This case emphasized the importance of considering vascular causes for Bilateral vertical gaze palsy.
Vertical gaze palsy (VGP) involves a limitation in upward, downward, or both, and can arise from supranuclear or infranuclear causes. It commonly localizes to midbrain structures such as the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), interstitial nucleus of Cajal (INC), and posterior commissure (PC), which regulate vertical eye movements. Causes of VGP include tumors, i.e. pineal gland manifesting as Parinaud syndrome, trauma, drug-induced conditions, and neurodegenerative diseases. Neurodegenerative conditions like Parkinson’s-plus syndromes and cortico-basal syndrome can also present with VGP as progressive supranuclear palsy. Vascular causes, such as ischemic strokes in the midbrain or thalamus, contribute to VGP as well, with the midbrain’s blood supply being derived from branches of the basilar and posterior cerebral arteries. This report discusses a rare case of bilateral VGP due to unilateral midbrain ischemia.
A 49-year-old woman with hypertension, hyperlipidemia, type 2 diabetes, and recent aortic dissection status post-surgical repair presented with recurrent falls and visual changes. In the emergency department, she developed confusion, prompting a stroke code. Imaging revealed a small left frontal subdural hemorrhage and stable dissection of the brachiocephalic artery. Thrombolysis was contraindicated due to recent surgery and hemorrhage. The patient reported new-onset diplopia. Neurological exam showed impaired bilateral upward gaze that could be overcome with vestibulo-ocular reflex, along with convergence difficulty. MRI revealed diffusion restriction changes in the left thalamus and paramedian midbrain, indicating a unilateral acute ischemic stroke affecting these regions.
When it comes to Bilateral VGP, etiology is often favored to be from non-vascular causes, but this case highlights importance of considering vascular causes as well. Lesions often localize to midbrain, with involvement of posterior circulation.