A 1-month-old male infant is brought to the physician because of inconsolable crying for the past 3 hours. For the past 3 weeks, he has had multiple episodes of high-pitched unprovoked crying every day that last up to 4 hours and resolve spontaneously. He was born at term and weighed 2966 g (6 lb 9 oz); he now weighs 3800 g (8 lb 6 oz). He is exclusively breast fed. His temperature is 36.9°C (98.4°F) and pulse is 140/min. Examination shows a soft and nontender abdomen. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?
Q112
A 4-year-old girl is brought to the doctor by her mother with the complaint of hearing loss, which her mother noticed a few days ago when the girl stopped responding to her name. The mother is anxious and says, “I want my child to get better even if it requires admission to the hospital.” Her family moved to a 70-year-old family home in Flint, Michigan, in 2012. The girl has a known history of beta-thalassemia trait. She has never been treated for hookworm, as her mother states that they maintain “good hygiene standards” at home. On examination, the girl currently uses only 2-syllable words. She is in the 70th percentile for height and 50th for weight. A Rinne test reveals that the girl’s air conduction is greater than her bone conduction in both ears. She does not respond when the doctor calls her name, except when he is within her line of sight. Her lab parameters are:
Hemoglobin 9.9 gm%
Mean corpuscular volume 80 fl
Red blood cell distribution width (RDW) 15.9%
Serum ferritin 150 ng/ml
Total iron binding capacity 320 µg/dL
A peripheral smear shows a microcytic hypochromic anemia with basophilic stippling and a few target cells. Which of the following is the next best step in the management of this patient?
Q113
A 9-year-old healthy female presents to her pediatrician for a healthy child visit. She is doing well in school and has good relationships with her teachers, friends, and family. Her temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 85/min, and respirations are 16/min. On examination, a minimal amount of pubic hair is noted. Her breasts and papillae are slightly elevated with enlargement of the areolas. Which of the following is the most likely Tanner stage of development in this patient?
Q114
A boy with diabetic ketoacidosis is admitted to the pediatric intensive care unit for closer monitoring. Peripheral venous access is established. He is treated with IV isotonic saline and started on an insulin infusion. This patient is at the highest risk for which of the following conditions in the next 24 hours?
Q115
A 3-day-old girl is brought to the general pediatrics clinic by her mother. She was the product of an uncomplicated, full-term, standard vaginal delivery after an uncomplicated pregnancy in which the mother received regular prenatal care. This morning, after changing the child's diaper, the mother noticed that the newborn had a whitish, non-purulent vaginal discharge. The mother has no other complaints, and the infant is eating and voiding appropriately. Vital signs are stable. Physical exam reveals moderate mammary enlargement and confirms the vaginal discharge. The remainder of the exam is unremarkable. What is the next step in management?
Q116
A 14-year-old boy presents to the office for a checkup. He is well-nourished and meets all developmental milestones. He denies any complaints, and you offer him counseling on adolescent issues. On examination, he appears to be a normal, healthy teenager. The only significant finding is the bilateral swelling of the tibial tuberosities. When asked about them, the patient denies trauma and states they are sore, especially when he runs or squats. Which of the following is the underlying cause of this finding?
Q117
A 9-month-old male infant is brought to his pediatrician by his mother with lethargy and decreased oral intake for one day. His mother also mentions that he did not sleep well the previous night. A review of the medical record reveals several missed appointments and that the boy was born at 36 weeks gestation via spontaneous vaginal delivery. At the clinic, his temperature is 37.2ºC (99.0ºF), pulse rate is 140/minute, respirations are 44/minute, and blood pressure is 92/60 mm Hg. On physical exam the infant is awake but irritable and the rest of the physical is within normal limits for his age. On ophthalmologic examination, there are multiple retinal hemorrhages that extend to the periphery in both eyes. Which of the following investigations is most likely to be helpful in the management of the infant?
