Role of Feed-Forward Inhibition in Neocortical Information Processing: Implications for Neurological Disorders

Evaluation of a Field-Ready Neurofunctional Assessment Tool for Use in a Military Environment

INTRODUCTION

The Office of Naval Research sponsored the Blast Load Assessment Sense and Test (BLAST) program to develop a rapid, in-field solution that could be used by team leaders, commanders, and medical personnel to provide a standardized approach to operationally relevant monitoring and analysis of service members exposed to single or repeated low-level blast. A critical piece of the BLAST team's solution was the development of the Brain Gauge technology which includes a cognitive assessment device that measures neurofunctional changes by testing sensory perceptions and a suite of mathematical algorithms that analyze the results of the test. The most recent versions of the technology are easily portable; the device is in the size and shape of a computer mouse. Tests can be administered in a matter of minutes and do not require oversight by a clinician, making Brain Gauge an excellent choice for field use. This paper describes the theoretical underpinnings and performance of a fieldable Brain Gauge technology for use with military populations.

MATERIALS AND METHODS

The methods used by the Brain Gauge have been documented in over 80 peer-reviewed publications. These papers are reviewed, and the utility of the Brain Gauge is described in terms of those publications.

RESULTS

The Brain Gauge has been demonstrated to be an effective tool for assessing blast-induced neurotrauma and tracking its recovery. Additionally, the method parallels neurophysiological findings of animal models which provide insight into the sensitivity of specific metrics to mechanisms of information processing.

CONCLUSIONS

The overall objective of the work was to provide an efficient tool, or tools, that can be effectively used for (1) determining stand-down criteria when critical levels of blast exposure have been reached and (2) tracking the brain health history until return-to-duty status is achieved. Neurofunctional outcome measures will provide the scientific link between blast sensors and the impact of blast on biological health. This calibration process is strengthened with outcome measures that have a biological basis that are paralleled in animal models. The integrative approach that utilizes the Brain Gauge technology will provide a significant advance for assessing the impact of blast exposure and support rapid, science-based decision-making that will ensure mission success and promote the protection of brain health in service members.

The Brain Gauge: a novel tool for assessing brain health

Background. A large number of neurological disorders (neurodegenerative, neurodevelopmental or trauma induced) are difficult to diagnose or assess, thus limiting treatment efficacy.  Existing solutions and products for this need are costly, extremely slow, often invasive, and in many cases fail to definitively (and quantitatively) diagnose or assess treatment.  Advances. For the past decade, we have been developing what we consider to be an innovative low-cost sensory testing device (the Brain Gauge) that non-invasively assesses the central nervous system (CNS).  The objective has been to develop an inexpensive, highly accurate, simple to use device to assess brain health in all environments: in the clinic, at home, at work, on the battlefield or sports field.  The device is non-invasive, generates no harmful radiation, requires no chemicals nor exposure to dangerous substances.  The device does not require expensive disposables and does not involve the use of samples that require physical processing in a central laboratory.  Tests can be administered in a matter of minutes and do not require expert oversight.  The most recent versions of the technology are easily portable; the device is the size and shape of a computer mouse.  As such, the technology is particularly well suited to non-drug, non-radiation based alternative and in-home care.  The device and methods have been used in numerous studies of neurological cohorts that are often considered difficult to diagnose or assess objectively. Based on over a decade of studies (currently an ontological database of over 10,000 subjects and over 60 peer reviewed publications), the system can be used to enable clinicians to have a much better view of a patient’s CNS health status.  The diagnostic system delivers a battery of sensory based (tactile) tests that are conducted rapidly – much like an eye exam with verbal feedback – and the tests were  designed to be predominantly impacted by specific mechanisms of CNS information processing.  Because of the broad diversity of the questions addressed by the different metrics, combining the metrics allows for the generation of a unique individual CNS profile that appears to be very sensitive to neurological status. Outlook.  A review of the development of the system and the application of the method in basic and clinical research is provided to give readers an insight into why the methods were developed, how the methods work and what the methods can be optimally utilized for. The methods provide an objective means for clinicians and researchers to track brain health, and examples of case studies of tracking recovery from concussion as well as response to treatments are provided.