e91CHAPTER 136 Board Review Questions not required for the diagnosis, unless the MRI raises concern for an alternative process, such as a neoplasm Chapter 60 Neurologic Assessment and Monitoring 1 In[.]
CHAPTER 136 Board Review Questions not required for the diagnosis, unless the MRI raises concern for an alternative process, such as a neoplasm Chapter 60: Neurologic Assessment and Monitoring In a child with brain injury, closely monitoring and controlling all of the following vital signs except for one may influence neurologic outcomes A Oxygen saturation B Blood pressure C Heart rate D Oxygen saturation E Temperature Preferred response: C Rationale While there is debate about the optimal intracranial pressure and cerebral perfusion pressure to target in the management of severe traumatic brain injury, the current guidelines recommend monitoring both and provide thresholds for intervention Similarly, hypoxia has been associated with poor outcome and should be monitored and corrected Heart rate monitoring is not a specific recommendation in the guidelines Where in the neuraxis does a pattern of weakness transition from upper motor neuron (increased tone and hyperreflexia) to lower motor neuron (flaccid tone and hyporeflexia)? A Anterior horn cell B Brainstem C Cerebral cortex D Peripheral nerve Preferred response: A Rationale This is a simple and effective component of the neurologic examination which can assist in localizing neurologic insults Loss of inhibitory input from the cortex to the spinal reflex arc results in hyperreflexia (an upper motor neuron sign) This lesion may occur along the pathways from the cortex via the white matter, the brainstem, corticospinal tracts in the spinal cord and terminates at the anterior horn cells Lesions at the anterior horn cell and distal to it will result in weakness, low tone and diminished or absent reflexes In which of the following scenarios would continuous electroencephalography (EEG) be the least helpful? A Adjunctive detection of cerebral ischemia in high risk patients B Detection of nonconvulsive seizures C Diagnosis of delirium D Prognostication after cardiac arrest and severe traumatic brain injury Preferred response: C Rationale The most robust indication for the use of cEEG in critically ill children is for the detection of nonconvulsive seizures When used in combination with serial neurologic examinations, the EEG background and reactivity may be used to guide assessment of prognosis The literature in children supporting its use to detect ischemia is limited, and this is not a standard indication cEEG is not used for the diagnosis of delirium e91 Which of the following neuroimaging modalities is most sensitive for detection of acute intracranial hemorrhage? A Computed tomography (CT) B Magnetic resonance imaging (MRI), gradient echo or susceptibility weighted image C Transcranial doppler (TCD) sonography D Ultrasound through an open fontanelle Preferred response: A Rationale Ultrasound may detect hemorrhage and is used as the first choice in neonates These specific MRI sequences are highly sensitive to blood, but CT is the most commonly used modality of evaluation for suspected cerebral hemorrhage in non-neonates Intracranial hemorrhage may result in abnormal cerebral blood flow and change TCD velocities, but this is not specific Which of the following is least likely to be associated with an acute increase in intracranial pressure (ICP)? A Bradycardia B Declining level of alertness C Hypotension D Restriction of eye movements Preferred response: C Rationale The Cushing response is a combination of hypertension and bradycardia resulting from increased intracranial pressure The associated pressure on the sixth cranial nerve may result in a lateral gaze palsy as the innervation to the lateral rectus muscle is compromised Hypotension may be a late finding with severe compromise of brainstem function but is not part of the acute response to increased ICP Intracranial pressure (ICP) monitoring has been shown to be most useful in directing therapy in which of the following situations in children? A Hypoxic-ischemic encephalopathy B Diabetic ketoacidosis (DKA) with cerebral edema C Stroke D Traumatic brain injury Preferred response: D Rationale The most common indication for ICP monitoring in critically ill children is traumatic brain injury (TBI), in which the measurement of ICP directs therapy with the goal of preventing the secondary complications of TBI resulting from cerebral hypoperfusion or metabolic stress For children with severe TBI, a cerebral perfusion pressure (CPP) between 40 and 65 mm Hg is recommended, and a CPP of 60 to 70 mm Hg is recommended for adolescents Optimal CPP levels for children younger than years of age have not been established The benefits and complications of ICP monitoring are unproved for other conditions in which ICP may be increased (e.g., DKA, meningitis, metabolic disorders, ALF, stroke, brain tumors, cardiac arrest, hypoxic-ischemic encephalopathy, drowning) Similarly, data on treatment goals of ICP or CPP specific to each insult are lacking e92 S E C T I O N XV Pediatric Critical Care: Board Review Questions Which of the following statements is correct regarding cranial nerve examination? A Absence of all eye movement with intact pupil light reflex suggests insult to the pons B Cold caloric stimulation that produces nystagmus with the rapid phase ipsilateral to the ear that has been stimulated indicates intact functioning of the cerebral cortex C Failure to move only the mouth with preservation of upper face movements indicates seventh nerve palsy D Roving eye movements are more common with metabolic disorders Preferred response: D Rationale The pupillary reaction to light is abolished only by structural damage to the midbrain or third cranial nerve Loss of the pupillary reflexes is always an ominous finding Preservation of pupillary reflexes in the presence of deep coma suggests a metabolic-toxic cause Eye movements are assessed first by observation and then elicited in the patient with depressed mental status by using the doll’s head maneuver (oculocephalic response) or cold caloric stimulation (oculovestibular response) In general, coma produced by metabolic dysfunction is initially associated with roving, dysconjugate movement and may progress to the cessation of movement Cold caloric stimulation produces nystagmus with the rapid phase contralateral to the ear that has been stimulated This rapid phase is the equivalent of saccadic eye movements and also indicates intact functioning of the cerebral cortex The ears are irrigated separately several minutes apart In comatose patients the fast “corrective” phase of nystagmus is lost, and the eyes are tonically deflected to the side irrigated with cold water or away from the side irrigated with warm water These vestibuloocular responses are lost or disrupted in brainstem lesions Versive eye deviation is a common finding suspicious for seizures In this case, the eye deviation is contralateral to the hemisphere with the ictal focus Alternatively, stroke in the ipsilateral hemisphere may also produce versive eye deviation toward the side of the stroke An abnormal corneal reflex may indicate either fifth nerve afferent disease (ipsilateral stimulation results in neither a direct nor consensual eye blink) or seventh nerve efferent disease (ipsilateral stimulation results in a brisk consensual but no direct response) Unilateral weakness of eye closure, forehead movement, and mouth movement indicates peripheral seventh cranial nerve palsy, whereas failure to move only the mouth with preservation of upper face movements indicates a central corticospinal tract lesion rostral to the pons Facial weakness may be noted during grimacing while responses to painful stimuli are evaluated Voluntary pharyngeal and laryngeal control can be tested by asking the patient to say “ah.” In the absence of voluntary movement, a hypoactive gag indicates medullary or vagal dysfunction, and a hyperactive gag indicates interruption of corticospinal inhibition to the medulla Which of the following lesions would most likely explain the presence of a distal pattern of weakness in a child? A Lower motor nerve (LMN) injury B Myopathic process C Neuropathic process D Upper motor nerve (UMN) injury Preferred response: C Rationale Acute UMN lesions result in a hypotonic or flaccid pattern of weakness, and in the legs they may be associated with the Babinski sign In contrast, chronic UMN injury results in a hypertonic limb with associated hyperreflexia A LMN pattern of weakness is more likely to be associated with a decrease in muscle tone and bulk and decreased or absent reflexes In general, proximal weakness suggests a myopathic process, whereas a distal pattern of weakness suggests a neuropathy The precise incidence of ICU-acquired weakness (ICU-AW) is uncertain in children An 8-month-old boy is admitted to the pediatric intensive care unit from the emergency department after presenting with a focal seizure followed by status epilepticus requiring treatment with two mg/kg doses of lorazepam and a single dose of 20 mg/kg phenytoin, after which he underwent intubation for airway protection A physical examination shows signs of inflicted trauma with retinal hemorrhages and bruises of different ages Twelve hours later, the examination is significant for normal vital signs, reactive pupils, and withdrawal to vigorous nailbed pressure Findings of a computed tomography (CT) scan of the head are normal Of the following options, which is the best approach for monitoring neurologic function in this case? A Monitor with continuous electroencephalography (EEG) for 12 to 24 hours B Perform a lumbar puncture C Perform repeat neurologic examinations with a repeat CT scan