MCQs in Pediatric Neurology Part 111

A 7-month-old male died following a progressive neurological illness over 6 weeks, with somnolence,

blindness, deafness, and generalized limb spasticity. Autopsy showed bilateral symmetric necrotic lesions of the thalamus, pons, inferior olive, and spinal cord. The most likely diagnosis is :

(A) Leber hereditary optic neuropathy

(B) mitochondrial neurogastrointestinal encephalopathy

(C) Leigh syndrome

(D) Alpers disease

(E) myoclonic epilepsy with ragged-red fibers

MCQs In Electrolyte Disorders

Q1 

You are evaluating a 2-week-old breastfed infant who is 15% below his birthweight and has been

lethargic and fed poorly over the past 4 days. You administer a normal saline fluid bolus.

Laboratory results include:

· Blood glucose of 126.0 mg/dl (7.0 mmol/L)

· Serum sodium of 170.0 mEq/L (170.0 mmol/L)

· Serum potassium of 5.0 mEq/L (5.0 mmol/L)

· Blood urea nitrogen of 31.0 mg/dL (11.1 mmol/L)

· Serum creatinine of 2.9 mg/dL (256.4 mcmol/L)

Of the following, the MOST appropriate initial fluid for correction is a solution containing 5%

dextrose and\

A. NaCl (%): 0.20

KCl (mEq/L): 40

Duration of Infusion(hr): 12 to 24

B. NaCl (%): 0.45

KCl (mEq/L): 0

Duration of Infusion(hr): 48 to 72

C. NaCl (%): 0.45

KCl (mEq/L): 40

Duration of Infusion(hr): 12 to 24

D. NaCl (%): 0.9

KCl (mEq/L): 0

Duration of Infusion(hr): 12 to 24

E. NaCl (%): 0.9

KCl (mEq/L): 40

Duration of Infusion(hr): 48 to 72

Answer:

B

 Hypernatremia results from excessive sodium administration (incorrectly mixed formula, sodium bicarbonate, hypertonic saline) or a deficit of water in relation to sodium. Such a deficit may occur from decreased water intake (inadequate breastfeeding, fluid restriction, lack of access to fluids), fluid losses (nephrogenic and central diabetes insipidus, increased insensible losses), or fluid losses in greater proportion than sodium losses (diarrhea, vomiting, diuretic use, burns).

Treatment of hypernatremia is directed at correction of both the serum sodium
concentration and the circulatory volume. Initially, some children may require isotonic fluid
boluses to restore circulation. It is important to note that children who have hypernatremia often
appear less dehydrated than they actually are due to preservation of the extracellular volume.
The following equation can be used to estimate the free water deficit:
Water deficit (mL)= 4 mL x ideal body weight (kg) x desired change in serum sodium
concentration

Hypernatremia, especially if chronic, should be corrected slowly, with a desired goal of
decreasing the serum sodium by 0.5 mEq/L per hour to avoid cerebral edema. Severe
hypernatremia (serum sodium >170.0 mEq/L [170.0 mmol/L]), as described for the child in the
vignette, should be corrected over 48 to 72 hours. Fluid administration generally consists of 1/4
to 1/2 normal saline solutions. Symptoms of overcorrection, such as changes in mental status or
onset of seizures, suggest the development of cerebral edema and should be treated with
hypertonic saline and slowing of the sodium correction. In general, potassium administration
should be withheld in cases of severe hypernatremic dehydration until adequate urine output is
assured

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MCQs In Metabolic Diseases

Q1:

The pregnant mother of a child in your practice recently learned that her grandmother had a

child who died of "probable metabolic disease" at 2 days of age. She does not know details, and

medical records on that child no longer are available. The mother asks if her pregnancy can be

tested to see if the fetus could be affected with the same disorder.

Of the following, the MOST accurate statement regarding metabolic disease in the prenatal

setting is that

A. fetuses affected with metabolic diseases are unlikely to come to term

B. knowing the parents’ ethnic backgrounds aids in determining which tests should be offered

C. level 2 ultrasonography during the second trimester is likely to be helpful in detecting metabolic

disease

D. poor fetal growth is common in metabolic diseases

E. prenatal metabolic screening panels are widely available

Answer

B

The vignette highlights the importance of accessing as much information as possible
regarding family members who die from metabolic causes. Even if a diagnosis cannot be made
in a particular instance, medical records may be helpful in offering the expectant couple
guidance or in making a diagnosis posthumously. Taking a careful family history, with attention
to familial ethnic, religious, and geographic origins, may bring to light conditions that are likely to
run in families. For example, because of the high carrier rate for some metabolic diseases,
parents of Ashkenazi Jewish descent, whose ancestors originated from Eastern Europe, are at
increased risk for having children affected by Tay-Sachs disease  and people of
French-Canadian heritage are at increased risk for having children affected by tyrosinemia.

