Epidemiology of concussion: Risk factors, sequelae and implications for tactical athletes

Transcription

1 Epidemiology of concussion: Risk factors, sequelae and implications for tactical athletes Dennis E. Scofield Joseph R. Kardouni Disclaimers The opinions or assertions contained herein are the private views of the author(s) and are not to be construed as official or reflecting the views of the Army or the Department of Defense. Any citations of commercial organizations and trade names in this presentation do not constitute an official Department of the Army endorsement of approval of the products or services of these organizations.

2 Objectives Learning Objective 1: Define concussion and identify risk factors. Learning Objective 2: Identify acute and chronic concussion sequelae. Learning Objective 3: Learn novel methods for concussion mitigation, detection, and treatment. Learning Objective 4: Prescribe and implement appropriate physical training programs during reintegration and beyond. Definition of Concussion A brain injury defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces. Several common features that incorporate clinical, pathologic and biomechanical injury constructs that may be utilized in defining the nature of a concussive head injury include: McCrory P, Meeuwisse WH, Aubry M, et al. Br J Sports Med 2013;47: Definition of Concussion cont d May be caused by either a direct blow to the head, face, neck, or elsewhere on the body with an impulsive force transmitted to the head. Typically results in the rapid onset of short lived impairment of neurological function that resolves spontaneously. However, in some cases, symptoms and signs may evolve over a number of minutes or hours. May result in neuropathological changes, but the acute clinical symptoms largely reflect a functional disturbance rather than a structural injury and, as such, no abnormality is seen on standard structural neuroimaging studies. Results in a graded set of clinical symptoms that may or may not involve loss of consciousness. Resolution of the clinical and cognitive symptoms typically follows a sequential course. However, it is important to note that in some cases symptoms may be prolonged. McCrory P, Meeuwisse WH, Aubry M, et al. Br J Sports Med 2013;47:

3 Categories of Severity > 80% of non fatal concussions are classified as mild. Severity Mild (Concussion) Moderate Severe Structural Imaging (Computed tomography) Loss of consciousness (LOC) Normal Normal or abnormal 0 to 30 minutes 30 minutes and < 24 hours Normal or abnormal > 24 hours Alteration of consciousness (AOC) A moment up to 24 hours > 24 hours Post traumatic amnesia (PTA) 0 to 1 day > 1 day < 7 days > 7 days Source: Assistant Secretary of Defense for Health Affairs. Health Affairs Memorandum (October 1, 2007). Traumatic Brain Injury: Definition and Reporting Significance of the problem From years 2000 to 2015 there were more than 270,000 diagnosed mtbi cases among U.S. service members. Army soldiers accounted for nearly half (120,000) of these cases. DoD Worldwide Numbers for TBI. 2015; Available at: TBI Worldwide Totals_ Q1 Q2 Aug pdf. Accessed October 29, 2015, Image Source: USAMRMC Products Portfolio

4 All Army and marine Corps personnel who underwent disability evaluation for a combat related disability between 2004 and Combat related TBI cases were significantly more likely to be medically retired than other combat related disability cases. Post traumatic stress disorder present in 50% of TBI disability cases. Blast injury is the most common cause of traumatic brain injury on the current battlefield. Blast related injury occurs through the effects of the blast overpressure wave as wells as objects propelled by the blast wave. The primary blast wave can induce injury (degree of brain damage is unclear in humans). There is a high association of mtbi with PTSD in OIF/OEF Veterans. Blast Wave Primary Blast injuries Secondary Injuries Tertiary Injuries Quarternary Injuries

5 Investigated cognitive function and other risk factors for mtbi in 305,885 men conscripted in the Swedish military. Low cognitive function found in men who later sustained mtbis. Low cognitive function may be a risk factor vs. long term consequence of mtbi. Other risk factors included low education, low socioeconomic status, intoxication, and high physical fitness. Good Poor Risk As cognitive function declines, risk of mtbi increases. Risk Factors cont d Preliminary TAIHOD data: Prior non head injury Being younger, male, and attained only a high school education (unpublished data). Image Source: USAMRMC Products Portfolio

