COMSAE Phase 1 (ASA 115) — Level 1 questions with correct answers 2026/2027
version with rationales/instant pdf
1. A 24-year-old patient has acute low back pain after lifting a heavy object.
Osteopathic examination reveals a neutral, rotated-right, sidebent-left
dysfunction at L3. Which diagnosis best describes this finding?
A. ERLSL
B. FRRSR
C. NSRRL
D. FRSLL
Correct answer: C. NSRRL
Rationale: A neutral group dysfunction is named by the direction of rotation followed by
sidebending. The vertebrae rotate and sidebend in opposite directions.
2. A patient with somatic dysfunction of the upper thoracic region has restricted
motion, tissue texture changes, asymmetry, and tenderness. These findings
represent which components of TART?
A. Tissue texture abnormality, asymmetry, restriction of motion, and tenderness
B. Temperature, activity, reflexes, and tone
C. Tenderness, alignment, rotation, and tissue strength
D. Tension, autonomic activity, reflexes, and temperature
Correct answer: A. Tissue texture abnormality, asymmetry, restriction of motion, and tenderness
Rationale: TART findings are Tissue texture abnormality, Asymmetry, Restriction of motion,
and Tenderness.
3. A patient has a posterior fibular head dysfunction. Which muscle is most likely
associated with this dysfunction?
A. Biceps femoris
B. Tibialis anterior
C. Gastrocnemius
D. Sartorius
Correct answer: A. Biceps femoris
,Rationale: The biceps femoris attaches to the fibular head and can contribute to posterior fibular
head dysfunction.
4. A lesion affecting the left corticospinal tract above the pyramidal decussation
would most likely cause:
A. Left-sided upper motor neuron weakness
B. Right-sided upper motor neuron weakness
C. Bilateral lower motor neuron weakness
D. Contralateral loss of pain only
Correct answer: A. Left-sided upper motor neuron weakness
Rationale: Corticospinal fibers cross in the medullary pyramids. Lesions above the decussation
produce ipsilateral motor deficits.
5. A patient develops weakness of the right lower face but forehead movement is
preserved. Which lesion is most likely?
A. Left upper motor neuron lesion
B. Right facial nerve nucleus lesion
C. Right peripheral facial nerve lesion
D. Bilateral trigeminal nerve lesion
Correct answer: A. Left upper motor neuron lesion
Rationale: The upper face receives bilateral cortical innervation, while the lower face is
primarily controlled by the contralateral cortex.
6. A patient with a mutation affecting the CFTR chloride channel develops
recurrent respiratory infections and pancreatic insufficiency. Which mechanism
is most directly responsible?
A. Defective chloride transport causing thick secretions
B. Excessive surfactant production
C. Increased ciliary movement
D. Decreased mucus production
Correct answer: A. Defective chloride transport causing thick secretions
,Rationale: Cystic fibrosis results from defective CFTR function, causing abnormal chloride and
water movement and thick secretions.
7. A patient with severe fasting hypoglycemia has elevated insulin, C-peptide,
and proinsulin levels. Which condition is most likely?
A. Exogenous insulin use
B. Insulinoma
C. Glucagonoma
D. Type 1 diabetes mellitus
Correct answer: B. Insulinoma
Rationale: Endogenous insulin secretion causes elevation of insulin, C-peptide, and proinsulin.
Exogenous insulin increases insulin but suppresses C-peptide.
8. A patient has macrocytic anemia, paresthesias, and impaired vibration sense.
Which deficiency is most likely?
A. Vitamin B12
B. Iron
C. Vitamin C
D. Vitamin K
Correct answer: A. Vitamin B12
Rationale: Vitamin B12 deficiency causes megaloblastic anemia and neurologic dysfunction due
to impaired myelin maintenance.
9. A patient develops hemolytic anemia after taking an oxidant medication.
Blood smear shows bite cells and Heinz bodies. Which enzyme deficiency is most
likely?
A. G6PD deficiency
B. Pyruvate kinase deficiency
C. Hexokinase deficiency
D. Glucose-6-phosphatase deficiency
Correct answer: A. G6PD deficiency
, Rationale: G6PD deficiency decreases NADPH production, impairing protection against
oxidative stress.
10. A patient has a mutation affecting the LDL receptor. Which laboratory
finding is most likely?
A. Increased LDL cholesterol
B. Decreased LDL cholesterol
C. Increased HDL cholesterol only
D. Decreased triglycerides only
Correct answer: A. Increased LDL cholesterol
Rationale: Familial hypercholesterolemia results from impaired LDL clearance and markedly
elevated LDL levels.
11. A patient with severe diarrhea develops metabolic acidosis. Which
compensatory response is expected?
A. Hypoventilation
B. Hyperventilation
C. Decreased renal acid excretion
D. Increased bicarbonate production immediately
Correct answer: B. Hyperventilation
Rationale: Metabolic acidosis stimulates increased ventilation to reduce PaCO₂ and partially
compensate for the acidemia.
12. A patient has increased serum osmolarity and low blood pressure. Which
hormone is most likely increased?
