Neuro-Opt Tech for ABI Flashcards
Define: ABI + Examples
Any condition/event resulting in a sudden, non-progressive, or non-degenderative change in neurological processing; TBI, Stroke or Cerebral Vascular Accident, Post-Surgical Neuro Complications, Vestibular Dysfxns
Define: TBI + Examples
Occurrence of injury to the head that is documented in a med record with one or more of the following conditions as contributors: decreased level of consciousness, amnesia, skull fracture, neuro/neuropsych abnormality, intracranial lesion; mild/mod/severe
Open vs Closed TBI – diagnostic question
Did the skull remain intact
What is an MTBI and what are its consequences?
Mild TBI;
Post-Concussion Syndrome (lingering symptoms after injury - headache, fatigue, poor memory, insomnia, impaired gait, noise intolerance, etc.)
Post-Trauma Vision Syndrome (CI, high exophoria/tropia, accommodative dysfxn, oculomotor deficits, vis-spatial distortions, etc.)
Define CVA
Cerebral Vascular Accident
rapidly dev’d symptoms/signs of focal loss of cerebral fxn with no apparent cause other than of vascular origin
Loss of fxn can be global; recovery is full to severe disability
Strokes may be due to arterosclerosis, cerebral embolism, TIA (80% are ischemic)
What % of our environmentally received info is visual?
80%
How many areas of the brain are involved with visual processing?
35
T/F: More areas of the brain are dedicated to vision than any other sensory system?
True
Visual Processing fxn of Occipital Lobe
contour, contrast, depth
Visual Processing fxn of Frontal Lobe
Motor planning, self-directed eye movement
Visual Processing fxn of Temporal Lobe
recog people, places, things; object identification, motion processing
Visual Processing fxn of Parietal Lobe
spatial org of obj, vis attention
Describe: Parvocellular pathway
80% fibers, Ventral Stream, Central Processing/Focal Vision, representation/recog (what is it?), accommodation involved to tell details of obj (shape, colour)
LGN –> Occipital –> Temporal
Describe: Magnocellular pathway
20% fibers, Dorsal Stream, Peripheral Processing/Ambient Vision; visual-spatial, sensory modality of space (Where is it?), Pursuits, Saccades, Vergence for spatial relationships (where we are, where it is)
LGN –> Occipital –> Parietal
Describe: Central/Focal Processing
Parvocellular; detail, what is it?, high res, colour vis, conscious, central 2˚, static, innate
Describe: Peripheral/Ambient Processing
Gestalt, Where am I? Where is it?, Low res, non-conscious, non-colour, entire vis field, dynamic (integrates with other sensory systems), learned
What is Ambient Vision?
A constant stream of data about the location of your body in space, the location of other people and objs, and info about how quickly and in what direction those people/objects are moving
What does Ambient Vision lead to?
Binocularity, accurate judgement of distance and movement, defining our self image/view of our world
Interference with Central/Focal processing
Refractive, Accommodative Dysfxn
Interference with Peripheral/Ambient processing
Gaze palsy, fixation dysfxn, pursuit/saccadic dysfxn, binocular dysfxn, eye muscle paresis/paralysis
Q that Central/Focal processing answers
What is it?
Q that Peripheral/Ambient processing answers
Where is it?