Q118
A 10-year-old boy is brought in by his parents with increasing breathlessness. He was diagnosed with asthma about 2 years ago and has been on treatment since then. He was initially observed to have breathlessness, cough and chest tightness 2 or 3 times a week. He would wake up once or twice a month in the nighttime with breathlessness. At that time, his pediatrician started him on a Ventolin inhaler to be used during these episodes. His symptoms were well controlled until a few months ago when he started to experience increased nighttime awakenings due to breathlessness. He is unable to play outside with his friends as much because he gets winded easily and has to use his inhaler almost daily to help him breathe easier. He is able to walk and perform other routine activities without difficulty, but playing or participating in sports causes significant struggles. Based on his symptoms, his pediatrician adds an inhaled formoterol and budesonide combination to his current regime. During spirometry, which of the following peak expiratory flow rates will most likely be observed in this patient?
Q119
A 9-month-old boy is brought to the physician because of abnormal crawling and inability to sit without support. A 2nd-trimester urinary tract infection that required antibiotic use and a spontaneous preterm birth via vaginal delivery at 36 weeks’ gestation both complicated the mother’s pregnancy. Physical examination shows a scissoring posture of the legs when the child is suspended by the axillae. Examination of the lower extremities shows brisk tendon reflexes, ankle clonus, and upward plantar reflexes bilaterally. When encouraged by his mother, the infant crawls forward by using normal reciprocal movements of his arms, while his legs drag behind. A brain MRI shows scarring and atrophy in the white matter around the ventricles with ventricular enlargement. Which of the following is most likely associated with the findings in this child?
Q120
A 5-year-old boy is brought to the physician for excessive weight gain. The mother reports that her son has been “chubby” since he was a toddler and that he has gained 10 kg (22 lbs) over the last year. During this period, he fractured his left arm twice from falling on the playground. He had cryptorchidism requiring orchiopexy at age 2. He is able to follow 1-step instructions and uses 2-word sentences. He is at the 5th percentile for height and 95th percentile for weight. Vital signs are within normal limits. Physical examination shows central obesity. There is mild esotropia and coarse, dry skin. In addition to calorie restriction, which of the following is the most appropriate next step in management of this patient?
Growth/Development US Medical PG Practice Questions and MCQs
Question 111: A 1-month-old male infant is brought to the physician because of inconsolable crying for the past 3 hours. For the past 3 weeks, he has had multiple episodes of high-pitched unprovoked crying every day that last up to 4 hours and resolve spontaneously. He was born at term and weighed 2966 g (6 lb 9 oz); he now weighs 3800 g (8 lb 6 oz). He is exclusively breast fed. His temperature is 36.9°C (98.4°F) and pulse is 140/min. Examination shows a soft and nontender abdomen. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?
A. Administer simethicone
B. Perform lumbar puncture
C. Reassurance (Correct Answer)
D. Administer pantoprazole
E. Recommend the use of Gripe water
Explanation: ***Reassurance***
- The presented symptoms (inconsolable crying lasting hours, resolving spontaneously, in a healthy infant with normal examination) are classic for **infant colic**. Infant colic is a self-limiting condition, and reassurance of the parents is the most appropriate management.
- The "rule of threes" for colic includes crying for more than **3 hours a day**, for more than **3 days a week**, for longer than **3 weeks** in an otherwise healthy and well-fed infant.
*Administer simethicone*
- **Simethicone** is an anti-foaming agent proposed to reduce gas, but studies have not consistently shown it to be effective in treating infant colic.
- While generally considered safe, it is not the first-line or most effective intervention for colic.
*Perform lumbar puncture*
- A **lumbar puncture** is an invasive procedure indicated when there is suspicion of serious CNS infection (e.g., meningitis), which is not supported by the clinical picture here.
- The infant is afebrile, well-appearing apart from crying, and has a normal physical examination, making a lumbar puncture unnecessary and potentially harmful.
