INI-CET 2026 Practice Questions

Q: A 25-year-old college student presents with progressive headache, vomiting, and double vision. Examination reveals bilateral 6th nerve palsy and papilledema. CT brain shows hydrocephalus. CSF analysis reveals lymphocytic dominance, markedly low glucose, and elevated protein. What is the most likely diagnosis?

Tubercular meningitis. ***Tubercular meningitis*** - The classic CSF triad of **lymphocytic pleocytosis**, **markedly low glucose (hypoglycorrhachia)**, and **elevated protein** is highly characteristic of tuberculous meningitis. - The presentation of **hydrocephalus** and **cranial nerve palsies (like CN VI palsy)** is a hallmark complication caused by the thick, gelatinous **basilar exudates** associated with this condition. *Viral meningitis* - Typically presents with **normal glucose levels** in the CSF and generally does not cause profound hydrocephalus or cranial nerve palsies. - This condition is often self-limiting, whereas the progression of symptoms here suggests a more chronic, invasive process. *Fungal meningitis* - While fungal infections like *Cryptococcus* can cause lymphocytic meningitis and high intracranial pressure, the classic profile strongly pointing to TB is the profound glucose consumption and typical basilar inflammation. - Cryptococcal meningitis is more commonly seen in heavily **immunocompromised patients (e.g., AIDS)**, and diagnostic testing for cryptococcal antigen would be the first line of investigation. *Bacterial meningitis* - Typically exhibits **neutrophilic predominance** in the CSF, rather than the lymphocytic dominance described in this case. - CSF glucose levels in typical bacterial meningitis are usually low, but the clinical course is generally **acute and fulminant** (hours to days), unlike the subacute progression often seen in tuberculosis.

Q: A 28-year-old woman with severe anorexia is admitted for nutritional rehabilitation. Within 48 hours of initiating enteral feeding, she develops muscle weakness, cardiac arrhythmias, and respiratory distress. Which metabolic abnormality is most characteristically responsible?

Hypophosphatemia. ***Hypophosphatemia*** - This patient is presenting with classic signs of **refeeding syndrome**, which occurs when rapid insulin secretion after carbohydrate ingestion triggers intracellular uptake of electrolytes, depleting serum pools. - **Hypophosphatemia** is the hallmark metabolic abnormality, leading to **adenosine triphosphate (ATP) depletion** and subsequent muscle weakness, cardiomyopathy, arrhythmias, and respiratory failure due to diaphragmatic weakness. *Hyponatremia* - While electrolyte disturbances are common in anorexia, **hyponatremia** is typically associated with excessive water intake or volume depletion rather than the rapid physiological shift seen in refeeding. - It does not explain the specific constellation of profound muscular and respiratory failure seen shortly after the initiation of feeding in this clinical context. *Hypocalcemia* - Although **hypocalcemia** can occur in refeeding syndrome due to an influx into the intracellular space, it is usually secondary and less frequently the primary cause of the severe, acute respiratory and cardiac symptoms described. - It typically manifests with signs of **tetany**, **Chvostek's sign**, or **Trousseau's sign** rather than the primary respiratory distress pattern seen here. *Hyperkalemia* - In the context of refeeding, the risk is typically **hypokalemia** due to the insulin-stimulated shift of potassium into cells, not hyperkalemia. - **Hyperkalemia** would likely present with different ECG changes, such as peaked T-waves, which is contrary to the clinical presentation of refeeding syndrome.

Q: A 15-year-old boy presents with hypertension and salt-water retention. He is suspected to have 17-alpha hydroxylase deficiency. What is the expected serological profile?

High mineralocorticoid, low cortisol, low androgen. ***High mineralocorticoid, low cortisol, low androgen*** - In **17-alpha hydroxylase deficiency**, the conversion of pregnenolone and progesterone to 17-OH derivatives (cortisol precursors) is blocked, which shunts the substrate toward the **mineralocorticoid pathway**. - This leads to excessive production of **deoxycorticosterone** (a potent mineralocorticoid), causing hypertension and salt retention, while simultaneously causing **cortisol** and **androgen** deficiency due to downstream blockages. *High mineralocorticoid, high cortisol, high androgen* - This profile is not seen in 17-alpha hydroxylase deficiency; **high androgens** are typically seen in 21-hydroxylase deficiency (congenital adrenal hyperplasia). - High cortisol would contradict the block in the glucocorticoid synthesis pathway caused by the enzyme deficiency. *High mineralocorticoid, high cortisol, low androgen* - While the mineralocorticoid levels are correctly described as high, **cortisol** levels are typically low due to the enzymatic block. - The deficiency of cortisol leads to increased **ACTH** (adrenocorticotropic hormone) secretion via feedback, but the enzyme block prevents downstream cortisol production. *Low mineralocorticoid, low cortisol, low androgen* - This profile is more characteristic of **Addison's disease** (primary adrenal insufficiency) where total adrenal function is impaired. - In 17-alpha hydroxylase deficiency, the mineralocorticoid pathway is essentially hyperactive, so low mineralocorticoid is incorrect.

