Second Impact Syndrome

Tanvir Choudhri, MD

Assistant Professor of Neurosurgery Ichan School of Medcine at Mount Sinai Department of Neurosurgery

SIS: What is it?

  When repeat injury is sustained before symptoms of previous head injury have been resolved Rare, often fatal, traumatic brain injury occurs (Weinstein et al., 2013)

Department of Neurosurgery

SIS: What is it?

   Saunders RL, Harbaugh RE The second impact in catastrophic contact-sports head trauma JAMA 252:538-539, 1984

Department of Neurosurgery

SIS: How often does it occur?



Exact incidence unknown

 

Less than 20 documented SIS cases in world literature

(Randolph et al., 2009, Arch Clin Neuropsychol) 

1 possible SIS for every 205,000



player seasons

Annual participation rate: 1.8 million high school/collegiate subjects  (McCrory, et al., 2012, Current sports medicine reports)

Department of Neurosurgery

SIS: What are the risk factors?

  Males 16-23 years old (Mori et al., 2006, Acta Neurochirugica Supplementum) Most brain fatalities occurred during games (Boden et al., 2013. Am J Sports Med)    Fatal injury sustained most frequently either tackling or being tackled (Cantu & Mueller, 2003, Neurosurgery) History of 3+ concussions 3x more likely to sustain incident concussion (Guskiewicz et al., 2003, JAMA)

Department of Neurosurgery

SIS: How does it occur?

  Within vulnerable period from previous injury (Weinstein et al., 2013, J Neurosurg) Impairment of cellular energetic metabolism     Loss of autoregulation of cerebral blood flow Subsequent vascular engorgement Increased intracranial pressure Eventual herniation  Subdural hematoma  Brain Swelling

Department of Neurosurgery

SIS: Effects of 2

nd

Impact

     Loss of autoregulation Rapid onset massive cerebral edema Transtentorial brain herniation Raised intracranial pressure Death can be as early as 2-5 min (Zollman, 2011, Demos Medical Publishing)

Department of Neurosurgery

SIS: Pathophysiology

 Functional injury  Reinjury to neuronal cells within vulnerable period from previous injury (Weinstein et al., 2013, J Neurosurg Pediatrics)  Dysautoregulation   hyperemic brain swelling  Increased intracranial pressure  Herniation  Brainstem compression

Department of Neurosurgery

Concussion: Pathophysiology

    Neurometabolic cascade (Marshall, 2012, J Can Chiropr Assoc) Mechanical stretching/shearing of neurons   Disrupts ion channels Excitation phase  Neuronal suppression Net result = neuronal ion imbalance, cellular dysfunction, cerebral energy deficit Requires max function of Na+/K+ pump to restore homeostasis

Department of Neurosurgery

Concussion: Pathophysiology

▶ http://www.youtube.com/watch?v=KrvC2UUEJ8 Y ▶ http://www.youtube.com/watch?v=uEGXcNNyzp Y Mount Sinai / Presentation Slide / December 5, 2012 10

SIS: How to recognize it?

     2 nd injury generally not severe Remains standing - appears dazed Sec-min after 2 nd ground blow collapses to Semicomatose, dilating pupils, loss of eye movement, respiratory failure (Cantu & Gean, 2010, Journal of neurotrauma) Death can be as early as 2-5 min of 2 nd impact (Zollman, 2011, Demos Medical Publishing)

Department of Neurosurgery

          

SIS: Symptoms

Headache most commonly reported Dizziness Neck pain Nausea and vomitting Light/Noise sensitivity Sleep pattern changes Memory/Concentration problems Fatigue Respiratory arrest Aniscoria Coma

Department of Neurosurgery

SIS: Evaluation and Management

     Hyperemic swelling Brain Herniation Post-herniation ischemia    CT (Cantu & Gean, 2010, Journal of Neurotrauma) Engorged cerebral hemisphere Abnormal mass effect Midline shift  MRI (McCrory et al., 2012, Current sports medicine reports) Metabolic change up to 15 d after concussive injury

