To report a unique case with posterior reversible encephalopathy syndrome (PRES) who developed persistent dorsal midbrain syndrome and hemorrhagic component identified on susceptibility-weighted imaging (SWI).

A 65-year-old man with a history of long-standing uncontrolled hypertension presented with sudden-onset headache, blurred vision, and diplopia that persisted for several weeks before referral. On admission, his blood pressure was 190/130 mmHg. Neurological examination demonstrated features of dorsal midbrain syndrome, including vertical gaze palsy (more pronounced in upgaze), convergence-retraction nystagmus on attempted convergence, and pupillary light-near dissociation, with bilaterally symmetric 4-mm pupils showing sluggish light reaction but brisk near constriction. Routine laboratory studies, autoimmune antibody screening, angiotensin-converting enzyme testing, and chest radiography were normal. Initial brain CT was unremarkable. MRI of the brain revealed multiple hyperintense lesions on T2-weighted and fluid-attenuated inversion recovery sequences involving the left cerebellum, right dorsal pons, and bilateral dorsal midbrain and diencephalon. SWI demonstrated corresponding foci of intralesional hemorrhage. In the clinical context of uncontrolled hypertension, these findings were consistent with atypical PRES. Despite prompt blood pressure control, both the neurological deficits and MRI abnormalities persisted at two-month follow-up.

This case developed a classic dorsal midbrain syndrome due to PRES, a presentation seldom reported. In our patient, persistent neurological deficits and radiographic abnormalities despite timely antihypertensive treatment suggest that hemorrhage may limit the reversibility classically expected in PRES.