COMSAE Phase 1 Form 113 (2026) | Real Exam Predictor | 176 High-Yield Questions

COMSAE Phase 1 Form 113 | 2026 | Real Exam Predictor | 176 Questions Question 1 A 34-year-old male presents after a motorcycle accident. He cannot extend his wrist and has decreased grip strength. Sensation is diminished over the posterior arm and dorsal hand. The most likely site of nerve injury is: A) Median nerve at the wrist B) Ulnar nerve at the medial epicondyle C) Radial nerve at the mid-shaft humerus D) Musculocutaneous nerve at the upper trunk E) Axillary nerve at the surgical neck Correct Answer: C) Radial nerve at the mid-shaft humerus Rationale: The radial nerve (C5–T1) courses along the spiral groove of the mid-shaft humerus, making it vulnerable to fracture at this site. The classic finding is wrist drop (loss of wrist extension), decreased grip strength, and loss of sensation over the posterior arm and dorsal hand. The median nerve injury causes ape hand. The ulnar nerve injury at the medial epicondyle causes ulnar claw. The musculocutaneous nerve causes loss of forearm flexion and supination. The axillary nerve causes a flat deltoid (loss of arm abduction). Key Takeaway: Mid-shaft humerus fracture = Radial nerve = Wrist drop + loss of sensation posterior arm/dorsal hand. Hyperimmunoglobulinemia E (Job syndrome) An autosomal dominant condition characterized by the triad of eczema, eosinophilia, and recurrent skin and pulmonary infections. It is also associated with multiple connective tissue and skeletal abnormalities, including scoliosis, hyperextensibility, pathologic fractures, retained primary dentition, craniosynostosis, and vascular abnormalities Nitroblue Tetrazolium Dye Test It is used to detect the presence of NADPH oxidase, an enzyme used by neutrophils to make oxygen radicals for killing bacteria. The test is positive when the enzyme is present and not defective; the higher the blue score, the better the cell is at reproducing reactive oxygen species. NADPH oxidase is not affected in Job syndrome; thus, the nitroblue tetrazolium dye test should be positive. A negative test, as in chronic granulomatous disease, will show a lack of NADPH oxidase. Question 2 A 22-year-old gymnast presents with right foot drop and inability to evert the foot. She reports she recently began wearing a tight knee brace. Which nerve is most likely compressed? A) Tibial nerve at the ankle B) Common peroneal (fibular) nerve at the fibular head C) Femoral nerve at the inguinal ligament D) Sural nerve at the lateral malleolus E) Deep peroneal nerve at the dorsum of the foot Correct Answer: B) Common peroneal (fibular) nerve at the fibular head Rationale: The common peroneal nerve wraps around the fibular head and is the most commonly compressed nerve in the lower extremity. Compression here causes foot drop (loss of dorsiflexion) and loss of foot eversion. A tight brace or cast at the fibular head is a classic mechanism. The tibial nerve injury at the ankle causes loss of plantar flexion and toe flexion. The femoral nerve injury causes loss of knee extension (quadriceps weakness). The sural nerve is a pure sensory nerve to the lateral foot. Key Takeaway: Fibular head compression = Common peroneal nerve = Foot drop + loss of foot eversion. Question 3 A 45-year-old presents with pain and paresthesias radiating from the neck down the lateral forearm to the thumb. Examination reveals a diminished brachioradialis reflex and weakness of wrist extension. Which nerve root level is most likely affected? A) C5 B) C6 C) C7 D) C8 E) T1 Correct Answer: B) C6 Rationale: The C6 nerve root mediates: brachioradialis reflex, wrist extension, and sensation over the lateral forearm and thumb (dermatomal distribution). C5 affects the biceps reflex and shoulder abduction. C7 affects the triceps reflex and wrist flexion/finger extension. C8 affects finger flexion and sensation to the ring/small fingers. T1 affects intrinsic hand muscles. A herniation at the C5–6 disc level compresses the C6 root (the root always exits one level below the disc).