Traumatic Brain Injury Shantaveer Gangu Mentor- Dr.Baldauf MD Demographics • Account for 75% all pediatric trauma hospitalizations • 80% of trauma related deaths in children • Domestic falls, MVA’s, recreational injuries and child abuse account for majority of them. • Gang and drug related assaults are on a rise. • Firearm injuries to brain account for 12% pediatric deaths. Pathophysiology of Brain Injury Brain Injury Primary 2.Intracranial hypertension and mass lesion Secondary 1.Delayed cell death 3.Ischemia systemic hypoxia,hypercarbia and hypotension Primary Brain Injury @SITE Focal Primary Diffuse Contracoup DAI Cerebral Contusion Most common Focal brain Injury Sites Impact site/ under skull # Anteroinferior frontal Anterior Temporal Occipital Regions Petechial hemorrahges coalesce Intracerebral Hematomas later on. DAI Hallmark of severe traumatic Brain Injury Differential Movement of Adjacent regions of Brain during acceleration and Deceleration. DAI is major cause of prolonged COMA after TBI, probably due to disruption of Ascending Reticular connections to Cortex. Angular forces > Oblique/ Sagital Forces The shorn Axons retract and are evident histologically as RETRACTION BALLS. Located predominantly in 1. CORPUS CALLOSUM 2. PERIVENTRICULAR WHITE MATTER 3. BASAL GANGLIA 4. BRAIN STEM Secondary Brain Injury Biochemical Cascade Blood Flow changes(Global/regional) AA/Neurotransmitter release Uncoupling of Substrate delivery and extraction CBF Intracellular Ca++ accumulation and cytoskeletal/ enzymatic breakdown Extracellular Cytokines and GF Generation of free radicals CMRoxy CMRglucose External Compression Intraparenchymal Extraxial (subdural/epidural) OEF/GEF Pneumocephalus Depressed skull fracture Initial Stabilization • Initial assessment and resuscitative efforts proceed concurrently. Few things to watch for, 1.Airway 2.Cervical spine injury 3.Hypotension 4.Hypothermia 5.Neurogenic Hypertension Cervical Spine X-ray: Lateral view. 1, Vertebral body (TH1). 2, Spinous process of C7. 3, Lamina. 4, Inferior articular process. 5, Superior articular process. 6,Spinous process of C2. 7, Odontoid process. 8, Anterior arch of C1 (Atlas). 9,Trachea. Neurological Assessment • Rapid Trauma Neurological Examination 1. 2. 3. 4. 5. 6. 7. 8. 9. Level Of Consciousness Pupils Eom Fundi Extremity Movement Response To Pain Deep Tendon Reflexes Plantar Responses Brainstem Reflexes Level Of Consciousness • Glasgow Coma Scale Eye Opening Best Verbal Best Motor Spontaneous 4 Oriented 5 Obeys Command 6 To Voice 3 Confused 4 Localizes To Pain 2 Inappropriate 3 Withdraws 4 None 1 Incomprehensible 2 Flexion 3 None Extension 2 None 1 1 5 Children's Coma Scale Ocular response Verbal response Motor response Opens eyes spontaneously 4 Smiles, orientated to sounds, follows objects, interacts. 5 Infant moves spontaneously or purposefully 6 EOMI, reactive pupils ( opens eyes to speech) Cries but consolable, inappropriate interaction 4 Infant withdraws from touch 5 EOM impaired, fixed pupils (opens eyes to painful stimuli) 2 Inconsistently inconsolable, moaning 3 Infant withdraws from pain 4 EOM paralyzed, fixed pupils ( doesn’t open eyes) 1 Inconsolable, agitated 2 Abnormal flexion to pain for an infant (decorticate response) 3 No verbal response 1 Extension to pain (decerebrate response) 2 3 No motor response 1 Pupillary Exam Pupillary size is balance b/n Sympath and parasympathetic influences. Size, shape and reactivity to light are tested parameters. Mydriasis Miosis 3 Cr.N. damageMydriasis Carotid A. injury in neck or skull base Unilateral mydriasis – Transtentorial ( Uncal) Herniation Horner’s syndrome- Miosis with Ipsilateral ptosis and anhydrosis. Traumatic iridoplegia Hypothalamic, cervicothoracic