Fig. 9.1
Concussion pathophysiology
The force of the blow and resulting energy transfer sets off a complex cascade of neurochemical events that lead to the disruption of cell membranes and an indiscriminate efflux of ions. The disorganized efflux of ions results in an unregulated release of neurotransmitters that disrupts the ionic balance of the cell. Potassium goes to the extracellular space which results in the calcium-dependent release of excitatory amino acids (glutamate). This drives more potassium to the extracellular space. The Na/K ATP-dependent pump actively attempts to reestablish homeostasis which requires a large amount of energy, depleting cell energy stores (Barkhoudarian et al. 2016). This leads to an energy crisis. The depletion of glucose used for energy necessitates a trigger of anaerobic metabolism that leads to an accumulation of lactate. Further dysfunction leads to the activation of enzymes that cause cellular dysfunction and cell death. The excitatory neurotransmitters further cause a disruption of the ion transport and cellular membranes. The disrupted cascades impair the ability to metabolize glucose, and in the pediatric population, this is even more increased due to the ongoing maturation changes of the developing brain (Prins and Matsumoto 2016). The mitochondrial oxidative function is noted to be diminished up to 10 days after injury requiring alternative energy sources (Barkhoudarian et al. 2016). After this increase in metabolism, there is a hypometabolic state that may persist for up to 4 weeks after injury (Yoshino et al. 1991; Sunami et al. 1989; Halstead and Walter 2010; Barkhoudarian et al. 2016). The pediatric brain is extremely vulnerable to further injury during this time period.
The developing brain is more sensitive to glutamate-induced NMDA excitotoxicity than the fully developed adult brain. Animal models have shown NMDA receptors appear to play a role in the disruption of normal brain development and disruption of plasticity. The theories draw strongly on the diffuse brain injury temporarily arresting the capacity for plasticity due to the decreased NMDA receptor function (Fineman et al. 2000). Although there are many theories about the particular differences between pediatric and adult brain injury pathophysiology, as of yet there are few scientific studies.
9.7 Physical Exam
9.7.1 Initial Evaluation
The first step of concussion management is recognizing the concussion. Since there are no clear radiographic findings associated with concussion diagnosis and management, it is especially critical to use a multifaceted approach when assessing and treating concussion (Guskiewicz et al. 2013; Resch et al. 2013). It is not unusual that the signs of concussion present subtly, such as walking to the wrong side of the field after the hit or being amnestic to the injury event. The player may describe the event as having his/her “bell rung” or “seeing stars.” The player may appear stunned or dazed or have no recollection of the recent play. Retrograde (before the event) or anterograde (after the event) amnesia may be one of the only signs. Often the initial provider is a parent, trainer, coach, or even school nurse, and for this reason, it is important they be aware of the signs and symptoms of a concussion.
On field assessment tools can and should be used in order to ascertain if a player qualifies for return to play. There should be a systematic approach to on-field and sideline evaluation, first by using a basic neurological assessment to distinguish a more serious injury such as a neck injury or intracranial injury. Once the more serious injury has been excluded, the sideline evaluation can be as basic as reviewing a symptom checklist and cognitive evaluation including orientation, immediate memory, and fundamental balance testing. There are also more sophisticated tools such as the Maddocks Questions, the Standardized Assessment of Concussion, and the modified Balance Error Scoring System. Each of these provides a component of the concussion assessment.
Players frequently resist being withdrawn from play for concussion assessment. Despite their protestations, they should be removed and not allowed to return to play the same day or until symptom-free. It is also important to determine what is a concussive injury versus a more serious injury requiring immediate medical attention.
9.7.2 History of Injury
Acquiring a detailed history is extremely important for the evaluation of a concussion as well as the postconcussion management. The history should include the mechanism of injury; the initial signs and symptoms; amnesia; past diagnosed concussions; previous associated symptoms; any past injury that involved the head, face, and/or cervical spine; and the state of consciousness. The history should also include the use of protective equipment for sports-related injury. It is also important to note the severity of the concussive symptoms and if they are disproportionate to the injury as this may indicate an increased susceptibility to concussive injury. This information apprises the provider for current and ongoing care.
