Overview 

Progressive Supranuclear Palsy (PSP) is a rare brain disease that that causes problems with walking, swallowing, speech and eye-movements. Unfortunately, because PSP is a rare disease it is often misdiagnosed  as Parkinson’s disease (PD). Misdiagnosis of this disease is a problem for many reasons. Firstly, the medicines that are effective for treating PD do not work for PSP. They can also have unpleasant side effects such as nausea and vomiting, changes to blood pressure, loss of appetite, constipation, hallucinations, headaches & insomnia. Misdiagnosis therefore is both harmful to the patient and wasteful of scarce NHS resources. Secondly, the prognosis for PSP is much worse than that of PD and the disease progresses much more swiftly, so misdiagnosis makes it a lot harder for patients and carers to gain access to the financial support needed to adjust their lifestyle to maximise their quality of life. For example, patients with PSP often require home adaptations and wheelchairs to compensate for their reduced mobility. Finally, inaccurate diagnosis is distressing to patients and carers and leads to unnecessary hospital visits.

First steps

Figure 1: Average reaction times to spot an ‘odd one out’ among 4 or 8 distractors. From Smith et al., (2022)

In 2015 we collaborated with Dr Neil Archibald from James Cook University Hospital in Middlesbrough and the PSP Association on some focus groups. These groups  identifed early and accurate diagnosis as key concern for people with PSP.  A small pilot study (2016-2018) explored how cognitive functions such as attenton and short-term memory were affected in PSP and Parkinson’s disease. The key finding was that people with PSP had very severe problems with some types of visuosptatial attention, in particular the ability to spot the ‘odd one out’ in a cluttered scene. The figure shows reaction times for people with PSP, Parkinson’s diseases and age matched controls. As you can see, people with PSP were much slower to make correct responses. People with PSP also had reduced short-term memory.  We published our findings in the journal Cortex, and began developing plans for a larger study.

The Dunhill Medical Trust

The results of the pilot study were very promising but the sample of patients was small. One of the reasons for this was that the project relied on people coming to Durham to take part, which can be a problem for people with PSP who often have mobility problems. To try and address these issues we (Dan and Neil) joined with Drs Alison Lane and Tony Atkinson (Durham University), Dr Clare McDonald (Queen Elizabeth Hospital, Gateshead), Dr Uma Nath (City Hospitals, Sunderland), and Prof Richard Walker (Northumbria Healthcare NHSFT), and in 2018 we secured funding for a new three-year project from the Dunhill Medical Trust. This project will involve a much larger group of participants, and by taking the tests to people’s homes rather than asking people to travel to Durham, we hoped it would be much more inclusive and accessible than the pilot. However, just as we were about to begin the pandemic struck, and the project was put on hold.

Restarting

Alexis demonstrating the visual search task, which is a test that measures visual attention.

In January of 2022 our project got the green light to restart (REC: 19/NE/0369), and in March 2022 the Durham team were joined by a new team member, Dr Alexis Cheviet.  Alexis is an expert in eye-movements in clinical neuropsychology and will manage the project. The new project will continue to explore attention and memory, but also test other aspects of cognitive function. For example, some recent studies have shown that people with PSP can sometimes have problems recognising emotions, so one of the tests will examine whether emotion recognition is different in PSP and Parkinson’s disease. Another test will look at mental imagery (the ability to see pictures ‘in the minds eye’). This is because mental imagery can be affected by eye-movements, which are known to be much more seriously affected in people with PSP compared to Parkinson’s disease. The project will also explore whether or not people with PSP are using prism glasses to help compensate for problems with their eyes, and what they think about prisms. This is an important question, because prism glasses could be a relatively cheap and effective tool for helping people with PSP. However, there are almost no scientific studies about prism glasses in PSP, and little evidence about what makes them helpful or not. We hope to show that the scores on these tests can be used to classify a patient as having either PSP or PD. This research is an essential stepping-stone towards developing an accurate and accessible diagnostic test for PSP.

Get involved

We are now actively looking for people with PSP and Parkinson’s disease to take part in the study. We estimate that the tests will take about three hours, split over two appointments. People who wish to take part have the option of travelling to our laboratoy in Durham, or, if you live in the North East of England, we can come and see you. More specfic details about what taking part the project will involve can be found on our Participant Information Sheets:

People with PSP

People with Parkinson’s disease

People with no brain disease

You can also contact Alexis (alexis.Cheviet@durham.ac.uk) or Dan (daniel.smith2@durham.ac.uk) to discuss the project.

 

 

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