Closed Head Injuries in ChildrenWhere are we heading? Carlos A. Delgado M.D. FAAP Pediatric Emergency Medicine Children’s Healthcare of Atlanta Pediatric Emergency Medicine Associates (PEMA)
Background • Trauma is a leading cause of death in children older than 1 year in the United States, with head trauma representing 80% or more of the injuries. • 5% of head trauma cases, patients die at the site of the accident. • Head trauma has a high emotional, psychosocial, and economic impact • long hospital stays • 5-10% require discharge to a long-term care facility.
Anatomical differences with adults • The head is larger in proportion to the body surface area • Stability is dependent on the ligamentous rather than bony structure. • The pediatric brain has a higher water content, 88% versus 77% in adult, which makes the brain softer and more prone to acceleration-deceleration injury.
The water content is inversely related to the myelinization process. • The unmyelinated brain is more susceptible to shear injuries. • Infants and young children tolerate intracranial pressure (ICP) increases better because of open sutures.
Frequency • Head injury is estimated to occur in approximately 200 per 100,000 population per year. • The number includes all head injuries that resulted in hospitalization, death, or both in persons aged 0-19 years.
Mortality/Morbidity • Mortality rate from head trauma is 29% in pediatrics.- death certificate data, -underestimation of actual rate. • Head injury represents 75-97% of pediatric trauma deaths. • Neurologic deficits: 10 - 20% of children with moderate-to-severe head injury (GCS 6-8) • have short-term memory problems • delayed response times, if coma longer than 3 weeks. • More 50% with GCS 3-5 have permanent neurologic deficits
Age factor • At age 15 years, a dramatic increase occurs, mainly in males, related to their involvement in sports and driving activities. • Infants younger than 1 year have an elevated incidence of head trauma, due to falls and child abuse.
Basilar skull fracture • In 6-14% of pts with head trauma- hx of a blow to the back of the head. • Loss of consciousness, seizures, and neurologic deficits may or may not be present. • Prolonged nausea, vomiting, and general malaise, • Fracture near the emesis and vestibular brainstem centers. • Battle sign, raccoon eyes, and CSF otorrhea and rhinorrhea • Ocular nerve entrapment - 1-10% of patients.
Epidural hematoma • Between the skull and the dura and secondary to the laceration of an artery or vein • Epidural hematomas of arterial origin peak in size by 6-8 hours after the injury. • Epidural hematomas of venous origin may grow over 24 or more hours. • Common locations are the temporal, frontal, and occipital lobes. • An overlying skull fracture may be present. • Classic lucid interval between the initial loss of consciousness and subsequent neurologic deterioration- less frequent in the pediatric population.
Epidural hematoma • Neurologic deterioration: • hemiparesis • unconsciousness • posturing • pupillary changes • Expansion of hematoma and exhaustion of compensatory mechanisms and compression of the temporal lobe and/or brain stem.
Subdural hematoma • Between the dura and the cortex, subdural hematoma results from tearing of the bridging veins across the dura or laceration of the cortical arteries during acceleration-deceleration forces • Usually associated with severe parenchymal injury, and the presentation is that of profound and progressive neurologic deterioration.
Subdural hematoma • Subdural hematoma may develop secondary to birth trauma • Shaken baby syndrome: • New-onset seizures • Increased head circumference • Failure to thrive • Tense fontanel. • Focal neurologic deficits usually absent.
Subarachnoid hemorrhage • Most common form of hemorrhage associated with head trauma • Disruption of the small vessels on the cerebral cortex. • Location: falx cerebri or tentorium and the outer cortical surface. • Nausea, vomiting, headache, restlessness, fever, and nuchal rigidity - blood in the subarachnoid space.
Diffuse axonal injury • Rapid acceleration-deceleration forces • Disruption of the small axonal pathways. • Basal ganglia, thalamus, deep hemispheric nuclei, and corpus callosum. • Altered mentation and often prolonged vegetative state • Abnormal neurologic examination findings and the lack of findings on CT scanning. • Small petechial hemorrhages may be present. • Prognosis for full recovery often is poor.
Cushing triad • Bradycardia • Hypertension • Alteration of respiration Late manifestation indicative of herniation.
Hypotension • Should not solely be attributed to intracranial hemorrhage. • Other causes: • internal hemorrhages • spinal cord injury • cardiac contusion • dysrhythmias with secondary impaired cardiac output. • Hypotension with bradycardia in a trauma patient be suspicious of spinal cord injury.
Causes • MVA- 27-37% of all pediatric head injuries. • Children < 15 years, a pedestrian or a bicyclist • children aged 5-9 years are the second most frequent cause of death. • 15-19yo- passengers and alcohol is often a contributing factor. • Falls are the largest cause of injury in children < 4 years, contributing to 24% of all cases of head trauma.