of the head if extensor posturing develops D Perform brain magnetic resonance imaging (MRI) with MR spectroscopy and diffusion-weighted imaging now Preferred response: A Rationale The failure of the level of alertness to improve after resolution of clinical seizures should lead to a consideration of nonconvulsive seizures In this case, although several risk factors exist for increased intracranial pressure following inflicted head trauma, this is less likely based on the presence of normal vital signs, reactive pupils, and withdrawal to pain, in addition to the CT scan Therefore the next diagnostic study would be an EEG Prolonged EEG monitoring is preferred because of its greater sensitivity for detecting nonconvulsive seizures Infection is less likely given the evidence for trauma as the primary etiology Supratherapeutic phenytoin levels may cause obtundation, but given the patient’s history, nonconvulsive seizures are more likely 10 A 10-year-old boy is struck on the right temple by a car door He has no loss of consciousness and can recall the event Four hours later he reports having an occipital headache and a loss of vision in one eye In the emergency department, he is afebrile with a normal blood pressure and heart rate During the evaluation he reports having a worsening headache and cannot recall three objects during the mental status examination; acute left-sided weakness develops, and he becomes less responsive Findings of a head computed tomography (CT) scan are normal, and he is transferred to the pediatric intensive care unit for physiologic monitoring Which of the following options is the most appropriate next step in neurologic monitoring? A Perform an EEG to evaluate for presence of nonconvulsive seizures B Perform intracranial pressure monitoring C Perform an MRI scan with diffusion-weighted imaging D Perform a CT angiogram of the head with intra- and extracranial vessels Preferred response: D CHAPTER 136 Board Review Questions Rationale This case represents a stroke due to dissection, a mechanism that accounts for 10% to 20% of cases of stroke in the young The history of trauma followed by an occipital headache suggests a posterior circulation dissection with thalamic stroke This diagnosis is supported by the symptoms of memory loss and a vision field defect, along with the decline in responsiveness Findings of the initial head CT scan are normal because the scan was obtained early after the stroke Confirming the presence of a dissection with a CT angiogram will guide therapy, and anticoagulation will be indicated if the dissection is extracranial and a subarachnoid hemorrhage has been ruled out Chapter 61: Neuroimaging The radiographic shunt series is NOT the primary imaging modality in the diagnosis of which of these CSF shunt complications? A Disconnection of the reservoir from the proximal catheter B Fracture of the distal catheter C Migration of the distal catheter into the scrotal sac D Improper placement of the distal catheter tip in the subcutaneous tissues of the abdominal wall E Shunt infection Preferred response: E Rationale The most commonly performed radiographic study in neuroimaging is the radiographic shunt series The cerebrospinal fluid (CSF) shunt is imaged in the frontal and lateral projections to evaluate the location and course of the proximal catheter, reservoir, valve, and distal catheter and detect complications such as disconnection, fracture, improper placement, and migration Cranial ultrasound is NOT very sensitive in the diagnosis of which one of these entities in the neonate? A Germinal matrix hemorrhage B Hydrocephalus C Intraventricular hemorrhage D Large intraparenchymal hemorrhage E Noncystic periventricular leukomalacia Preferred response: E Rationale In the premature infant, ultrasound (US) is the primary modality for detection, grading, and follow-up of germinal matrix hemorrhage (grades to 4) and its complication, hydrocephalus US may be used to assess for large parenchymal and extraaxial hemorrhage as well as white matter injury including periventricular leukomalacia, especially the cystic form However, MRI will be more sensitive for noncystic periventricular leukomalacia Which structure has the highest density on CT? A Air B Fat C Bone D Brain E Cerebrospinal fluid Preferred response: C Rationale Bone and other calcifications have the highest density; the other components of the body in order of decreasing density are nonadipose soft tissue (e.g., brain and liver), water (e.g., CSF), fat, and air e93 A critically ill teenager in the ICU develops new-onset right arm weakness Which of the following MRI sequences would be most sensitive and specific to detect acute infarct? A Gradient echo sequences (GRE) B Diffusion-weighted imaging (DWI) C Magnetic resonance angiography (MRA) D T1-weighted imaging E T2-weighted imaging Preferred response: B Rationale Diffusion-weighted-imaging (DWI) is very sensitive to detect acute brain ischemia Signal abnormality is typically present within the first few hours following an infarct and has a typical pattern of evolution Other sequences can be complementary, such as T2 sequences, to look for cerebral edema and mass effect or GRE and T1 sequences to look for hemorrhage A 10-year-old child is admitted with subarachnoid hemorrhage (SAH) on computed tomography (CT) and concern for arteriovenous malformation (AVM) is raised What should be the gold standard exam for ruling out an AVM? A Conventional angiogram B Computed tomography angiogram (CTA) C Magnetic resonance angiogram (MRA) D Ultrasonography Preferred response: A Rationale CTA is not sensitive for the smallest vascular malformations and does not give temporal information (early venous filling) Magnetic resonance imaging (MRI) will show flow voids from a large malformation, but this is less sensitive than MRA, a CTA, or a catheter angiogram Though newer techniques can give some temporal information, MRA does not have the same sensitivity as conventional catheter angiogram A catheter angiogram presently has the best vascular resolution and is most sensitive for early venous drainage, the sine qua non of AVM Ultrasound cannot evaluate for early venous drainage In addition, it has a limited window, as the anterior fontanelle is closed by this age A 5-year-old boy is admitted with encephalopathy, with a clinical question of acute disseminated encephalomyelitis (ADEM) What is the most sensitive study to evaluate the brain in this scenario? A Computed tomography (CT) B Magnetic resonance imaging (MRI) C Nuclear medicine D Transcranial Doppler Preferred response: B Rationale • MRI with and without contrast is the modality of choice in this scenario • Although CT scan is fast and sensitive for many pathologic states, MRI has much greater sensitivity for brain parenchymal lesions • Nuclear medicine has limited use in brain imaging currently and is mostly employed to assess for shunt malfunction, CSF leak, and brain death • Ultrasonography has a limited window and tissue discrimination and is mostly employed for scanning through open fontanelle for germinal matrix hemorrhage and ventricle size e94 S E C T I O N XV Pediatric Critical Care: Board Review Questions • Transcranial Doppler has limited use in brain imaging (e.g., sickle cell disease) and vascular spasm (e.g., following subarachnoid hemorrhage) A 28-week preemie infant weighing 1200 g has a sudden unexplained drop in hematocrit levels What does cranial ultrasonography detect best in the premature infant? A Acute cerebral ischemia B Germinal matrix hemorrhage C Small subdural hemorrhage D Subarachnoid hemorrhage Preferred response: B Rationale A sudden drop in hematocrit in a premature infant is a cause for concern about the possible development of germinal matrix hemorrhage, because germinal matrix vessels have thin walls and are friable, and these patients frequently lack effective vascular autoregulation Cranial ultrasonography is useful for the evaluation of the various grades of germinal matrix hemorrhage but is insensitive for evaluating the other forms of intracranial hemorrhage listed It also is suboptimal in the differentiation of a parenchymal hematoma and a tumor Left hemiplegia develops in a 3-year-old patient who is known to have Moyamoya disease What is the most sensitive modality for detecting acute cerebral ischemia? A Contrast-enhanced computed tomography B Diffusion-weighted magnetic resonance imaging (MRI) C T1-weighted MRI D Transcranial Doppler Preferred response: B Rationale Anterior circulation cerebral vascular occlusions frequently develop in patients with Moyamoya disease Diffusion-weighted MRI is the most sensitive and definitive sequence for detecting acute cerebral infarction and parenchymal injury The affected area is seen as high signal on the diffusion trace image and low signal on the apparent diffusion coefficient map The other modalities and MRI sequences listed may have supportive roles in diagnosis Chapter 62: Coma and Depressed Sensorium A patient admitted to the PICU has a rapidly deteriorating level of consciousness On exam, he now has a unilateral, dilated and nonreactive pupil and contralateral hemiparesis What type of herniation syndrome is he demonstrating? A Central B Subfalcine C Tonsillar D Uncal E Upward transtentorial Preferred response: D Rationale Uncal herniation occurs when a lateral expanding mass or edema pushes the uncus and hippocampal gyrus over the lateral edges of the tentorium This puts pressure on the brainstem, especially the ipsilateral midbrain A unilateral, dilated pupil and contralateral hemiparesis are the hallmark findings of uncal herniation These are due to pressure on the oculomotor nucleus and the corticospinal tract A 16-year-old female is admitted to the PICU with altered mental status She has an