The Visual Consequences of when a Mild Concussion becomes a Severe Brain Injury…
…an Advanced Model for Neuro-Optometric Vision Rehabilitative Care Dan L. Fortenbacher, O.D., FCOVD Lindsey Stull, O.D., FCOVD Ryan Edwards, O.D. MVTSG 2014 – MCO January 25, 2014
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
• Why? – Because too many patients who have a “mild concussion” exacerbate into a more severe brain injury, resulting in severe visual problems, often weeks and months after the injury
• What? – We will attempt to remove some of the mystery surrounding acquired brain injury (ABI) and show how even a “mild concussive event” can lead to serious vision problems
• How? – Show how you can apply the principals of this advanced model for effective neuro-optometric vision rehabilitative treatment in your patient care Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
According to the US Centers for Disease Control and Prevention • Mild traumatic brain injury (mTBI) is: …”the occurrence of injury to the head arising from blunt trauma or acceleration or deceleration forces with one or more of the following conditions attributable to the injury: any period of observed or self –reported transient confusion, disorientation or impaired consciousness, dysfunction of memory around the time of injury, or loss of consciousness lasting less than 30 minutes.” Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
mTBI continued • …“In addition, observed signs of injury to the head, irritability, lethargy, or vomiting following head injury, especially among infants and very young children; headaches, dizziness, irritability fatigue or poor concentration, especially among older children and adults” Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
CDC 2003 Report to Congress • Of the more than 1.5 million people experiencing TBI each year in the United States, it has been estimated that 75% experience mTBI
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Unified approach to managing mTBIs • Department of Defense and Department of Veterans Affairs • Majority of TBIs in military and civilian population are considered mild • “Mild” shouldn’t be used to define the severity of symptoms
•
www.ncbi.nlm.nih.gov/pmc/articles/PMC3021720 Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Diagnosing with Imaging • Common feature of mTBI is Diffuse Axonal Injury (DAI) • Symptoms are primary tool for diagnosis of mTBI because: •
CT scans often normal with mTBI patients and poor at detecting DAI Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
MRI
• DAI is difficult to detect using conventional MRI
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Advancements in Imaging • Goal is create a unified approach to diagnose mTBI • MRI technique called Diffusion Tensor Imaging (DTI) • Detects microscopic brain matter tract lesions • Measures Fractional Anisotropy (FA)- flow of water molecules along axons in brain
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Fractional anisotropy (FA) readings that were detected using diffusion tensor imaging. Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Interpretation of Low FA • Low FA represents disorganized movement of water molecules • More disruption indicates more severe injury and more symptomatic • High correlation between low FA and impaired executive function testing* http://www.ncbi.nlm.nih.gov/pubmed/19567646 * Lipton, et al. Diffusion-Tensor Imaging Implicates Prefrontal Axonal Injury in Executive Function Impairment Following Very Mild Traumatic Brain Injury. Radiology 2009; 252: 816-824
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Interpretation of High FA • High FA indicates more organization and therefore may represent less injury or brain is already trying to compensate for injury
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Conclusions • An increase in the FA value may represent a measurement of neuroplasticity and improvement in brain organization • FA values may give rehabilitation team a marker to show progress and determine if patient is responding well to treatment Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
“Post Trauma Vision Syndrome is the most common visual sequel to mTBI.” 1998 Study guide: brain injury rehabilitation, pain rehabilitation, Supplement to Archives of Physical Medicine and Rehabilitation, 79(3)(Supple.1), S10-S14
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Post Trauma Vision Syndrome Characteristics • Convergence insufficiency • Exotropia or high exophoria • Defective stereopsis • Accommodative dysfunction • Oculomotor dysfunction • Low blink rate • Spatial disorientation Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Post Trauma Vision Syndrome Symptoms • Diplopia • Dizziness • Headaches especially with visually demanding tasks • Light sensitivity • Difficulty reading • Skipping, repeating lines when reading • Blurred vision especially at near • Poor spatial judgment and depth perception • Poor concentration and attention • Poor balance, coordination, posture • Poor visual memory Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
William Padula, O.D. • Hypothesize that PTVS is due to shearing injury particularly at the midbrain level where the superior colliculi integrates and organizes visual spatial information • Disruption between focal and ambient visual system
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Neural Substrates of Vision
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Four Anatomical Components • • • •
Cerebral Hemispheres Diencephalon Brainstem Cerebellum
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Cerebral Hemispheres (2)
• Four Lobes
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Frontal Lobe • Most complex • Last area of the brain to mylenate • Not a single functional unit
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Frontal Lobe – 3 major divisions • Precentral area • Premotor area • Prefrontal area
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Precentral and Premotor • Work as a unit or team • Planning and carrying out motor behavior • Including saccadic eye movement
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Prefrontal area • Cognitive sophisticated integrative system • Highest level of visual and other sensory modality processing • Results in higher action planning • Incorporate meaning and intention
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
3 subdivisions of Prefrontal • Dorsolateral – Working memory – Executive functioning
• Orbital frontal – Personality – Self Control
• Medial frontal – Motivation for goal oriented activities
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Prefrontal Lobe
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Books on the Frontal Lobe
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Books on Frontal Lobe
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Books on Frontal Lobe
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Books on Frontal Lobe
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Books on Frontal Lobe
