A patient presented with his head tilted towards left. On examination, he was having left hypertropia which increased on looking towards right or medially. The muscle which is most likely paralyzed
**Core Concept**
The patient's presentation suggests an issue with horizontal gaze and eye movement, which is controlled by the lateral rectus muscle and the medial rectus muscle. The primary action of the lateral rectus muscle is abduction, while the medial rectus muscle is responsible for adduction. The patient's symptoms, specifically the left hypertropia that increases on looking towards the right or medially, indicate an imbalance in the extraocular muscles.
**Why the Correct Answer is Right**
The patient's symptoms are consistent with a left lateral rectus muscle palsy. When the left lateral rectus muscle is paralyzed, the left eye cannot abduct properly, leading to hypertropia (elevation) of the left eye when looking towards the right or medially. This is because the left medial rectus muscle, which is responsible for adduction, is not counteracting the action of the left lateral rectus muscle. The resulting hypertropia is due to the unopposed action of the left superior rectus muscle.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because a left medial rectus muscle palsy would cause esotropia (inward deviation) of the left eye, not hypertropia.
**Option B:** This option is incorrect because a left superior rectus muscle palsy would cause hypotropia (downward deviation) of the left eye, not hypertropia.
**Option D:** This option is incorrect because a left inferior oblique muscle palsy would cause hypotropia of the left eye when looking towards the right or medially, not hypertropia.
**Clinical Pearl / High-Yield Fact**
When evaluating patients with strabismus or eye movement disorders, it's essential to assess the direction of deviation and the specific movements that exacerbate or alleviate the deviation. This can help identify the affected muscle and guide further diagnostic testing.
**Correct Answer:** C.