Gait impairments are common in people with Parkinson's and have a huge impact on their daily lives. ‘Walking deteriorates in many people with Parkinson's when their arousal is increased’ Nonnekes explains. ‘Think, for example, of anxiety or stress. This increased tension causes brain regions to communicate more strongly with each other, as if the volume knob was turned up too loud.’ This amplified signal can cause gait disorders to worsen, and in some cases even lead to ‘freezing of gait’, an episode during which a person literally cannot move forward.
Nonnekes' research focuses on understanding this dynamic between arousal, walking, and developing new ways to reduce negative effects. ‘We want to know whether increased arousal leads to an excess of communication between brain regions, and how we can regulate this,’ he says. ‘Our suspicion is that, if arousal is too high, this disrupts effective connectivity between brain regions. For walking, it is essential that this effective connectivity is optimal.’
New technology including augmented reality
Nonnekes and his team measure brain activity during walking, both in the lab and in participants' daily lives. They do this using advanced wearable technology, including a special EEG device with a cap and a portable backpack. ‘This allows us to collect data not only in controlled environments, but also at home,’ Nonnekes says. In addition, the influence of situations such as cognitive tasks and stress will also be tested, to see how these factors affect arousal and thus walking. During another part of the study, augmented reality technique will be applied where people with Parkinsons walk while having the illusion of walking at high altitude.
Treatment strategies
A key goal of this research is to eventually develop new treatment strategies to help patients better regulate their arousal and thus improve walking. ‘In previous studies, we already saw that people try to reduce their arousal themselves, for example by thinking of a pleasant memory or using music that calms them,’ Nonnekes explains. ‘We want to use this knowledge to develop methods that actually help the brain to optimize arousal and thus reduce gait problems.’
The results of this research may also be more widely applicable to other conditions where stress and tension affect movement. Nonnekes: ‘We expect that the knowledge we gain can also be used in people with ataxia or after a stroke, for example, because stress can have a negative impact on movement there too.’