Question
Patient walks with left head tilted and exaggerated on dextroversion & right head tilt and what is the diagnosis?
| A. |
Right Superior oblique
|
| B. |
Right inferior oblique
|
| C. |
Right Superior rectus
|
| D. |
Left lateral rectus
|
Show Answer
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Correct Answer » A
Explanation
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This question is based on Park’s Three-Step Test, used to diagnose vertical diplopia due to extraocular muscle palsy.
The key muscle involved in such questions is usually the Superior Oblique (SO), supplied by the Trochlear nerve (CN IV).
Actions of Superior Oblique (SO)
- Intorsion (primary action)
- Depression (in adducted eye)
- Abduction
Step-by-Step Clinical Reasoning
- Head Tilt (Compensatory Mechanism)
- Patient tilts head away from the affected muscle to minimize diplopia
- Left head tilt → suggests right superior oblique palsy
- Dextroversion (Right Gaze)
- In right gaze, right eye is adducted
- Superior oblique acts maximally in adduction
- Worsening in right gaze → confirms right SO involvement
- Right Head Tilt
- Head tilt to the same side (right) increases need for intorsion by right SO
- Since SO is weak → deviation worsens
Why Right Superior Oblique Palsy Fits All Findings
- Left head tilt (compensatory)
- Diplopia worse in right gaze (SO acts in adduction)
- Worse on right head tilt (failure of intorsion)
Why Other Options Are Incorrect
- Option B: Right Inferior Oblique
- Causes different pattern (elevation in adduction), not matching head tilt findings
- Option C: Right Superior Rectus
- Acts in elevation, not primarily involved in torsion
- Option D: Left Lateral Rectus
- Causes horizontal diplopia, not vertical/torsional
