COMPLEX COMSAE Phase 1 Form 112 Exam
Prep Questions And Well Graded Solutions
With Rationales Updated 2026-2027
Master the COMLEX Level 1 with this ultimate high-yield study resource for the COMSAE Phase 1 Form
112 exam. Features 150 highly realistic, comprehensive multiple-choice practice questions tracking
the official NBOME blueprint. Accelerate your revision with an intense focus on heavy-yield
concepts: neuroanatomy, musculoskeletal medicine, extremity innervations, and OMM/OPP
viscerosomatic reflex levels. Includes unbolded questions, isolated answers, and deeply detailed
conceptual rationales.
1. A 24-year-old male is brought to the emergency department after being struck in the
temporal region of the skull with a baseball bat. He initially lost consciousness but
recovered and was lucid for approximately 30 minutes before rapidly deteriorating. A
non-contrast head CT demonstrates a lens-shaped hyperdensity. Which of the
following vessels is most likely lacerated in this patient?
A) Bridging cortical veins
B) Anterior communicating artery
C) Middle meningeal artery
D) Ophthalmic artery
Rationale: The patient is presenting with a classic classic epidural hematoma
following trauma to the pterion. The middle meningeal artery, a branch of the
maxillary artery, runs directly beneath the pterion and is highly susceptible to
laceration from temporal skull fractures. The resulting arterial bleed creates a
biconvex, lens-shaped hematoma that cannot cross cranial suture lines.
2. A 74-year-old female with a history of chronic atrial fibrillation presents with
progressive confusion, gait instability, and frequent falls over the past three weeks.
Her family notes she bumped her head on a kitchen cabinet a month ago but
seemed fine at the time. A head CT reveals a crescent-shaped collection of fluid
crossing suture lines. What is the primary pathophysiology underlying this condition?
A) Rupture of bridging cortical veins
B) Rupture of the posterior communicating artery
C) Laceration of the middle cerebral artery branches
D) Shear injury to the corpus callosum axons
Rationale: This patient is suffering from a chronic subdural hematoma, which is
common in elderly individuals due to age-related brain atrophy. Atrophy stretches the
bridging cortical veins as they traverse from the cortex to the dural sinuses, making
them prone to shearing from minor trauma. The venous nature of the bleed results in
a slow, gradual accumulation of blood that forms a crescent shape on CT.
,3. A 43-year-old female presents to the emergency department reporting the
"worst headache of her life," which began suddenly while she was lifting weights.
She also complains of photophobia and neck stiffness. Physical examination reveals
nuchal rigidity. If a lumbar puncture is performed, which of the following findings is
most diagnostic for this acute condition?
A) Oligoclonal bands
B) Xanthochromia
C) Elevated protein with normal glucose and no red blood cells
D) Marked polymorphonuclear leukocytosis
Rationale: The sudden onset of a "thunderclap" headache during exertion strongly
indicates a subarachnoid hemorrhage, most commonly due to the rupture of a
saccular (berry) aneurysm in the Circle of Willis. Xanthochromia, a yellowish
discoloration of the cerebrospinal fluid resulting from hemoglobin breakdown
products, confirms the presence of blood in the subarachnoid space and
differentiates true hemorrhage from a traumatic lumbar puncture spinal tap.
4. A 28-year-old male is involved in a high-speed motor vehicle collision. On
arrival, he is comatose with a Glasgow Coma Scale score of 5. Head CT
demonstrates normal ventricular size and no large focal extra-axial fluid collections,
but reveals multiple punctate hemorrhages isolated to the gray-white matter junction
and the corpus callosum. What is the most likely diagnosis?
A) Glioblastoma multiforme
B) Chronic traumatic encephalopathy
C) Communicating hydrocephalus
D) Diffuse axonal injury
Rationale: Diffuse axonal injury (DAI) is caused by severe rotational acceleration or
deceleration forces during trauma, which leads to the shearing of axons at the gray-
white matter junction. While the initial CT can appear surprisingly normal or show
minimal punctate hemorrhages, the clinical state is profound. MRI is the preferred
modality to fully visualize the widespread axonal lesions.