abnormal breathing pattern with rhythmic waxing and waning of respiratory amplitude She has small, equally reactive pupils She has no spontaneous movements but does demonstrate withdrawal of extremities to pain What is the most likely etiology of her coma? A Acute liver failure B Brain tumor causing uncal herniation C Medullary infarction D Pontine hemorrhage E Ruptured aneurysm at the level of the midbrain Preferred response: A Rationale The patient is demonstrating Cheyne-Stokes respirations, withdrawal of extremities to noxious stimuli, and equally reactive pupils The combination of above signs indicates cortical dysfunction, likely from a metabolic cause Of the above answer choices, only acute liver failure would cause cortical dysfunction without other ominous signs of brainstem dysfunction A 4-year-old male is transferred to the PICU with coma due to a newly diagnosed brain tumor On exam, he is unresponsive, with extensor posturing to noxious stimuli He has an abnormal breathing pattern with prolonged pauses after inspiration His pupils are pinpoint, bilaterally He has no corneal reflex, bilaterally Based on the above physical exam, what type of brain tumor is most likely? A Cerebellar medulloblastoma B Cervicomedullary astrocytoma C Diffuse intrinsic pontine glioma D Frontal cortical glioblastoma E Thalamic ependymoma Preferred response: C Rationale The patient is demonstrating signs of pontine dysfunction He has apneustic respirations and pinpoint pupils, which localize to the pons He also has dysfunction of cranial nerve VII, as indicated by a lack of corneal reflex A 3-year-old boy is in the PICU after a submersion injury He has intracranial hypertension and is on high doses of sedation to control his intracranial pressure On his fourth admission day, his parents ask about his neurologic prognosis Which of the following is the strongest indicator of a poor prognosis? A Absent somatosensory evoked potential on today’s exam B Computed tomography (CT) from admission with no evidence of cerebral edema C Electroencephalogram (EEG) from today showing lowamplitude waves D Lack of motor response on today’s exam E Pupils on admission that are mm and unreactive Preferred response: A Rationale Providing prognostication can be difficult in the setting of brain injury Physical examination findings on admission have not been shown to predict outcome, and are best evaluated at least CHAPTER 136 Board Review Questions 24 hours after presentation Sedative medications can impact both the physical exam, including pupillary size, and EEG findings Magnetic resonance imaging (MRI) has been shown to be more helpful in predicting outcome than CT, especially the diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) sequences Somatosensory evoked potentials (SSEP) are not affected by sedation, which make these a good choice when you have a patient that is requiring deep levels of sedation to control intracranial hypertension However, SSEPs can be affected by focal lesions such as hemorrhage or mass that interrupt conduction between the periphery and the somatosensory cortex However, in this patient with submersion injury, he is unlikely to have an intracranial hemorrhage or mass Therefore absent SSEPs are very concerning and predict an unfavorable outcome A 10-year-old male presents with altered mental status His parents mention that he plays shortstop on the little league baseball team and he was struck in the left side of his head by a foul ball as he stood in the on deck circle waiting to bat Though dazed, he was initially fine without complaints The patient’s coach, his parents, and emergency medical personnel evaluated him immediately after the injury and found no deficits The patient’s parents were reluctant to go to the emergency room, as he appeared well and no abnormality could be found His pediatrician was called, and given the reported normal exam and the fact that the patient was wearing a helmet, the pediatrician felt that his parents could watch him closely and report for evaluation should there be any change Regardless of his exam, the pediatrician requested that the patient be seen in the office the following day The patient was allowed to sit on the bench during the last two innings of the game The patient went to sleep shortly after arriving home After an hour the parents began to worry and woke him only to find that he would awaken but remained disoriented As they traveled to the ED, the parents noted that the patient had become less active and more difficult to arouse On physical exam, the patient lies still and he awakens to pain, but he never awakens to alertness A large hematoma is noted above his left ear The eyes are dysconjugate and the patient has a left-sided ptosis The left eye is fixed in a downward lateral gaze and the left pupil is dilated and only sluggishly reactive to light A brisk consensual response is noted