Introduction To Mild TBI. Not Just Less Severe But Different

Transcription

1 Introduction To Mild TBI Not Just Less Severe But Different

2 Purpose Provide a discussion of issues related to diagnostic criteria for mild brain injury and concussion To present incidence data on MTBI and Post Concussion Syndrome Discuss the alternative explanations of symptoms such as factitious disorder, pain, vestibular problems, ptsd etc.

3 Definitions of MTBI DSM V: loss of consciousness < 30 minutes; PTA < 24 hours; GCS Disorientation and confusion initially Rehab Med: any loss of consciousness or PTA or alteration of mental state/ neurologic signs of injury

4 Continuum of Injury To the Brain

5 Days to Recovery by Age

6 REMINDER Mechanics of Severe TBI Diffuse Axonal Injury: shearing of long axons Rotational effects especially on the brain stem Contusions and hemorrhages Hypoxia (respiratory depletion)

7 Metabolic Cascade after Concussion % of normal Glutamate K minutes hours days (Giza & Hovda, 2001) UCLA Brain Injury Research Center

8 Metabolic Cascade after Concussion % of normal K+ Glucose Glutamate minutes hours days (Giza & Hovda, 2001) UCLA Brain Injury Research Center

9 Metabolic Cascade after Concussion Calcium % of normal K+ Glucose Glutamate minutes hours days (Giza & Hovda, 2001) UCLA Brain Injury Research Center

10 Metabolic Cascade after Concussion Calcium % of normal K+ Glucose Glutamate minutes hours days Cerebral Blood Flow (Giza & Hovda, 2001) UCLA Brain Injury Research Center

11 PCS fmri PCS vs Normal (Recovered) (Leddy et al 2013) Recovered

12 Metabolic Cascade Massive release of Potassium Vascular constriction (reduced cerebral blood flow) Increased demand for glucose and oxygen by injured areas (despite reduced blood flow): Brain Energy Crisis Body produces various proteins that might serve as biochemical markers (e.g. S100ß) which may be neuroprotective or bi-products of neurological insult Cytochrome P450 is reduced during the first day and then increased during the next two weeks

13 Implications of Metabolic Cascade In extreme, extra cellular K plays a role in convulsions Tremendous Metabolic Stress Placed on Already Damaged Neural Tissue Disturbance of Metabolic Autoregulation: ANS: Sympathetic overdrive CBF: Increased during exercise Brain is very vulnerable to subsequent injury Rest is recommended (Additional) Oxygen does not speed recovery Takes 7 to 14 days to recover metabolic stability ( after symptoms have disappeared)

14 Post Concussion Disorders Persistent symptoms following MTBI or concussion Time since injury varies according to definition: from 3 weeks to 6 months Risk factors: Lesions APOE epsilon 4 Prior concussions Female

15 Cognitive Reading comprehension difficulties Problem solving difficulties Lost easily Confusion Planning difficulties Easily distracted Forgetting Losing train of thought Somatic Headache Dizziness Sleepiness Behavioral/Affective Job performance Interpersonal relations Impatience PCS Symptoms

16 Other Important Signs of PCS Fatigue Cognitive or Behavioral? Associated with every source of disability Attention deficit Does not generally appear as a symptom Reaction Time Speed of information processing Most commonly associated with metabolic changes

17 Further Signs of mtbi Exercise Intolerance Decreased CO2 SensiNvity Decreased blood flow at rest Decreased ability to control cerebral blood flow during exercise Ocular- Motor difficulnes

18 Diagnosis of Concussion and PCS Anxiety (20) 5% Migraine (15) 5% Diagnoses PCS (22) 20% CVO (22) 55% Resolved (19) 15%

19 Differential Diagnosis Somatization, Factitious Disorder Depression (reactive) Possible to have neurologically based symptoms of depression Pain/Neck (Whiplash) Vestibular damage Chronic Fatigue

20 Clinical Interview Symptoms at the time of the injury and after (compared to pre-trauma) Presence of amnesia Retrograde amnesia Anterograde (post traumatic) amnesia Long term (behavioral effects) Be alert to vestibular problems Be alert to cervicogenic issues

21 Depression About 25% of those with mild TBI who retain symptoms Influences cognitive performance (on neuropsychological tests) Diagnosis complicated by similar symptoms to TBI: fatigue, subjective slowing, sleep disturbance Do not see loss of appetite or agitation

22 Return to Play Decisions Return to previous level of cognitive function? Symptoms free state No symptoms with exercise

23 Treadmill Test Results Predict Recovery Rate 13 98

24 CBF in Adolescents SaYerthwaite et al 2014 (N=922)

25 CBF In Adolescent Females In early adolsecence males and females demonstrate idenncal decline in CBF In Mid to Late adolescence females increase in CBF while males connnue to decline Females greater CBF than males throughout adulthood