or direct orbital injury. Seizure/ postictal state Atropine / Sympathomimetics Eye Movements • SO4,LR6, All3 Injury location Abnormality Cavernous sinus/Sup Orbital fissure All 3 Cr.N’s ( 3,4,6) are affected + V1 division Transtentorial ( Uncal ) herniation 3 Cr.N Raised ICP ( false localizing sign) Isolated Abducens(6) palsy Frontal eyes field ( brodman’s area 8) Ipsilateral tonic conjugate deviation Seizure involving frontal eyes field Conjugate deviation to contralateral side Occipital lobe injury ( unilateral) Hemianopsia + ipsilateral conjugate gaze preference Brainstem Reflexes Facial palsy unilateral 7 N injury- Basilar skull # Corneal reflex ( V1+V2) Rostral Pontine function Dolls eye maneuver Vestibuloocular function Ice water caloric test ( never in awake child) COWS normal response Coma – same side deviation Stuporous/obtunded – nystagmus to contralateral rapid component Gag and cough reflex 9,10th N + brainstem swallowing centers Periodic( Cheyne-stokes) b/l hemispheric/diencephalic injury to as caudal as upper pons Apneustic ( prolonged ispiratory plateau) Mid- caudal pons injury Ataxic breathing( irregular stuttering resp) Medullary respiratory generator center. Deep tendon and superficial reflexes • DTR’s exaggerated after TBI due to cortical disinhibition • Decreased / absent after Spinal cord injury • Asymmetric DTR’s unilateral brain/spine injury • Superficial lost/decreased in corticospinal dysfunction and helpful in localizing lesions • Plantar response Normal reflex Intact descending corticospinal inhibition Positive Babinski Interrupted inhibition pathways Neurodiagnostic Evaluation Skull Radiograph Controversial usage, costs> benefits CT Contiguous slices from vertex to foramen Magnum. Extend to C3 if upper spine # suspected Brain, Blood and Bone windows May miss # that run parallel to CT slice and located at vertex. Indications controversial, a must in 1.Penetrating head trauma 2.basilar/ depressed skull # 3.Posttraumatic seizure 4.Severe head injury In addition anyone with, 1.Altered level of consiousness 2.Focal deficits 3.Persistent headaches/ repeated emesis MRI Better than CT in subacute and chronic phases of injury to detect contusions/shearing in white matter/c.callosum Invaluable in spinal cord injury Cerebral angiography Carotid/vertebrobasilar dissections/occlusions Pesudoaneurysms Clinical Features In Head Trauma • • • • • • • Scalp Injuries Skull Fractures Depressed Skull Fractures Basilar Skull Fractures Vascular Injuries Penetrating Head Injury Intracranial Hemorrhage – – – – Epidural Hematoma Subdural Hematoma Subarachnoid Hemorrhage Intracerebral Hemorrhage Scalp Injuries • Most are laceration – Simple Linear/ Stellate ED Rx – Extensive, Degloving/Avulsion Repair GA – Overlying Depressed Skull#, Infections Repair+ Elevation Of # – Hematomas Subgaleal Cephalohematomas Galeal Apo & Periost Periost & Skull Cross Suture Lines Limited By S.Lines Hypotension & Anemia(bp,hct) Calcify And Disfiguring Sx Skull Fractures • Thin skull #’s common place. • Risk of # associated intracranial injuries? • CT to R/o 1. Open 2. Closed 3. Linear (3/4) 4. Comminuted ( multiple branches) 5. Diastatic ( edges split apart)<3yrleptomeningeal cyst, cephalomalacia, 6. Depressed 7. Basilar Depressed Skull # • From focal blow • Closed 10% FND/15% seizures Rx, for cosmetic reasons • < skull thickness- no elevation • Open/ frontal sinus intracranial wall elevate and Sx + frontal sinus irrigation • Free floating – remove/replace wrt size and after soaking in abx Basilar Skull # Basilar Petrous Bone Longitudinal Cribriform Plate Transverse Rhinorrhea Epidural Hematomas (EDH) • Peak incidence in 2nd decade • Source meningeal vessel, Dural venous