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Pediatric Neurologic Disorders

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Question 61Question →

A 4-year-old boy is evaluated in the pediatric clinic due to a 4-week history of increasing unsteadiness and frequent falls. His parents note that he was previously running and climbing without difficulty but has recently begun walking with his feet wide apart. He also complains of head pain upon waking in the mornings, accompanied by two recent episodes of non-bilious emesis. His developmental history was previously normal. On physical examination, his temperature is 37.0°C (98.6°F), blood pressure is 115/75 mm Hg, pulse is 80/min, and respirations are 20/min. Fundoscopic examination reveals blurred optic disc margins bilaterally. He exhibits truncal ataxia and nystagmus on lateral gaze. Which of the following is the most appropriate next step in the management of this patient?

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Answer: Magnetic resonance imaging of the brain

Answer

Magnetic resonance imaging of the brain
The patient's presentation of a new-onset wide-based gait, morning headaches, vomiting, and bilateral papilledema is highly suspicious for a posterior fossa tumor (such as a medulloblastoma or pilocytic astrocytoma) leading to increased intracranial pressure. The most appropriate next step in management is to obtain neuroimaging, with an MRI of the brain being the modality of choice to clearly delineate the structural anatomy and identify the mass.

Step-by-Step Solution

1
Analyze the patient's presenting symptoms and timeline.
The patient has a 4-week history of morning headaches, non-bilious emesis, and progressive unsteadiness (ataxia).
Identifying the pattern of symptoms helps localize the lesion and determine the acuity of the disease process.
2
Interpret the physical examination findings.
Bilateral blurred optic disc margins (papilledema) indicate increased intracranial pressure, while truncal ataxia and nystagmus localize the pathology to the cerebellum.
Correlating physical findings with symptoms establishes a working clinical diagnosis of a posterior fossa mass.
3
Select the most appropriate next diagnostic step based on the suspected pathology.
Magnetic resonance imaging (MRI) of the brain is chosen to visualize the suspected tumor and evaluate the extent of ventricular enlargement.
MRI is the preferred imaging modality for the posterior fossa, and performing a lumbar puncture is contraindicated due to the risk of herniation from increased intracranial pressure.

Key Concept

Patients presenting with morning headaches, vomiting, papilledema, and cerebellar signs require urgent neuroimaging (preferably an MRI) to evaluate for a posterior fossa tumor. A lumbar puncture is strictly contraindicated in this scenario.
Estimated Time:1m 30s
Question 62Question →

During a routine health maintenance visit, the parents of a 5-year-old child express concern about multiple dark spots that have appeared on the child's skin over the past few years. The parents state that the child has generally been healthy. The father notes he was briefly worried when the child began walking independently at 14 months of age, but the child now runs, climbs stairs, and speaks in complete sentences. Vital signs are within normal limits for age. Physical examination reveals seven flat, uniformly hyperpigmented, oval macules measuring 10 to 15 mm in diameter scattered across the thorax and back. Distinct clusters of small freckles are also observed in the axillary and inguinal regions. The remainder of the physical and neurological examination is unremarkable. Based on the most likely diagnosis, which of the following are appropriate components of this patient's ongoing management? (Select 2)

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Answer: Referral for a comprehensive ophthalmologic evaluation; Close monitoring of blood pressure at regular intervals

Answer

The correct steps in management are referral for a comprehensive ophthalmologic evaluation and close monitoring of blood pressure at regular intervals.
The patient's clinical presentation of six or more café-au-lait macules and axillary/inguinal freckling (Crowe sign) is highly diagnostic of Neurofibromatosis Type 1 (NF1). In children diagnosed with NF1, routine management must include annual comprehensive ophthalmologic evaluations to screen for optic pathway gliomas and Lisch nodules (iris hamartomas). Additionally, children with NF1 are at an increased risk for hypertension due to vascular dysplasia (such as renal artery stenosis) or, less commonly, pheochromocytoma; therefore, regular and close monitoring of blood pressure is a critical component of their ongoing primary care.