Closed head injuries – what’s common knowledge • Kids experiencing low altitude falls, fall from standing and/or weak mechanisms of injury rarely sustain intracranial injuries. • If asymptomatic after the injury and unchanged by the time of exam, the probability of an intracranial injury is low. • If initial Head CT is neg, the chances of unsuspecteddeterioration is also low. • Long-term outcomes for children with mild head injury, without of significant intracranial bleed, are generally very good, with only a small increase in risk for subtle specific deficits in particular cognitive skills.
Epidemiology • Nonfatal injuries • 219 per 100,000 per year • 1.5 million head injuries- 20% sports related • 5-10k /100,000 ED visits per year • 1/10th require admission • Fatalities • 75% of trauma deaths involve brain injury • 30-60% fatality if hospitalized in coma
Epidemiology of Pediatric Head Trauma • Trauma is the leading cause of death among children >1yr. • Traumatic brain injury (TBI) is the leading cause and disability due to trauma. • Annually in the U.S. blunt head trauma (BHT) results in: • 3,000 deaths • 50,000 hospitalizations • 650,000 ED visits (325,000 evaluated with CT scans) CDC, 2002
Epidemiology • Hospital admissions for most serious category of head injury increased 38% between 2001 and 2004. • 2004 there where 204,000 hospitalizations for TBI • 65 and older – 36% of hospitalizations • 45- 64 yo – 18% • 18- 44 yo – 31% • Adolescents and children - 15% • 13% of all admissions with TBI died while hospitalized Agency for Healthcare Research and Quality (AHRQ) 4/24/2007
Definitions • Current literature terms: • Head trauma • Traumatic brain injury • Closed head injury • Blunt head trauma • Head injury • Concussion • Traumatic brain injury (TBI): subset of pts with head trauma and an underlying brain injury detected by CT or also someone with trauma to the head without CT evidence of intracranial injury (ICI) but clinically symptomatic.
Radiological evaluation of the patient with CHI • Skull films • Head CT • Neurosurgical consultation • MRI
What about skull films? • Limited role if no physical findings • + skull fracture and no intracranial injury • - skull fracture and intracranial injuries
Skull films • It is still a good test for evaluating CHI’s • Skull radiographs are 94-99% sensitive for detecting linear or depressed skull fractures. • CT imaging has a lower sensitivity, ranging from 47-94%
Skull films When would it be OK to order one? • Scalp hematoma over course of the middle meningeal artery • Children < 1yr of age with a scalp hematoma • Suspected abuse
Head CT • Use has skyrocketed in the past 10 yrs. • Has become the gold standard in evaluation children with CHI • Newer faster scanners have reduced the need for sedation • Available 24/7 in most ED’s
Controversy over CT for Minor BHT Arguments for liberal use of CT: • Preventable morbidity/mortality due to unrecognized TBI’s • Preverbal children difficult to evaluate • When indicated benefits of CT greatly outweigh risk
Controversy over CT for Minor BHT Arguments against liberal use of CT: • Of the 325,000 children evaluated with CT after BHT, ≤ 10 % have TBI • Drawbacks of CT include: transport outside the ED, pharmacological sedation, costs, etc. • Most important (theoretical) risk : • lethal malignancy risk from CT may be as high as 1:5000
CT radiation risks • Helical CT scanners have enhanced diagnostic possibilities and reduced the need for sedation. • Radiation exposure, however, not reduced with helical CT • Radiation exposure with CT 300-600 times of a CXR. Brenner, 2001,2002,Hall 2002, http:/cancer.gov,2002
CT Radiation Risks • Estimates (theoretical, not observed) of risks of lethal malignancies extrapolated from survivors of WW II atomic explosions: • 1/2000 head CT scans for children younger than 1 yr. • 1/5000 for 10 yo • Age and size based radiation reduction efforts are ongoing • 4/5th of CT studies in children are not managed by pediatric radiologists.
325,000 CT’s for BHT - 2.7 million total pediatric CT’s annually. CT radiation risks important public-health issue • There are about 600,000 abdominal and head CT examinations annually on children under age of 15. It is therefore estimated that this could result in 500 deaths from cancer attributable to CT radiation.
Emergency Management • Major vs.. minor trauma • Mechanism of injury • Initial manifestations • Glasgow coma scores
Emergency Management • Low risk injuries • Children who present within 24 hours of the injury with isolated mild HT and have a normal mental status at presentation, a normal neurologic exam, and no evidence of skull fracture on physical examination. • Headache • Vomiting • Dizziness • Management • Discharge
Emergency Management • Moderate risk • Hx. of LOC • Progressive headache • Vomiting > 6hrs • Seizures • Amnesia • Associate injuries • Drug or alcohol intoxication • Suspected child abuse • Basilar skull fracture
Emergency Management Moderate risk injuries • Management • Observation for 4-6 hrs • CT scan • Neurosurgical consultation • Consider admission
Emergency Management • High risk injuries • Depressed level of consciousness • Penetrating injury • Depressed skull fracture • Focal neurologic exam • Management • Immediate neurosurgical consultation
Emergency Management • Airway and c-spine immobilization • Breathing • Circulation • Disability • Exposure