Treatment of Chronic Constipation in Parkinson's Disease

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder characterized by motor symptoms. In recent years it has become clear that motor symptoms are associated with non-motor and non-dopaminergic symptoms throughout the natural progression of the disease, and sometimes even before the onset of motor manifestations.

Chronic constipation is the most common gastrointestinal symptom reported by PD patients; it could be one of the manifestations of disease onset.

In the past, constipation was considered a side effect of neurological therapy, but more recent studies have evidenced that it is widely present in patients with early untreated PD too and it may precede of years the onset of motor symptoms.

The prevalence of constipation can reach 80% of patients with PD, with an incidence of decreased stool frequency (less than 3 bowel movements per week) of 57-67% of patients.

Although constipation should be interpreted as part of the disease, patients often don't link it to PD, with the result that it may be neglected or poorly managed. Moreover, continuous and incongruous use of laxatives, that are often used in increasing doses in order to maintain efficacy, may cause the onset of abdominal pain and diarrhoea with the risk of bowel incontinence and other side effects.

Constipation also adversely affects quality of life of PD patients: beyond being an annoying symptom, it may also cause other serious gastrointestinal pathologies (i.e. magacolon, intestinal pseudo-obstruction, volvolus, bowel perforation). Moreover, constipation can directly or indirectly influence the absorption of PD drugs, with the result of a poor control on motor symptoms.

Afterwards, finding an effective treatment of constipation would be very important for quality of life of PD patients; this treatment should be easy to be administered and should not have any interference with other PD drugs.

PHGG fiber is extracted from a herbaceous plant (Cyamopsis Tetra-Gonolobus, family: Leguminosae) of Indian origin: it produces 5/9 pods containing seeds which produce the famous guar gum, that is a natural polysaccharide. It differs from fibers derived from other plants for its high content of Galactomannan. Guar gum (referred to as GG) is classified in the European list of additives under the symbol E 412. Recently, a partially hydrolyzed guar gum (indicated with the abbreviation PHGG) has been developed. Unlike the original and other fibers (eg. Psillium), it has the characteristic to remain liquid and, due to its low molecular weight, to not turn into gel. The introduction of molecules of water (hydrolysis), by an enzyme called Mannanase, reduces the length and the molecular weight of guar gum and creates a fiber with unique properties: by remaining liquid, it does not cause bloating, flatulence and meteorism, that are adverse events typically associated to other fibers. The association with sodium hyaluronate (low molecular weight depolymerizes) rapidly attracting water and amplifying the desired clinical effect.

The aim of this pilot research study is to investigate the effectiveness of this formula (Stick pack 30 ml containing PHGG 5 g and Hyaluronic 200 mg) in PD patients affected by constipation.

Inclusion criteria

• Idiopathic PD according to UK PDS Brain Bank Clinical Diagnostic Criteria.
• Chronic constipation according to Roma III criteria for chronic functional constipation lasting from at least 6 months.
• Absence of dementia.
• Patients who are able to understand and sign the informed consent for participation in the study

Exclusion criteria

• People who suffer from other comorbidities that could interfere with the results of the study according to the investigator.
• People who are not able to provide reliable answers to the questionnaire according to the opinion of the investigator.
• Inclusion in other clinical trials at the time of the visit.