a. If hydrocephalus is acquired and the con- dition that caused it is treatable, temporary CSF diversion may control and arrest the CSF accumulation.
b. Minimize the risk of acquired hydrocepha- lus through prevention measures:
i. Meningitis. Keep vaccinations current and restrict travel to known infectious regions.
ii. TBI. Wear seatbelts and helmets and use appropriate safety equipment.
2. Direct Care
a. For rapid-onset hydrocephalus with symp- tomatic increased ICP, emergent procedures include a ventricular tap (infant) or open ven- tricular drainage through a ventriculostomy.
b. An LP may be used for conditions that pro- duce hydrocephalus, but it is expected resolve spontaneously (e.g., IVH).
c. Ventricular shunts are used in the major- ity of patients with hydrocephalus (see section on “Intracranial Devices”). Shunt technology has improved significantly over the last several decades; however, they are not without flaws.
Complications may include infection, mechani- cal failure, and obstructions, and the distal cath- eter will most likely need lengthening as the child grows.
d. Alternatives to shunting are less common and include cerebral aqueductoplasty, tumor removal, and endoscopic fenestration of the third ventricle.
3. Supportive Care
a. Provide serial neurologic assessment, includ- ing head circumference in infants; assess for increased ICP; and monitor fluid and electrolyte status.
b. Maintain cardiorespiratory functioning.
c. Shunt systems need to be monitored for complications.
d. Provide routine postoperative care follow- ing surgical insertion of shunt (e.g., pain control, incision care, infection).
E. Outcomes
1. Because hydrocephalus is not a disease, but a final common pathway for a number of disorders, it is difficult to predict outcome.
2. Children with well-controlled hydrocephalus have the best outcomes.
3. Children with chronic hydrocephalus have increased risk for cognitive and physical develop- mental abnormalities.
TRAUMATIC BRAIN INJURY A. Definition and Etiology
1. TBI has been defined inconsistently in the past, but there are key elements that all current defini- tions have in common: There is an alteration in brain function or evidence of brain pathology, and it is caused by an external force. The alterations in brain function may be temporary or permanent.
2. Beyond the first year of life, multiple trauma is the leading cause of death and disability among children. Approximately 500,000 children are admit- ted to an emergency department annually. Boys are victims almost twice as often as girls.
3. The most common causes of TBI are related to falls and motor vehicle-related accidents (Faul, Xu, Wald, Coronado, & Dellinger, 2010). Children younger than 2 years of age who sustain a TBI are usually occupants of motor vehicles and are often not restrained or improperly restrained. Infants sus- tain TBIs in falls, walker-related injuries, and non- accidental injuries. Older children and adolescents are injured in bicycle-related or motorcycle-related accidents, with firearms and assaults, and during recreational activities. Risk factors include young age, substance abuse, and lack of protective devices (e.g., helmets; see discussion on multiple trauma in Chapter 9).
B. Pathophysiology
1. Primary injuries occur at the time of or within sec- onds of traumatic impact.
a. Skull fractures are usually linear in infants and occur along a suture line or perpendicular to a suture line. Diastasis (separation of cranial sutures) may occur in infants and small chil- dren; the separation may progress to growing fractures (i.e., a gradual erosion and separa- tion of the fracture line) when accompanied by dural tears. Depressed fractures may represent depressed bone fragments or indentation of pli- able skull bone without loss of bone integrity (“ping pong” depression in an infant). Basilar fractures are a break in the basilar portions of the frontal, ethmoid, sphenoid, temporal, or occipi- tal bones.
b. A concussion is defined by the Third International Conference on Concussion in Sport as (McCrory et al., 2009):
a complex pathophysiological process affect- ing the brain, induced by traumatic biome- chanical forces. Several common features that incorporate clinical, pathologic and biome- chanical injury constructs that may be utilized in defining the nature of a concussive head injury include
• External force transmitted to head
• Short-term neurologic impairment
• Functional disturbance without structural disturbance
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• Results in clinical symptoms that resolve;
post-concussion symptoms may persist
• Neuroimaging is negative
2. Secondary injuries develop after the traumatic event and are a consequence of the primary injury.
a. Cerebral lacerations are tears in the brain tissue often associated with skull fractures.