Q: A 10-year-old boy presents with excessive eating (hyperphagia) and obesity, with a BMI of 33. Genetic testing shows a deletion on chromosome 15. What is the most likely diagnosis?

Prader-Willi syndrome. ***Prader-Willi syndrome*** - This condition is caused by a **paternal deletion** of the **15q11-q13** region or **maternal uniparental disomy**, which is consistent with the described genetic finding. - The classic clinical presentation includes **hyperphagia**, leading to severe **obesity**, alongside **intellectual disability**, almond-shaped eyes, and hypogonadism. *Angelman syndrome* - While also involving the **15q11-q13** region, this is caused by a **maternal deletion** or **paternal uniparental disomy**. - Clinically, patients present with a **happy demeanor**, frequent laughter, ataxia, and seizures, rather than hyperphagia and obesity. *Rett syndrome* - An **X-linked dominant** disorder caused by mutations in the **MECP2 gene**, typically affecting females due to male lethality. - Characterized by the **loss of purposeful hand movements**, developmental regression, and **stereotypical hand-wringing** behaviors. *Down syndrome* - Caused by **trisomy 21**, not a deletion on chromosome 15. - Features include **distinctive facial dysmorphology**, such as **epicanthic folds** and a flat nasal bridge, along with congenital heart defects and varying degrees of intellectual impairment.

Q: A 66-year-old female has normal calcium, elevated PTH, low phosphate, and raised ALP. What is the diagnosis?

Vitamin D deficiency. ***Vitamin D deficiency*** - In early or mild **Vitamin D deficiency**, the **parathyroid hormone (PTH)** is elevated (secondary hyperparathyroidism) to compensate for low calcium absorption, which often keeps serum **calcium** levels within the low-normal range. - The elevated **PTH** causes increased renal phosphate excretion (leading to **low phosphate**) and increased bone turnover (leading to **raised ALP**). *Primary hyperparathyroidism* - Typically characterized by **hypercalcemia** alongside elevated **PTH**, unlike the normal calcium seen here. - While elevated **ALP** and low **phosphate** can occur, the calcium profile is the primary differentiator. *Hypoparathyroidism* - Characterized by **low PTH** levels and **hypocalcemia**, which directly contradicts the lab findings presented. - It is usually due to surgical damage to the glands or autoimmune destruction, not a metabolic state of compensation. *Chronic kidney disease* - Often presents with **hyperphosphatemia** (high phosphate) due to impaired renal excretion, not the low phosphate seen in this patient. - While secondary hyperparathyroidism can occur, the typical profile is **low/normal calcium**, **high phosphate**, and **high PTH**.

Q: A neonate presents with prolonged neonatal jaundice, an umbilical hernia, and generalized hypotonia. Which of the following is the most likely underlying diagnosis?

Congenital hypothyroidism. ***Congenital hypothyroidism*** - Prolonged neonatal jaundice is a classic finding due to delayed maturation of hepatic glucuronyl transferase, often combined with an umbilical hernia caused by hypoventilation/hypotonia. - Generalized hypotonia, lethargy, macroglossia, and a large posterior fontanelle are key clinical signs requiring early diagnosis through newborn screening to prevent intellectual disability. *Galactosemia* - Typically presents with vomiting, poor feeding, lethargy, and failure to thrive shortly after milk ingestion, leading to E. coli sepsis and liver failure. - While jaundice is present, the diagnosis is primarily characterized by hepatosplenomegaly and cataracts, rather than umbilical hernia and isolated hypotonia. *Down syndrome* - Features such as hypotonia, upslanting palpebral fissures, and epicanthal folds are common, but they do not typically cause prolonged pathological jaundice. - An umbilical hernia is frequently seen in Down syndrome, but the child would exhibit other dysmorphic stigmata rather than the specific constellation of hypothyroidism signs. *Biliary atresia* - Presents with persistent conjugated hyperbilirubinemia, acholic stools, and hepatomegaly, rather than generalized hypotonia or umbilical hernia. - It is a surgical emergency characterized by progressive fibrosis of the extrahepatic biliary tree, not a metabolic or endocrine issue like the patient's presentation.

