Higher Cortical

Front 1

o Involuntary failure to attend to or respond to meaningful sensory stimuli presented in the affected hemispace
• These patients do know that they are missing a part of their vision
o Frequently accompanied by hemianesthesias, hemiplegias, and homonymous hemianopsias
o Usually right (non-dominant) parietal lobe lesion
• The right parietal coordinates a lot of things like sensory and motor function
o Extinction: patient fails to perceive the stimulus in the field contralateral to the lesion, while correctly perceiving the stimulus in the ipsilateral field
• Because of extinction, the person may only shave half of their face of eat from half of their plate.
• Mild neglect: may not recognize two similar objects from each other. But they may be able to differentiate dissimilar objects in each field
• Severe: may neglect their own arm and leg

Back 1

Spatial Inattention to neglect

Front 2

o Inability to recognize an object by sight, despite adequate cognition, language skills, and visual acuity and visual fields.
• i.e., Unable to name object, describe its use or demonstrate its use
• A-non and gnos-knowledge
• These patients have the ability to talk to you, but they may not be able to name a particular object
o Pure form: achieved only by auditory, tactile, or olfactory stimuli
• An example of this: being able to recall the name of an orange after smelling one
• Another example: a patient may see the keys on the table, but may not be able to name them as keys until they touch or jingle themo Bilateral lesions in occipitotemporal lobes with damage to cortex and white matter
• Infarct in vertebrobasilar artery circulation
• This can lead to a perfusion problem, tumor metastasis or a parietal problem
• Usually it seems to be the junction in between the parietal and occipital that seems to be affected
• Tumor, carbon monoxide poisoning, Alzheimer’s
• Other findings
• VF defects (HH / quad)
• Prosopagnosia
• Alexia
• Achromatopsia

Back 2

Visual Object Agnosia

Front 3

Type of VOA, • Inability to recognize familiar faces
• Ask patient to identify photos of famous people or family members
• Lesion bilateral occipitotemporal lobes

Back 3

Prosopagnosia

Front 4

• Inability to integrate components of a visual scene
• These people can only see the trees…they can’t see the forest
• When looking at a baseball, they call the seams on the baseball railroad tracks
• Constriction of spatial attention
• Patients function as though looking through a peep hole
• Severe cases: only aware of object they are fixating on
• Unable to perceive more than one stimulus or more than one part of a visual stimulus
• Unable to recognize the “whole” picture despite accurate recognition of its parts

Back 4

• Visual Inattention:
o Simultanagnosia

Front 5

o Patient cannot name visually presented objects, but he can signal his recognition by demonstrating their use, or by pointing to objects named by the examiner.
• They can describe the function of an object without touching it, but they can’t name it
• DDx: Visual object agnosia

Back 5

Optic Aphasia

Front 6

o Inability to comprehend written or printed material
• Intact writing spontaneously or to dictation
• Acquired disturbance with reading
o Associated findings: VF defects and defective color recognition / identification

Back 6

Alexia

Front 7

o Gross lack of coordination of muscle movements
• Unable to visually guide their hand toward an object
• Reach for object in uncertain manner
• Over-reaching (pastpointing)
• Under-reaching
• Unilateral parieto-occipital lesions involving contralateral field and hand
• You need to ask if it is a depth perception/BV problem or something else

Back 7

Optic Ataxia

Front 8

o “psychic paralysis of gaze”
o Inability to execute purposeful eye movements
• Difficulty directing their gaze toward a specific target
• Once achieved, fixation lost easily and difficult shifting gaze to new stimulus
• Associated findings: also occur in response to auditory and tactile-proprioceptive

Back 8

Oculomotor Gaze Apraxia