A team of researchers from UCLA has been working on a new PET imaging approach to track and predict the progression of cognitive decline in patients from diseases such as Alzheimer’s disease. The researchers have reported in this month’s issue of the Archives of Neurology that the technique successfully tracked and predicted cognitive decline in individuals with and without mild cognitive impairment.
The approach uses a chemical biomarker [18f]FDDNP which binds to both plaque and tangle deposits, key indicators of Alzheimer’s disease, which can then be viewed and quantified using a PET scanner.
From the Archives of Neurology abstract:
Objective: To determine whether 2-(1-{6-[(2-fluorine 18–labeled fluoroethyl)methylamino]-2-napthyl}ethylidene) malononitrile ([18F]FDDNP) brain regional values in individuals without dementia predict and correlate with future cognitive change.
Design: Two-year, longitudinal follow-up study.
Setting: A university research institute.
Participants: Volunteer sample of 43 middle-aged and older persons (median age, 64 years), including 21 with mild cognitive impairment (MCI) and 22 with normal aging.
Main Outcome Measures: Longitudinal [18F]FDDNP positron emission tomography (PET) binding values in the medial and lateral temporal, posterior cingulate, parietal, frontal, and global (mean) regions of interest; neuropsychological test battery measuring 5 cognitive domains, including memory, language, attention (and information-processing speed), executive functioning, and visuospatial ability.
Results: For the entire study group (MCI and normal aging), increases in frontal, posterior cingulate, and global binding at follow-up correlated with progression of memory decline (r = –0.32 to –0.37, P = .03 to .01) after 2 years. Moreover, higher baseline [18F]FDDNP binding was associated with future decline in most cognitive domains, including language, attention, executive, and visuospatial abilities (r = –0.31 to –0.56, P = .05 to .002). For the MCI group, frontal and parietal [18F]FDDNP binding yielded the greatest diagnostic accuracy in identifying converters to Alzheimer disease vs nonconverters after 2 years, with an area under the receiver operating characteristic curve of 0.88 (95% CI, 0.72-1.00) compared with 0.68 (95% CI, 0.45-0.91) for medial temporal binding.
Conclusions [18F]FDDNP PET regional binding patterns are consistent with known neuropathologic patterns of plaque and tangle brain accumulation, spreading from the medial temporal to other neocortical regions as disease progresses. Because binding patterns predict future cognitive decline and increase over time along with clinical decline, [18F]FDDNP PET scanning may have practical utility in identifying people at risk for future cognitive decline and in tracking the effectiveness of novel interventions designed to prevent or delay neurodegeneration and cognitive decline.
The bio-marker has also been used to quantify plaque and tangle deposits in adults with Down Syndrome, and a number of patents have been issued on the bio-marker which seems to be yielding some impressive results already.
Press release: UCLA brain-imaging technique predicts who will suffer cognitive decline over time
Abstract in Archives of Neurology: Prediction of Cognitive Decline by Positron Emission Tomography of Brain Amyloid and Tau