9.8 Signs and Symptoms
While most concussions are mild, there are some that require emergent attention. It is vital to identify these signs especially in the first 24–48 h. The child should be taken to the nearest emergency room if there is persistent headache that increases in severity or a neurological change such as drowsiness or lethargy. Other signs that require emergency attention include persistent vomiting, slurring of speech, any loss of consciousness, seizures, or increased agitation (Table 9.1). Any of the symptoms can manifest in varying degrees of severity and should be taken seriously. Children should be observed closely by a responsible adult for the first 24 h after a concussion to assess for any decrease in neurological status.
Table 9.1
Warning signs requiring immediate medical attention
Warning signs |
|---|
Loss of consciousness |
Agitation |
Confusion |
Slurred speech |
Persistent headache |
Persistent vomiting |
Unequal pupils (new onset) |
9.9 Concussion Symptoms
Concussion symptoms can be physical, cognitive, and emotional and can disturb sleep. The physical symptoms include headache, nausea, vomiting, photophobia, tinnitus, visual disturbance, balance problems, and dizziness. Rarely, these symptoms include loss of consciousness. The cognitive symptoms include fogginess, psychomotor retardation, difficulty with concentration, reduced short-term memory, irritability, sleep disturbance, and emotional lability (Table 9.2).
Table 9.2
Symptoms of concussion
Physical | Cognitive | Emotional | Sleep |
|---|---|---|---|
Headache | Foggy | Irritability | Drowsiness |
Nausea/vomiting | Slowed down | Sadness | Sleeping more than usual |
Balance problems | Difficulty concentrating | More emotional | Sleeping less than usual |
Visual problems | Difficulty remembering | Nervousness | Difficulty falling asleep |
Fatigue | Forgetful | ||
Sensitive to light and noise | Confused | ||
Dazed | Answers slowly | ||
Stunned | Repeats questions |
In the very young, many of these same symptoms may be present; however, the infant, toddler, or preschool-age child may not have the vocabulary or communication skills required to express a severe headache or visual disturbances. A headache and irritability may be represented by inconsolability and increased crying. These factors should be taken into consideration in the decision-making for treatment management. If there is a suspicion of a concussion in the very young, then immediate medical attention should be sought. Small children are often admitted to the hospital for symptomatic treatment with antiemetics, intravenous fluid administration, and close monitoring for any neurological decline.
Frequently, someone with a concussion will exhibit a multitude of symptoms that can be self-limited and short lived but cause acute impairment of neurologic function. This is a functional disturbance rather than a structural injury, as the radiographic imaging is negative. These symptoms do not necessarily require the loss of consciousness and in most cases the symptoms are self-reported with a variability in severity. Usually the patient returns to baseline anywhere from several days to several weeks. The vast majority of concussions (80–90%) are reported to resolve within 7–10 days, although children and adolescents may take a longer time to recover (McCrory et al. 2013). However with the fluctuation in symptoms and severity, there must be appropriate care by a medical provider knowledgeable about concussion management.
9.9.1 Physical Examination and Objective Assessments
A full physical exam should be completed to ensure that no other injuries are missed. Special attention should be paid to the neurological exam with particular consideration to balance and cognitive testing.
Initial management incorporates a period of brain rest such as refraining from the use of computer, phone, or television screens. This includes abstaining from reading and minimizing situations that would overstimulate the patient with sound or lights. If there is no improvement of symptoms after 7–10 days, there should be serious consideration made to referring the patient for specialized concussion care and further testing.
9.9.2 Balance
Significant balance problems or postural instability has been noted in patients with concussion (McCrory et al. 2012, 2013). Balance testing is used as an objective assessment tool (Furman et al. 2013; McCrory et al. 2012). The most common assessment of balance is the Balance Error Scoring System (BESS).
