Clinical Pearls Recognizing Cortical Visual Dysfunction Is - - PowerPoint PPT Presentation

Clinical Pearls Recognizing Cortical Visual Dysfunction Is neurodegenerative disease the cause of my patient’s visual problems?

Victoria S. Pelak, MD

University of Colorado School of Medicine Professor of Neurology and Ophthalmology The Center for NeuroScience; The Rocky Mountain Lions Eye Institute; Rocky Mountain Alzheimer’s Disease Center

Financial Disclosures

• Current Grant Funding:

– Alzheimer’s Association – North American Neuro-ophthalmology Society

• Royalties: Up-to-Date, Inc.

Neurodegenerative Dementing Diseases (NDD)

Cortical Visual Regions Alzheimer’s Disease (AD)

Corticobasal Degeneration Progressive Supranuclear Palsy + LBD

Creutzfeldt-Jakob Disease LBD AD + Lewy Body Dementia (LBD) 47.5 million

Parkinson’s Disease Dementia (PDD)

spare

Neurodegenerative Dementia (NDD): Visual Dysfunction is Common

• 33% Alzheimer’s Disease (AD)

ü AD Neuroimaging Initiative

ü visual >> memory dysfunction (Crutch et al. 2015)

• 25% AD have atypical presentation

ü present with visual or language dysfunction (Whitwell et al. 2012) ü Young onset (<65 years)

https://en.wikipedia.org/wiki/Hippocampus

Signs and Symptoms of Visual Cortical Dysfunction

Not very specific for the type of NDD

Ø overall clinical picture provides specificity

E.g. Lewy Body Dementia Criteria:

• prominent visual cortical dysfunction
• cognitive fluctuations, Parkinsonism, visual

hallucinations, orthostasis, REM sleep behavior disorder

Gowers 1886

Symptoms with 20/20 vision

• Early (1-12 months)

– Vague (repeated lens changes) – “Blurred, difficult to focus, diplopia, problems judging distances, can’t see ‘details’” – Functional impairment – Task specific ”I can’t see well while…” looking at spreadsheets, using the computer, scrolling tv text, reading cursive

• Later (12-36 months)

– Extensive list (next slide) – Moderate to severe impairment in function – Affect job performance – Driving impairment

• Late (>36 months)

– Can’t see – VA <20/40

Typed list presented at visit 1 by friend and family Look for symptoms of apraxia!

Signs: Visual Cortical Functional Anatomy

Pelak 2009 Exp Rev Oph

Visual Cortical Function

V4 Face and object recognition Motion Color Spatial perception and action Basic

Modified from: S. Zeki, 1993

Occipital: Striate/Extrastriate Regions (V1-V3)

Decreased visual acuity

• crowding
• attention can play a role

Homonymous visual field loss

• Atypical presentations
• MRI subtle asymmetry of atrophy

Left Eye Right Eye Left Eye Right Eye

Pelak 2009 Exp Rev Oph

Dorsal Pathway (Parietal)

Elements of Bálint Syndrome Triad

– bilateral occipitoparietal

1. Ocular motor apraxia

• poor saccade visual target

2. Optic ataxia

• misreaching under visual guidance

3. Simultanagnosia

• poor global visual percept
• Associations: apraxia, aphasias

Pelak 2009 Exp Rev Oph

Video: Bálint Syndrome

• Late 50s: (young-onset AD)
• Tendency for dorsal stream (spatial and

action)

• Can still identify objects, faces, colors

Associations: Apraxia Constructional

Copy a design and draw a clock (10 after 11)

2.5 yrs later

Associations: Apraxia Ideational

• Pinhole apraxia

Ventral or What Pathway Temporal (less common)

• Central achromatopsia

– True color vision loss – Farnsworth-Munsell testing

• Prosopagnosia (face)
• Object agnosia (objects)

Pelak 2009 Exp Rev Oph

Montreal Cognitive Assessment (MoCA)

– Trails A, design copy, and clock – Serial 7s

Summary: When to consider visual cortical dysfunction

1. Visual complaints without “basic exam” findings & decreased functional capacity 2. Unexplained visual field defects 3. Unexplained color plate testing abnormality 4. Apraxia à inability to perform motor tasks

• 5. Formal cognitive testing (neuropsychology)

Thank you

“I want every doctor to know about this because I went years before I knew what was wrong with me, and that might have been the worst part of having this.”