Faster brain tau buildup linked to faster progression of rare neurological disease

Chiba, Japan, September 5, 2026 ― A team of researchers from National Institutes for Quantum Science and Technology (QST) has shown that the speed at which abnormal tau protein accumulates in the brains of people with progressive supranuclear palsy (PSP) is closely linked to how quickly their symptoms worsen. The discovery could help researchers objectively measure disease progression and accelerate the development of desperately needed treatments for this rare and devastating neurological disorder.  This study was published in Movement Disorders on September 4, 2026.

PSP is a progressive neurodegenerative disease that typically develops in middle-aged and older adults. Patients experience increasing difficulty with balance, motor function, eye movements, and cognition. Although abnormal accumulation of tau protein is known to be a hallmark of the disease, scientists have long struggled to determine how changes in tau over time relate to the worsening of symptoms in living patients.

To address this challenge, the researchers used florzolotau (18F) ([¹⁸F]PM-PBB3), a highly sensitive tau PET tracer developed by QST, to follow 26 people with PSP and 10 healthy volunteers over approximately one year. By comparing PET scans taken at two time points, the team examined how tau accumulation changed throughout the brain and whether those changes were associated with clinical decline.

The study revealed that tau accumulation increased over time in several brain regions affected by PSP, including the basal ganglia, frontal and parietal cortices, and the cerebellum. Most importantly, among patients with Richardson’s syndrome, the most common and fastest-progressing form of PSP, greater increases in tau accumulation within the globus pallidus were strongly associated with greater worsening of symptoms. Patients whose tau burden increased more rapidly experienced faster disease progression.

The findings provide some of the strongest longitudinal imaging evidence to date that longitudinal changes in PET-measured tau pathology are associated with clinical deterioration in PSP. They also suggest that therapies capable of slowing tau accumulation may help slow the course of the disease itself.

“Until now, we could see tau pathology in the brains of people with PSP, but we did not know whether changes in tau over time truly reflected the progression of symptoms,” said Hironobu Endo, Principal Researcher at the Advanced Neuroimaging Center, Institute for Quantum Medical Science, QST. “Our study demonstrates that patients with faster tau accumulation experience faster clinical decline. This provides important support for the development of treatments aimed at reducing tau pathology and offers a promising imaging biomarker for evaluating their effectiveness.”

Beyond PSP, the researchers believe the imaging approach could benefit studies of other neurological disorders in which tau plays a central role, including Alzheimer’s disease and related dementias. Because the method can detect changes over time even in relatively small patient groups, it may help researchers evaluate new therapies more efficiently and objectively.

Looking ahead, the researchers believe that imaging biomarkers such as this could accelerate the development of disease-modifying therapies, enable clinicians to monitor disease progression more precisely, and help patients maintain independence for longer while reducing the burden on caregivers.

Reference:
Title of the Manuscript: Spatiotemporal Tau Accumulation and Its Clinical Impact on Progressive Supranuclear Palsy: Longitudinal Florzolotau (18F) Positron Emission Tomography
Journal: Movement Disorders
DOI:  https://doi.org/10.1002/mds.70468

About National Institutes for Quantum Science and Technology, Japan
The National Institutes for Quantum Science and Technology (QST) was established in April 2016 to promote quantum science and technology in a comprehensive and integrated manner. The new organization was formed from the merger of the National Institute of Radiological Sciences (NIRS) with certain operations that were previously undertaken by the Japan Atomic Energy Agency (JAEA).
QST is committed to advancing quantum science and technology, creating world-leading research and development platforms, and exploring new fields, thereby achieving significant academic, social, and economic impacts.

About Dr. Hironobu Endo
Hironobu Endo is a Principal Researcher at the Brain Disorder Translation Research Group at the Advanced Neuroimaging Center, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST) in Japan. He specializes in neurological disorders and cutting-edge brain and neural imaging techniques, including functional brain imaging. He has published over 50 research papers on these topics, which have been cited over 300 times.