The BESS entails testing the patient on a firm surface, in addition to an irregular surface such as foam, for three separate sections that last 20 seconds each. The first section has the patient standing with feet together and hands on the hips while the eyes are closed. The test is scored based on any fluctuation from this stance such as opening eyes, hands off hips, a step, a stumble, a fall, or movement of the hips more than 30°. Each of these is considered an error. The test is repeated with single leg stance on the nondominant leg and then once again with a heel-toe stance with the dominant leg in front (a tandem stance). The BESS best separates the healthy participant from a patient with a concussion (Furman et al. 2013). The BESS has been noted to be highly specific but with low sensitivity rate (Giza et al. 2013). The BESS data is most useful when there is an established baseline for comparison, and there should be some consideration to the fatigue of the patient as well as any injury that may impede participation such as ankle or leg instability or pain.
There are several other balance assessment tools that obtain computerized posturography data to assess the amount of sway in certain positions on a force plate. Although these tests may provide greater sensitivity, the equipment can be cost prohibitive and has not been studied to the degree of the BESS. These other technological methods will require further investigation before definitive conclusions can be drawn.
9.9.3 Cognitive Assessment
The cornerstone of concussion diagnosis and evaluation is subjective symptom reporting. Since the diagnosis is made on the basis of subjective symptoms, the cooperation of the athlete is paramount. However, standardized cognitive measures of memory can be used as possible indicators of concussion. There are objective measures to assess short-term memory, working memory, attention, and concentration, all areas that can be affected by a concussion. Neuropsychological and cognitive testing has been a useful tool for determining return to play and return to learn decisions. This testing is especially useful when there is a baseline for comparison. Many schools do cognitive testing before the season and use that as a baseline after concussion or at the end of the season.
Neuropsychological testing can be done with paper and pencil as well as in a computerized setting. One example of computerized testing is the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). The ImPACT test is a 20 min computerized test used to assess verbal memory, visual memory, reaction time, impulse control, and information processing. The greatest advantage of computerized testing is the ease of administration and scoring. However, the disadvantages include the need for specialized training for evaluation and the cost. The Sport Concussion Assessment Tool 3rd edition (SCAT3) is a paper and pencil tool for use only by medical professionals to evaluate for concussion in athletes 13 years and older. It assesses cognitive function, level of consciousness, balance, and symptoms. For children 12 years and younger, the Child SCAT3 can be used (bjsm.bmj.cm 2016). The Zurich Consensus Statement recommends neuropsychological testing be administered and interpreted by a licensed neuropsychologist( McCrory et al. 2013). The use of neuropsychological testing in the pediatric population is especially useful for determining readiness for return to school. Since most concussion management strategies often include some extended cognitive rest, such as “screen rest” and restricted school/class attendance, testing can direct the extent of modification for academic accomodations. This testing is also useful in the identification of attention deficit disorders as well as learning disabilities.
9.9.4 Vestibular Testing
Vestibular and ocular motor deficiencies have been noted in patients with concussions. As of yet there is still not a gold standard clinical screening tool for assessing and monitoring these abnormalities. The King-Devick (K-D) test is a visual recognition and reaction time test to track rapid eye movements and detect reading difficulty. The K-D requires the participant to read unevenly spaced single digits left to right as quickly and accurately as possible. The results provide objective measures of brain function and eye movement impairments, as well as balance, attention, language, and visual recognition skills. The K-D test is also sensitive to neurological changes seen in concussion. It can be used to identify patients who have not reported or shown signs or symptoms of a concussion but actually have sustained a meaningful head injury (Galetta et al. 2011; King et al. 2013).
Vestibulo-oculo dysfunction (VOD) has been detected in the pediatric population with acute concussions and postconcussion syndrome (PCS) (Ellis et al. 2015). Vestibular/Ocular Motor Screening (VOMS) includes assessment of smooth pursuit, horizontal and vertical saccades, near point convergence distance, horizontal vestibular reflex, and visual motion sensitivity. VOMS testing has demonstrated the ability to identify patients with a concussion (Anne Mucha et al. 2014), but there is still not enough data to incorporate into a concussion treatment and management strategy.
9.10 Treatment
9.10.1 Management Strategies
Although most concussed athletes can be managed on an outpatient basis, initial management may include addressing severe symptoms, such as nausea and vomiting that may require an antiemetic or intravenous fluid resuscitation. Headache may be managed with nonsedating medication such as acetaminophen. Nonsteroidal medication should be avoided in the very early period due to possible risk of bleeding. Increased severity in these symptoms may need to be further explored with a CT or MRI to rule out more severe intracranial pathology.