Q: A neonate presents with differential cyanosis, characterized by pink upper extremities and cyanosed lower extremities. Which of the following congenital heart diseases is most likely responsible for this clinical presentation?

Large patent ductus arteriosus (PDA). ***Large patent ductus arteriosus (PDA)*** - Differential cyanosis occurs when **deoxygenated blood** from the pulmonary artery is shunted right-to-left through a large **patent ductus arteriosus** into the descending aorta, affecting distal perfusion while leaving the pre-ductal (upper extremity) circulation supplied by the oxygenated blood from the ascending aorta. - This is typically associated with **pulmonary hypertension** or other conditions causing **reversed (right-to-left) shunt** across the ductus, leading to cyanosis strictly in the lower body. *Atrioventricular septal defect* - This condition results in central mixing of blood, typically leading to generalized (not differential) cyanosis and **congestive heart failure** symptoms. - It is classically associated with **Down syndrome** and involves defects in the atrial and ventricular septa. *Severe mitral stenosis* - Pulmonary venous hypertension and congestion are the primary findings, which lead to **pulmonary edema** and respiratory distress rather than differential cyanosis. - Cyanosis in left-sided obstructive lesions is usually late-stage or secondary to severe **pulmonary hypertension** affecting both upper and lower body circulation globally. *Peripheral vascular disease* - This condition is extremely rare in neonates and typically suggests anatomical obstructions like **coarctation of the aorta** or thromboembolic events rather than congenital cardiac defects. - Clinical presentation involving **pulm pulses** or blood pressure discrepancies in coarctation is distinct from the cyanotic manifestation of a shunted PDA.

Q: A female child had normal developmental milestones until 6-8 months of age, after which she developed progressive regression in language, social interaction, and adaptive behavior. The regression was accompanied by loss of purposeful hand use replaced by stereotyped repetitive hand-wringing or clapping movements, and deceleration of head circumference growth. Which of the following is the most likely diagnosis?

Rett syndrome. ***Rett syndrome*** - This condition is characterized by **normal development** until 6-18 months, followed by characteristic **regression** that includes loss of purposeful hand skills and the development of **stereotyped hand movements** like wringing or clapping. - It is classically associated with **deceleration of head growth** (acquired microcephaly) and is most commonly caused by **MECP2 gene mutations** on the X chromosome. *Childhood disintegrative disorder* - This disorder requires a period of **normal development for at least 2 years** followed by the loss of previously acquired skills. - It involves a more profound regression in multiple areas (social, communication, play) than is typically seen in the early phases of Rett syndrome. *Down syndrome* - This is a chromosomal disorder caused by **trisomy 21**, typically presenting with **intellectual disability** and characteristic dysmorphic facial features from **birth**. - Developmental delays are usually present early, rather than characterized by a distinct period of normal development followed by regression. *Asperger syndrome* - Historically defined as a high-functioning form of autism, it is characterized by social impairment and repetitive behaviors but **lacks the loss of acquired skills** or motor regression seen in Rett syndrome. - There is typically no associated **deceleration in head circumference** or specific hand stereotypies characteristic of Rett syndrome.

Q: A 6-week-old infant with prolonged NICU stay with presentation of fever, lethargy, poor feeding with CSF analysis showing features of bacterial meningitis. Which of the following are responsible? a. Staphylococcus aureus b. Hemophilus influenzae c. Streptococcus pneumoniae d. Listeria Choose the correct answer:

All of the above. ***All of the above*** - In a **6-week-old infant** who has stayed in the **NICU**, the etiology of meningitis is broad and reflects both community-acquired and hospital-acquired (**nosocomial**) risk factors. - All listed organisms—**Staphylococcus aureus**, **Haemophilus influenzae**, **Streptococcus pneumoniae**, and **Listeria monocytogenes**—are clinically relevant pathogens capable of causing meningitis in this population depending on maternal transmission, colonization, and environmental exposure. *Listeria* - While classically associated with **neonatal early-onset disease** (transplacental transmission), it remains a significant pathogen in this age group due to its ability to persist. - It is a facultative intracellular organism that often requires specific suspicion, especially in infants with compromised immunity or history of NICU admission. *b and d* - This option is incomplete as it ignores **Staphylococcus aureus** and **Streptococcus pneumoniae**, which are common causes of **healthcare-associated meningitis** in NICU environments. - Excluding these common pathogens fails to account for the risk of indwelling lines and procedure-related infections prevalent in NICU stays. *a, b, d* - This option is incorrect because it erroneously omits **Streptococcus pneumoniae**. - **Streptococcus pneumoniae** is a leading cause of bacterial meningitis in infants, and excluding it provides an insufficient assessment of the differential diagnosis.