Step-by-Step Solution

1
Identify the clinical syndrome based on the dermatologic findings.
The presence of seven café-au-lait macules (>5 mm before puberty) and axillary/inguinal freckling meets the diagnostic criteria for Neurofibromatosis Type 1 (NF1).
Recognizing the hallmark cutaneous signs of NF1 is necessary to determine the appropriate evidence-based screening and management guidelines.
2
Evaluate the patient's developmental history.
Walking independently at 14 months is within the normal developmental window (typically acquired between 9 and 15 to 18 months).
Accurately assessing milestones prevents unnecessary interventions for normal developmental timelines.
3
Determine the appropriate ongoing management and screening for the identified condition.
Standard management for asymptomatic children with NF1 includes annual ophthalmologic exams and regular blood pressure monitoring.
Ophthalmologic exams screen for optic pathway gliomas and Lisch nodules. Blood pressure monitoring is critical to detect secondary hypertension caused by renal artery stenosis or pheochromocytoma.

Key Concept

Neurofibromatosis Type 1 (NF1) Clinical Diagnosis and Screening
Question 63Question →

A 5-month-old male infant is brought to the pediatric neurology clinic by his parents due to concerns about his motor development. The parents report that he "feels like a rag doll" when lifted and has never rolled over or been able to support his head. He was born at 39 weeks gestation via uncomplicated vaginal delivery and has been exclusively breastfed. On physical examination, the infant appears alert and tracks the examiner's face with normal extraocular movements. He exhibits severe generalized hypotonia and assumes a "frog-leg" posture when placed in the supine position. Deep tendon reflexes are absent bilaterally in both the upper and lower extremities. Examination of the oral cavity reveals fine, rapid, continuous twitching movements of the resting tongue. Which of the following is the most appropriate next step in the evaluation of this patient?

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Answer: Targeted molecular genetic testing

Answer

Targeted molecular genetic testing
The correct answer is targeted molecular genetic testing. This infant's presentation of severe generalized hypotonia, absent deep tendon reflexes, and pathognomonic tongue fasciculations in the setting of normal alertness and extraocular movements is highly characteristic of Spinal Muscular Atrophy (SMA) type 1 (Werdnig-Hoffmann disease). SMA is a progressive lower motor neuron disease caused by mutations in the SMN1 gene. The diagnosis is confirmed directly by molecular genetic testing showing a homozygous deletion or mutation of this gene, which has largely replaced electromyography (EMG) and muscle biopsy as the initial diagnostic step.

Step-by-Step Solution

1
Analyze the patient's age, milestone delays, and physical examination findings.
A 5-month-old infant presenting with severe generalized hypotonia, absent deep tendon reflexes, and fine tongue movements (fasciculations), alongside normal alertness and normal extraocular movements.
Accurate identification of the pattern of weakness is necessary to localize the lesion within the nervous system.
2
Differentiate between central and peripheral causes of infantile hypotonia based on the physical exam.
The presence of absent reflexes and tongue fasciculations localizes the lesion to the lower motor neurons (peripheral nervous system).
Central hypotonia (e.g., hypoxic-ischemic encephalopathy) typically involves altered mental status and eventual hyperreflexia, whereas peripheral hypotonia features profound areflexia and fasciculations.
3
Determine the most likely diagnosis and the corresponding, least invasive diagnostic test.
The pathognomonic presentation strongly suggests Spinal Muscular Atrophy (SMA) type 1, which is definitively confirmed by targeted molecular testing for the SMN1 gene.
SMA is an autosomal recessive lower motor neuron disorder caused by a deletion or mutation in the survival motor neuron 1 (SMN1) gene. Genetic testing is now the standard initial diagnostic step.

