Reader response: Teaching Video NeuroImages: Pulsatile proptosis and wall-eyed bilateral internuclear ophthalmoplegia.

Abstract

We read with interest the Papageorgiou et al.1 Teaching Video NeuroImage on pulsatile proptosis and wall-eyed bilateral internuclear ophthalmoplegia. While this is a well-written case report with a good quality video, we offer an alternative interpretation of the MRI findings. At the pontine level, the medial longitudinal fasciculus (MLF) is situated beneath the floor of the fourth ventricle on either side of the midline,2 and lesions involving bilateral MLFs can cause wall-eyed bilateral internuclear ophthalmoplegia (WEBINO).3 However, the lesion that the authors indicated with the arrow on the T2-weighted MRI (figure, white arrow)1 is located more anteriorly compared to the area of the MLF on MRIs in previous reports3 and on anatomic templates.2 In addition, the lesion indicated appears chronic given the strong high signal intensity, similar to that of the CSF, even though the interval from the symptom onset to MRI was not provided. Instead, we propose that the symmetric high signal intensity lesions just beneath the facial colliculi were responsible for WEBINO in this patient (figure, black arrow added).