Interference with Central and Peripheral Processing
altered vision: trouble with balance, moving with coordination, walking correctly, knowing where body ends and outside world begins; inability to correctly perceive space and time;
a receptive problem not an expressive problem
Oculomotor Dysfunction deficits
Limitations of gaze, nystagmus, speed and quality of pursuits and saccades
Oculomotor Dysfunction potential symptoms:
Inability to follow objects smoothly, Reading problems, skipping words, re-reading words, word/letter reversals
Accommodative Dysfunction deficits
accommodative insufficiency, pseudo-myopia, speed and quality of accommodative response
Accommodative dysfunction potential symptoms
blur, headache, pain, double vision, squinting, closing an eye, reading problems, ocular discomfort, tired eyes, watery eyes, falling asleep when reading, task avoidance
Binocular Dysfunction deficits
Strabismus, muscle paresis/paralysis, convergence insufficiency, reduced or slow fusional ability
Binocular Dysfunction potential symptoms
Head turn/tilt, diplopia, poor depth/spatial judgements, closing an eye, headaches, asthenopia, reading difficulty, tired eyes, watery eyes, fall asleep with reading, task avoidance
Visual-Spatial/Visual Information Processing Dysfunctions: Deficits
Visual-vestibular integration problems, visual-motor integration problems, difficulty understanding spatial coordinates, disturbances in body image, disturbance in spatial relationships, difficulty sustaining visual attention
Visual-spatial/visual information processing dysfunctions: Potential Symtoms
Balance issues, poor distance judgment, motor coordination problems, eye-hand coordination issues, left-right confusion, objects appear to move, agnosia=difficulty in object recognition, apraxia=difficulty in manipulation of objects, difficulty with differentiation, analyzing categorizing, sequencing, etc., inattentive, difficulty with visual closure/recognizing faces, difficulty with visual memory, difficulty with figure-ground analysis, difficulty with writing
Visual Field Loss/Visual-Spatial Neglect Deficits
Visual Field Cut (ex: homonymous hemianopsia), visual-spatial attention/neglect
Visual Field Loss/Visual-Spatial Neglect Potential Symptoms
Oculomotor related symptoms, difficulty locating objects, difficulty with gait, dificulty with alance, bumps into chairs, objects, etc., difficulty seeing at night, spatial insecurity(holds onto walls, etc.), unable to drive, disturbances in spatial relations
Other (Acquired Injury) Deficit
Low blink rate, staring
Other (acquired injury) potential symptoms
dry eyes, red eyes
Why have an ABI patient close eyes in-between tests?
Patient might have a peripheral processing issue, so things like the flickering of fluorescent lights can provoke symptoms
How to give an exam to an ABI patient
minimize movements in front/around patient, keep room illumination del dim (incandescent rather than fluorescent), speak clearly and more slowly, provide lens choices slowing in refraction, slowly change prism magnitudes in vergence tests, have patient close eyes in-between tests
Management of ABI patient
Optical correction of ametropia, added lens power for near, horizontal or vertical prism, segmental occlusion, yoked prism, vision therapy, surgery
Visual field loss is typically measured by
confrontational visual fields, tangent screen, automated perimetry
Two types of visual field loss due to retrochiasmal lesion
homonymous hemianopsia (incl. macular sparing), quadrantopsia
What happens the more posterior a retrochiasmal lesion is?
the more congruent the hemianopsia
What are treatment options for visual field expansion
Fresnel prisms, Gottlieb and Peli lenses
What is visual neglect
cognitive deficit that refers to thr unawareness of obj, people, and visual stimuli presented in a visual space contralateral to the cerebral lesion
What will patients with visual spatial neglect also likely have?
visual field loss
Asking a patient to draw a face of a clock or to bisect lines - used to evaluate what?
Visual neglect
Define: Visual Midline Shift Syndrome
Mismatch of information and distorting of space due to disruption of ambient system
What can Visual Midline Shift Syndrome lead to?
alteration of posture, difficulty with balance
What is visual midline shift syndrome associated with?
hemiplegia, hemiparesis, flexion/extension, neglect
What can be used to shift the midline in visual midline shift syndrome?
yoked prisms
What treatment may be recommended to photophobic patients.
Outdoor tint (brown or gray), indoor tint (blue or gray; blue for fluoresecent lighting)
In what directions can diplopia be?
horizontal, vertical, or cyclotorsional
Diplopia due to what can resolve on its own over a period of months?
ABI
What are treatment options for diplopia
grint in prisms, fresnel prisms
What visual deficits are amenable to vision rehab?
oculormotor deficits, vergence deficits, accommodative deficits, visual-vestibular disturbances, photodensitivity due to deficits in bunocularity, impared visual field integrity
Vision rehab for oculomotor deficits
basic scanning and searching exercises
Visual rehab for oculomotor deficits
create an aperture/window highlighting text of regard while obscuring non-pertinent text
Visual rehab for vergence deficits
stabilize vergence in primary gaze (far and near), facility and sustainability of fusional vergence (far and near)
Visual rehab for accommodative deficits
build up and equalize accommodative amplitudes, work on improving weaker aspect of focusing, work on maintaining the ability to rapidly change focus and sustain focus; use loose lenses and flip lenses, in free space using targets at different viewing distances
Visual rehab for visual-spatial function
work on central-peripheral integration
Visual rehab for visual field loss
practice scanning into blind field, borderzone stimulation (new therapy system to map blind field and increase visual field over time)