Key Concept

Spinal Muscular Atrophy (SMA) Type 1 presents with profound lower motor neuron signs, including generalized hypotonia, areflexia, and pathognomonic tongue fasciculations, with spared extraocular movements and normal cognition. It is diagnosed via SMN1 genetic testing.
Question 64Question →

A worried couple arrives at the urgent care clinic with their 18-month-old son shortly after he experienced a full-body convulsion. According to the parents, the episode involved rhythmic shaking of all four extremities, lasted approximately 2 minutes, and stopped on its own. The child has been irritable for the past 24 hours with a prominent runny nose and a rectal temperature of 39.6°C (103.3°F). His immunizations are up to date. Vital signs are stable. On physical examination, the boy is postictal but arousable, demonstrating normal tone and no focal neurological deficits. During the interview, the parents express significant anxiety, stating they fear the seizure was caused by an underlying neurological problem. They point out that his development seems 'slow' because he 'can barely run stiffly' and only says about 15 to 20 single words. Which of the following statements are accurate regarding this patient's current status and management? (Select 2 answers)

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Answer: The patient's current expressive vocabulary and gross motor abilities reflect normal neurodevelopmental progress.; The most appropriate management for the neurological event includes parental education and discharge without routine electroencephalography.

Answer

The correct statements correctly identify that the child's developmental milestones (15-20 words, stiff running) are completely normal for an 18-month-old, and that his generalized, brief seizure in the setting of fever represents a simple febrile seizure requiring only parental education without extensive diagnostic testing.
The correct statements recognize two key clinical assessments. First, an 18-month-old is typically expected to speak 10 to 25 words and run stiffly; therefore, this child's development is normal and should not cause concern for an underlying neurological deficit. Second, the child experienced a classic simple febrile seizure (generalized, lasting less than 15 minutes, with no focal postictal deficits). The standard of care for a simple febrile seizure in a well-appearing, fully immunized child is parental education and reassurance without the need for blood tests, lumbar puncture, EEG, or neuroimaging.

Step-by-Step Solution

1
Analyze the seizure characteristics to classify the neurological event.
The event was a generalized tonic-clonic seizure, lasted less than 15 minutes (2 minutes), and occurred in the setting of a fever in an appropriately aged child, classifying it as a simple febrile seizure.
Differentiating between simple and complex febrile seizures directly dictates the management pathway.
2
Determine the appropriate workup and management for a simple febrile seizure.
Routine neuroimaging (MRI/CT), electroencephalography (EEG), and lumbar puncture are not indicated. Reassurance and antipyretics are the mainstays of treatment.
Simple febrile seizures are benign and have a very low risk of progressing to epilepsy or being caused by severe intracranial pathology.
3
Evaluate the parental concerns regarding the child's neurodevelopment.
An 18-month-old is expected to have a 10 to 25-word vocabulary and run stiffly. The child meets these criteria perfectly.
Accurately identifying normal developmental milestones is crucial to avoid unnecessary interventions and appropriately reassure anxious parents.

Key Concept

Diagnosis and management of simple febrile seizures paired with the accurate assessment of 18-month neurodevelopmental milestones.
Estimated Time:1m 15s
Question 65Question →

A 6-month-old girl is brought to the pediatric emergency department by her parents due to worsening weakness and poor feeding over the past three days. Her parents report that she previously breastfed vigorously and was able to roll from front to back, but she has progressively lost these abilities. Additionally, she has not passed a stool in five days. The family lives on an older rural property and recently began excavating soil to build a large garden. On physical examination, the infant appears lethargic. Her temperature is 37.1°C (98.8°F), heart rate is 110/min, and respiratory rate is 28/min. Neurological evaluation reveals bilateral ptosis, sluggish pupillary light reflexes, and a weak gag reflex. There is profound generalized hypotonia with marked head lag, and deep tendon reflexes are absent bilaterally. Which of the following is the most appropriate initial treatment for this patient?

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Answer: Intravenous human-derived botulism immune globulin

Answer

Intravenous human-derived botulism immune globulin
The correct answer is intravenous human-derived botulism immune globulin. This infant's presentation of severe constipation, poor feeding, bilateral ptosis, sluggish pupillary reflexes, and descending flaccid paralysis is highly characteristic of infant botulism. The condition is caused by the ingestion of Clostridium botulinum spores, which are commonly found in environmental dust and soil (consistent with the family's recent excavation). Because infants have an immature intestinal microbiome, these spores germinate in the gastrointestinal tract and continuously produce neurotoxin. The neurotoxin irreversibly inhibits acetylcholine release at the presynaptic neuromuscular junction. The definitive and immediate treatment is human-derived botulism immune globulin (BIG-IV). This therapy neutralizes circulating toxin before it can bind to nerve endings, significantly reducing the severity of illness, the need for mechanical ventilation, and the length of hospital stay.

