| 본문 : Purpose: To report a case of trochlear nerve palsy caused by quadrigeminal cistern lipoma located in dorsal midbrain.
Case Summary: A 65-year-old male visited our clinic for intermittent vertical diplopia for 2 years period. Symptoms of diplopia have worsened over the past two weeks. He had no previous medical history except diabetes for 1 month. The best corrected visual acuity was 20/25 at right eye and 20/20 at left eye. Pupillary examination was not remarkable. The extraocular examination showed 4 prism diopters (PD) left hypertropia at distant gaze and 4 PD exotropia at near gaze with elevation in adduction of left eye. The Bielschowsky head tilt test revealed 6 PD of left hypertropia on left gaze and orthotropia on right tilt. The fundus examination showed excyclotorsion of right eye and incyclotorsion of left eye. Brain magnetic resonance imaging (MRI) showed quadrigeminal cistern lipoma. Prism glasses were prescribed to alleviate diplopia and we followed up the lesions without further treatment.
Conclusions: The trochlear nerve palsy can be caused by quadrigeminal cistern lipoma. The trochlear nerve palsy caused by compressive lesion is uncommon, however, prompt neuroimaging can be helpful to rule out the cause of trochlear nerve palsy in patient with atypical symptoms. |