sinus, diploic vein from skull # • H/o minor head injury Viz fall • C/f wrt size, location, rate of accumulation – Lucid interval (33%), non specific – Confusion, lethargy, agitation, focal neurological deficits. Diagnosis • CT is diagnostic • Initial Ct Hyperdense Lentiform collection beneath skull • Actively bleeding- Mixed densities • Severe anemia- isodense/hypodense • Untreated EDH imaging over days Hyperdense Isodense Hypodense w.r.t. brain Treatment Non surgical Minimal / no symptoms Should be located outside of Temporal or Post fossae Should be < 40 ml in volume Should not be associated with intradural lesions Should be discovered 6 or more hours after the injury Surgical Subdural Hematoma • Common in infants. • Cause high velocity impact/ assault/ child abuse/ fall from significant height. • Associated with cerebral contusions + DAI • Source cortical bridging veins/ Dural venous sinuses. Adults Child/infants Cerebral convexities over frontal/ temporal regions Occipital + Parietal cortex Parafalcine ( post falx cerebri), supratentorial { abuse} 50% are unconscious immediately. Focal deficits common Hemiparesis – 50% Pupillary abnormality- 28-78% Seizures – 6-22% Rx- larger- urgent removal Small Small with mass effect/ significant change in conscious/ focal deficits Removed Small with significant brain injuries + mass effect out of proportion to size of clot Non operative approach SDH’s are High density collections on CT conforming to convex surface of brain Cant cross falx cerebri/ tentorium cerebelli { compartmentalized} Can cross beneath suture lines Distorstion of cortical surface/ effacement of ipsilateral ventricle/ shift of midline often noted. SAH • Trauma is leading cause. • Acute from disruption of perforating vessels around circle of Willis in basal cistern • Delayed from ruptured pseudo aneurysm. • Rx maintain intravascular vol to prevent ischemia from vasospasm. • Mortality 39% { national traumatic coma databank} Intracerebral • CT- hyperdense/mixed Bleed • MRI- small petechial bleed+ Rare in Peds. 60% from small contusions coalesce to form larger hematoma. Rarely , violent angular acceleration bleed in deep white matter, basal ganglia, thalamus Transtentorial Herniation midbrain bleed ( Duret hemorrhages) Common sites Ant Temporal and Inf Frontal lobes { impact against lateral sphenoid bone/ floor of ant fossa} DAI • Rx- small- non operative. Resolve in 2-3 weeks • Large- Sx drainage. • Repeat CT in small bleeds after 12-24 hr is warranted to r/o coalescence to form large hematoma. Penetrating Head Injury Infants and children fall on sharp objects with thin skull and open foraminae could predispose for these injuries. R/o child abuse Rx Surgical. Entry wound debrided and FB removed with in driven bone fragments. Peri and post op ABX Prophylactic anticonvulsants Adolescents and children Gun Shot Wounds. ( 12%) and increasing annually. Higher mortality when 1.Low GCS on presentation (3-4) 2.B/L hemispheric /brainstem injury/ intraventricular tracking 3.Hemodynamic instability/ apnea/both 4.Uncontrolled ICP. • CT- localizes bullet and bone fragments • MRI- non advised till magnetic properties of bullet known. • Rx. Surgical – Debridement of entry and exit wounds – Remove accessible bullet and bone – Control hemorrhage – Repair Dural lacerations + closure of wounds. – NO ATTEMPT TO REMOVE BULLET OR BONE BEYOND ENTRY AND EXIT WOUNDS. Intracranial Hypertension • Pathophysiology – ICP monitoring and control are the cornerstones of TBI management – Normal ICP • Adults <10mmhg • Children 3-7mmhg • Infants 1.5- 6mmhg – When to treat? • Adults > 20 • Children >15 • Infants >10 { Arbitrary numbers most commonly used, pending outcome studies} CBF Autoregulation CPP = MAP- ICP { mmhg} Normal Brain • CBF maintained within CPP range of 50-150mmhg as vessels can expand / constrict accommodate p changes. •<50 CPP maximal Dilation occurs CBF falls as CPP drops •>150CPP maximal Constriction occurs CBF raises with CPP TBI • CBF falls b/n 50-80 mmhg of CPP Range of Hypo perfusion •Auto regulation may be , 1. Completely lost linear relation B/n CBF & CPP 2. Incompletely lost Plateau after CPP of 80 mmhg Monro-Kellie doctrine – Vol of intracranial compartment must remain constant because of inelastance of skull Normal State- ICV is a balance b/n Blood, brain & CSF. With ICSOL ICP remains normal till compensation can occur At the Point of decompensation The ICP starts to increase. The brains compensatory reserve is called Compliance Measure of compliance 1.Volume pressure response 2.Pressure Volume Index ( PVI) = V/ LOG P1P2 Transient elevation in ICP Lundberg Waves 1. A wave Duration = 2-15 min Amplitude = 50-80mmhg Results from Transient occlusion of venous outflow as bridging veins occlude against compressed dura. Or transient vasodialtion and hence increase CBF as a response to ischemia Sustained A waves may indicate sustained elevation in ICP and hence low brain compliance 2. B waves changes in ICP w.r.t. Ventilation 3. C waves short lived waves w.r.t. arterial Traube-Herring waves Shape of ICP wave form as an indicator of Compliance Normal ICP has 3 wave forms. 1.Percussion wave- first and highest amplitude wave 2.Dicrotic wave – second wave 3.Tidal wave- third and lowest amplitude In reduced brain compliance the Dicrotic and Tidal waves augment exceeding the percussion waves. ICP measurement Intraventricular Cath coupled to ICP transducer is Gold standard. Which patients need ICP monitoring?? 1.TBI + abnormal CT scan who are not following commands ( 5063%) 2.Comatose + Normal CT had lower risk ( 13%) unless associated with 1. Older age 2. Systemic Hypotension , <90mmhg 3. Motor posturing, with these risk is upto 60% 3.Most clinicians use abnormal CT scan result + low GCS scores ( < 8) as candidates for ICP monitoring Device / method Risk / benefit 1. Intraventricular catheter Adv- drainage of CSF to reduce ICP DisAdv- infection/ ventricular compression leads to inaccuracy 2. subdural/ subarachnoid bolts ( Philadelphia, Leeds, Richmond bolts) Occlusion of port in device leads to inaccuracy 3. Fiberoptic cath ( Camino labs) Improved fidelity & longevity Can be placed Intraparenchymal/ intraventricular/ subdural Used to drain CSF Accuracy maintained even with fully collapsed ventricles Single cath can be used as long as needed Non invasive ICP measurement Ultrasonographic tech Pediatr Crit Care Med 2010 Vol. 11, No. 5 Audiological tech- displacement of TM and perilymphatic pressure as a correlate of ICP Infrared light- thickness of CSF from reflected light as a correlate of ICP Arterial BP wave contours and blood flow velocity – mathematical model Changes In optical nerve head with optical coherent tomography IOP as correlate of ICP With ICP cutoff of 20mmhg it has Specificity of 0.7 and sensitivity of 0.97 Mangement of ICP • Goal to maintain CPP by – Reducing ICP, and/or – Increasing MAP { hyper/normo volumia preffered as opposed old school Hypovol} Brief periods of hypotension can double the mortality rates CPP should be match with cerebral metabolic demand to avoid hypoperfusion / hypeeperfusion. Cerebral OEF is helpful as, Decrease in CBF increase OEF increase AvDo2 fraction AvDo2= diff b/n O2 content of Arterial – jugular mixed venous blood. Considering Ao2 as constant, venous O2 alone can solely be assessed. Normal svJo2 is 65%, a drop to 50-55% global cerebral ischemia Hyperdynamic therapy • • • • • • To maintain CPP of about >70, by increasing MAP { CPP= MAP-ICP} IVF- crystalloid/colloid PRBC if low HCT(<30%) Pressors as needed ( Dopa, Dobu,Phenylephri) if autoregulation is intact? incres CPP vasoconstriction constant CBFless volume reduction in ICP. • Systemic Hypo ? Vice versa Increasing CPP by reducing ICP Sedation and pain control Fentanyl/ midazolam drip Etomidate in initial phase Quiet envir + min extern stimuli Pharmacological paralysis if needed Increase in Pneumonia+ sepsis IV/ ET lidocaine ( ET > IV) During intubation, before ET suctioning,ET manipulation Elevation of head end by 20-30deg Red venous press ICP Can cause orthostatic changesfall CPP rebound ICP rise Excessive PEEP, tight cervical collar, neck flexion/ rotation Can rise ICP Bladder distention rise Contin drainage Occult seizures unexplained rise Prophylactic Anticonvulsants Fever rise Rx + hypothermia. Specific measures to reduce ICP Hyperventilation Rapid & effective response. Red Paco2/incr pH vasoconstricton Red CBF Disadvantages 1.paco2 < 30 torr red CBF to ischemic level 2.Regional variation in autoreg hyperventilation induced reverse vascular steal Current recommendations 1. routine hypervent ( 35 ) not be used in first 24 hrs 2.Chronic hypervent be avoided in absence of documented ICP rise 3.Reserved for deterioration not responding to other measures. 4.When needed with caution, PaCo2 never <30 torr. 5.svJo2 can be used as indicator of extreme ischemia( CBF fall) 6.If used, withdrawn slowly to avoid rebound rise • CSF drainage- effective and safe. • Provides gradient for bulk flow of edema fluid from parenchyma of brain to ventricles. • Continous – 5-10 torr gradient • Intermittent for 1-5 min when needed. Diuretics Mannitol – works as osmotic diuretic extract extra and intra cellular edema fluid from brain Disadv- may preferentially affect normal areas ( intact BBB) vs affected zones ( disrupted BBB) Additional mech reduces blood viscocity ( by hemodilution) and improves Rheology Increas CBF vasocons decreas volume red ICP. 3 dosing methods • intermittant boluses when ICP 15-20 •Intermittant Q6 hrly •Continous infusion Risks 1. Repeated dose reduced osmotic gradient 2. Hyperosmolar state ( serum osm>320 mOsm) renal failure, rhabdomyolysis, hemolysis • Steroids – No role currently in TBI • Barbiturates- usually last resort med. Pros Cons Reduce ICP , CBF, CMRO2 Inhibit free lipid peroxidation reduce cellular damage Close ICU monitoring Hypotension Hyponatremia Myocardial depression ALGORITH for treatment of elevated ICP with severe head injury. ( Brain trauma Foundation, American Association of neurological Surgeons, Joint section of Neurotrauma and critical care) Bispectral Index • Bispectral index (BIS) is one of several recently developed technologies which purport to monitor depth of anesthesia. • Uses , 1. Monitor depth of anesthesia 2. Reduce incidence of intraoperative awareness 3. Monitor recovery from brain injury 4. With ICP to monitor during therapeutic burst suppression. 5. 0-100 scale. 6. 40-60 good depth of Anesthesia. POST TRAUMATIC SEIZURES • Complicate 10% pediatric head injuries 1. Impact seizures follow minor injury , occur on impact 2. Early posttraumatic seizures within min to hours of injury. 1. No radiological intracranial injury noted in many cases 2. Do not portend later epilepsy 3. Most do not need Rx 4. Outcome good. • Late seizure >24 hrs after injury – Visible intracranial injury. – Penetrating injuries/ depressed #/ SDH/ Lower GCS score – Long term risk of epilespy high- need Rx for 6-12 mo. • Seizure prophylaxis Only during first week Or till intracranial hypertension phase is passed. Prolonged usage has cognitive deficits on long term follow ups. Phenytoin commonly used Thank You