*Administer pantoprazole*
- **Pantoprazole** (a proton pump inhibitor) is used to reduce stomach acid in conditions like gastroesophageal reflux disease (GERD).
- While GERD can cause crying in infants, the description of crying as "unprovoked" and resolving spontaneously, coupled with normal weight gain and examination, makes GERD less likely and PPI administration unwarranted.
*Recommend the use of Gripe water*
- **Gripe water** is a combination of herbal remedies (e.g., ginger, fennel, chamomile) and bicarbonate, marketed for colic and gas.
- Its efficacy is not scientifically proven, and some formulations may contain alcohol or sugar, making it an unrecommended and potentially unsafe option.
Question 112: A 4-year-old girl is brought to the doctor by her mother with the complaint of hearing loss, which her mother noticed a few days ago when the girl stopped responding to her name. The mother is anxious and says, “I want my child to get better even if it requires admission to the hospital.” Her family moved to a 70-year-old family home in Flint, Michigan, in 2012. The girl has a known history of beta-thalassemia trait. She has never been treated for hookworm, as her mother states that they maintain “good hygiene standards” at home. On examination, the girl currently uses only 2-syllable words. She is in the 70th percentile for height and 50th for weight. A Rinne test reveals that the girl’s air conduction is greater than her bone conduction in both ears. She does not respond when the doctor calls her name, except when he is within her line of sight. Her lab parameters are:
Hemoglobin 9.9 gm%
Mean corpuscular volume 80 fl
Red blood cell distribution width (RDW) 15.9%
Serum ferritin 150 ng/ml
Total iron binding capacity 320 µg/dL
A peripheral smear shows a microcytic hypochromic anemia with basophilic stippling and a few target cells. Which of the following is the next best step in the management of this patient?
A. Multivitamins with iron supplementation
B. Chelation therapy if the blood lead level is more than 25 µg/dL
C. Blood transfusion
D. Treatment for hookworm
E. Remove and prevent the child from exposure to the source of lead (Correct Answer)
Explanation: ***Remove and prevent the child from exposure to the source of lead***
- The patient's presentation with **hearing loss**, developmental delay (only using two-syllable words), and anemia with **basophilic stippling** and **microcytic hypochromic anemia** strongly suggests **lead poisoning**. The history of living in an old home in Flint, Michigan further supports this, as older homes and the Flint water crisis are known sources of lead exposure.
- The most crucial step in managing lead poisoning is to **eliminate the source of lead exposure** to prevent further accumulation and toxicity.
*Multivitamins with iron supplementation*
- While the patient has **anemia**, the peripheral smear findings of **basophilic stippling** and family history of residence in Flint, Michigan point towards lead intoxication as the underlying cause, not simple iron deficiency.
- Iron supplementation alone would not address the **neurotoxic effects** of lead or the root cause of the anemia.
*Chelation therapy if the blood lead level is more than 25 µg/dL*
- **Chelation therapy** is indicated for significantly elevated blood lead levels, typically above 45 µg/dL, and sometimes considered between 25-44 µg/dL depending on symptoms and clinical context.
- However, the **most important initial step** is still to remove the source of lead exposure, as chelation without source removal is less effective and may lead to re-exposure and continued toxicity.
*Blood transfusion*
- The patient has a **hemoglobin of 9.9 gm%**, which, while anemic, is not critically low enough to warrant immediate blood transfusion unless there are signs of severe symptomatic anemia or hemodynamic instability.
- Addressing the **underlying cause (lead poisoning)** and providing supportive care is prioritized over transfusion for this level of anemia.
*Treatment for hookworm*
- Although hookworm can cause **iron deficiency anemia**, the patient's normal **serum ferritin (150 ng/ml)** and absence of other signs like eosinophilia make hookworm an unlikely cause of her anemia.
- The presence of **basophilic stippling** and the history of potential lead exposure strongly point away from hookworm as the primary diagnosis.