Cases

A 3 year old male child born of non consanguineous marriage presented with bilateral cataracts since 10 months. Birth history and milestones were normal. There was no jaundice, failure to thrive or dysmorphic features. On examination, apart from bilateral white reflex, other systems were normal.

Question :

How to approach such a case_?

Answer 

Causes of cataracts in a child are varied and include intrauterine infections, genetic disorders, metabolic disorders, hypoparathyroidism and even prematurity. This child has no prematurity, dysmorphic features or delayed milestones. 

Thus, most likely cause of cataract in this child would be metabolic disorder. Common metabolic disorders leading to white cataract are:

 • Hypoparathyroidism 

• Galactosemia 

• Lowe’s syndrome 

• Diabetes mellitus

 In this child, since there is no jaundice or hepatomegaly, galactosemia type 1 and 3 seem unlikely. 

Lowe’s syndrome is associated with RTA and mental retardation. 

Diabetes mellitus would have additional features of polyuria, polydipsia. Thus in this child, one must rule out Hypoparathyroidism. 

The calcium, phosphorus, alkaline phosphatase in this child was normal. Galactosemia type 2 is a possibility and one must do the galactokinase enzyme levels.

 Galactosemia workup for galactokinase deficiency was positive.

MCQs In Muscular diseases

Q1 :

A 6-year-old boy has had difficulty walking and lower leg pain for 2 days. Five days ago, he had

fever and cough that had lasted for 3 days. On physical examination, the child has no fever, and

vital signs are normal, as are cranial nerves, speech, and language. Muscle bulk, tone, and

reflexes are normal and symmetric, but his lower legs are painful to palpation. Serum creatine

kinase is 2,000 U/L, and urine is negative for myoglobin.

Of the following, the MOST likely diagnosis is

A. dermatomyositis

B. Duchenne muscular dystrophy

C. Guillain-Barré syndrome

D. metabolic myopathy

E. viral myositis

Answer

E


A gait disturbance, such as described for the boy in the vignette, can result from a variety of
potentially serious disease processes and, therefore, requires urgent evaluation. The muscle
pain and otherwise normal neurologic findings prompted measurement of serum creatine kinase,
which can help to localize the problem rapidly. The prodrome of an upper respiratory tract illness
and rapid onset of symptoms is suggestive of viral myositis.

Dermatomyositis is a more indolent, chronic process and should not present acutely with
muscle pain. Moreover, dermatomyositis is characterized by specific skin findings such as the
heliotrope rash over the eyelids and Gottron papules .

 Duchenne muscular dystrophy presents with more chronic weakness. Although Guillain-Barré syndrome
can present with pain and weakness, the preserved reflexes, focal pain over the leg muscles, and elevated creatine kinase value are not consistent with that diagnosis. Metabolic myopathies due to mitochondrial dysfunction can present with acute pain, weakness, tender muscles, and rhabdomyolysis. However, the prevalence is much lower than viral myositis. Influenza A and B and enteroviruses may cause viral myositis.

MCQs In Pediatric Cardiology Part II

Q 1:

You are evaluating a 12-year-old boy in the emergency department who presents with fever,

chills, malaise, and blood in his urine. On physical examination, he appears comfortable and alert

and has a temperature of 102.7°F (39.3°C), a blood pressure of 110/40 mm Hg, no rashes, and

clear breath sounds. He has a diastolic murmur heard best in the sitting position (Item Q133).

You elicit no abdominal or flank tenderness.

Of the following, the BEST next step in the management of this patient is

A. administration of broad-spectrum antibiotics

B. blood cultures

C. renal ultrasonography

D. transesophageal echocardiography

E. urine culture

Answer

B

The patient described in the vignette has history and physical examination findings that are
highly suggestive of infective endocarditis. These include symptoms of chills and malaise; a
history of fever; and the findings of hematuria, a new murmur, and fever. Typically, the diagnosis
is confirmed by isolation of the offending organism from blood cultures. Blood cultures from three
to five sites should be obtained prior to initiation of antibiotic therapy. Because the bacterial
shedding is constant, the practitioner should not wait until the patient is febrile to obtain blood
cultures. Viridans streptococci (eg, S bovis, S mitis) as well as Staphylococcus aureus are the
most common bacterial pathogens causing endocarditis in children. However, clinicians must be
concerned about organisms such as Enterococcus, coagulase-negative Staphylococcus, fungi,
and a group of bacteria referred to as the HACEK organisms (Haemophilus sp, Actinobacillus
actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae).

The HACEK organisms are gram-negative oral and pharyngeal flora that are fastidious and slow growing,
often requiring growth factors and carbon dioxide to be isolated in cultures.

Treatment of endocarditis depends on the isolated organism. In general, long-term antibiotic
treatment (4 to 6 weeks) is undertaken in an effort to eradicate completely the bacteria that have
been sequestered in a nonvascular vegetation. Surgery is reserved for patients who develop
severe congestive heart failure from severe valve regurgitation or deterioration.

