Neurodegenerative Clinical Research Group - Research

Progressive supranuclear palsy (PSP) has no known effective treatment or cure. PSP affects brain cells that control walking, balance, mobility, vision, speech, swallowing, thinking and behaviour. It is a devastating neurodegenerative condition, often misdiagnosed as Parkinson's Disease, that affects people over the age of 40 years old, for which there is currently no disease-modifying treatment. 

We are part of a collaborative group of clinical neurology researchers who have been awarded more than $2.6 million from the Medical Research Future Fund to study a trial of sodium selenate as a disease-modifying treatment of PSP. 

Seventy patients from specialist movement disorders services across Australia will be recruited to the study, receiving either sodium selenate or a placebo for 12 months. Because PPS is caused by an accumulation of the protein, tau, in the brain (as is also seen in Alzheimer’s Disease), the researchers will be looking for a reduction in this protein on positron emission tomographic (PET) scanning, and for changes in atrophy or reduction in regional brain volumes on magnetic resonance imaging (MRI). 

Currently the diagnosis of Parkinson’s disease is based on clinical features. Some patients have atypical features resulting in diagnostic uncertainty which impacts on their treatment and their prognosis.  Nuclear medicine scans including Fluorodopa Positron Emission Tomography (F-Dopa PET) is helpful in diagnosis of Parkinson’s disease but has very limited availability. Recent studies have suggested that changes on magnetic resonance imaging (MRI) might be helpful in diagnosing Parkinson’s disease.   

In this study we are comparing clinical diagnosis with MRI and with F-Dopa to determine if the MRI changes will be helpful to assist in the diagnosis of Parkinson’s disease. 

The aim of this study is to determine the efficacy of Livaux, a prebiotic supplement made from gold kiwifruit, in improving the gut microbiome and symptoms of constipation in patients with diagnosed Parkinson's disease.

Patients will be randomised to receive either 2400mg of Livaux or placebo daily for six weeks in a double-blind cross-over study. Livaux 2400mg is the approximate equivalent to one quarter of a whole gold kiwifruit. The study will last for approximately 20 weeks with a 4-week screening period, and two 6-week treatment periods with a washout period of 4 weeks in between. 

Patients will be required to maintain a bowel diary for the duration of the study, provide food and fluid diaries during the screening and treatment periods, and provide faecal and other specimens on four occasions to enable quantification of the microbiome and its metabolites. Colonic transit time will be measured at the end of each treatment period to determine the effect of transit time on constipation. The final study endpoints will be to determine whether Livaux has any impact on transit time, symptoms of constipation, and the quality of the microbiome. 

Gastrointestinal problems are common in Parkinson's disease (PD) and amongst the earliest symptoms, often preceding classic motor symptoms by several years or decades. Pathological changes in gut microbes are believed to mirror the early gastrointestinal dysfunction in PD which occurs years to decades before diagnosis.

This research project in conjunction with Dr Richard Gordon, funded by Wesley Medical Research, will identify the gut microbiome changes in PD patients at much high resolution than previously possible. This will uncover new potential therapeutic targets and diagnostic signatures that can be used to enable earlier clinical diagnosis of PD.

Our results will provide new insights into how the gut microbiome signalling is dysregulated at the gut-brain axis in PD. This will facilitate new therapeutic approaches around restoration of the microbiome and inflammasome signalling in PD to be developed along with clinical diagnostics for precision and personalized treatments based on individual microbiome composition.