Question 113: A 9-year-old healthy female presents to her pediatrician for a healthy child visit. She is doing well in school and has good relationships with her teachers, friends, and family. Her temperature is 98.6°F (37°C), blood pressure is 110/70 mmHg, pulse is 85/min, and respirations are 16/min. On examination, a minimal amount of pubic hair is noted. Her breasts and papillae are slightly elevated with enlargement of the areolas. Which of the following is the most likely Tanner stage of development in this patient?
A. Tanner stage 5
B. Tanner stage 1
C. Tanner stage 3
D. Tanner stage 2 (Correct Answer)
E. Tanner stage 4
Explanation: ***Tanner stage 2***
- The presence of **minimal pubic hair** and **slightly elevated breasts and papillae with enlarged areolas** are characteristic signs of **Tanner stage 2** breast and pubic hair development, respectively.
- This stage marks the **earliest physical changes of puberty** in girls, typically starting between ages 8 and 13.
*Tanner stage 5*
- This stage represents **adult-like development**, with mature breast contour where only the papilla projects (areola recesses to breast contour), and pubic hair extending to the medial thighs.
- The patient's presentation clearly indicates she is in an earlier stage of pubertal development.
*Tanner stage 1*
- This stage describes a **prepubertal state** with no visible breast development (flat chest) and no pubic hair.
- This patient already shows clear signs of breast and pubic hair development.
*Tanner stage 3*
- **Tanner stage 3** involves further enlargement of the breasts and areola, with no separation of the contours, and darker, coarser, and more curled pubic hair covering the mons pubis.
- The patient's description of "slightly elevated with enlargement of the areolas" is less advanced than stage 3.
*Tanner stage 4*
- In **Tanner stage 4**, the areola and papilla form a secondary mound projecting above the rest of the breast, and pubic hair is adult-like but does not extend to the thighs.
- This stage is more advanced than the findings described, lacking the specific "secondary mound" of the areola.
Question 114: A boy with diabetic ketoacidosis is admitted to the pediatric intensive care unit for closer monitoring. Peripheral venous access is established. He is treated with IV isotonic saline and started on an insulin infusion. This patient is at the highest risk for which of the following conditions in the next 24 hours?
A. Cerebral edema (Correct Answer)
B. Intrinsic kidney injury
C. Cognitive impairment
D. Hyperkalemia
E. Deep venous thrombosis
Explanation: ***Cerebral edema***
- **Cerebral edema** is a severe and potentially fatal complication of **diabetic ketoacidosis (DKA)** treatment, particularly in children.
- It results from a rapid decrease in serum osmolality during treatment, causing water to shift into brain cells.
*Intrinsic kidney injury*
- While dehydration in DKA can lead to **prerenal acute kidney injury**, **intrinsic kidney injury** is less common as an acute risk directly from DKA treatment in the first 24 hours.
- Initial fluid resuscitation often improves renal perfusion, reducing the risk of intrinsic damage unless other predisposing factors are present.
*Cognitive impairment*
- Cognitive impairment after DKA is more commonly observed in the long term, potentially due to recurrent episodes or severe DKA with cerebral edema.
- It is not the most immediate and highest risk acute complication in the short-term (next 24 hours).
*Hyperkalemia*
- Patients with DKA typically present with **hyperkalemia** due to acidosis and insulin deficiency, which resolves with insulin therapy as potassium shifts back into cells.
- The more immediate risk during treatment, especially after initial fluid resuscitation and insulin, is **hypokalemia**, not hyperkalemia, due to the intracellular shift of potassium.
*Deep venous thrombosis*
- **Dehydration** and **hyperviscosity** associated with DKA can increase the risk of **thrombosis**, but **deep venous thrombosis** is not the highest or most immediate acute risk in the next 24 hours.
- **Cerebral edema** is a more specific and life-threatening complication directly related to the treatment of DKA in children.