They are less common in children because the smoother inner table of the skull offers less resis- tance between bone and brain tissue.
b. Cerebral contusions are heterogeneous areas of hemorrhage and edema within the brain tis- sue. They begin as primary injuries, but swell- ing, hemorrhage, and subsequent increased ICP produce secondary injuries. These are less com- mon in young children compared to adolescents and adults.
c. Extradural hematomas. Subdural hema- toma represents bleeding into the dural space, usually venous in origin from bilateral bridg- ing of cerebral veins. They are more common than epidural hematomas in children. Epidural hematoma represents a collection of blood (usu- ally arterial in origin) in the extradural space.
The most common location is under the tem- poral bone from the middle meningeal artery.
These are less common in children compared to adults.
d. Diffuse generalized cerebral swelling following a severe TBI is more common in children than adults. Edema is classified into two main cate- gories: cytotoxic (cellular) and vasogenic. Early studies proposed that the cerebral swelling seen following TBI was predominantly from a vasogenic cause. Newer studies propose that TBI swelling is from a combination of vasogenic and cytotoxic mechanisms. Donkin and Vink (2010) state that early cerebral swelling is vasogenic from opening of the BBB and cytotoxic edema progresses more slowly with a peak of 48 to 72 hours. Despite the cause, when swelling is extensive, there is a rapid increase in ICP, which results in compression and herniation of brain structures.
C. Clinical Presentation 1. History
a. Falls are responsible for the majority of TBI in children younger than 9 years old. Infants and toddlers are more likely to fall from furniture,
beds, or parents’ arms while older children are more likely to fall from playground equipment.
b. Children older than 9 years with a TBI are most likely to have a history of a motor vehi- cle-related accident (Tracy et al., 2013).
2. Physical examination findings depend on the type and severity of the injury.
a. Simple linear fractures usually are asymptomatic.
b. Basilar fractures present with specific physi- cal findings.
i. Battle’s sign represents postauricular hematoma and swelling from damage to the sigmoid sinus temporal bone.
ii. The raccoon or panda sign represents a periorbital blood collection from an anterior skull base fracture (there is absence of a sub- conjunctival hemorrhage).
iii. Rhinorrhea represents CSF leakage into the middle ear cavity with drainage through the Eustachian tube into the nose. Anosmia is the lack of smell from damage to the olfac- tory nerve. Both are usually related to mid- dle fossa basilar fracture.
iv. Hemotympanum represents a blood col- lection behind the tympanic membrane from a temporal bone fracture. If the dura mater is torn at the same time, CSF may leak out of the ear canal (otorrhea).
v. Vertigo may occur with damage to the inner ear.
vi. Acute deterioration with associated hem- orrhage and increased ICP is most often seen with occipital transverse fractures because of the close proximity to the vital centers of the brainstem.
c. Cerebral contusion findings depend on loca- tion of the injury. Most injuries occur on the cor- tical surface of the temporal and frontal lobes from acceleration–deceleration forces, placing the patient at risk for focal seizures. The size of the injury and the shift in brain structures also affect presentation. Large contusions can produce a significant mass effect with shifting of intracranial structures and increased ICP.
Clinical signs of increased ICP and herniation may present. Symptoms also depend on the degree of associated swelling. Swelling occurs around the contusion 3 to 4 days following the injury. Significant swelling can also cause shift- ing of brain structures and increased ICP.
d. Concussion may present with loss of consciousness, retrograde amnesia, headaches, vomiting, fatigue, and posttraumatic seizures.
Diaphoresis, pallor, and lethargy may occur in infants.
e. Physical findings of epidural hematoma vary.
Infants may present with a bulging fontanelle, anemia with significant bleeding, and separa- tion of cranial sutures. Older children demon- strate hemiparesis or hemiplegia and anisocoria (anisocoria is an inequality of the pupils, usually greater than 1 mm difference; some individuals normally have unequal pupils, usually less than 1 mm difference). All ages may have symptoms of increased ICP in severe epidural hematoma.
f. Physical findings of subdural hematoma are usually nonspecific and may include drowsi- ness, lethargy, and irritability. Retinal hemor- rhages and seizures may occur especially in children younger than 3 years of age. Significant bleeding produces tense, bulging, and pulse- less fontanelles. Retinal hemorrhages in a child younger than 3 years old are highly suggestive of intentional injury.
g. Physical findings of generalized cerebral swell- ing are associated with increased ICP; however, significant swelling may not peak for 2 to 3 days.
