Final answer:
CN IV palsy involves the fourth cranial nerve and results in double vision and a characteristic head tilt to compensate for the eye misalignment.
Step-by-step explanation:
When discussing CN IV palsy, it refers to a medical condition implicating the fourth cranial nerve, also known as the trochlear nerve. This condition can lead to a characteristic eye movement disorder. Patients with CN IV palsy often present with diplopia, or double vision, especially when looking downwards. The trochlear nerve innervates the superior oblique muscle, which is responsible for downward and inward movement of the eye. Therefore, patients may have difficulty with vision while reading or descending stairs. Additionally, to compensate for the misalignment of their eyes, patients with CN IV palsy may tilt their head toward the shoulder opposite the affected eye in an attempt to align their eyes and reduce the double vision.