Question 115: A 3-day-old girl is brought to the general pediatrics clinic by her mother. She was the product of an uncomplicated, full-term, standard vaginal delivery after an uncomplicated pregnancy in which the mother received regular prenatal care. This morning, after changing the child's diaper, the mother noticed that the newborn had a whitish, non-purulent vaginal discharge. The mother has no other complaints, and the infant is eating and voiding appropriately. Vital signs are stable. Physical exam reveals moderate mammary enlargement and confirms the vaginal discharge. The remainder of the exam is unremarkable. What is the next step in management?
A. Order a karyotype
B. Begin a workup for 21-hydroxylase deficiency
C. Begin a workup for 11 beta-hydroxylase deficiency
D. No tests are needed (Correct Answer)
E. Begin a workup for 17 alpha-hydroxylase deficiency
Explanation: ***No tests are needed***
- The **whitish, non-purulent vaginal discharge** and **moderate mammary enlargement** in a 3-day-old female are normal physiological responses to the withdrawal of maternal hormones after birth.
- These transient estrogenic effects typically resolve within the first few weeks of life and require no intervention.
*Order a karyotype*
- A **karyotype** is indicated when there are ambiguous genitalia or other signs suggestive of a chromosomal abnormality, which are not present here.
- The infant's physical exam is otherwise unremarkable, and her presentation is consistent with normal newborn physiology.
*Begin a workup for 21-hydroxylase deficiency*
- **21-hydroxylase deficiency** is the most common cause of **congenital adrenal hyperplasia (CAH)**, presenting in females with **virilization** (e.g., clitoromegaly, labial fusion), which is not described.
- This condition also presents with **salt-wasting crises** or precocious puberty, none of which are evident in this stable infant.
*Begin a workup for 11 beta-hydroxylase deficiency*
- **11-beta-hydroxylase deficiency** is another form of CAH that, like 21-hydroxylase deficiency, causes **virilization** in females.
- It also leads to **hypertension** due to increased deoxycorticosterone, a symptom not mentioned in this normotensive newborn.
*Begin a workup for 17 alpha-hydroxylase deficiency*
- **17-alpha-hydroxylase deficiency** presents differently, typically causing **lack of pubertal development** and **hypertension** due to mineralocorticoid excess.
- In females, it can result in an **XY genotype with female external genitalia** due to impaired androgen synthesis, which is not suggested by the normal female external genitalia described.
Question 116: A 14-year-old boy presents to the office for a checkup. He is well-nourished and meets all developmental milestones. He denies any complaints, and you offer him counseling on adolescent issues. On examination, he appears to be a normal, healthy teenager. The only significant finding is the bilateral swelling of the tibial tuberosities. When asked about them, the patient denies trauma and states they are sore, especially when he runs or squats. Which of the following is the underlying cause of this finding?
A. Ewing sarcoma
B. Osgood-Schlatter disease (Correct Answer)
C. Paget disease
D. Osteopetrosis
E. Osteitis fibrosa cystica
Explanation: ***Osgood-Schlatter disease***
- This condition is characterized by **tibial tuberosity swelling** and pain, worsened by activity, in **adolescent males** undergoing rapid growth spurts.
- It results from repetitive stress and microtrauma where the **patellar tendon** inserts into the immature **tibial tuberosity**, causing inflammation and bone fragmentation.
*Ewing sarcoma*
- This is a rare, malignant bone tumor that would present with more severe, persistent pain, often with a **palpable soft tissue mass** and systemic symptoms like fever and weight loss.
- It would typically appear as a **lytic lesion** with an **"onion skin" periosteal reaction** on radiographs, not just bilateral tuberosity swelling in an otherwise healthy child.
*Paget disease*
- This chronic bone disorder primarily affects individuals over 50 years old and involves **abnormal bone remodeling**, leading to enlarged and weakened bones.
- It typically doesn't present with isolated tibial tuberosity swelling in adolescents and would involve widespread bone abnormalities.