Step-by-Step Solution

1
Identify the key clinical syndrome based on the infant's presentation.
The patient has an acute onset of descending flaccid paralysis (ptosis, sluggish pupils, poor gag reflex, head lag) preceded by severe constipation.
Recognizing the sequence of autonomic dysfunction (constipation) followed by descending cranial-to-caudal paralysis is crucial for differentiating this from other causes of pediatric weakness.
2
Determine the most likely etiology given the age and environmental exposures.
The clinical picture combined with exposure to excavated soil strongly points to infant botulism caused by the ingestion of Clostridium botulinum spores.
Infant botulism occurs when environmental spores (from soil, dust, or honey) germinate in the infant's immature gastrointestinal tract and produce neurotoxin in situ.
3
Select the appropriate targeted and safe therapy for this specific diagnosis.
The correct treatment is human-derived botulism immune globulin (BIG-IV).
BIG-IV safely neutralizes circulating toxin in infants, whereas equine antitoxin poses severe hypersensitivity risks, and antibiotics can lyse bacteria to release more toxin.

Key Concept

Infant botulism presents with severe constipation followed by symmetric descending flaccid paralysis and bulbar palsies. It is caused by the ingestion of environmental spores (soil, dust, honey) and must be treated immediately with human-derived botulism immune globulin.
Question 66Question →

A 12-year-old boy is brought to the pediatric emergency department after a high-speed motor vehicle collision. On arrival, he is unresponsive, withdraws from painful stimuli, makes no verbal sounds, and does not open his eyes (Glasgow Coma Scale score of 6). Physical examination reveals that his right pupil is 7 mm and nonreactive to light, while the left is 3 mm and reactive. Vital signs demonstrate a heart rate of 48/min, blood pressure of 165/95 mmHg, and irregular, shallow respirations.

Assuming each step represents the standard progression of care from initial emergency resuscitation to the intensive care management of refractory intracranial hypertension, arrange the following interventions in the most appropriate chronological order.

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Answer

The correct chronological sequence is: 1) Perform endotracheal intubation, 2) Administer a rapid intravenous bolus of hypertonic saline, 3) Obtain an emergent non-contrast CT scan of the head, 4) Place an external ventricular drain (EVD), 5) Initiate a continuous pentobarbital infusion.
The management of severe pediatric traumatic brain injury with signs of impending herniation follows a strict chronological escalation. The initial priority is addressing the airway and breathing; a Glasgow Coma Scale score of 6 necessitates immediate endotracheal intubation to protect the airway and ensure normocarbia. Because the patient demonstrates signs of uncal herniation (fixed and dilated right pupil) and Cushing triad (bradycardia, hypertension, irregular breathing), immediate medical management with an osmotic agent (intravenous hypertonic saline or mannitol) is required to reduce cerebral edema. Once the patient is stabilized, they must be safely transported for a non-contrast head CT scan to identify any surgically evacuatable lesions. Following imaging, the patient will undergo placement of an external ventricular drain to continuously monitor intracranial pressure (ICP) and therapeutically drain cerebrospinal fluid. Finally, if the ICP remains elevated despite maximal standard medical and surgical interventions, third-tier therapies such as a continuous barbiturate infusion (pentobarbital coma) are initiated to reduce cerebral metabolic demand.

