How do you test the trochlear nerve?
How do you test the trochlear nerve?
To assess the trochlear nerve, instruct the patient to follow your finger while you move it down toward his nose. Cranial nerve V covers most of the face. If a patient has a problem with this nerve, it usually involves the forehead, cheek, or jaw—the three areas of the trigeminal nerve.
What does trochlear nerve palsy look like?
Thus, a trochlear nerve palsy causes an ipsilateral higher eye (i.e., hypertropia) and excyclotorsion (the affected eye deviates upward and rotates outward). Patients may report vertical and/or torsional diplopia that is usually worse on downgaze and gaze away from the affected side.
How common is trochlear nerve palsy?
The annual incidence of trochlear nerve palsy was found to be 5.73 per 100,000 per year. [2] In several studies, it has been observed that this entity is much more common in the male gender. [5] This may be due to a higher incidence of head trauma in males.
What are the signs and symptoms of trochlear nerve palsy?
What are the signs and symptoms of trochlear nerve palsy (fourth nerve palsy)? Author: Zafar A Sheik, MD, MD; Chief Editor: Andrew G Lee, MD more… The superior oblique muscle intorts, depresses, and abducts the globe. In acquired lesions of fourth nerve, patients report vertical, torsional, or oblique diplopia.
Where is the trochlear nerve located in the body?
Trochlear Nerve Palsy – StatPearls – NCBI Bookshelf The fourth cranial nerve, also known as the trochlear nerve, arises from the midbrain at the level of the inferior colliculus (ventral to the Sylvian aqueduct). This nerve supplies only a single muscle – the superior oblique (SO) muscle.
How is fourth cranial nerve palsy a neurologic disorder?
Fourth cranial nerve palsy impairs the superior oblique muscle, causing paresis of vertical gaze, mainly in adduction. (See also Overview of Neuro-ophthalmologic and Cranial Nerve Disorders .) Fourth cranial (trochlear) nerve palsy is often idiopathic.
What does the Maddox rod test tell you about trochlear nerve palsy?
Maddox Rod test helps to determine ocular cyclotorsion. When the lines of a Maddox rod are oriented vertically, a horizontal line is seen by normal eyes. In the case of trochlear nerve palsy, the horizontal line will be perceived as tilted downwards nasally because of the excyclotorsion. [13]