*Osteopetrosis*
- This rare genetic disorder is characterized by **abnormally dense bones** due to defective osteoclast function, leading to marrow abnormalities and increased fracture risk.
- It would present with diffuse skeletal density, bone fragility, and neurological complications, not localized tibial swelling in an otherwise healthy teenager.
*Osteitis fibrosa cystica*
- This is a bone pathology associated with **severe hyperparathyroidism**, leading to increased osteoclastic activity, bone resorption, and replacement with fibrous tissue and cysts.
- It would manifest with diffuse bone pain, fractures, and elevated parathyroid hormone levels, which are not described in this patient.
Question 117: A 9-month-old male infant is brought to his pediatrician by his mother with lethargy and decreased oral intake for one day. His mother also mentions that he did not sleep well the previous night. A review of the medical record reveals several missed appointments and that the boy was born at 36 weeks gestation via spontaneous vaginal delivery. At the clinic, his temperature is 37.2ºC (99.0ºF), pulse rate is 140/minute, respirations are 44/minute, and blood pressure is 92/60 mm Hg. On physical exam the infant is awake but irritable and the rest of the physical is within normal limits for his age. On ophthalmologic examination, there are multiple retinal hemorrhages that extend to the periphery in both eyes. Which of the following investigations is most likely to be helpful in the management of the infant?
A. Bone marrow aspiration
B. Peripheral blood smear
C. Lumbar puncture
D. Hemoglobin electrophoresis
E. Noncontrast computed tomography of head (Correct Answer)
Explanation: ***Noncontrast computed tomography of head***
- The combination of **lethargy**, decreased oral intake, irritability, and **bilateral retinal hemorrhages** in an infant strongly suggests **abusive head trauma (shaken baby syndrome)**, requiring urgent neuroimaging to assess for intracranial hemorrhage.
- A **noncontrast CT of the head** is the immediate and most appropriate investigation to identify acute intracranial bleeds, such as subdural or subarachnoid hemorrhages, which are common in abusive head trauma.
*Bone marrow aspiration*
- This procedure is primarily used to diagnose **hematologic malignancies** (e.g., leukemia) or certain storage disorders.
- It is not indicated as a first-line investigation for lethargy and retinal hemorrhages, as these symptoms do not specifically point to a bone marrow pathology.
*Peripheral blood smear*
- A peripheral blood smear is useful for evaluating **anemia**, **thrombocytopenia**, or abnormal cells in the circulation.
- While it can help assess for underlying blood disorders, it will not directly diagnose or localize the cause of the suspected intracranial injury.
*Lumbar puncture*
- A lumbar puncture is used to analyze **cerebrospinal fluid (CSF)**, primarily to diagnose infections like meningitis or encephalitis, or certain inflammatory conditions.
- Performing a lumbar puncture in suspected abusive head trauma can be dangerous if there is significant intracranial pressure or a mass lesion, making neuroimaging a necessary prerequisite.
*Hemoglobin electrophoresis*
- This test is used to detect **hemoglobinopathies** like sickle cell disease or thalassemia.
- While useful in specific contexts, there are no symptoms or signs in this case to suggest a hemoglobin disorder.
Question 118: A 10-year-old boy is brought in by his parents with increasing breathlessness. He was diagnosed with asthma about 2 years ago and has been on treatment since then. He was initially observed to have breathlessness, cough and chest tightness 2 or 3 times a week. He would wake up once or twice a month in the nighttime with breathlessness. At that time, his pediatrician started him on a Ventolin inhaler to be used during these episodes. His symptoms were well controlled until a few months ago when he started to experience increased nighttime awakenings due to breathlessness. He is unable to play outside with his friends as much because he gets winded easily and has to use his inhaler almost daily to help him breathe easier. He is able to walk and perform other routine activities without difficulty, but playing or participating in sports causes significant struggles. Based on his symptoms, his pediatrician adds an inhaled formoterol and budesonide combination to his current regime. During spirometry, which of the following peak expiratory flow rates will most likely be observed in this patient?
