439 - A Case of Fourth Nerve Cranial Palsy

Thursday, February 22, 2024

5:00 PM – 6:30 PM EDT

Presenting Author(s)

ST

Sudeepti Trivedi, MD

Resident Physician
Tower Health
Wyomissing, Pennsylvania, United States
BV

Beata Vayngortin, BS

Medical Student
Drexel University School of Medicine
San Francisco, California, United States

Case Diagnosis: Fourth Nerve Cranial Palsy

Case Description: Our 68 year old gentleman presented to the emergency room with acute onset dizziness and nausea of one day duration. CT head and MRI brain were unremarkable, and carotid ultrasound did not reveal significant stenosis. His symptoms were initially attributed to vestibular neuritis, and he was started on a steroid taper. He was admitted to acute rehabilitation for deconditioning secondary to ALS. Four days into his rehabilitation admission, the patient began endorsing new onset intermittent diplopia. He was evaluated by ophthalmology and was suspected to have fourth nerve cranial palsy of unknown etiology. Exam remarkable for unidirectional left beating nystagmus. Repeat MRI did not reveal any acute findings. CTA head and neck did not reveal acute abnormalities. Ophthalmology recommended eye patching as needed.

Discussions: Trochlear nerve palsy commonly presents with binocular vertical or torsional diplopia. The fourth cranial nerve is a purely motor nerve, which innervates the superior oblique muscle. This report details a case of suspected fourth nerve cranial palsy in a patient with newly diagnosed ALS.

Conclusions: Patient worked with physical therapy on gaze stabilization exercises VORx1 as well as exercises aimed at strengthening his superior oblique muscle. His symptoms improved over the course of his admission and he was discharged with instructions to follow with ENT as an outpatient.