Grand Rounds Conference

Janelle Fassbender, MD, PhDUniversity of Louisville

Department of Ophthalmology and Visual SciencesJuly 18, 2014

SubjectiveCC: Neurologist requesting full exam

HPI: 15 year old girl with epilepsy referred to pediatric ophthalmology by her neurologist.

History

POH: Strabismus surgery 3 years prior by outside ophthalmologist

PMH: epilepsy, asthma, attention deficit disorder

Eye Meds: NoneMeds: lamotrigine, oxcarbazine,

lisdexamfetamineAllergies: NKDA

Objective

OD OSBCVA: 20/25 20/25Pupils: 5 to 3 mm OU, No

RAPDIOP: 17 17EOM: Full FullCVF: Superonasal

Superotemporal defect defect

ObjectiveSlit Lamp Exam: External/Lids Normal OUConjunctiva/Sclera Normal OUCornea Clear OUAnterior Chamber Deep, quiet OUIris Normal OULens Clear OUVitreous Normal OU

Dilated Fundus Exam

OD: OS:

*Inferior camera artifact

Visual Fields (24-2)

OD:OS:

Left superior homonymous quandrantanopia

Pre-operative MRI BrainNormal brain MRI*Patient is rotated on table, yielding asymmetry between right and left lobes.

Post-operative MRI BrainAnterior, inferior and lateral resection of temporal lobe with cystic hygroma and normal post-operative changes.

Diagnosis Left superior quandrantanopia secondary

to right temporal lobectomy for temporal lobe epilepsy.

Treatment plan

Observe

Follow-up Year 2

Stable visual field defect

The Visual Pathway

High anatomical variability in the optic radiations Up to 15 mm anteriorly

and 15 mm posteriorly (Winston, 2013).

Optic Radiations

3 Bundles (Winston, 2013): Anterior bundle

(Meyer’s Loop) – Sharp inferolateral turn to end in lower calcarine fissure

Central bundle – passes lateral and posterior to the occipital pole

Posterior bundle – direct posterior course to the upper calcarine fissure

Optic radiationsPatient post-op

Diffusion tensor tractography – representative image (Bartroli, 2010)

Temporal lobe surgery Temporal lobe

resective surgery (Georgiadis, 2013): Broad range of

surgical options: Anterior temporal lobe resection, selective amygdalohippocampectomy

Newer approaches may spare optic radiations (Winston, 2013)

Visual field defects following temporal

lobectomy Visual field defects – 50-100%

Most commonly superior quadrantanopia (Piper et al, 2014)

Other noted complications (Georgiadis, 2013): Trochlear nerve palsy – 2.6 to 19% Transient oculomotor nerve palsy – 2.1% Hemiparesis – 4.6%

Visual cortex activity outside of scotoma expected from automated perimetry.

Population receptive field analysis of primary visual field cortex complements perimetry in

patients with homonymous visual field defects.Papanikolaou A, et al. 2014. PNAS, 11(16):E1656-1665.

References Krolak-Salom P, et al. 2000. Anatomy of optic nerve radiations as

assessed by static perimetry and MRI after tailored temporal lobectomy. British Journal of Ophthalmology, 84:884-889.

Piper RJ, et al. 2014. Application of diffusion tensor imaging and tractography of the optic radiation in anterior temporal lobe resection for epilepsy: A systematic review. Clinical Neurology and Neurosurgery, 124:59-65.

Fong KCS. 2003. Eye, 17:330-333. Winston GP. 2013. Epilepsia, 54(11): 1877-1888. Papanikolaou A, et. Al. 2014. Proc Natl Acad Sci U S A, 111(16):

E1656–E1665. Georgiadis et al. 2013. Epilepsy Research and Treatment. Bartroli V. 2010.

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