6 Objectives Learning Objective 1: Define concussion and identify risk factors. Learning Objective 2: Identify acute and chronic concussion sequelae. Learning Objective 3: Learn novel methods for concussion mitigation, detection, and treatment. Learning Objective 4: Prescribe and implement appropriate physical training programs during reintegration and beyond. Evaluation SLAM: Sports as a Laboratory Assessment Model initiated by the University of VA. Collect brief baseline neurocognitive data on contact sports participants. Data would be compared to post concussion data at 24 hours, 5 days, and 10 days post injury. Significant differences were noted at 24 hours and 5 day assessments. By 10 day reevaluation test was close to baseline. Evaluation Military uses the Military Acute Concussion Evaluation (MACE). In 2008 the military began using the Automated Neuropsychological Assessment Metric (ANAM) to collect baseline neurocognitive data to compare to post concussive data.

7 Acute Sequelae Cognitive deficits Fatigue Dizziness Headache Irritability Depression Relationship issues Impede psychosocial functioning Anxiety Disorders Insomnia PCS/PCD Metabolic Brain Disruptions Concussion alters brain cell metabolism (energy supply pathways, oxidative and nitrosative stress pathways) for days after injury. Vagnozzi et al. Neuosurgeryonline, 62: , A second concussion during this vulnerability period can lead to disproportional brain damage. Brain N Acetylaspartate (NAA) concentrations. Source: Vagnozzi et al. Neuosurgery online, 62: , Evidence of Endocrine Dysfunction Gonadotropic levels were inversely related to severity of TBI. At 24 months gonadotropic axis completely resolved. Eight had somatotropic insufficiency beyond 24 months. Time course of insufficiency of hormonal axis in 23 patients followed longitudinally after TBI.

8 IGF 1 below the 10 th PCTL in the mtbi group. LH and Testosterone below the 10 th and 5 th PCTL, respectively, in mtbi group. APA in 44% of TBI patients. Significant association between APA and hypopituitarism. Substantial risk of hypopituitarism even in mtbi patients. Autoimmunity may have an impact on the development of pituitary dysfunction. 72% of depressive disorders were novel. 74% of post TBI anxiety disorders were novel. TBI creates a risk for development of psychiatric disorders including depression and anxiety.

9 Objectives Learning Objective 1: Define concussion and identify risk factors. Learning Objective 2: Identify acute and chronic concussion sequelae. Learning Objective 3: Learn novel methods for concussion mitigation, detection, and treatment. Learning Objective 4: Prescribe and implement appropriate physical training programs during reintegration and beyond. Neuroprotection and Mitigation Combat Casualty Care Research Program (CCCRP). Primary mission to conduct pre clinical studies of neuroprotection therapies aimed at mitigating TBI. Current studies: Longitudinal and multi modal designs to characterize neuromotor, cognitive, emotional, and neuropatholgical evidence of mtbi. Demonstrated pre clinical efficacy of over 130 drugs. 20 drugs are in Phase II/III clinical trials.

10 Immediate Post Concussion Assessment and Cognitive Testing (ImPACT) Demographic data Neuropsychological tests And Post Concussion Symptom Scale (PCSS) Baseline data is compared to post injury. Can assist clinicians in making safer return to play decisions. Multi modal Early Detection Interactive Classifier (MEDIC) for mtbi Assessment Flexible platform amenable to interchange of modalities, protocols, and disorders Chin Rest Eyelink camera Stimulus monitor Laptop Purdue University collaboration 32 subjects HS football, soccer Measurements included ImPACT MEDIC fmri Longitudinal testing Subjects Ages Sport Head phones Microphone 8 female Modalities Initial focus: Vocal 24 male Vocal Biomarkers Hearing skills Pre-season (Baseline) In-season Testing (1-2 tests) Post-season (thru March) July Aug Sep Oct Nov Dec Eye Movement Optic Nerve Sheath Diameter ImPACT = Immediate Post concussion Assessment and Cognitive Testing Detection of mtbi Motivation: Slurring and incoordination observed by speech pathologists Biomarkers: Dynamics and coordination of vocal articulators Articulation Vocal tract resonances Dynamics: Variance, velocity, acceleration Coordination Classification Experiments: Binary detection problem: Decline/no decline Features: articulatory coordination complexity Method: Support vector machine trained with crossvalidation Probability of Detection vs. False Alarm Coordination Vs. Raw Dynamics Allows quantifying cognitive readiness for return-to-duty

