Development of a New Technology to Prevent TBI with eStim VLR (Electrical Stimulation of a Valsalva-Like Response)
Abstract
Traumatic Brain Injury (TBI) has been described as the signature injury of the recent armed conflicts in Iraq and Afghanistan. In addition to this, TBI plays a major role outside of the military setting. Between 2000 and 2010, the incidence of TBI, including concussions (also known as mild TBI or mTBI), increased by 60%. TBIs, even those that are caused by repeated sub-concussive impacts, have now been linked to long-term problems with cognition, mental health, and neurodegenerative processes, including Alzheimer’s and Parkinson’s diseases, as well as a condition known as chronic traumatic encephalopathy (CTE). After exposure to an impact of blast, brain injury occurs when the forces exceed the brain’s tolerance limits, which results in damage as the different structures in the brain become compressed or pulled apart (also known as shearing). The cells in these areas of the brain can become directly damaged or lose the ability to communicate effectively with one another. This is what is thought to cause the early symptoms as well as the long-term brain changes seen in those exposed to TBI. However, to date, most of the focus on TBI is diagnosis or treatment, with less focus being placed on preventing TBIs in those that will always have a high risk of brain injury, e.g., athletes and the elderly, as well as those serving in the military. The goal of this proposal is to develop and test an intervention that induces a normal human response to an incoming impact – the Valsalva maneuver. Individuals perform the maneuver every day, for instance when preparing to lift a heavy object or when expecting a punch to the gut. Importantly, this response also protects the brain at the moment of impact. By increasing the pressure in the chest and abdomen, blood is prevented from draining from the head. This is easily demonstrated by those whose faces go red when preparing to lift a heavy object. The extra blood in the head momentarily increases the pressure in the brain (also known as intracranial pressure or ICP), which makes the brain more stiff and less likely to be compressed or shear when the head is hit. Multiple studies in rodents have shown that increasing ICP reduces brain injury after TBI. However, as most people who get TBIs do not see the impact coming, they are unable to anticipate the blow and perform their own Valsalva maneuver. Therefore, we are developing a product that will sense the environment and create an electrically stimulated Valsalva-like response (eVLR) when an unanticipated impact is incoming, which will perform the same job of protecting the brain. This proposal describes an approach to assess the neuroprotective effects of eVLR in a ferret model of TBI. The ferret is an appealing species in which to model human brain injury because, compared to rodents, they have brains that are much more similar to human brains. This is particularly noticeable for the regions of the brain that are most susceptible to TBI, some of which rodents do not have at all. Our first aim is to show that ICP can be transiently increased in ferrets using a partial Valsalva maneuver by compressing the abdomen with an inflatable cuff. We will then test the neuroprotective effects of this abdominal compression to increase ICP in a TBI model in the ferret. Our second aim is to develop a ferret eVLR protocol using neuromuscular electrical stimulation of muscles in the abdomen and neck, which will replicate the normal Valsalva maneuver that humans do every day. We will then test the eVLR during TBI to determine how neuroprotective a device like this might be in humans. This will allow us to continue development of the device, including ways to sense incoming impacts and deliver an eVLR to protect the brains of individuals who do not or cannot see an impact coming.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 28, 2022
- Source ID
- W81XWH2210444
Entities
People
- Thomas E Wood
Organizations
- United States Army
- University of Washington