Step-by-Step Solution

1
Secure the airway
Endotracheal intubation is performed.
Patients with a GCS less than 8 require definitive airway protection. Furthermore, adequate oxygenation and ventilation are critical to prevent hypoxia and hypercapnia, which cause cerebral vasodilation and exacerbate elevated intracranial pressure.
2
Treat impending brain herniation medically
Intravenous hypertonic saline (or mannitol) is administered.
The patient exhibits Cushing triad (bradycardia, hypertension, irregular respirations) and a unilateral blown pupil, indicating impending uncal herniation. Osmotic therapy is indicated immediately to reduce brain edema prior to patient transport.
3
Identify the underlying etiology
A non-contrast head CT scan is obtained.
Once the patient is stabilized and temporizing measures for herniation are actively running, rapid neuroimaging is required to identify potentially reversible or surgically evacuatable lesions (e.g., hemorrhage).
4
Implement invasive monitoring and targeted fluid diversion
An external ventricular drain (EVD) is placed.
Severe traumatic brain injury requires invasive intracranial pressure monitoring to guide ongoing intensive care management. An EVD provides the dual benefit of monitoring and therapeutic cerebrospinal fluid drainage.
5
Manage refractory intracranial hypertension
A pentobarbital coma is initiated.
If standard medical therapies (sedation, hyperosmolar therapy) and surgical interventions fail to control intracranial pressure, high-dose barbiturate therapy is utilized as a later-tier intervention to drastically decrease the cerebral metabolic rate and cerebral blood volume.

Key Concept

The management of acute impending brain herniation in pediatric traumatic brain injury follows a strict algorithmic escalation: securing the airway (ABCs), initiating immediate empiric osmotic therapy, obtaining urgent neuroimaging, establishing invasive neuromonitoring, and escalating to tier-3 therapies (e.g., barbiturate coma) for refractory cases.
Estimated Time:1m 30s
Question 67Question →

A 4-year-old boy is brought to the pediatric clinic by his parents due to concerns about his frequent falls and difficulty climbing stairs. The parents report that he tires more easily than his peers when playing at the local park. When getting up from a sitting position on the floor, he uses his hands to push himself up his thighs to stand upright. His developmental history is significant for walking independently at 16 months, and he currently speaks in short sentences. His temperature is 37.0°C (98.6°F), pulse is 95/min, respirations are 20/min, and blood pressure is 95/60 mm Hg. Physical examination reveals bilaterally enlarged, firm calf muscles and a waddling gait. Which of the following is the most appropriate next step in evaluation?

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Answer: Serum creatine kinase level

Answer

Serum creatine kinase level
The patient presents with frequent falls, a waddling gait, and the use of his hands to push himself up from the floor (Gowers sign). These findings indicate proximal muscle weakness. Combined with bilaterally enlarged, firm calf muscles (pseudohypertrophy), the clinical picture is highly suspicious for Duchenne muscular dystrophy (DMD). DMD is an X-linked recessive disorder caused by a frameshift mutation in the dystrophin gene. The absence of dystrophin leads to muscle fiber fragility and necrosis. Because muscle damage occurs early and continuously, the most appropriate initial screening test is a serum creatine kinase (CK) level, which is typically markedly elevated (often 10 to 20 times the upper limit of normal). If the CK level is elevated, the diagnosis is subsequently confirmed with genetic testing.

Step-by-Step Solution

1
Analyze the patient's motor symptoms and physical examination findings.
The 4-year-old boy demonstrates proximal muscle weakness (Gowers sign) and bilaterally enlarged, firm calf muscles (pseudohypertrophy).
Recognizing the constellation of Gowers sign and calf pseudohypertrophy in a young male points to a progressive neuromuscular disease, specifically Duchenne muscular dystrophy (DMD).
2
Determine the most appropriate initial diagnostic approach for the suspected condition.
Obtain a serum creatine kinase (CK) level.
Because DMD is caused by an absence of the dystrophin protein, the muscle membrane becomes fragile, leading to muscle breakdown. This results in a massive release of CK into the blood, making it the most sensitive initial screening test before definitive genetic testing.

Key Concept

Diagnosis of Duchenne Muscular Dystrophy
Question 68Question →

A 6-year-old girl is brought to the pediatric emergency department via ambulance due to a prolonged seizure. The parents report that she started having generalized tonic-clonic movements 15 minutes ago, which have been continuous since onset. She has no prior history of seizures. On arrival, she is unresponsive and actively convulsing. Her vital signs are temperature 37.8°C (100°F), blood pressure 110/70 mm Hg, pulse 145/min, and respirations 24/min. Paramedics were unable to establish intravenous access during transport.

Arrange the following management steps in the most appropriate chronological order for this patient.

