Neuroprotective Effects of Cannabidiol Following Concussion: A Case Study

Abstract

Mild traumatic brain injury, such as concussion, can lead to physiological impairments. Although these changes in physiology are not always characterized by symptoms, they can be reflective of how the body is attempting to adjust and adapt to these consequences. Cannabidiol can aid with some of the physiological and symptomatic changes due to concussion, and the therapeutic properties of cannabidiol can be enhanced when administered with other cannabinoids, specifically, tetrahydrocannabinol. These cannabinoids can work together on the endogenous cannabinoid system within an individual, thereby influencing their effects on cerebrovascular and cardiovascular physiology. Specifically, the psychoactivity of the cannabinoids can regulate cerebral blood flow parameters and heart rate metrics. The purpose of this study was to observe the effects of different dosages of a 20:1 cannabidiol:tetrahydrocannabinol formulation on an individual suffering from post-concussion like symptoms. Psychological assessments include the Patient Health Questionnaire-9 item, Generalized Anxiety Disorder-7, 36-item Short Form Health Survey, and the Positive and Negative Affect Schedule. Physiological assessment was done using non-invasive near-infrared spectroscopy for cerebrovascular responses, and electrocardiography (ECG) and finger plethysmography to record continuous cardiovascular responses. End-tidal carbon dioxide was measured using a breath-by-breath capnograph. The protocol consisted of: 5-minute sitting rest, 6 breaths·minute-1 paced breathing maneuver, a hypercapnic challenge (20sec breath-hold:40sec normal breathing x 5 repeats), a 5-minute (20sec eyes closed:40sec eyes open x 5 repeats) object identification protocol (“Where’s Waldo”), and a squat-stand baroreflex maneuver (0.05 3 and 0.1 Hz frequency). Descriptive physiological results of the participant’s cardiovascular and cerebrovascular parameters suggest the largest changes (322% increase in deoxyhemoglobin and 53% increase in systolic pressure standard deviation during 10 second squat stands; 130% increase in systolic pressure 10 seconds post 20 second breath holds) occurred when the participant consumed 2mL of the formulation (40mgCBD:2mg THC) as compared to 1mL (20mgCBD:1mg THC) or 1.2mL (24mgCBD:1.2mg THC) (a half dose at 9:30am and a half dose prior to sleep). These results suggest that an optimal dosage is necessary for improved physiological functioning post-concussion when using cannabis products. This research warrants further investigation on cardiovascular and cerebrovascular metrics following cannabinoid administration.