A. 65% (Correct Answer)
B. 55%
C. 90%
D. 40%
E. 85%
Explanation: ***65%***
- The patient's presentation of symptoms suggests **moderate persistent asthma**. This is characterized by daily symptoms, nighttime awakenings more than once a week but not nightly, and significant limitation in activity where playing causes struggles.
- In moderate persistent asthma, the **peak expiratory flow rate (PEFR)** or forced expiratory volume in 1 second (FEV1) is typically between **60% and 80%** of the predicted value. Therefore, 65% falls within this range.
*55%*
- A PEFR of 55% would indicate **severe persistent asthma**, which is characterized by continual symptoms throughout the day, frequent nighttime awakenings (often nightly), and extreme limitations in physical activity.
- While the patient's asthma is worsening, it does not yet meet the criteria for severe, as he can still perform routine activities without difficulty.
*90%*
- A PEFR of 90% would be consistent with **intermittent asthma** or **mild persistent asthma** that is very well controlled.
- The patient's symptoms, including daily inhaler use, nighttime awakenings, and activity limitations, clearly indicate that his asthma is not well-controlled and is more than mild.
*40%*
- A PEFR of 40% would suggest an **acute severe asthma exacerbation** or **very severe persistent asthma**.
- The patient's symptoms describe increasing frequency and severity, but not an acute, life-threatening exacerbation or such profound chronic lung function impairment.
*85%*
- A PEFR of 85% would typically be seen in **mild persistent asthma** or intermittent asthma, where symptoms are less frequent and less severe.
- The patient's current symptoms, including daily inhaler use and inability to play without significant struggles, are indicative of moderate asthma that is not well controlled.
Question 119: A 9-month-old boy is brought to the physician because of abnormal crawling and inability to sit without support. A 2nd-trimester urinary tract infection that required antibiotic use and a spontaneous preterm birth via vaginal delivery at 36 weeks’ gestation both complicated the mother’s pregnancy. Physical examination shows a scissoring posture of the legs when the child is suspended by the axillae. Examination of the lower extremities shows brisk tendon reflexes, ankle clonus, and upward plantar reflexes bilaterally. When encouraged by his mother, the infant crawls forward by using normal reciprocal movements of his arms, while his legs drag behind. A brain MRI shows scarring and atrophy in the white matter around the ventricles with ventricular enlargement. Which of the following is most likely associated with the findings in this child?
A. Antenatal injury
B. Genetic defect
C. Postnatal head trauma
D. Intrapartum asphyxia
E. Preterm birth (Correct Answer)
Explanation: ***Preterm birth***
- The combination of **abnormal crawling**, **inability to sit without support**, **scissoring posture**, **spasticity**, and **periventricular white matter scarring** (periventricular leukomalacia, PVL) are classic signs of **spastic cerebral palsy**.
- **Preterm birth** is the most significant risk factor for **PVL** and the subsequent development of spastic cerebral palsy, particularly spastic diplegia.
- The **periventricular white matter** in preterm infants (especially <34 weeks, but also late preterm at 34-37 weeks) is highly vulnerable to ischemic injury due to immature vascular development and susceptibility to hypoxic-ischemic insults during the perinatal period.
- This infant was born at **36 weeks (late preterm)**, which is a known risk factor for PVL and cerebral palsy.
*Antenatal injury*
- While brain injury can occur in the antenatal period, the specific finding of **periventricular leukomalacia** is most characteristically associated with **prematurity** and perinatal/early postnatal events rather than purely antenatal injury.
- The term "antenatal injury" is too vague and doesn't capture the specific pathophysiology of PVL, which occurs around the time of birth in vulnerable preterm infants.
*Genetic defect*
- While some forms of cerebral palsy can have a genetic component, the clinical picture here, especially the MRI findings of **periventricular leukomalacia**, strongly points to an acquired brain injury rather than a primary genetic defect.
