When the Brain Hits Pause: New Study Reveals Why People with Parkinson’s Freeze Mid-Step

Freezing of gait, often called FOG, is one of the most frustrating and dangerous symptoms people with Parkinson’s can face. It’s that strange moment when the brain says “walk,” but the feet refuse to move, as if glued to the floor. It can strike when turning, walking through a doorway or trying to multitask. Beyond the embarrassment, it raises the risk of falls and makes everyday life more difficult. A new study published in BMC Neurology has taken a closer look at what’s happening in the brain during these freezing episodes, using brain imaging and artificial intelligence to uncover some revealing patterns. Researchers compared three groups of people: those with Parkinson’s who experience freezing, those with Parkinson’s who don’t, and a group of healthy volunteers. Everyone underwent a type of brain scan called an 18F-FDG PET, which measures how much glucose different parts of the brain are using. Since glucose is the brain’s fuel, these scans show which regions are working harder or have slowed down. The team then used a deep learning model — a kind of artificial intelligence — to see whether brain activity patterns could distinguish between people who do and don’t experience freezing. The results were fascinating. In those who froze, certain areas of the brain were unusually active, particularly regions in the frontal and parietal lobes involved in planning and movement control. At the same time, other areas were less active, especially those linked to sensory-motor coordination and the smooth execution of movement. When compared to healthy volunteers, the pattern was even broader, with higher activity in the cerebellum, thalamus and insula, and lower activity in the basal ganglia and supplementary motor areas — regions that are vital for automatic, fluid movement. What this seems to show is that freezing of gait doesn’t stem from one faulty spot in the brain. Instead, it’s a network problem. Some areas appear to go offline while others overcompensate, working overtime to keep movement going. The brain seems to be trying to patch up the system on the fly — and sometimes, it just can’t. The artificial intelligence model proved remarkably accurate at spotting these differences, correctly identifying people with freezing about 95 per cent of the time. It could even predict how severe their freezing was, suggesting that one day such tools could help doctors track and manage the symptom more precisely. For clinicians and researchers, this study helps map the networks that underlie freezing of gait, offering clues that could shape new therapies — from brain stimulation to targeted physiotherapy. For people living with Parkinson’s, it reinforces that freezing isn’t “just in your head” in a dismissive sense, but that it quite literally involves measurable changes in how the brain uses energy and coordinates movement. Of course, the research is still at an early stage. The study involved only a small group of participants, and the imaging shows associations rather than causes. Larger, longer-term studies will be needed to confirm these results and understand how these brain changes evolve over time. Researchers also want to test how well these AI models work in real clinical settings, and whether the technology could eventually help detect freezing risk before it begins. Even so, this work marks an important step forward. It moves the conversation about freezing of gait from the realm of frustration and mystery toward a clearer understanding of what’s really going on inside the brain. As science digs deeper into these networks, the hope is that one day freezing can be anticipated, managed, and perhaps even prevented altogether — helping people with Parkinson’s keep moving with confidence.