Profile: Alasdair MacLullich
In the first of a series of scientist profiles taken from our Annual Review 2011/12, Sarah Harrop speaks to the University of Edinburgh’s Professor Alasdair MacLullich about how he’s enlisted the skills of a toy maker to develop a new test for delirium in the elderly.
With its grey plastic case and chunky buttons, the device on the table in front of Professor Alasdair MacLullich looks like something from a 1980s episode of Tomorrow’s World. Affectionately known as the ‘Delbox’, this is the first computerised test specifically designed for detecting delirium. To the uninitiated, the word delirium might sound like a Victorian malady; a disease confined to history books. But it’s a common modern-day problem and a major risk factor for dementia and death in the elderly. New ways of detecting and treating the condition are urgently needed.
Alasdair is a professor of geriatric medicine. His interest in this area was sparked during his PhD, which looked at the link between stress hormones and cognitive impairment in the elderly. More recently, an opportunity for further research came along when Alasdair was awarded an MRC Clinician Scientist Fellowship.
“That was when I really changed tack to start doing delirium research. As a clinician I’d noticed that delirium was a problem, it was very common and yet it had hardly been touched by research – and I was lucky enough get an MRC fellowship to investigate it,” he says.
Having time away from being a busy hospital doctor allowed Alasdair the thinking space to come up with ways to understand and measure delirium, and to distinguish patients with delirium from those with dementia. He homed in on the fact that delirium sufferers cannot focus their attention for more than a few seconds, whereas a dementia patient usually can, even if brain functions such as memory are severely impaired.
Alasdair enlisted the help of a toy maker and electronic engineer to make a prototype Edinburgh Delirium Test Box, or Delbox.
The device is a simple box with two buttons (taken from a fruit machine) which flash on and off. The researcher sets the number of flashes and the timing between them and the patient is asked to count the number of flashes. Alasdair and colleagues deliberately made the design ‘retro’ in appearance so that it would feel more familiar and acceptable to the elderly patients being tested.
“It’s still got a ‘workshop in the back garden’ appearance to it,” says Alasdair. “It’s funny because I also work in the labs at the Queen’s Medical Research Institute where people do very sophisticated things like genome-wide association studies. When they see my device they’re sort of thinking so….is this it?
“But I think we have to fit our science to the problem here, not to some kind of spuriously sophisticated concept. Can delirium patients count the number of flashes or not? No they can’t. Can people with dementia do it? Generally, yes.”
Delirium affects around one in eight hospital patients, but it’s most common in older people. It can come on within hours or days after surgery or infection, or as a result of drug side-effects, and lasts for anything from hours to several months.
Alasdair explains: “Delirium’s a serious problem. That’s not just because it affects outcomes like death, institutionalisation and length of hospital stay – which obviously carry an economic burden – but also because it’s very distressing for the patient.
“They can have vivid, horrible hallucinations. I treated one lady who thought she was tiny and that people around her were giants. Others see blood coming out of the walls or crocodiles swimming around their beds. There’s actually evidence that people get post-traumatic stress disorder afterwards.”
Soberingly, there’s also emerging evidence that delirium is associated with an eight-fold risk of developing dementia in the future, a raised risk of losing the ability to live independently and increased risk of death.
“These patients are actually getting brain injury – which is quite a stark and alarming concept. The scale of it is so enormous that the research community is talking about this being important for secondary or even primary prevention of dementia. So if we can get a hold of what delirium is, detect it and then use this to improve patient care, we might even be able to prevent some cases of dementia.”
A critical step towards this goal will be to improve measurement of delirium, so the Delbox has attracted interest from delirium researchers worldwide. Ultimately the device could help to improve clinical detection of delirium; presently only 20 per cent of cases are picked up. With the help of an MRC Development Pathway Funding Scheme grant, and support from theUniversity of Edinburgh, Alasdair is working on further prototypes and getting them commercialised. Plans are afoot to develop a software version of the test which could be downloaded to a PC or iPad.
“I see the value of using the business route to get money in to help fund research,” says Alasdair. “I want to be involved in problem solving, getting it out there and helping people to use the device if they want to. If it makes money I’ll be happy with that – it’s good for the university and good for our country.”
Download the MRC Annual Review 2011/12: Advancing medicine, changing lives, available in pdf or ebook formats.