Dorsal Midbrain Syndrome

Dorsal Midbrain Syndrome
SYMPTOMS Diplopia, Photophobia, Transient vision loss in the presence of papilledema
SIGNS Typically bilateral
Lid retraction (Collier’s sign), Impairment of voluntary upgaze and when attempting to look up will exhibit a convergence retraction nystagmus (Downgaze movement is typically preserved), Large pupils with a poor direct light response but a normal near response (Light-near dissociation), Possible papilledema if the underlying etiology is hydrocephalus
WORK-UP Pupils | EOMs | Doll head maneuver (While maintaining fixation on a distance target, if the head is moved down the eyes will be able to move up)
Full eye exam with dilation | Cranial nerve testing | Visual field | OCT of the optic nerve
TREATMENT Refer to neuro-ophthalmologist/neurologist for further evaluation and treatment
Even with treatment of the underlying etiology, most patients will experience ocular motor deficits. Treatment for this includes vision rehabilitation and vision restorative training (glasses, prism, tint, etc).
FOLLOW-UP Patient will likely be monitored by neurology/neuro-ophthalmology on a regular basis.
Patient should be evaluated once underlying neurological etiology is in control or stable. Monitor in 4-6 months
ADDITIONAL LAB | TESTS MRI with and without contrast of the brain | Neurological evaluation | Infectious antibody screening | CSF analysis
ETIOLOGY Caused by a lesion that affects the rostral midbrain and pretectum at the level of the superior colliculus
Etiologies include pineal tumors (most common cause), hydrocephalus, trauma, stroke, multiple sclerosis, AV malformations, encephalitis, and infections
DIFFERENTIAL DX Progressive supranuclear palsy, Argyll-Robertson pupil, Adie’s syndrome, Whipple’s disease
NOTES Dorsal midbrain syndrome is also known as Parinaud’s syndrome