Department of Neurosurgery

SIS: Neurosurgeon’s role

       Neurosurgical consult in case of anatomic abnormality (Bey & Ostick, 2009, Western Journal of Emergency Medicine) Attention for potential c-spine injury Patient immediately stabilized Airway management Rapid intubation Mannitol to minimize morbidity Surgery generally not effective for treatment of impaired autoregulation

Department of Neurosurgery

Case

(Weinstein et al., 2013, J Neurosurg Pediatrics)

- Previously healthy 17 yo M - Helmet to helmet hit - Felt dizzy, played immediately after - Reported H/A after game from hit - Resumed typical activities - c/o fatigue and persistent H/A

Department of Neurosurgery

Case

(Weinstein et al., 2013, J Neurosurg Pediatrics)

- Normal evaluation/neurological exam with PCP 4d after game - Head CT: WNL

Department of Neurosurgery

Case

(Weinstein et al., 2013, J Neurosurg Pediatrics)

- Persistent H/A, difficulty with concentration - 5 days after initial injury participated in practic (including hitting drills) - After a hit on fourth drill: slow to get up “OK” but H/A - Several plays later  headache  down on one knee couldn't feel legs   dizziness and unresponsive  generalized seizure activity - Local ER: intubated, treated with lidocaine, mannitol, fosphenytoin, fentanyl, midazolam - Air transport to trauma/NS center - 143/79, HR 93, GCS 7T, 3mm sluggish pupils, ICP 25-30 - Coagulation studies normal, Utox neg

Department of Neurosurgery

Case

(Con’t)

- Brain/cervical spine MRI: mild downward transtentorial herniation, bilateral subdural hematomas, abnormal T2 signal restricted diffusion in medial left thalamus - Midline structures displaced caudally (thalamus hypothalamus)

Department of Neurosurgery

Case

(Con’t)

Hospital course: Episode of hypotension, severe metabolic acidosis and renal failure, Sepsis, ventilator-assoc. pneumonia with empyema, disseminated intravascular coagulation, cardiac arrest Later resolution of subdural hematomas and areas of encephalomalacia At time of discharge (day 98) nonverbal and nonambulatory

Department of Neurosurgery

Case

(Con’t)

3+ years after injury living at home regained limited verbal, motor, cognitive skills

Department of Neurosurgery

SIS

http://www.youtube.com/watch?v=V12Z qmd3Btc

Department of Neurosurgery

Traumatic Subdural Hematoma

     Bleeding into the space between the dura mater and the brain From venous hemorrhage 12-30% of patients with severe head injury 36-79% mortality Often requires surgical intervention

Department of Neurosurgery

Traumatic Epidural Hematoma

     Bleeding into the space between the dura mater and the skull From arterial laceration Typically from disruption of middle meningeal artery Arterial bleeding  increased intracranial pressure  cell lesion & brain damage ~20% mortality

Department of Neurosurgery

Post Concussion Syndrome

    Persistent post-concussion symptoms 3+ months Increased risk of depression Working memory and Info processing speed impairments in mild TBI and persistent PCS (Dean & Sterr, 2013, Frontiers in Human Neuroscience)

Department of Neurosurgery

Chronic Traumatic Encephalopathy

   Repetitive brain trauma necessary for development of CTE Progressive neurodegenerative disease       Symptoms present years after trauma (Stern et al., 2011, American Academy of Physical Medicine and Rehabilitation) Decline of memory/cognition  Depression  Suicidal behavior Poor impulse control Aggressiveness Parkinsonism Dementia Generalized atrophy

Department of Neurosurgery

Conclusions

    Vulnerable window following TBI Second impact before resolution of symptoms can result in catastrophic brain injury/ fatality Highlights importance of return-to-play decisions PCS and CTE represent long-term consequences of repetitive head impacts

Department of Neurosurgery

Future Directions

 Better identification of concussions X2 Helmet   Better protocols (sideline, ER, etc) Increased awareness

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Acknowledgements

    Alexa Dessy, BA Jonathan Rasouli, MD Mount Sinai PLAYSAFE team Alex Gometz, DPT, CIC (Concussion Management of New York)

Department of Neurosurgery