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Temporal Lobe • Object recognition • Memory acquisition • Emotional Variance
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Parietal Lobe • Processing motion and location • Multisensory integration
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Occipital • Reception and early visual processing • V1, V2 – Depth perception • V3,V4,V5 – motion detection, size and color • V6- unknown • V8 – Color analysis Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Diencephalon
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Pulivinar
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Diencephalon • Thalamus – Pulvinar • Integration of somatosensory and visual information • Visual feature discrimination • Analysis of vision
– Lateral Geniculate Nucleus – LGN • Part of afferent visual system • Higher order visual processing at an early stage
• Hypothalamus – circadian rhythms and under control of the amygdala and prefrontal cortex Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Brainstem • Diverse collection of nuclei related to altering-arousal system that helps mediate attention
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Cerebellum • Spatial organization and memory • Refining motor control and motor learning • Vestibular input for balance and spatial orientation • Some cognitive functions
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
The 2 visual processing streams of the brain
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Two major visual processing streams • Ventral stream – Connection to the temporal lobe – Object recognition
• Dorsal stream – Connection to the parietal lobe – Spatial concepts Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Dorsal Stream splits into 3 pathways at Posterior Parietal Cortex
• Parieto-prefrontal pathway • Parieto-premotor pathway • Parieto-medial temporal pathway
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Each pathway of the PPC controls different elements of visuo-spatial function
• Neural nexus of visuo-spatial processing and intermodal processing • receives input from – the auditory cortex – vestibular input – other areas of the brain Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Parieto-prefrontal pathway • Eye movements important for reading • Spatial working memory – Important for navigating through new environment
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Parieto-premotor pathway • Has projections to both dorsal and ventral premotor cortex • Receives vestibular input from cerebellum
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Parieto-premotor pathway • Visually guided action • Navagation • Integration of body movement and vision
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Parieto-medial temporal pathway • Connections to limbic areas • Crucial for navigation • Most complex, least understood
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Pre-Frontal Cortex –The Conductor
• Eye movements • Visual attention • Working memory • Goal directed behavior Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Effects of mTBI on Prefrontal Cortex • Oculomotor Dysfunction – Deficiency in Saccadic Eye movement
• • • •
Vergence disorders Poor Visual Attention Trouble Interpreting visual space Poor working memory Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Effects of mTBI on PPC • Dizziness, loss of balance • Poor intersensory/intermodal integration – Poor eye hand coordination – Visual motor integration (fine motor, gross motor) • Clumsiness
– Visual vestibular integration
• Disorientation • Poor spatial judgments
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Summary • The visual process is intimately woven throughout the entire brain • Even a “mild concussive event” can result in serious compromise to the neural substrate, neural software, of the brain • This can lead to serious visual problems that require neuro-optometric vision rehabilitation Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
An effective neuro-optometric vision rehabilitation model based on the principles of: • Learning dependent neuroplasticity • Top-Down (intrinsic motivation) processing
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
A model based on 5 Elements 1. 2. 3. 4. 5.
Intrinsic motivation and engagement Variety and repetition Feedback Motor match to sensory mismatch Intersensory Loading and integration
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Lenses • The role of the lens – Refractive correction– Aid accommodation• Influence binocular vision via AC:A
– Aid spatial awareness – Aid peripheral awareness – Aid focal-ambient integration •
http://maunsell.med.harvard.edu/Downloads/publications/87bMaunsell.pdf
• http://www.oepf.org/jbo/journals/2-1%20Marrone.pdf
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Prisms • Compensatory • Spatial
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Yoked Prisms
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Bi-nasal occlusion • Diplopia management • Emphasize peripheral awareness • Facilitate focal ambient integration
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
A model based on 5 Elements 1. 2. 3. 4. 5.
Intrinsic motivation and engagement Variety and repetition Feedback Motor match to sensory mismatch Intersensory Loading and integration
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Spatial Floor Plan • Alyson Olmstead, COVT
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Spatial Floor Pattern
• • •
Intersensory Loading-yoked prisms Feedback-draw and compare pattern Variety and Repetition- complexity of patterns, memory, reverse steps, draw out patterns Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Modified Marsden Ball Rail Walk • Monica King, COVT
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Modified Marsden Ball Rail Walk
• • •
Variety and Repetition- yoked prisms, peripheral stimuli, fixation target Motor match to sensory mismatch- yoked prisms Intrinsic Motivation and Engagement- maneuver safely in home and in public Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Multi-Matrix • Debra Irwin, COVT
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Multi-Matrix
• • • •
Intrinsic Motivation and Engagement- sports vision and competition Motor Match to Sensory Mismatch- yoked prism Intersensory Loading and Integration- vestibular, auditory, yoked prism Variety- patterns, different setup or instructions Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Our patient Thomas • • • • •
Age – 17 Myopia Excellent student Stellar tennis player- rated in the state Suffered head injury from a fall in January 2012 • Dx: Post Concussive Syndrome Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Thomas’ Neuro-optometric Diagnosis • Post Trauma Vision Syndrome (PTVS) • Oculomotor dysfunction
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Thomas video before and after neuro optometric vision rehabilitation
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
Questions
Drs. Fortenbacher, Stull, Edwards - MVTSG 2014 MCO