Question 1

A 25-year-old college student presents with progressive headache, vomiting, and double vision.
Examination reveals bilateral 6th nerve palsy and papilledema. CT brain shows hydrocephalus. CSF
analysis reveals lymphocytic dominance, markedly low glucose, and elevated protein. What is the
most likely diagnosis?

Accepted Answer

Tubercular meningitis

Answer

Viral meningitis

Answer

Fungal meningitis

Answer

Bacterial meningitis

Question 2

A 28-year-old woman with severe anorexia is admitted for nutritional rehabilitation. Within 48
hours of initiating enteral feeding, she develops muscle weakness, cardiac arrhythmias, and
respiratory distress. Which metabolic abnormality is most characteristically responsible?

Accepted Answer

Hypophosphatemia

Answer

Hyponatremia

Answer

Hypocalcemia

Answer

Hyperkalemia

Question 3

A 15-year-old boy presents with hypertension and salt-water retention. He is suspected to have
17-alpha hydroxylase deficiency. What is the expected serological profile?

Accepted Answer

High mineralocorticoid, low cortisol, low androgen

Answer

High mineralocorticoid, high cortisol, high androgen

Answer

High mineralocorticoid, high cortisol, low androgen

Answer

Low mineralocorticoid, low cortisol, low androgen

Question 4

A 10-year-old boy presents with excessive eating (hyperphagia) and obesity, with a BMI of 33.
Genetic testing shows a deletion on chromosome 15. What is the most likely diagnosis?

Accepted Answer

Prader-Willi syndrome

Answer

Angelman syndrome

Answer

Rett syndrome

Answer

Down syndrome

Question 5

A 66-year-old female has normal calcium, elevated PTH, low phosphate, and raised ALP. What is
the diagnosis?

Accepted Answer

Vitamin D deficiency

Answer

Primary hyperparathyroidism

Answer

Hypoparathyroidism

Answer

Chronic kidney disease

Question 6

A neonate presents with prolonged neonatal jaundice, an umbilical hernia, and generalized
hypotonia. Which of the following is the most likely underlying diagnosis?

Accepted Answer

Congenital hypothyroidism

Answer

Galactosemia

Answer

Down syndrome

Answer

Biliary atresia

Question 7

A child diagnosed with Dravet syndrome is receiving multi-drug anti-seizure therapy and is being
considered for add-on treatment with fenfluramine. Which of the following monitoring strategies is
most critical before initiating and during the course of this therapy, given the known
pharmacological adverse-effect profile of fenfluramine?

Accepted Answer

Serial echocardiography to evaluate for cardiac valvular disease and pulmonary hypertension

Answer

Monthly complete blood count to monitor for agranulocytosis and aplastic anemia

Answer

Baseline and periodic ophthalmic examinations to monitor for visual field defects

Answer

Serial liver function tests and serum ammonia levels to monitor for hepatotoxicity

Question 8

A neonate presents with differential cyanosis, characterized by pink upper extremities and
cyanosed lower extremities. Which of the following congenital heart diseases is most likely
responsible for this clinical presentation?

Accepted Answer

Large patent ductus arteriosus (PDA)

Answer

Atrioventricular septal defect

Answer

Severe mitral stenosis

Answer

Peripheral vascular disease

Question 9

A female child had normal developmental milestones until 6-8 months of age, after which she
developed progressive regression in language, social interaction, and adaptive behavior. The
regression was accompanied by loss of purposeful hand use replaced by stereotyped repetitive
hand-wringing or clapping movements, and deceleration of head circumference growth. Which of
the following is the most likely diagnosis?

Accepted Answer

Rett syndrome

Answer

Childhood disintegrative disorder

Answer

Down syndrome

Answer

Asperger syndrome

Question 10

A 6-week-old infant with prolonged NICU stay with presentation of fever, lethargy, poor feeding
with CSF analysis showing features of bacterial meningitis. Which of the following are responsible?
a. Staphylococcus aureus
b. Hemophilus influenzae
c. Streptococcus pneumoniae
d. Listeria
Choose the correct answer:

Accepted Answer

All of the above

Answer

Listeria

Answer

b and d

Answer

a, b, d

INI-CET 2026

Internal Medicine

Pediatrics