3. Diagnostic Tests
a. Routine laboratory studies include CBC with differential, metabolic panel, coagulation studies, electrolytes, urine and serum osmolali- ties, and serum glucose.
b. Neuroimaging
i. CT scan remains the gold standard for acute evaluation of a TBI. Mass lesions are identified with and without shifts in brain structures. Bone windows iden- tify basilar fractures. Epidural hematoma demonstrates a double-convex (lentiform), hyperdense area, and does not cross cranial suture lines (Figure 4.16B). Subdural hema- toma demonstrates a more diffuse blood collection crossing cranial suture lines.
The acute phase is usually hyperdense and crescent shaped (Figure 4.16A). Cerebral swelling and edema results in changes in density.
ii. MRI is indicated in acute TBI when the clinical examination is not consistent with CT scan findings. It is superior to the CT scan in imaging nonhemorrhagic contu- sions, white matter abnormalities, and pos- terior fossa and small vascular lesions.
iii. Advanced neuroimaging techniques (e.g., diffuse-weighted imaging and diffu- sion-tensor imaging) are beneficial in iden- tifying abnormalities in the brain that have implications for long-term sequelae. They are not available in most centers, and are used primarily in research studies.
iv. Routine skull radiographs are no longer used to evaluate acute TBI and have been supplanted by the CT scan. However, skull radiographs are useful in identifying missile injuries and some depressed skull fractures.
4. Clinical Course
a. The clinical course depends on the type of TBI and the presence of increased ICP.
b. Patients with brain lesions that can be sur- gically evacuated or do not have increased ICP usually respond to supportive care with a good recovery.
c. TBIs that result in uncontrolled ICP usually progress to brain herniation, ischemic injury and death.
D. Patient Care Management 1. Preventive Care
a. Beyond safety measures to prevent a TBI, prevention is directed at minimizing secondary brain injury.
b. The cervical spine should be immobilized until the cervical spine has been cleared of injury.
2. Direct Care
a. In 2012, Guidelines for the Acute Medical Manage- ment of Severe Traumatic Brain Injury in Infants, Children, and Adolescents were revised (Kochanek et al., 2012). These guidelines provide a foundation for how children are managed with a TBI.
b. Initiate immediate resuscitation and sup- port of airway, breathing, and circulation.
c. Initiate neuromonitoring. ICP monitor- ing is usually recommended for patients with severe injury, including those with a Glasgow Coma Score (GCS) <8, abnormal CT findings with potential for increased ICP, and comatose patients with or without an abnormal CT scan.
Advanced neuromonitoring may include tran- scranial Doppler, NIRS, and jugular oximetry (see “Neurologic Monitoring” section).
d. Surgical management depends on the type of lesion. In general, children require surgery less often. Extradural hematomas are evacuated.
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Large intracerebral hemorrhages producing mid- line shifts may be removed. Growing fractures are repaired with cranioplasty. Decompressive craniectomy with duraplasty may be considered for children with acute deterioration from herni- ation or uncontrolled ICP elevation.
3. Supportive Care
a. Medical management is supportive and directed toward preventing secondary injury, including hypoxia and ischemia, increased ICP, and complications (e.g., seizures, obstructive hydrocephalus, hypotension).
b. Maintain ventilation and oxygenation by controlling ventilation (e.g., intubation and man- ual ventilation) and administering supplemental oxygen. Support the cardiovascular system (e.g., cardiac compressions, inotropic agents, fluids).
c. Provide baseline and serial cardiovascular, respiratory, and neurologic assessments.
d. Administer oxygen to maintain SaO2 >95%.
Maintain good pulmonary toilet and PEEP when a patient is receiving manual ventila- tion. Preoxygenate and sedate patient prior to suctioning. Administer fluids as ordered while maintaining adequate perfusion. Administer diuretics as ordered. (A complete description of ICP and CPP management is discussed in the section “Intracranial Hypertension: Patient Care Management”).
E. Outcomes
1. Morbidity and mortality from a TBI vary consid- erably and depend on severity of injury, presence of comorbidities, age of patient, and location of injury.
2. Diffuse cerebral swelling with increased ICP is responsible for significant morbidity and mortality in children.
ENCEPHALOPATHY A. Definition and Etiology
1. Encephalopathy is a broad term used to describe any condition that produces a generalized distur- bance in brain cellular metabolism resulting in an alteration of consciousness. In infants and children, the list of potential etiologies is endless; causes may be chronic or acute, static or progressive, and inher- ited or acquired. The prototypic encephalopathy seen in critically ill infants and children is HIE.
2. HIE is a final common pathway for a number of pathologies that produce brain injury from two physiologic abnormalities: damage to brain tissue from ischemia (reduction in CBF) and damage to brain tissue from hypoxia (decreased oxygen) or anoxia (absence of oxygen).
