upwardgazing

Upward gaze refers to the voluntary or reflexive movement of the eyes toward the superior visual field. The control of vertical gaze relies on a brainstem and midbrain network, especially the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) and the posterior commissure, which coordinate commands from higher areas such as the frontal eye fields and the superior colliculus. The movements involve the superior rectus and inferior oblique muscles for upward gaze, with integration of saccadic and smooth pursuit systems.

Upward gaze can be impaired in a range of conditions, a situation described as upward gaze palsy or vertical gaze palsy. It may be partial or complete and can affect conjugate movements or be limited to slow or disconjugate movements. In dorsal midbrain syndrome, also known as Parinaud syndrome, upward gaze is preferentially limited while convergence may be preserved; additional signs include light-near dissociation of the pupils and eyelid retraction (Collier’s sign). In neurodegenerative diseases such as progressive supranuclear palsy (PSP), vertical gaze palsy is a hallmark, often with earlier restriction of downward gaze.

Common causes include lesions or compression of the dorsal midbrain (for example, pineal region tumors), hydrocephalus, vascular lesions, multiple sclerosis plaques, or neurodegenerative diseases. In adults, upward gaze palsy is classically associated with PSP, whereas dorsal midbrain syndromes are linked to structural mass effects.

Assessment involves bedside testing of vertical gaze, saccades, and smooth pursuit, along with evaluation of convergence and pupillary responses. Imaging with MRI helps identify structural causes. Management focuses on treating the underlying condition when possible (tumor resection, hydrocephalus management) and providing supportive care, including vision rehabilitation for diplopia and mobility.