Traumatic Brain Injury: Overview & Perspectives September 27, 2013 Louis T. Giron, Jr., M.D Neurology Section VAMC Kansas City, Missouri
Johnny, I hardly knew ye. Popular English song, 19 th Century
Definition of TBI (CDC, 1995) Head injury with one of the following: Decrease in level of consciousness Amnesia Skull fracture Objective neurologic or neuropsychological abnormalities Diagnosed intracranial lesions
Definition (exclusions) For this presentation, we will exclude 1) those acute conditions requiring emergent neurosurgical intervention such as intracerebral hemorrhage, skull fracture & penetrating brain injury 2) acute (transient) postconcussive syndrome
Are we having fun yet?
Epidemiology Combat About 23 % (immediate report) in combat brigade or 7.5% reported after deployment IED (blast injury) Other Civilian 519/100,000 (US Census, 1996) or about 1.3 million (TBI) injuries per year MVA Occupational Sports Alcohol Elderly (falls) Assaults 6
IED Explosion
Shell shock Term from WWI, somewhat controversial even during WWI, considered to be more psychological than neurological Now recognized as a consequence of blast injury (highly energetic pressure waves transmitted through atmosphere) Sometime used to indicate PTSD
Epidemiology/ Consequences Functionally impairs (long-term disability) from 3.2 to 5.2 million or 1-2% of the population of the US. A silent epidemic of immense consequences economically and in terms of human suffering.
Epidemiology Male predominance, favored by psychiatric & cognitive disturbance Higher in US than in Europe Chief cause of death in individuals ages 1 to 45 75% treated in ER only 19% hospitalized 3% fatal
GLASCOW COMA SCALE
Military head trauma differs from civilian counterpart More likely from repeated concussions Polytrauma more likely (amputations, etc.) Visual, hearing and vestibular dysfunction common Blast injury more often the cause Penetrating injuries more likely -------- but like civilian counterpart tends to be under reported
Severity of TBI Mild GCS 13-15 Moderate GCS 9-12 Severe GCS 8 or less Other indications of severity Duration of LOC Duration of post-traumatic amnesia
Head Strap
Epidemiology Mild TBI Sports Under-reporting common (43% with concussion knowingly hid symptoms) Football High School: 20% College: 10% NFL veterans: 35%
Double Impact Syndrome Rare neurologic syndrome from 2nd injury occuring in a vulnerable period following an initial injury resulting in deficits (including death) far in excess of those expected from apparent simple additive effects
Prevention of Sports Concussion Conditioning and training Helmets (protective gear) Rules favoring safe conduct Enforcement of rules clean play e.g., ban spear tackling. Educate athletes, parents and coaches
Management of Sports Concussion Rest the mind (avoid computer use, texting, returning to school or other activities too quickly). The pain in brain is mainly in the strain. Ask responsible adult to observe Do not take medications without doctor s permission Eat nutritious foods, drink plenty of water Rest the body (at least 7-8 hours of sleep/night)
Return to Play Step-wise No RTP in current game Physician evaluation following injury Rule out more serious injury & prevent complications cognitive rest Gradual return to school & work Gradual return to sports competition (when school performance returns to base-line) Legislation in many states requires these or similar precautions. Kansas requires physician OK for return to play.
On-line aid/apps www.kansasconcussion.org Heads Up/app Concussion/app www.aan.com/concussion
Coup & Countre-coup
Gross neuropathology
Conventional/Ideal Neuroimaging CT head: identifies lesions demanding acute neurosurgical intervention MRI: may identify region responsible for focal deficits or seizures Ideal MRI : should identify those patients with mild TBI who will be more likely to have persistent cognitive/behavioral
Diffuse Axonal Injury Diffusion Sequence MRI
Mechanisms of Injury (Direct and Immediate) Shearing: diffuse axonal injury, usually at the grey-white matter junction Focal contusions: hemorrhages, coupcountre-coup Extra-axial (outside substance of brain); e.g., subdural and extradural hematomas,
Principles Each TBI case is unique The exact physical conditions can never be duplicated Each individual differs biologically; e.g., previous injury, biological reserve, etc. The consequence is that the clinical picture varies enormously
Symptoms of TBI Psychological/Psychiatric Depression Guilt Anxiety PTSD?? Amotivation Neurologic Cognitive: memory, executive function Headache Vertigo Sensory impairment Seizures Parkinsonism Neuroendocrine Sleep disturbances
Cognitive Symptoms of Mild TBI Immediately Slowed reaction time Headache Inattention Dizziness Typically resolve after 1-3 months
Chronic Traumatic Encephalopathy Made headlines when NFL veterans have been diagnosed with condition Controversial how distinct a syndrome Dementia pugilistica or punch drunk Insidious, progressive Associated with cerebral atrophy, esp medial temporal lobe, thalamus, brainstem. A possible contributing factor to Alzheimer s disease 35
Fractional Anisotropy in Mild TBI
Relation to PTSD Complex & poorly understood Damage to prefrontal cortex may disrupt neural pathways that regulate anxiety. Post-concussive symptoms may increase likelihood of PTSD
Relation to PTSD (2) Controversial as prolonged unconsciousness had been tied to lower chance to acquire PTSD However, in soldiers with TBI with LOC, the incidence of PTSD was slightly more than 27%
Relation to PTSD (3) Cognitive or neurobehavioral changes from TBI may interfere with the efficacy of ungoing psychotherapy
The polytrauma triad Blast-related co-morbidities Chronic pain 82% PTSD 68% Persistent postconcussive symptoms 67% About 42% will have all 3 conditions concurently
Prediction on return to work in civilian practice Minimal extracerebral injuries Low level of pain
Factors Contributing to Functional Impairment Extracranial injuries Amputation of limb. Hemorrhagic shock Hypoxemia Sensory impairment PTSD
Sleep Disturbances in TBI (1) About 46% of chronic TBI will have sleep disorders, but they are often unrecognized May result from hypothalamic dysregulation Hypersomnia: OSA, narcolepsy, PLMS Insomnia: sleep maintenance as well as sleep onset insomnia Parasomnias: REM behavior most common
Sleep Disturbances in TBI (2) Circadian rhythm sleep disorders: delayed sleep phase syndrome & irregular sleepwake patterns Conventional therapies appear effective Therefore, these conditions ought to be recognized since they can contribute significantly to neurocognitive deficits and functional impairment
Other Diagnostic Methods Now, almost-now & future MRI with Diffusion Tensor Imaging Voxel based morphometry MRI-SPECT fused imaging NMR spectroscopy Correlation of neuropsychological impairment to specific regions Quantitative electroencephalography
Fractional Anisotropy in TBI a: tracts are displayed b: chaos normal noise/physical disruption TBI
Current Treatment Multi-disciplinary Treat pain Treat contributory &/or co-morbid conditions Prevent future injury (traumatic or otherwise) Cognitive rehabilitation Appropriate psychoactive agents Vocational training
What does the future hold? Prevention: e.g., world peace, better helmets, etc. Early identification of those more severely affected, the ideal MRI, functional test, etc. NMDA antagonists: amantadine, memantine Identification and treatment of genetic risk factors for progressive encephalopathy Improved auto safety, traffic control & sport rules Change in awareness of consequences of even mild TBI
Future Combat Helmet with input from Tom Clancy
Summary: TBI Silent epidemic, affecting large numbers Often overlooked, under-reported & underestimated in significance Variable in severity, but often catastrophic Controversial if causative but adversely interacts with PTSD High economic & human cost May be responsible for and in turn worsened by sleep disorders Treatment & management are in infancy