3. In neonates, HIE is the most common type of neonatal encephalopathy and results from hypoxia and ischemia during the prenatal, intranatal, or postnatal periods.
4. In older infants and children, a common cause of encephalopathy is HIE from cardiac arrest or low perfusion states (e.g., heart disease).
B. Pathophysiology
1. The pathophysiology of HIE is complex, mul- tifactorial, interrelated, and not completely under- stood. Several mechanisms may be activated during and after an hypoxic–ischemic event and include brain energy failure, calcium-mediated injury, exci- totoxic injury, activation of intracellular proteases, release of free fatty acids, activation of nitric oxide synthesis, formation of oxygen radicals, reperfusion injury, and inflammatory injury. The progression of damage starts with alteration in the cell mem- brane, then cellular metabolism ceases, and finally neurons die. Shortly after a hypoxic–ischemic insult, brain damage may not be apparent. If the patient survives and perfusion is restored, changes to brain tissue appear within hours. Some cells of the brain are more sensitive to hypoxic–ischemic insults and sustain more injury. For example, neu- rons are more vulnerable compared to glial cells due to their high energy requirements. Gray matter uses more than twice the ATP compared to white matter;
consequently, the cerebral cortex is damaged more often than other areas of the brain with a hypoxic–
ischemic insult (Perkin & Ashwal, 2012).
2. With severe HIE, cytotoxic edema develops in the initial phase of injury followed by vasogenic edema. Both types edema can increase ICP, which compounds the effects with compression of blood vessels and further ischemia.
C. Clinical Presentation 1. History
a. Because HIE is not a disease entity, the clin- ical history is as varied as the number of disor- ders that cause it.
b. Important interview questions include length of hypoxic–ischemic event, precipitating
events, presence of cardiac or respiratory arrest, neurologic symptoms during event, and inter- ventions used to restore perfusion.
c. Newborns presumed to have HIE have a history of fetal heart rate abnormalities, fetal dis- tress, or acute sentinel event.
2. Physical Examination
a. Physical findings may be minor (e.g., amne- sia) or severe (e.g., coma or death) and relate to the severity of injury.
b. In newborns, a significant number of hypoxic–ischemic events occur before birth. The newborn is presumed to have HIE with nonspe- cific clinical findings: fetal heart rate abnormal- ities, fetal distress, cord arterial acidemia, low Apgar scores, and need for respiratory support.
Other physical findings that have been catego- rized to reflect the severity of HIE in newborns (Horn et al., 2013; Sarnat & Sarnat, 1976):
i. Mild HIE. Hyperalert, normal tone and activity, exaggerated Moro reflex, and nor- mal autonomic function
ii. Moderate HIE. Lethargic, decreased activity; distal flexion; hypotonia; primitive reflexes sluggish; constricted pupils; brady- cardia; and periods of apnea
iii. Severe HIE. Coma, decerebrate postur- ing, absent spontaneous activity, flaccid, apnea, nonreactive pupils, and absent neo- natal reflexes
3. Diagnostic Tests
a. Routine laboratory studies include CBC with differential, serum electrolytes with renal function, metabolic panel, blood gas, and coag- ulation studies.
b. Neuroimaging for HIE is with a head MRI.
It is considered to be the best neuroimaging study to identify the presence and pattern of injury, and to predict long-term outcome in term infants. DWI MRI is better at identifying early insults.
c. EEG findings depend on the extent of corti- cal damage. In newborns, characteristic patterns were originally described by Sarnat and Sarnat (1976):
i. Mild HIE may have a normal EEG.
ii. Moderate HIE may show early low voltage and continuous delta and theta waves. Later changes show periodic pattern (awake) and seizures.
iii. Severe HIE may show early periodic pat- tern with isopotential phases and later all isopotential.
d. Older children may have EEG patterns that are more variable and relate to severity and etiology. Slight to moderate insults demon- strate changes in peak frequency or asymmetric rhythms from homotopic regions in each hemi- sphere. Severe insults demonstrate progressive slowing of electrical activity. EEG is used for sei- zure monitoring.
4. Clinical Course
a. Patients with short episodes (1–2 minutes or mild newborn HIE) of hypoxic–ischemic events usually recover fully.
b. Patients with longer episodes of hypoxic–
ischemic have a more protracted course with increased mortality.