11 PURETECH Giving Life to Science August 2015 Expansion to other Disorders and Collections Laboratory or Clinic Based Traumatic Brain Injury Parkinson s Disease Dementia Cognitive stress Increase access to large populations Mobile Device Based Depression Altitude effects Pilot fatigue Traumatic Brain Injury PTSD Cognitive stress with heat Spinoffs to the civilian sector Tech transfer to health based company MIT campus collaboration (Gabrieli Lab) Emerging Treatment Modalities Pharmaceutical Calcium channel blockers Poly ADP ribose polymerase inhibitors Cyclosporine IGF 1 therapy Dietary Zinc, magnesium Ketone diet Non Invasive technology Pre clinical studies employing both pre and post injury implementation of the ketogenic diet demonstrated improved structural and functional outcomes in mtbi models.

12 Near Infrared Light The two videos above capture a mouse fibroblast 3T3 cell migrating to a pulsating near infrared light. Guenter Albrecht Buehler, Ph.D. Fellow, European Academy of Sciences, Brussels Fellow, Institute for Advanced Studies, Berlin Robert Laughlin Rea Professor Emeritus of Cell Biology Feinberg School of Medicine Northwestern University, Chicago Treatments are needed that directly target injured brain cells to improve brain systems that regulate cognition. Near Infrared (NIR) ( nm) can penetrate through scalp and skull (2 3%, ~1 CM). Potential for neurogenesis and synaptogenesis Improvements in cognition, PTSD, and sleep. Source: Boston University School of Medicine Red photons reported to increase melatonin levels. NIR photons may reach areas of the brain responsible for memory. Source: DCoE blog

13 Objectives Learning Objective 1: Define concussion and identify risk factors. Learning Objective 2: Identify acute and chronic concussion sequelae. Learning Objective 3: Learn novel methods for concussion mitigation, detection, and treatment. Learning Objective 4: Prescribe and implement appropriate physical training programs during reintegration and beyond. Physical and cognitive rest until acute symptoms subside (24 48 hours) Stepwise progression of RTP with each step taking 24 h. and no symptoms. Modifying factors may influence the investigation and management of concussion and may predict the potential for prolonged/persistent symptoms.

14 Compared 26 Division I athletes who sustained a concussion with 36 matched controls. Two measures of postural stability. 5 neurocognitive tests. Sensory Organization Test (SOT) on the NeuroCom Smart Balance Master System. 3 Visual Conditions: Eyes open, eyes closed, sway referenced visual surround. Results: Athletes recovering from concussion demonstrated postural stability deficits during immediate post injury. Postural stability returned to baseline score around day 3. The concussed group were 2.2 and 1.97 times for likely to suffer a lower extremity injury at 180 and 360 days post concussion respectively. Conclusion: There is an increased risk of lower extremity injury up to 365 days following concussion in college athletes.

15 Health history data on 2429 retired NFL players ( ). 61% reported a concussion while playing. Players with 1, 2, or 3+ concussions had bewtween 18 63%, %, and % higher odds of various musculoskeletal injuries. Incidence of acute non contact lower extremity injury during the 90 day post injury period was higher in concussed athletes. Odds of sustaining a lower extremity injury were 2.48 times higher in concussed athletes.

16 Contact Information Dennis E. Scofield 10 General Greene Ave Bldg. 42 Natick, MA (508) Joseph R. Kardouni 10 General Greene Ave Bldg. 42 Natick, MA (508)