brain_circuit

Today’s guest blogger is Dr. Hannu Laukkanen.  Dr. Laukkanen earned his bachelor’s degree from the University of Oregon and a doctorate of optometry degree from the Pacific University College of Optometry as well as a master’s degree in education, also from Pacific University. He serves as a clinical professor and the Chief of Vision Therapy Services at Pacific’s College of Optometry.  Dr. Laukkanen is involved with Pacific’s Vision Performance Institute research, teaches courses in neurorehabilitative optometry, and serves as an attending doctor in the Vision Therapy & Pediatrics Service. He also teaches at Aalen University in Germany. He is the only optometrist on the board of directors for Brain Injury Connections-Northwest (BIC-NW), is a Fellow of American Academy of Optometry (FAAO), and has an Academic Fellowship in the College of Optometrists in Vision Development (FCOVD-A). In 2012, Dr. Laukkanen spent his sabbatical at Walter Reed National Military Medical Center (WRNMMC) helping to establish the optometric brain injury clinic,  treating brain-injured wounded warriors and mentoring providers at WRNMMC.

When WK first walked down our clinic corridor, heads turned. She looked to be in her mid-twenties, vivacious, and with a dancer’s body–not the typical profile of a vision therapy patient. She had nicely coiffed auburn hair and was appropriately dressed, but there was something amiss as she made her way down the hallway.

There was something odd about her gait, a subtle drift to the left wall with her left arm and fingers slightly extended and following the wall via touch. Another telltale incongruity was how timorous her walk was for a seemingly well-coordinated athletic individual. To an eye familiar with how people walk, she revealed herself in a dozen brief steps as a person insecure within her visual space.

What does insecure in her visual space mean? Imagine hiking on a winding uneven path in the forest. For most, this is a relatively easy task requiring little conscious effort, despite the path’s lack of directional linearity, changes of elevation, debris and much unevenness underfoot. To walk on such a path with grace requires a myriad of neurological compensations in the central nervous system for terrain. Of the senses, the visual system is the leader in providing a wealth of information needed for guidance. Interestingly, most of this goes on “under the hood” with very little awareness by the individual of the many complex neurological calculations needed to compute one’s own location within the surrounding space.

Nearly every part of the brain is involved in some part of the “visual-process”. The visual process is a complicated amalgam of focusing, teaming, moving the two eyes and many other skills in order to extract meaning from the flood of input flowing in through the eyes.

One of the most common consequences of brain insult is disruption of the normally efficient visual process. The prevailing view amongst brain injury experts is that after a traumatic insult (such as hitting your head during a fall, etc.) there is a chemical “fire-storm” of inflammation in the brain that can persist for quite a while. In response, the brain goes into a “survival mode” of operation.

According to this model, many habitual brain functions (even those that may have been previously effortless) are suspended or de-emphasized; particularly those requiring complex computation such as eye movements, eye teaming, and focusing, along with being able to understand what is being seen. These basic visual skills allow us to walk on uneven ground, guide a key into a lock, parallel-park, or even catch a ball.  These and many other everyday tasks become undoable or become much more difficult after even a “mild” brain injury such as a concussion.

WK was a person whose life had been upended from a single blow to the head. Although the blow had not caused her to lose consciousness, she lost fluency with many skills that had previously been effortless for her; moreover, she lost the sense of who she was.

Although she had a lot of ailments related to vision, the most pronounced areas of complaint were clarity, comfort, light sensitivity, and reading. Visual clarity had not previously be a problem area for her but after her brain insult the clarity of her vision had diminished despite a recent lens correction update.  Even worse, her eyesight clarity began to fluctuate at different times during the day.

WK complained of acute visual discomfort: eyestrain, soreness, “pulling” around the eyes and headaches and dizziness after using her eyes. Indoors she said, “lights were too bright”, especially fluorescent lights. Print seemed to come in and out of focus.

When WK tried to read she was extremely vulnerable to distraction and struggled with remembering what she had just read. She asserted that all of these complaints had either newly emerged or had worsened since her TBI. On the Brain Injury Vision Symptom Survey (BIVSS), her questionnaire score was more than twice the threshold indicating a significant brain injury-related vision problem.

WK looked fine and functioned fine to the untrained eye, but she herself neither felt fine nor felt she functioned fine. This is a common experience with those who have suffered brain injury. Just because they have been labeled, as having a “mild” TBI doesn’t mean the impact on his/her life is mild. Not infrequently it is devastating–it can alter a person’s, social and emotional fabric as well as cognitive and psychological function, and greatly the diminish quality of life. The cruel paradox is that to the outside observer unfamiliar with brain injury, the sufferer usually appears quite normal.

In future blogs, I would like to introduce the concept that vision test results may not predict visual discomfort and vice versa. In other words, why are vision complaints sometimes disproportionally much worse than vision test results following brain injury? Why did WK have so many diverse and significant vision complaints? Could it be related to her sense of space and balance? Did she get better? If so what helped?

Stay tuned, more to come in future blog posts.

Advertisements