- Genetic conditions typically present with more widespread or specific neurodevelopmental abnormalities, often without the focal periventricular white matter scarring seen in PVL.
*Postnatal head trauma*
- **Postnatal head trauma** would typically present with a history of injury and more acute neurological deficits or focal lesions on imaging (e.g., subdural hematoma, contusions), rather than the characteristic **periventricular white matter scarring** observed here.
- The presentation is consistent with a developmental disorder from perinatal brain injury, not an acute traumatic event from infancy.
*Intrapartum asphyxia*
- **Intrapartum asphyxia** (hypoxic-ischemic encephalopathy) in term infants characteristically leads to damage in the **deep grey matter** (e.g., basal ganglia, thalamus) and cortex, not primarily **periventricular white matter** as seen here.
- The MRI findings of **periventricular leukomalacia** are pathognomonic for **prematurity-related injury**, not term asphyxia.
Question 120: A 5-year-old boy is brought to the physician for excessive weight gain. The mother reports that her son has been “chubby” since he was a toddler and that he has gained 10 kg (22 lbs) over the last year. During this period, he fractured his left arm twice from falling on the playground. He had cryptorchidism requiring orchiopexy at age 2. He is able to follow 1-step instructions and uses 2-word sentences. He is at the 5th percentile for height and 95th percentile for weight. Vital signs are within normal limits. Physical examination shows central obesity. There is mild esotropia and coarse, dry skin. In addition to calorie restriction, which of the following is the most appropriate next step in management of this patient?
A. Levothyroxine
B. Fluoxetine
C. Laparoscopic gastric banding
D. Growth hormone therapy (Correct Answer)
E. Octreotide
Explanation: ***Growth hormone therapy***
- This patient's constellation of symptoms, including **obesity**, **short stature**, developmental delay (**1-step instructions, 2-word sentences at age 5**), **cryptorchidism**, and **bone fractures**, is highly suggestive of **Prader-Willi syndrome (PWS).**
- **Growth hormone therapy** is the most appropriate next step and is crucial for improving growth, body composition, muscle strength, and bone density in patients with Prader-Willi syndrome.
- Growth hormone therapy should be initiated in early childhood and has been shown to significantly improve height, lean body mass, and motor development in PWS patients.
- **Note:** While PWS is associated with hypogonadism, testosterone replacement is not initiated at age 5; it is typically reserved for adolescent males approaching puberty.
*Levothyroxine*
- While **coarse, dry skin** can suggest **hypothyroidism**, the overall clinical picture, including developmental delay, cryptorchidism, hyperphagia with obesity, and short stature, is classic for **Prader-Willi syndrome** rather than primary hypothyroidism.
- There are no other clear signs of hypothyroidism such as bradycardia, lethargy, or significant goiter.
*Fluoxetine*
- **Fluoxetine** is an SSRI that may be used for behavioral issues like hyperphagia, compulsive behaviors, or anxiety often seen in Prader-Willi syndrome, but it does **not address the underlying hormonal deficiencies** or growth failure.
- Behavioral management and psychiatric medications are adjunctive but secondary to addressing the growth and metabolic issues with hormone therapy.
*Laparoscopic gastric banding*
- This is a surgical option for severe, refractory obesity, but it is **not appropriate for a 5-year-old child**, especially not as a first-line treatment for obesity in Prader-Willi syndrome.
- The **underlying hormonal and metabolic issues** must be addressed first with growth hormone therapy and dietary management, and such invasive bariatric procedures carry significant risks and are not indicated in young children.
*Octreotide*
- **Octreotide** is a somatostatin analog used to inhibit growth hormone secretion in conditions like acromegaly or to manage symptoms of neuroendocrine tumors.
- In Prader-Willi syndrome, the issue is **growth hormone deficiency**, not excess, making octreotide contraindicated as it would worsen the growth failure.
