Measure of Cerebrovascular Dysfunction After TBI With fNIRS

Study Overview
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Brief Summary
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The goal of this project is to determine if it is possible to assess Cerebrovascular Reactivity (CVR) to hypercapnia with functional Near Infrared Spectroscopy (fNIRS). Such a method would be particularly helpful in traumatic brain injury (TBI), where objective measures are needed, and would greatly expand the capacity to make such assessments in standard clinical practice.

Detailed Description
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The prospective study design will consist of two study groups; the experimental group and the control group. In the Experimental Group (Group 1) we will enroll adult participants with TBI with persistent post-concussion symptoms or abnormalities on neuropsychological testing. In Group 2 we will enroll adult participants to serve as age and gender-matched healthy controls. Our goal is to recruit 100 subjects total in two groups of age and gender matched subjects, as follows: TBI (n = 50) and non-TBI (n = 50). Participants in both groups will undergo NIRS testing with hypercapnia challenge, to measure the increase in hemodynamic flow signal during hypercapnia challenge via 2 methods, the breath holding and the Douglas bag methods. We will test intersessional validity of the NIRS-hypercapnia challenge in the first 20 (10 TBI and 10 non-TBI) subjects who are willing to return for a second visit of repeat testing. The NIRS system is composed of 4 light sources and 10 detectors with a 16 point configuration system applied on the forehead of the subject. In our experiment, light intensity collected at each detector will be transformed into a signal related to the local concentrations of oxy- and de-oxyhemoglobin during the challenge. Each experiment will give a set of subject data, consisting of the peak amplitude and time-to-peak of the hemodynamic signals measured.

Official Title
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Measure of Cerebrovascular Dysfunction After Truamatic Brain Injury With Functional Near Infrared Spectroscopy

Conditions
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Traumatic Brain Injury, Post-concussion Syndrome

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ALL participants (TBI and non-TBI) subjects Males and females, ages 18 to 60 years, inclusive Able to read, write, speak and understand English A history of TBI Persistent post-concussive symptoms, according to the DSM-IV Research Criteria for Post-Concussional Disorder, including: Evidence from neuropsychological testing of difficulty in attention or memory. (refers to neuropsychological testing done as a part of the patient's hospital or rehabilitation care not as a part of screening for this study) Three or more of the following symptoms, which started shortly after the trauma and persist for at least three months: Fatigability Disordered sleep Headache Vertigo or dizziness Irritability or aggression Anxiety, depression, or affective instability Changes in personality (e.g. social or sexual inappropriateness) Apathy or lack of spontaneity Symptoms in criteria (a) and (b) must have their onset after trauma, or there was a significant worsening of pre-existing symptoms after trauma. Exclusion Criteria: History or evidence of pre-existing neurological or psychiatric disorder not related to TBI, such as: Multiple sclerosis, pre- or co-existing Stroke (other than stroke at the time of TBI) Pre-existing developmental disorder Pre-existing epilepsy Pre-existing major depressive disorder Pre-existing schizophrenia Known allergy to latex (used in the NIRS apparatus band applied to the forehead)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy group<br>Healthy group with no history of TBI or concussion. Gender matched non-TBI volunteers | |
| TBI group<br>Males and females between 18 and 60 years who have a diagnosis of TBI and are symptomatic with DSM-IV Research Criteria for Post-Concussional Disorder (see below), gender matched non-TBI volunteers | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reproducibility of CVR measurements with fNIRS during intersession and intra-session testing | Establish reproducibility of CVR measurements with fNIRS during intersession and intra-session testing. Additionally, we will examine two methods of producing hypercapnia, breath holding and the Douglas bag methods to establish whether the two methods give similar NIRS results. | Two years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Examine the following hypothesis: TBI subjects have a lower CVR compared to healthy controls |  | Two years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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TBI, fNIRS, hypercapnea, Cerebrovascular reactivity