Scientists in Norway and Sweden have discovered a potential breakthrough for blood tests to detect Parkinson’s years before the disease’s gruelling symptoms start to take their toll.

Based at Sweden’s Chalmers University of Technology in Gothenburg and Norway’s University of Oslo, the researchers said they had detected early-stage “biomarkers” of the debilitating neurological disorder in blood.

The findings could open “a window of opportunity that could be crucial for future treatment, but also for early diagnosis via blood tests,” the team said.

They also noted “there is neither an effective cure nor an established screening method” for picking up the often-fatal disease’s presence “before it has caused significant damage to the brain.”

Usually, by the time it becomes apparent that a person is afflicted by Parkinson’s, the damage is already done, with up to 80% of the relevant brain cells “already damaged or gone,” according to the researchers, whose potential breakthrough was published by npj Parkinson’s Disease, part of the Nature group of journals.

“This means that we have found an important window of opportunity in which the disease can be detected before motor symptoms caused by nerve damage in the brain appear,” said Chalmers’ Annikka Polster.

The Scandinavian study is the latest of several published in recent years pointing to “biological indicators of the early stage of the disease.”

A team based at Zhejiang University in Guangzhou revealed in mid-2025 that testing ear wax could help with early detection, while around the same time scientists from the Quadram Institute and the European Molecular Biology Laboratory (EMBL) said they had detected alterations in the gut microbiomes of Parkinson’s patients that could be linked to exposure to solvents and pesticides.

In late 2024, a team made up mostly of scientists from the University of California zeroed in on a molecule found to play a role in the disease’s onset.

And in 2021, a University of Cambridge-led group said they had found “compelling new evidence” about a “key protein” affecting neurons.