5. A 62-year-old male presents with sudden onset of weakness in his left leg and
foot. On neurological examination, he demonstrates a loss of crude touch and
vibration sensation localized strictly to the left lower extremity, along with a positive
Babinski sign on the left. His upper extremities and face are entirely spared.
Obstruction of which of the following arteries is responsible for these symptoms?
A) Right middle cerebral artery
B) Right anterior cerebral artery
,C) Left posterior cerebral artery
D) Vertebral artery
Rationale: The anterior cerebral artery (ACA) supplies the medial surface of the
cerebral hemisphere, which contains the motor and sensory cortices responsible for
the contralateral lower extremity (leg and foot). An occlusion of the right ACA
manifests as left-sided lower extremity weakness and sensory loss, sparing the face
and arm which are mapped to the lateral hemisphere supplied by the middle cerebral
artery.
Block 2: Musculoskeletal Medicine and Extremity Innervations
6. A 19-year-old college football player lands awkwardly on his right shoulder
during a tackle, forcing his head and neck violently to the opposite side. Examination
reveals a loss of shoulder abduction, external rotation, and forearm supination,
causing the arm to hang internally rotated and adducted. Injury to which portion of
the brachial plexus explains this presentation?
A) Upper trunk (C5–C6)
B) Lower trunk (C8–T1)
C) Posterior cord
D) Medial cord
Rationale: This presentation describes Erb-Duchenne palsy ("waiter's tip" position),
which occurs following an injury to the upper trunk of the brachial plexus (C5–C6
roots). This traction injury disrupts the axillary nerve (leading to deltoid paralysis and
loss of abduction), the suprascapular nerve (loss of external rotation), and the
musculocutaneous nerve (loss of biceps brachii function and forearm supination).
7. A 32-year-old factory worker presents with a tingling sensation and numbness
in her thumb, index finger, and middle finger that worsens significantly at night. She
notes that shaking her hands provides temporary relief. Physical examination
demonstrates atrophy of the thenar eminence. Through which anatomical structure
does the affected nerve pass?
A) Guyon's canal
B) Carpal tunnel
C) Cubital fossa
D) Triangular space
Rationale: The patient exhibits classic signs of carpal tunnel syndrome, which
involves compression of the median nerve as it passes beneath the flexor
retinaculum within the carpal tunnel. Long-term compression leads to sensory loss in
the lateral three and a half digits and motor weakness of the thenar muscles
, (abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis), resulting in
thenar atrophy.
8. A 45-year-old male presents following a laceration to his posterior arm after
falling through a glass window. Physical examination reveals an inability to extend
the wrist against resistance, resulting in a persistent "wrist drop," along with sensory
loss on the dorsal aspect of the first web space. Which nerve has been damaged?
A) Ulnar nerve
B) Median nerve
C) Axillary nerve
D) Radial nerve
Rationale: The radial nerve originates from the posterior cord of the brachial plexus
and innervates the extensor muscles of the arm and forearm (including the triceps
and wrist extensors). Injury to this nerve, often associated with mid-shaft humeral
fractures or deep posterior arm lacerations, leads to a paralysis of the wrist
extensors ("wrist drop") and sensory deficits over the dorsal aspect of the lateral
hand.
9. A 55-year-old administrative assistant complains of persistent pain and
numbness along the medial aspect of his left hand, specifically involving the ring and
pinky fingers. He notes that he spends most of his workday leaning his elbows firmly
against a hard wooden desk. Which nerve is compressed?
A) Ulnar nerve
B) Radial nerve
C) Median nerve
D) Musculocutaneous nerve
Rationale: The ulnar nerve passes posteriorly to the medial epicondyle of the
humerus within the cubital tunnel. Chronic pressure on the elbow, such as leaning on
a hard desk, compresses the ulnar nerve, causing paresthesias and sensory loss in
the ulnar distribution (the 5th digit and medial half of the 4th digit) along with intrinsic
hand muscle weakness.
10. A 22-year-old female runner trips and severely twists her right ankle,
sustaining an isolated fracture of the fibular neck. On examination, she is completely
unable to dorsiflex her foot, causing her to drag her toes when walking. She also
demonstrates sensory loss on the dorsum of the foot. Which nerve was injured by
the fracture?