The mainstay of management includes cognitive and physical rest (McCrory et al. 2013). Cognitive rest requires minimizing unnecessary auditory and visual stimulation. The concussed brain needs to rest, much like resting a physical injury such as a sprained ankle. The patient may need to refrain from schoolwork or work and abstain from reading, television viewing, use of computers, texting, video games, or cell phone use. Lights may need to be dimmed and noise level may need to be reduced. There may need to be a reduction in social outings and trips out of the home, with an environment that promotes rest as well as a restful sleeping environment (Moser et al. 2012). Care must be taken when recommending cognitive rest. Not only can the effects of concussion cause depression, but keeping the athlete away from their sport, school, and friends can further contribute to their depression.
Physical activity and exertion should be introduced slowly with coach/trainer input for return to play decisions after return to learn has been completed. The reintroduction of physical activity should be done at a graduated level not all at once (Meehan et al. 2011). Exposure to activities that may cause a concussion should also be eliminated until there has been resolution of symptoms and clearance from a medical professional experienced in concussion management (Majerske et al. 2008).
Vestibular rehabilitation is used for evaluation and as a treatment modality of select concussion symptoms such as dizziness and gait instability. Improvement has been noted for self-reported symptoms as well as objective evaluation of dizziness and gait in all age groups (Alsalaheen et al. 2010; Thornton and Carmody 2009).
The upper cervical spine is more vulnerable to trauma due to the increased mobility in this particular region of the vertebral column (Kristjansson and Treleaven 2009). There has been a noted difference in the strength of male and female athletes (Tierney et al. 2005). The neck strength of the male athlete is stronger than in the female athlete and also stronger in the collegiate athlete as compared to the high school athlete (Hildenbrand and Vasavada 2013). Cervical therapy has been integrated with vestibular rehabilitation with reported results of quicker return to baseline (Hugentobler et al. 2015; Leddy et al. 2012; Schneider et al. 2014). The use of cervical therapy focuses on the positioning of the cervical joint position into a neutral position and assisting with the range of motion of the cervical spine (Kristjansson and Treleaven 2009). This therapy has had some success with cervicogenic headaches, and the treatment has been extrapolated for use with postconcussion symptoms (Racicki et al. 2013).
Biofeedback and neurofeedback have also been proposed as treatment modalities for concussion symptoms. There are select studies indicating some success with feedback therapy involving headache and concussion (Andrasik 2010; Thornton and Carmody 2009).
Neuropsychology testing, as all other testing, should not be attempted until the patient is able to tolerate the stimuli testing might introduce. Neuropsychological testing is most useful when interpreted by a neuropsychologist and compared to baseline studies but is beneficial for return to learn and return to play decisions (McCrory et al. 2013).
9.11 Diagnostic Findings
Conventional neuroimaging is usually normal in patients with concussion as the injury is metabolic rather than structural. However, computed tomography (CT) and magnetic resonance imaging (MRI) are diagnostic tools for acute brain injury management and should be obtained for symptoms such as severe headache, seizures, focal deficits, repeated emesis, significant drowsiness or difficulty awakening, slurred speech, poor orientation, or significant irritability. CT is most useful for radiographically visible changes such as acute hemorrhage, contusions, or skull fractures but does not show structural damage related to concussion diagnosis. The accessibility and ease of a acquiring a CT is often why it is obtained in the acute period, but it has the risk of radiation exposure. Standard MRI is also helpful in showing acute changes such as blood and cerebral edema and in some instances diffuse axonal injury, but it too lacks the ability to indicate concussion-related structural changes (Lee et al. 2008). An MRI takes longer than a CT scan and can require sedation in the pediatric population. A CT scan is recommended for patients with altered mental status (LOC), severe mechanism of injury, or acute worsening of symptoms. This tool is more for differentiating a more underlying serious injury from a concussion.
Functional MRI (fMRI) evaluates the measures of brain function based on changes in blood flow in the cranial capillaries (Raichle and Mintun 2006) and may be helpful in identifying concussion injury not seen on standard CT or MRI and may provide information of residual deficits (Chen et al., 2004).