A. Antidiuretic hormone
B. Atrial natriuretic peptide
C. Aldosterone only
D. Calcitonin
Correct answer: A. Antidiuretic hormone
version with rationales/instant pdf
1. A 24-year-old patient has acute low back pain after lifting a heavy object.
Osteopathic examination reveals a neutral, rotated-right, sidebent-left
dysfunction at L3. Which diagnosis best describes this finding?
A. ERLSL
B. FRRSR
C. NSRRL
D. FRSLL
Correct answer: C. NSRRL
Rationale: A neutral group dysfunction is named by the direction of rotation followed by
sidebending. The vertebrae rotate and sidebend in opposite directions.
2. A patient with somatic dysfunction of the upper thoracic region has restricted
motion, tissue texture changes, asymmetry, and tenderness. These findings
represent which components of TART?
A. Tissue texture abnormality, asymmetry, restriction of motion, and tenderness
B. Temperature, activity, reflexes, and tone
C. Tenderness, alignment, rotation, and tissue strength
D. Tension, autonomic activity, reflexes, and temperature
Correct answer: A. Tissue texture abnormality, asymmetry, restriction of motion, and tenderness
Rationale: TART findings are Tissue texture abnormality, Asymmetry, Restriction of motion,
and Tenderness.
3. A patient has a posterior fibular head dysfunction. Which muscle is most likely
associated with this dysfunction?
A. Biceps femoris
B. Tibialis anterior
C. Gastrocnemius
D. Sartorius
Correct answer: A. Biceps femoris
,Rationale: The biceps femoris attaches to the fibular head and can contribute to posterior fibular
head dysfunction.
4. A lesion affecting the left corticospinal tract above the pyramidal decussation
would most likely cause:
A. Left-sided upper motor neuron weakness
B. Right-sided upper motor neuron weakness
C. Bilateral lower motor neuron weakness
D. Contralateral loss of pain only
Correct answer: A. Left-sided upper motor neuron weakness
Rationale: Corticospinal fibers cross in the medullary pyramids. Lesions above the decussation
produce ipsilateral motor deficits.
5. A patient develops weakness of the right lower face but forehead movement is
preserved. Which lesion is most likely?
A. Left upper motor neuron lesion
B. Right facial nerve nucleus lesion
C. Right peripheral facial nerve lesion
D. Bilateral trigeminal nerve lesion
Correct answer: A. Left upper motor neuron lesion
Rationale: The upper face receives bilateral cortical innervation, while the lower face is
primarily controlled by the contralateral cortex.
6. A patient with a mutation affecting the CFTR chloride channel develops
recurrent respiratory infections and pancreatic insufficiency. Which mechanism
is most directly responsible?
A. Defective chloride transport causing thick secretions
B. Excessive surfactant production
C. Increased ciliary movement
D. Decreased mucus production
Correct answer: A. Defective chloride transport causing thick secretions
,Rationale: Cystic fibrosis results from defective CFTR function, causing abnormal chloride and
water movement and thick secretions.
7. A patient with severe fasting hypoglycemia has elevated insulin, C-peptide,
and proinsulin levels. Which condition is most likely?
A. Exogenous insulin use
B. Insulinoma
C. Glucagonoma
D. Type 1 diabetes mellitus
Correct answer: B. Insulinoma
Rationale: Endogenous insulin secretion causes elevation of insulin, C-peptide, and proinsulin.
Exogenous insulin increases insulin but suppresses C-peptide.
8. A patient has macrocytic anemia, paresthesias, and impaired vibration sense.
Which deficiency is most likely?
A. Vitamin B12
B. Iron
C. Vitamin C
D. Vitamin K
Correct answer: A. Vitamin B12
Rationale: Vitamin B12 deficiency causes megaloblastic anemia and neurologic dysfunction due
to impaired myelin maintenance.
9. A patient develops hemolytic anemia after taking an oxidant medication.
Blood smear shows bite cells and Heinz bodies. Which enzyme deficiency is most
likely?
A. G6PD deficiency
B. Pyruvate kinase deficiency
C. Hexokinase deficiency
D. Glucose-6-phosphatase deficiency
Correct answer: A. G6PD deficiency
, Rationale: G6PD deficiency decreases NADPH production, impairing protection against
oxidative stress.
10. A patient has a mutation affecting the LDL receptor. Which laboratory
finding is most likely?
A. Increased LDL cholesterol
B. Decreased LDL cholesterol
C. Increased HDL cholesterol only
D. Decreased triglycerides only
Correct answer: A. Increased LDL cholesterol
Rationale: Familial hypercholesterolemia results from impaired LDL clearance and markedly
elevated LDL levels.
11. A patient with severe diarrhea develops metabolic acidosis. Which
compensatory response is expected?
A. Hypoventilation
B. Hyperventilation
C. Decreased renal acid excretion
D. Increased bicarbonate production immediately
Correct answer: B. Hyperventilation
Rationale: Metabolic acidosis stimulates increased ventilation to reduce PaCO₂ and partially
compensate for the acidemia.
12. A patient has increased serum osmolarity and low blood pressure. Which
hormone is most likely increased?
A. Antidiuretic hormone
B. Atrial natriuretic peptide
C. Aldosterone only
D. Calcitonin
Correct answer: A. Antidiuretic hormone