D. Patient Care Management 1. Preventive Care
a. Initiate resuscitation immediately to restore oxygenation and perfusion to minimize hypoxic–ischemic insult or secondary reperfu- sion injury.
b. Neuroprotective measures to prevent second- ary brain injury include
i. Therapeutic hypothermia (33°C–35°C depending on type of cooling) for 72 hours with selective head cooling or systemic cooling is recommended for newborns with HIE. The inclusion criteria include (Committee on Fetus and Newborn et al., 2014):
• ≥36 weeks gestation and <6 hours
• Apgar ≤5 at 10 minutes
• Continued need for resuscitation at 10 minutes after birth or
• pH <7.0 or base deficit ≥16 mmol/L and
• Moderate or severe encephalopathy on clinical examination
ii. Therapeutic hypothermia for children with HIE has not been studied exten- sively and recommendations do not exist (Imataka & Arisaka, 2015).
2. Direct Care
a. Immediate care is directed at resuscitation and stabilization of the child.
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b. There is no specific treatment for HIE that is widely accepted. Interventions are support- ive and directed at the cause of the hypoxic–
ischemic event.
3. Supportive Care
a. Support normal hemodynamics for ade- quate CBF.
b. ICP monitoring is not recommended. NIRS may be used for trending brain tissue oxygenation.
c. Maintain normothermia in the child; thera- peutic hypothermia is recommended for neona- tal HIE.
d. Maintain normal serum glucose levels.
e. Prevent and control seizures.
E. Outcomes
1. Outcomes vary and depend on the characteris- tics of the hypoxic–ischemic event, age of patient, and interventions.
2. Neurologic signs on admission are not always predictive of neurologic outcome.
3. Although the data are inconsistent, several pre- dictors associated with poor outcome include
a. In normothermic children, absence of motor and pupillary (Abend et al., 2012)
b. Presence of seizures c. Cardiopulmonary arrest
d. Severe MRI and EEG abnormalities
SPINAL CORD INJURY A. Definition and Etiology
1. Complete cord injury is the complete loss of motor and sensory function due to interruption of nerve pathways below the level of the injury. Quadriplegia is the complete loss of leg function and loss or lim- ited use of arms from cervical injury. Paraplegia is the loss of leg function alone from high lumbar injury.
2. Incomplete cord injury causes some loss of motor and sensory function with some sparing of function below the level of the injury.
a. Posterior cord syndrome is caused by injury to the dorsal columns. There is loss of proprio- ception but other sensory and motor function is preserved.
b. Anterior cord syndrome from injury to the anterior cord results in loss of motor function below the level of the injury. Sensory function is lost except for proprioception and vibration sense.
c. Central cord syndrome is caused by injury or edema to the central spinal cord in the cervical area. Greater motor deficits occur in the upper extremities compared with the lower extremi- ties. Sensory deficits are variable but are usually greater in the upper extremities. Bowel and blad- der dysfunction is common.
d. Partial spinal cord syndrome (Brown–Séquard’s syndrome) results from injury to one side of the spinal cord, resulting in loss of voluntary motor function on the same side as the injury. Loss of pain, temperature, and touch occurs on the con- tralateral side.
e. Conus medullaris is an injury to the sacral cord and lumbar nerve roots, resulting in an are- flexic bladder, bowel, and lower limb.
3. SCI is rare in children compared to adults, but when it does occur, the upper cervical spine is more commonly injured in small children than in adoles- cents and adults (J. R. Leonard, Jaffe, Kuppermann, Olsen, & Leonard, 2014).
4. Children have a higher incidence of spinal cord injury without radiographic abnormality (SCIWORA).
This condition occurs predominantly in younger children and is thought to result from severe sub- luxation and trauma of the vertebral column. Infants and young children (usually <8–10 years of age) have ligamentous flexibility and elasticity of the imma- ture spine. The spinal column can withstand signif- icant stretching without disruption. In contrast, the spinal cord cannot withstand significant stretch. The mismatch between the spinal column and the spi- nal cord predisposes the young child to SCI. Young children are also more prone to dislocation without fracture. When fractures do occur, the characteristics of the fracture vary with skeletal maturation.
5. Adolescents have a higher incidence of SCI and the mechanisms and patterns of injury closely resemble those of adults. Unlike young children, fractures are more common and soft tissue injury is less common. Subaxial cervical spine injuries (C5 and C6) are more common than axial injuries.
6. Mechanisms of SCI differ between children and adults. In children younger than 8 years old, the most common cause of SCI is motor vehicle related followed by falls. Motor vehicle and sports-related