There have been some preliminary studies using diffusion tensor imaging (DTI), an advanced neuroimaging modality that is based on tissue water diffusion rate. DTI views soft tissue on a microstructural scale and can detect subtle changes in a three-dimensional visualization of white matter tracts. The focus of these studies is to determine any correlation of postconcussive symptoms with white matter integrity (Toledo et al. 2012). Although studies have demonstrated changes in the white matter integrity, it is still unclear what this signifies or what it might mean in the short or long term to concussion management or diagnosis (Mayer et al. 2013).
Recently, there has been some work toward identifying TBI biomarkers present in human serum. The biomarker glial fibrillary protein (GFAP) is found in the serum of patients with TBI at high levels within a few hours of injury (Papa et al. 2012). It is still early days in the study of biomarkers, and it is unclear what role this will have in managing TBI patients during initial injury or subsequent injuries, or if this could be an indicator for return to play or return to school. Although preliminary studies have indicated some positive results for human serum biomarkers, there is still no clinical indication for use, and further study will be needed (Papa et al. 2015).
9.11.1 Nursing Care
Pediatric concussion patients may be seen in the emergency department but are typically not admitted. Many centers now have nurse-led concussion clinics where children and adolescents are managed on an outpatient basis.
The developmental age of the child needs to be considered, as well as symptoms such as amnesia, depression, LOC, and female gender. Determining a concussion evaluation should be based on the ability of the patient to advocate for themselves and individual considerations. Pediatric vs. adolescents require different tools to determine efficacy. An age-appropriate pain scale may be used for pediatric patients that are not able to verbalize feelings, whereas a symptom checklist would be appropriate in the adolescent population. Anxiety or depression may affect recovery. The patient should be evaluated as a whole by utilizing symptom checklists, neurocognitive evaluations (testing memory and recall), and neurological exam including balance and reaction (Apps and Walter 2012).
Pain control (pharmacological and nonpharmacological) should be considered for patients using self-reported and parent-reported symptoms. However medication intervention should be restricted to nonnarcotic medication such as acetaminophen. Nonsteroidal and aspirin-containing products should be avoided in the acute period. Narcotics can mask symptoms of neurological decline, and nonsteroidal medication such as ibuprofen or aspirin may cause bleeding. Antiemetics can be given for persistent nausea and vomiting.
Managing the environment is key for inpatient care. Environmental stimulation should be minimized and nursing care bundled so as not to inundate the patient and allow time for rest. Lowering the lights and decreasing noise and activity are also significant components. If the patient must have a roommate, assign a patient with similar issues that would benefit from a restful environment. Encourage ice packs at the base of the neck and fluid intake to flush proteins from the brain.
9.11.2 Patient and Family Education
Nurses play an essential role in the treatment and education of patients and their families after a concussion (Evans 2014). From the standpoint of education, Table 9.3 shows some of the common myths or misconceptions that nurses should be aware of. Care extends to the home environment. Decreasing visual stimulation in the early days postconcussion encourages brain rest. Decreased visual stimulation includes decreased screen time (phones, television, computer, etc.). It also includes decreased reading. Cognitive rest breaks are also encouraged. When the patient has a trigger that brings on a symptom (such as light, noise, activity, computer activity, or walking), it is advisable to take a cognitive rest break. Recognizing activities that trigger symptoms and stepping back from the activity for a 5 min break may be a sufficient amount of time for the patient’s symptoms to decrease.
Table 9.3
Common concussion myths
Myth: everyone with a concussion needs a CT scan or MRI right away |
Fact: while there is damage to the brain cells in a concussion, the damage is at a microscopic level and cannot be seen on MRI or CT scans. The concussed brain looks normal on these tests, even though it has been seriously injured. These modalities are reserved to ensure there is not a more serious intracranial injury. |
Myth: do not treat the headache from concussion with any medications because it may mask some symptoms |
Fact: over-the-counter pain relievers, as ordered by the physician, are fine to use. At times prescription medicine may be needed |
Myth: someone with a concussion should be awakened every 2–3 h
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