations of its symptoms, but do not stop its evolution.