Outcomes Following Mild Traumatic Brain Injury (TBI) Michael J. Larson July 13, 2006

Mild Traumatic Brain Injury Duration LOC:None to 30 minutes Duration Post-traumatic amnesia: Minutes to 24 hours Glasgow Coma Scale (GCS): 13 to 15 Appearance:Stunned, dazed, drowsy, headache, nausea, disoriented

Glasgow Coma Scale Motor Response Obeys commands Localizing responses to pain Generalized withdrawal to pain Flexor posturing to pain Extensor posturing to pain No motor response to pain Verbal Response Oriented Confused conversation Inappropriate speech Incomprehensible speech No speech Eye Opening Response Spontaneous eye opening Eye opening to speech Eye opening to pain No eye opening GCS Mild TBI = Moderate TBI = 9 – 12 Severe TBI = 3 - 8

Epidemiology of Mild TBI Approximately 80% of all head injuries are mild –~145 per 100,000 –~400,000 new cases each year 2:1 male-to-female ratio Age (bi-modal): 14 to 24 or 75+ years Treatment costs > $1 billion yearly see McAllister, 2005

Modality of Injury 1) Transportation accidents –MVA, motorcycle, boating 2) Falls 3) Assaults/guns 4) Sports and recreation

Individuals Most Likely Age, gender Ethnicity: (controversial) higher in minorities with previous TBI with lower SES with substance abuse with previous psychiatric diagnosis From Kraus & Chu, 2005

Cognitive Function After Mild TBI

3 Cognitive LevelCognitive Level Preinjury Functioning PTA Coma INJURYINJURY Retro- Grade Amnesia Months Mild TBI Moderate TBI Severe TBI Ongoing Cognitive Problems Brief PTA PTA Ongoing Cognitive Problems Vanderploeg, 2006

Cognitive Sequelae Short-term (i.e., first week post) –Slowed processing speed –Poorer performance on tests of attention –Decreased working memory and verbal/visual memory performance Bohnen et al., 1993; Dikmen, 1986; Gronwall, 1989; McAllister, 2005

Cognitive Sequelae Long-term – controversial –Several studies show no long-term cognitive effects of mild TBI Dikmen et al., 1986 and 1995 Levin et al., 1987 Meta-Analyses: –Binder et al., 1997 –Schretlen et al., 2003

Cognitive Sequelae TAKE HOME MESSAGE: 90 to 95% of Mild TBI have full recovery after one year –Most asymptomatic after 3-to-6 months –Little-to-no residual effects –Neuropsych measures may not be extremely sensitive

Cognitive Sequelae Cognitive profile of the 5 to 10% who don’t recover in a year?

“Miserable Minority” What are some of the main reasons these individuals do not fully recover? What is the base rate for litigation in the “miserable minority?” What is the estimated base rate for malingering in litigating patients?

Predictors of Poor Cognitive Outcome Abnormal MRI/CT scan findings Depressed skull fracture History of previous mild TBI GCS of 13 rather than 14 or 15 History of psychiatric d/o Litigation

Self- Expectation mTBI Psychiatric Conditions Personality Traits Medical Conditions Intelligence Level Demographic Characteristics Medical Iatrogenesis Litigation Iatrogenesis Acute Symptoms Chronic Symptoms Psychiatric Conditions Personality Traits Medical Conditions Intelligence Level Coping Abilities Social Support Coping Abilities Adapted from Vanderploeg, 2006

Cognitive AffectiveSomatic

Post-Concussive Syndrome CognitiveAffectiveSomatic Decreased: Memory Attention Concentration Depression Irritability Anxiety Headache Fatigue Insomnia Dizziness Photophobia

Post-Concussive Syndrome Pattern and course generally follows cognitive dysfunction –At one month: 55% headache 65% fatigue 40% dizziness 65% irritability –At one year few to no symptoms

Post-Concussion Syndrome PCS sxs prevalent in general population and what people expect after mild TBI –Mittenberg et al., 1992 –Lees-Haley & Brown, 1993 PCS sxs correlate: –Poorly with neuropsych. –Highly with depression and anxiety

Self- Expectation mTBI Psychiatric Conditions Personality Traits Medical Conditions Intelligence Level Demographic Characteristics Medical Iatrogenesis Litigation Iatrogenesis Acute Symptoms Chronic Symptoms Psychiatric Conditions Personality Traits Medical Conditions Intelligence Level Coping Abilities Social Support Coping Abilities Adapted from Vanderploeg, 2006 Brain Trauma

Risk of Psychiatric D/O Increased propensity toward: –Depression (20 to 30% of MTBI) –Anxiety (24 to 55%) –PTSD/Acute Stress D/O (3 to 48%) –Obsessive-compulsive disorder??

A Final Case We now know his expected outcome He comes to us in litigation one-year after the fight. He wants to sue the referee for not stopping the fight earlier. He complains of dizziness, fatigue, depression, and memory difficulties. What tests might you give a year-post to confirm brain injury? Differential diagnoses?

Conclusions Majority sxs. of mild TBI will resolve in less than 6 months Post-Concussive Syndrome is controversial Stress-diathesis approach to symptoms warranted Litigation status and malingering may play a large role in outcomes (David will discuss) Increased propensity to psychiatric D/Os