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Answer

The correct sequence is: 1) Perform initial stabilization and blood glucose testing, 2) Administer intramuscular midazolam, 3) Establish intravenous access and administer intravenous fosphenytoin, 4) Perform endotracheal intubation and initiate a continuous midazolam infusion, and 5) Admit to the pediatric intensive care unit and initiate continuous electroencephalography.
The sequence follows the standard algorithmic approach to status epilepticus: Stabilization phase (ABCs and glucose), Initial therapy phase (IM midazolam due to no IV access), Second therapy phase (IV fosphenytoin), Third therapy phase for refractory status (Intubation and continuous infusion), and finally post-stabilization intensive care (PICU and cEEG).

Step-by-Step Solution

1
Recognize the stabilization phase (0-5 minutes).
Prioritize ABCs, oxygenation, and bedside glucose testing.
Hypoxia and hypoglycemia are life-threatening and potentially reversible causes of continuous seizures that must be addressed before or concurrent with anti-seizure medications.
2
Identify the initial therapy phase (5-20 minutes) and the lack of IV access.
Select intramuscular midazolam as the first-line pharmacological treatment.
When IV access is unavailable or delayed, IM midazolam is proven to be as effective and faster to administer than waiting to establish an IV for lorazepam.
3
Determine the second-therapy phase (20-40 minutes) for persistent seizures.
Proceed with establishing IV access to deliver a second-line agent like fosphenytoin.
A long-acting, non-benzodiazepine anti-seizure medication is required to break seizures that fail to respond to initial benzodiazepines.
4
Recognize refractory status epilepticus (40-60 minutes).
Intubate the patient and start a continuous anesthetic infusion.
Third-line therapy requires airway protection due to the severe respiratory depressant effects of continuous anesthetic infusions.
5
Plan post-stabilization monitoring.
Transfer the patient to the PICU and attach continuous EEG.
cEEG is necessary to monitor the efficacy of the continuous infusion and ensure that subclinical (electrographic) seizures have stopped.

Key Concept

The time-based, stepwise algorithmic management of pediatric status epilepticus.
Question 69Question →

During a parent-teacher conference, a first-grade educator expresses concern regarding a 7-year-old student's classroom behavior. The teacher notes that the child frequently halts his activities, stares into space with intermittent eyelid fluttering, and remains entirely unresponsive to verbal prompts for approximately 10 to 15 seconds. Following these brief interruptions, he immediately resumes his tasks with no apparent awareness of the pause. The student's father brings him to an outpatient clinic for evaluation. The father reports that his son has always met developmental expectations and performs well academically overall. The patient's vital signs are within normal limits. A comprehensive neurologic examination reveals no focal deficits.

Which of the following is the most appropriate next step in the management of this patient?

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Answer: Perform an electroencephalogram with hyperventilation

Answer

Perform an electroencephalogram with hyperventilation
The most appropriate next step in management is performing an electroencephalogram with hyperventilation. The child's symptoms are highly suspicious for childhood absence epilepsy, which is characterized by brief periods of impaired consciousness without a loss of postural tone. The hallmark diagnostic test is an EEG demonstrating generalized 3-Hz spike-and-wave complexes. Because hyperventilation induces respiratory alkalosis which easily triggers absence seizures, it is routinely used in the clinic to provoke these characteristic EEG findings.

Step-by-Step Solution

1
Analyze the clinical presentation
Identified brief staring spells with eyelid fluttering, complete unresponsiveness, and immediate recovery without a postictal state.
To differentiate between psychiatric, behavioral, endocrine, and neurologic etiologies of inattention.
2
Formulate a working diagnosis
Childhood absence epilepsy.
The specific pattern of sudden-onset, brief loss of awareness accompanied by minor motor automatisms is the classic clinical hallmark of absence seizures.
3
Determine the diagnostic standard
Electroencephalogram (EEG) provoked by hyperventilation.
Hyperventilation reliably triggers the characteristic 3-Hz spike-and-wave discharges on EEG, confirming the diagnosis and guiding subsequent pharmacotherapy.

Key Concept

Diagnosis of childhood absence epilepsy utilizing electroencephalography with hyperventilation
Estimated Time:1m 15s
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