A) Tibial nerve
B) Saphenous nerve
Prep Questions And Well Graded Solutions
With Rationales Updated 2026-2027
Master the COMLEX Level 1 with this ultimate high-yield study resource for the COMSAE Phase 1 Form
112 exam. Features 150 highly realistic, comprehensive multiple-choice practice questions tracking
the official NBOME blueprint. Accelerate your revision with an intense focus on heavy-yield
concepts: neuroanatomy, musculoskeletal medicine, extremity innervations, and OMM/OPP
viscerosomatic reflex levels. Includes unbolded questions, isolated answers, and deeply detailed
conceptual rationales.
1. A 24-year-old male is brought to the emergency department after being struck in the
temporal region of the skull with a baseball bat. He initially lost consciousness but
recovered and was lucid for approximately 30 minutes before rapidly deteriorating. A
non-contrast head CT demonstrates a lens-shaped hyperdensity. Which of the
following vessels is most likely lacerated in this patient?
A) Bridging cortical veins
B) Anterior communicating artery
C) Middle meningeal artery
D) Ophthalmic artery
Rationale: The patient is presenting with a classic classic epidural hematoma
following trauma to the pterion. The middle meningeal artery, a branch of the
maxillary artery, runs directly beneath the pterion and is highly susceptible to
laceration from temporal skull fractures. The resulting arterial bleed creates a
biconvex, lens-shaped hematoma that cannot cross cranial suture lines.
2. A 74-year-old female with a history of chronic atrial fibrillation presents with
progressive confusion, gait instability, and frequent falls over the past three weeks.
Her family notes she bumped her head on a kitchen cabinet a month ago but
seemed fine at the time. A head CT reveals a crescent-shaped collection of fluid
crossing suture lines. What is the primary pathophysiology underlying this condition?
A) Rupture of bridging cortical veins
B) Rupture of the posterior communicating artery
C) Laceration of the middle cerebral artery branches
D) Shear injury to the corpus callosum axons
Rationale: This patient is suffering from a chronic subdural hematoma, which is
common in elderly individuals due to age-related brain atrophy. Atrophy stretches the
bridging cortical veins as they traverse from the cortex to the dural sinuses, making
them prone to shearing from minor trauma. The venous nature of the bleed results in
a slow, gradual accumulation of blood that forms a crescent shape on CT.
,3. A 43-year-old female presents to the emergency department reporting the
"worst headache of her life," which began suddenly while she was lifting weights.
She also complains of photophobia and neck stiffness. Physical examination reveals
nuchal rigidity. If a lumbar puncture is performed, which of the following findings is
most diagnostic for this acute condition?
A) Oligoclonal bands
B) Xanthochromia
C) Elevated protein with normal glucose and no red blood cells
D) Marked polymorphonuclear leukocytosis
Rationale: The sudden onset of a "thunderclap" headache during exertion strongly
indicates a subarachnoid hemorrhage, most commonly due to the rupture of a
saccular (berry) aneurysm in the Circle of Willis. Xanthochromia, a yellowish
discoloration of the cerebrospinal fluid resulting from hemoglobin breakdown
products, confirms the presence of blood in the subarachnoid space and
differentiates true hemorrhage from a traumatic lumbar puncture spinal tap.
4. A 28-year-old male is involved in a high-speed motor vehicle collision. On
arrival, he is comatose with a Glasgow Coma Scale score of 5. Head CT
demonstrates normal ventricular size and no large focal extra-axial fluid collections,
but reveals multiple punctate hemorrhages isolated to the gray-white matter junction
and the corpus callosum. What is the most likely diagnosis?
A) Glioblastoma multiforme
B) Chronic traumatic encephalopathy
C) Communicating hydrocephalus
D) Diffuse axonal injury
Rationale: Diffuse axonal injury (DAI) is caused by severe rotational acceleration or
deceleration forces during trauma, which leads to the shearing of axons at the gray-
white matter junction. While the initial CT can appear surprisingly normal or show
minimal punctate hemorrhages, the clinical state is profound. MRI is the preferred
modality to fully visualize the widespread axonal lesions.