The boy in the vignette requires intravenous antibiotic treatment, but blood cultures should
be obtained before therapy is begun. He also should undergo echocardiography, which may be
performed from the transesophageal approach to improve the sensitivity, but similar to renal
ultrasonography, such a study is performed after blood cultures have been obtained. The
absence of vegetation at the time of echocardiography does not rule out a diagnosis of infective
endocarditis. Patients who have infective endocarditis may exhibit hematuria from the deposition
of immune complexes resulting in glomerulonephritis. Although fever and hematuria may be
associated with urinary tract infection, the presence of a diastolic murmur and absence of
urinary symptoms make such a diagnosis unlikely.

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Q2:

 A 5-year-old full term male infant was severely cyanotic at birth. Prostaglandin E was administered
initially and later balloon atrial septostomy was done which showed improvement in oxygenation. The most
likely diagnosis of this infant is:

a. Tetralogy of Fallot
b. Transposition of great vessels
c. Truncus arteriosis
d. Tricuspid atresia
e. PDA


Answer

B

Q 3:

Which one of the following CHD has cyanosis without cardiomegaly and/or CCF?

a. TGV
b. TOF
c. Congenital MR
d. Congenital PS


Answer

B

Q 4:

One-year-old child with PDA; which is true:

a. Symptoms are similar to aortopulmonary window
b. Chances of spontaneous closure is high
c. Indomethacin may help in closure
d. Endocarditis is rare

Answer

A

Q5:

An 8-yr-old male child is admitted with a diagnosis of rheumatic fever with arthritis, carditis and CCF, with
reference to this case, consider the following as initial lines of management:

a. Eradication of remnant streptococcal infection
b. Administration of an anti-inflammatory drug
c. Institution of decongestive therapy
d. Institution of graded and gradually increasing exercise

Answer

C

Q6:

 A young boy had developed CCF, found to have membraneous VSD. He showed spontaneous improvement. This is most likely due to:

a. Perimembraneous closure of VSD
b. Development of AR
c. Pulmonary vascular changes
d. Infective endocarditis

Answer

C


---------------------------

Q 7

A full-term newborn develops cyanosis a few hours after birth. Oxygen administration does
not improve color or oxygen saturations. Which of the following is the most likely diagnosis?

(A) atrial septal defect
(B) ventricular septal defect
(C) patent ductus arteriosus
(D) aortic stenosis
(E) pulmonary stenosis

MCQs In Pediatric Toxicology

Q1 : 

A resident in continuity clinic approaches you to review the laboratory values obtained at a

patient’s 12-month health supervision visit. The fingerstick hemoglobin measurement was 10.5

g/dL (105.0 g/L), and the lead concentration was 11.0 mcg/dL (0.53 mcmol/L).

Of the following, the next BEST step for this boy is to

A. admit him to the hospital for chelation therapy

B. call child protective services to move him to a shelter

C. call the health department to arrange for an environmental investigation

D. measure the venous lead concentration

E. refer him for formal developmental evaluation and neuropsychometric testing

Answer:

D

The American Academy of Pediatrics policy statement recommends the use of venous
samples for initial screening whenever possible. If capillary testing is performed and the lead
concentration is greater than 10.0 mcg/dL (0.5 mcmol/L), the lead concentration must be
confirmed by a venous sample because microlead sampling is more likely to yield false-positive
results due to contamination from environmental lead.

Lead ingestion may cause a microcytic anemia by interfering with iron absorption and
utilization in heme production and can inhibit enzymes required for heme synthesis directly.
Children who have lead poisoning may have pica either as a cause or symptom of lead
poisoning. In these children, iron supplementation should be initiated until the presence or
absence of iron deficiency is determined.

Most asymptomatic children who have mildly elevated blood lead concentrations are not
candidates for chelation therapy with the currently available drugs because the toxicity of these
drugs outweighs the potential benefit of treatment, and chelation is unlikely to increase lead
excretion significantly. Chelation therapy should be considered, however, if lead concentrations
are higher than 44.0 mcg/dL (2.12 mcmol/L). The role of chelation is not clearly defined for
children whose blood lead concentrations range from 20.0 to 45.0 mcg/dL (0.97 to 2.17
mcmol/L). In this range, the clinician may choose to pursue further environmental screening,
attempt to eradicate lead from the child's environment, and measure blood lead concentrations
monthly. If the concentration remains in this range, despite successful eradication of the lead
source, the physician should institute behavior modification, nutritional sufficiency, or chelation
treatment.
Succimer is the drug of choice for children whose blood lead concentrations are 45.0 to
100.0 mcg/dL (2.17 to 4.8 mcmol/L). At values higher than 69.0 mcg/dL (3.3 mcmol/L), a second
drug, CaNa2EDTA, is added.

Blood lead concentrations fall precipitously after completion of chelation, but rebound within
weeks, even if there is no further exposure to lead, due to release of lead from bone stores. In
general, the concentrations do not return to the high values seen before chelation, and a second
course of chelation rarely is indicated.