Abstract title: Management of Vertical Gaze Paresis from an of Percheron Infarction.

Abstract: A patient presents with vertical gaze paresis (down gaze > up gaze), a ‘drunk’ feeling when in a visually stimulating environment, speech impairment and memory impairment all stemming from a recent Artery of Percheron Infarction.

Case History

 40 year old white male  Chief vision complaints on July 15, 2016: o Vertical gaze difficulty down gaze > up gaze o ‘Drunk’ feeling when in a visually stimulating environment (supermarket, crowd)  Eye exam from 2015 was unremarkable o No glasses Rx was given o Patient has never worn glasses before  Patient currently on Plavix and Lipitor medications  Patient medical history: unremarkable, no prior medical issues o After event patient had speech impairment and mild memory impairment

Pertinent findings

 Recent diagnosis of Artery of Percheron infarction (May 29, 2016) o Magnetic Resonance Imaging/Magnetic Resonance Angiogram images are available for viewing  Poor convergence (27 cm) o Poor convergence even when adjusted for age  Very low amplitude of accommodation for age: 2 D o Avg Amps for 40 yo = 5 D o Min Amps for 40 yo = 1.67 D  Restricted down gaze > up gaze on EOM testing  BCVA 20/20 OD/OS o Low Hyperopic Rx found o Minimal reading Rx found o Patient appreciated better vision with trial of glasses with manifest Rx  Mild Meibomian Gland Dysfunction  Posterior: unremarkable  Blood work was negative except mildly elevated Protein S

Differential diagnosis and reasons excluded

 Primary: ‘Top of the Basilar’ Syndrome o Basilar artery and Posterior Cerebral Artery were patent on MRA  Primary: Deep cerebral venous thrombosis o Usually involved basal ganglia and cerebral cortex on MRI/MRA  Secondary: Extrapontine myelinosis o Putamen, caudate nucleus, internal/external/extreme capsules, lateral geniculate nucleus or white matter are involved on MRI/MRA  Secondary: Wernicke’s encephalopathy o No involvement of periaqueductal grey, mammillary bodies, tectal plate or third ventricle o Also associated with chronic alcoholism  Secondary: Metabolic or toxic etiology o Specific imaging patterns on MRI/MRA o Patient history  Secondary: Wilson’s disease o Metabolic disorder o Patient history and clinical findings  Secondary: Creutzfeldt-Jakob disease o Neurodegenerative disease, usually occurs in 7th decade of life o Classic ‘hockey stick’ sign of pulvinar and dorsomedial nuclei on MRI/MRA o Putamen, caudate nuclei and periaqueductal gray are involved on MRI/MRA  Secondary: Bilateral thalamic glioma o Usually presents in young children or young adults o Personality changes

Diagnosis and discussion

 Normal blood supply of region is many small (para-median) branching from posterior cerebral artery  The Artery of Percheron is a single artery originating from either posterior cerebral artery and bifurcating to supply the para-median thalamus region  The artery of Percheron is a variation of blood supply to the para-median thalamus region  Another variation to blood supply will have the para-median arteries also supplying the rostral midbrain and anterior thalamic region  An infarction of the artery of Percheron will limit supply to the entire para-median thalamus region since it is only artery supplying it  If both variations of blood supply exist, it can lead to more serious consequences as midbrain involvement has a less favorable long-term prognosis  The main clinical findings of this infarction are altered mental status, memory impairment, speech impairment, vertical gaze paresis, motor deficits, cerebellar signs and others  MRI and MRA are used to diagnosis condition and rule out certain etiologies

Treatment and management  Correct any refractive error with glasses as needed  Glasses Rx for temporary use or with Fresnel prism to realign vertical gaze palsy o Separate distance and near glasses if prism is needed  Vision therapy for convergence insufficiency and poor accommodation o Rehab supra-vergences/infra-vergences can improve outcome  Lid hygiene and AT to manage MGD  Long-term prognosis is favorable if midbrain is not involved  Refer to speech therapist/psychiatry/neurology/neuro-ophthalmology as needed for treatment and follow up

Conclusion

 Will not see first line in optometry o Will likely be referred due to vision problems  Correct any visual acuity deficit if any are found o Distance and/or near can be affected  If vertical gaze palsy is found, manage with Fresnel prism since gaze palsy will likely not last or improve over time  If convergence and accommodation are found to be deficient then address as needed, especially in younger patients o Supravergence/infravergence vision rehabilitation can reduce need for prism  This patient will need reading glasses due to onset of presbyopia, but convergence insufficiency and Accommodation rehabilitation therapy may increase comfort of reading  Monitor patient for improvement and change prism/glasses/vision therapy as needed