5. A 62-year-old male presents with sudden onset of weakness in his left leg and
foot. On neurological examination, he demonstrates a loss of crude touch and
vibration sensation localized strictly to the left lower extremity, along with a positive
Babinski sign on the left. His upper extremities and face are entirely spared.
Obstruction of which of the following arteries is responsible for these symptoms?
A) Right middle cerebral artery
B) Right anterior cerebral artery
,C) Left posterior cerebral artery
D) Vertebral artery
Rationale: The anterior cerebral artery (ACA) supplies the medial surface of the
cerebral hemisphere, which contains the motor and sensory cortices responsible for
the contralateral lower extremity (leg and foot). An occlusion of the right ACA
manifests as left-sided lower extremity weakness and sensory loss, sparing the face
and arm which are mapped to the lateral hemisphere supplied by the middle cerebral
artery.
Block 2: Musculoskeletal Medicine and Extremity Innervations
6. A 19-year-old college football player lands awkwardly on his right shoulder
during a tackle, forcing his head and neck violently to the opposite side. Examination
reveals a loss of shoulder abduction, external rotation, and forearm supination,
causing the arm to hang internally rotated and adducted. Injury to which portion of
the brachial plexus explains this presentation?
A) Upper trunk (C5–C6)
B) Lower trunk (C8–T1)
C) Posterior cord
D) Medial cord
Rationale: This presentation describes Erb-Duchenne palsy ("waiter's tip" position),
which occurs following an injury to the upper trunk of the brachial plexus (C5–C6
roots). This traction injury disrupts the axillary nerve (leading to deltoid paralysis and
loss of abduction), the suprascapular nerve (loss of external rotation), and the
musculocutaneous nerve (loss of biceps brachii function and forearm supination).
7. A 32-year-old factory worker presents with a tingling sensation and numbness
in her thumb, index finger, and middle finger that worsens significantly at night. She
notes that shaking her hands provides temporary relief. Physical examination
demonstrates atrophy of the thenar eminence. Through which anatomical structure
does the affected nerve pass?
A) Guyon's canal
B) Carpal tunnel
C) Cubital fossa
D) Triangular space
Rationale: The patient exhibits classic signs of carpal tunnel syndrome, which
involves compression of the median nerve as it passes beneath the flexor
retinaculum within the carpal tunnel. Long-term compression leads to sensory loss in
the lateral three and a half digits and motor weakness of the thenar muscles
, (abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis), resulting in
thenar atrophy.
8. A 45-year-old male presents following a laceration to his posterior arm after
falling through a glass window. Physical examination reveals an inability to extend
the wrist against resistance, resulting in a persistent "wrist drop," along with sensory
loss on the dorsal aspect of the first web space. Which nerve has been damaged?
A) Ulnar nerve
B) Median nerve
C) Axillary nerve
D) Radial nerve
Rationale: The radial nerve originates from the posterior cord of the brachial plexus
and innervates the extensor muscles of the arm and forearm (including the triceps
and wrist extensors). Injury to this nerve, often associated with mid-shaft humeral
fractures or deep posterior arm lacerations, leads to a paralysis of the wrist
extensors ("wrist drop") and sensory deficits over the dorsal aspect of the lateral
hand.
9. A 55-year-old administrative assistant complains of persistent pain and
numbness along the medial aspect of his left hand, specifically involving the ring and
pinky fingers. He notes that he spends most of his workday leaning his elbows firmly
against a hard wooden desk. Which nerve is compressed?
A) Ulnar nerve
B) Radial nerve
C) Median nerve
D) Musculocutaneous nerve
Rationale: The ulnar nerve passes posteriorly to the medial epicondyle of the
humerus within the cubital tunnel. Chronic pressure on the elbow, such as leaning on
a hard desk, compresses the ulnar nerve, causing paresthesias and sensory loss in
the ulnar distribution (the 5th digit and medial half of the 4th digit) along with intrinsic
hand muscle weakness.
10. A 22-year-old female runner trips and severely twists her right ankle,
sustaining an isolated fracture of the fibular neck. On examination, she is completely
unable to dorsiflex her foot, causing her to drag her toes when walking. She also
demonstrates sensory loss on the dorsum of the foot. Which nerve was injured by
the fracture?
A) Tibial nerve
B) Saphenous nerve
