Summary: Researchers at Lund University have developed a new imaging method that can help doctors detect and track Alzheimer’s disease in people of different ages more effectively.
Source: Lund University.
Alzheimer’s disease can lead to several widely divergent symptoms and, so far, its various expressions have mainly been observed through the behaviour and actions of patients. Researchers at Lund University in Sweden have now produced images showing the changes in the brain associated with these symptoms – a development which increases knowledge and could facilitate future diagnostics and treatment.
Symptoms vary in cases of Alzheimer’s disease and often relate to the phase of life in which the disease first occurs. People who become ill before the age of 65 often suffer early on from diminished spatial perception and impaired orientation. Elderly patients more often suffer the symptoms traditionally associated with the disease: above all, memory impairment.
“Now we have a tool which helps us to identify and detect various sub-groups of Alzheimer’s disease. This facilitates the development of drugs and treatments adapted to various forms of Alzheimer’s”, explains Michael Schöll, researcher at Lund University and the University of Gothenburg.
Diagnostics could also be facilitated, mainly among younger patients in whom it is particularly difficult to arrive at a correct diagnosis.
Confident in approval for clinical use
The findings, published in the journal Brain, are based on studies of around 60 Alzheimer’s patients at Skåne University Hospital and a control group consisting of 30 people with no cognitive impairment.
Once Alzheimer’s disease has taken hold, it gradually results in the tau protein, present in the brain, forming lumps and destroying the transport routes of the neurons. This can be clearly detected with the new imaging method.
The method includes a device known as a PET camera and a trace substance, a particular molecule, which binds to tau. The imaging method is currently only used in research, where the current study is one of several contributing to increased knowledge about the disease:
“The changes in the various parts of the brain that we can see in the images correspond logically to the symptoms in early onset and late onset Alzheimer’s patients respectively”, explains Oskar Hansson, professor of neurology at Lund University and consultant at Skåne University Hospital.
Oskar Hansson believes that the imaging method will be in clinical use within a few years.
Facts/Tau and beta-amyloid – illustrate different things in image analysis:
Tau analysis constitutes a new addition to Alzheimer’s research, which was previously associated with the analysis of another protein in the brain, beta-amyloid. Both methods of analysis have their limitations.
For example, previous studies have shown that the connection between the various Alzheimer’s symptoms and changes in the brain – which were investigated in the current study – cannot be visualised using beta-amyloid analyses.
However, for research into the earliest stages of Alzheimer’s disease and its precursors, among other things, beta-amyloid studies have advantages and will continue to be important, in Oskar Hansson’s assessment.
Funding: The study was funded by the European and Swedish Research Councils, The Swedish Alzheimer foundation and ALF funding from Region Skåne, among others.
Source: Oskar Hansson – Lund University
Image Source: NeuroscienceNews.com image is credited to Schöll et al./Brain.
Original Research: Full open access research for “18 F-AV-1451 tau PET imaging correlates strongly with tau neuropathology in MAPT mutation carriers” by Ruben Smith, Andreas Puschmann, Michael Schöll, Tomas Ohlsson, John van Swieten, Michael Honer, Elisabet Englund, and Oskar Hansson in Brain. Published online September 1 2017 doi:10.1093/brain/aww163
18 F-AV-1451 tau PET imaging correlates strongly with tau neuropathology in MAPT mutation carriers
Tau positron emission tomography ligands provide the novel possibility to image tau pathology in vivo. However, little is known about how in vivo brain uptake of tau positron emission tomography ligands relates to tau aggregates observed post-mortem. We performed tau positron emission tomography imaging with 18F-AV-1451 in three patients harbouring a p.R406W mutation in the MAPT gene, encoding tau. This mutation results in 3- and 4-repeat tau aggregates similar to those in Alzheimer’s disease, and many of the mutation carriers initially suffer from memory impairment and temporal lobe atrophy. Two patients with short disease duration and isolated memory impairment exhibited 18F-AV-1451 uptake mainly in the hippocampus and adjacent temporal lobe regions, correlating with glucose hypometabolism in corresponding regions. One patient died after 26 years of disease duration with dementia and behavioural deficits. Pre-mortem, there was 18F-AV-1451 uptake in the temporal and frontal lobes, as well as in the basal ganglia, which strongly correlated with the regional extent and amount of tau pathology in post-mortem brain sections. Amyloid-β (18F-flutemetamol) positron emission tomography scans were negative in all cases, as were stainings of brain sections for amyloid. This provides strong evidence that 18F-AV-1451 positron emission tomography can be used to accurately quantify in vivo the regional distribution of hyperphosphorylated tau protein.
“18 F-AV-1451 tau PET imaging correlates strongly with tau neuropathology in MAPT mutation carriers” by Ruben Smith, Andreas Puschmann, Michael Schöll, Tomas Ohlsson, John van Swieten, Michael Honer, Elisabet Englund, and Oskar Hansson in Brain. Published online September 1 2017 doi:10.1093/brain/aww163