in the right eye The patient’s right side is weak and hypertonic A positive Babinski reflex is noted in the right toe The patient’s eye exam indicates which of the following conditions? A A left optic nerve lesion B A left oculomotor injury C A right optic nerve lesion D A right oculomotor injury Preferred response: B Rationale This patient is likely in an early third nerve phase of uncal herniation due to an epidural hematoma that occurred as a result of his injury during the baseball game earlier in the day The patient displays signs of third nerve compression, oculomotor nerve involvement of the eye ipsilateral to the injury, depressed consciousness, upper motor neuron dysfunction, and contralateral weakness The abnormal gaze and pupillary dilation noted in the left eye are signs of left oculomotor nerve injury Because the e95 parasympathetic fibers that supply the sphincter pupillae muscles and the motor supply to all the extraocular muscles except the superior oblique (supplied by the fourth cranial nerve) and the lateral rectus (supplied by the sixth cranial nerve) are located peripherally around the third nerve, they are susceptible to early injury due to compression The result is an eye with a dilated pupil and a fixed gaze that is positioned inferiorly and laterally (“down and out”) The pupillary light reflect can evaluate the optic nerve (afferent—senses light) and the oculomotor nerve (efferent—pupillary and extraocular motor function) This patient’s left pupil has no response to direct light, but his consensual response is intact, suggesting that his motor function is impaired on the left but intact on the right His ability to sense light is intact on the left Therefore the ocular nerve is intact, and the patient has an oculomotor nerve defect In a patient with an acute brain injury, these findings are consistent with brainstem compression A 15-year-old boy is found unresponsive by a friend at home He is very bright and until recently has been a straight A student His parents state that lately he has become a victim of severe hazing and bullying at school He has a seizure that demonstrates a perfect Jacksonian March Your suspicion is pseudo seizure after you are told that he spent the summer working with his favorite aunt in her pediatric neurology office Following the seizure, you place his right hand over his forehead and allow it to drop It lands hard between his eyes Which test would most definitively suggest that this patient is not comatose? A A cold caloric test is performed, and you notice a slow conjugate deviation of the eyes toward the canal that is irrigated B A cold caloric test is performed, and you notice dysconjugate deviation of the eyes C A cold caloric test is performed, and you notice a slow conjugate deviation away from the canal that is irrigated D A cold caloric test is performed, and you notice fast jerky eye movements back to the midline Preferred response: D Rationale In an intact individual, rotational movement of the head produces eye movement of equal magnitude in the opposite direction Rotational movements of the head cause the endolymphatic fluid in semicircular canals to stimulate sensors (the ampulla and the cupula) within the inner ear that send excitatory and inhibitory signals to vestibular nuclei that cause the muscular contraction that moves the eyes in the opposite direction In general, the purpose of the vestibuloocular reflex is to maintain visual stability when the head moves (an advantage for hunters tracking prey) Both the doll’s eye response and caloric testing evaluate the integrity of the vestibuloocular motor response Although the doll’s eye response creates the rotational movement required to initiate movement of endolymphatic fluid in the semicircular canals, changing the temperature within the auditory canal will create similar movement Therefore, irrigation of the auditory canal with cold or warm water will produce a similar movement of fluid in the semicircular canals Cold water instilled in one ear causes endolymph in the ipsilateral semicircular canal to cool and sink, the same movement of endolymph that is created by moving the head away from that ear being irrigated (cold water in the right ear causes the same movement of endolymph in the right semicircular canal as moving ... of a distal pattern of weakness in a child? A Lower motor nerve (LMN) injury B Myopathic process C Neuropathic process D Upper motor nerve (UMN) injury Preferred response: C Rationale Acute UMN... consideration of nonconvulsive seizures In this case, although several risk factors exist for increased intracranial pressure following inflicted head trauma, this is less likely based on the presence... by this age A 5-year-old boy is admitted with encephalopathy, with a clinical question of acute disseminated encephalomyelitis (ADEM) What is the most sensitive study to evaluate the brain in this