Accompanying neurological symptoms and signs are diagnostic hallmarks of fourth nerve palsy (4NP) from an intra-axial lesion. Due to the proximity of the trochlear nucleus and fascicles to the inferior colliculus (IC), auditory symptoms including tinnitus may occur with an intra-axial 4NP. A 53-year-old man with hypertension and diabetes developed right 4NP with a sudden worsening of tinnitus. MRI disclosed an infarction involving the trochlear fascicle and IC in the left dorsal midbrain. Tinnitus may be a symptom indicating an intra-axial lesion causing a 4NP.
Department of Neurology (SYC, JSK), Seoul National University College of Medicine, Seoul National University Bundang Hospital; Eulji University College of Medicine (SYC); and Department of Otorhinolaryngology (JJS) and Ophthalmology (JMH), Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, Republic of Korea.
Supported by grant of the Korea Health 21 R&D Project, Ministry of Health & Welfare, Republic of Korea (A080750).
Address correspondence to Ji Soo Kim, MD, PhD, Department of Neurology, College of Medicine, Seoul National University, Seoul National University Bundang Hospital, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do, 463-707, Korea E-mail: email@example.com