Frequently Over-looked Issues

by Judith Bluestone
Clinical and Educational Director, The HANDLE Institute  

At The HANDLE Institute we have found a common pattern in TBI clients in that two primary functions have been weakened. They are the vestibular functions, and the functions provided us through the process of interhemispheric integration. The balance of this article will relate to the immense impact of damage/change to these two functions, and some practical ways to re-establish their smooth function. Of course, each individual with TBI comes with an individualized profile, both from the accident and from life experiences.

The Vestibular System: What It Is

Some physical/sensory disorders common to a vast majority of TBI individuals include issues of altered muscle tone, visual disturbances, heightened sensitivity to sound, diminished sense of balance and body in space, etc. Frequently rehabilitation specialists work on these areas as splinter skills, instead of dealing with the sub-system that supports all of these abilities--the vestibular system. The vestibular system comprises the inner ear, including the semi-circular canals, otolith organs, sacules, etc., as well as projections to the ears, eyes, and cerebellum. When the vestibular system is treated as a whole interactive system, it can be gently enhanced and frequently returned to normal or near normal function.

The Vestibular System: What It Does

The vestibular system is well documented as supporting numerous basic functions, primarily:

equilibrium	(Not losing our balance is one of our greatest priorities, perhaps second only to breathing)
proprioception	(The brain's unconscious awareness of the sense of body in space is vital to dynamic movement and even to restful sleep)
muscle tone	(The state of readiness or degree of tension in the resting muscle develops as we practice tensing and relaxing muscles for postural adjustments)
audition	(This area includes hearing, filtering and focusing auditory attention, sustaining auditory attention, and transmitting the sequence of auditory input)
vision	(Visual tracking in particular is directly controlled by vestibulo-ocular connections, and the muscle tone required for binocular teaming is an indirect function of proprioception)

The vestibular system also helps us control the speed and acceleration of our movements, adapt to the speed of others, etc. It allows us to listen to a verbal communication from a person who is gesturing, while we look at other objects, keep ourselves from slumping or falling over, filter out irrelevant noises, not be disturbed by visual patterns that imply movement (such as flickering lights, patterned clothing, etc.). When we cannot do and sustain all of these things simultaneously, we cannot perform well on many of the tests we face nor can we gain benefit from many of the therapeutic tasks we are asked to perform. Lack of awareness of vestibular overload by caregivers may cause patients to become extremely anxious, perform with reduced functions or impulsive behaviors, to tune out and even to lose consciousness.

Any activity requiring multi tracking of listening, looking, and knowing where the body is in space demands a great deal of vestibular strength. The longer these demands continue, and as they shift in intensity and priority, the more the system needs to stay fine-tuned and adaptive. The vestibular systems of many individuals with TBI are no longer as adaptive as before the trauma. This may, for some, be due to damage to the vestibular system itself. For others problems may involve a no-longer appropriate perception of their body in space if it has not incorporated a real change (such as paralysis or weakness) or that a past dependence on visual input to monitor other functions is no longer reliable due to shifts in visual processing. For those with a compromised vestibular system, seeing things moving in front of their eyes can be disorienting. Even stationary visual images that insinuate movement (such as swirls, drawings with perspective, etc.) can cause disorientation. Similarly, hearing certain rhythms or pitches can be stressful. Activities such as changing position in space, or barometric pressure changes, or entering environments with flickering lights, or needing to move quickly and perhaps pivot--any of these may place stress on a fragile vestibular system. When we heed the body's warnings to reduce stress to the system, we preserve the sense of well-being. By not stressing the vestibular system, we also reduce the possibility of it compounding problems as it interacts with other elements of the nervous system.

The Vestibular System: Its Interactive Modes

The vestibular system has projections, linking it strongly to the cerebellum, which not only regulates much of our movement, but also provides a direct connection to the functions of our autonomic nervous system, responsible for such functions as pulse, breathing, etc. Our cranial nerves, particularly our trigeminal nerves (which pick up sensory input from the eyes, forehead, jaws, nose, tongue, and even the otic nerve of the middle ear), have profound and direct interaction with our vestibular system. They also interact with our parasympathetic nerves--the nerves that stimulate much of our production of those biochemicals.

We all have experienced how our systems react to stress even when those systems are intact. We shut down and regress. Where the systems are only functioning marginally, and other areas of the brain and central nervous system are already over-taxed in compensating for this major deficit, stress can cause profound effects.

A Note on Balance

Any way in which we can provide a person with a weak and/or irregular vestibular system with a balance point, we help the process of healing. Some individuals find a balance point is their faith. Some people find oral and tactile fixations as balancing, because these provide strong sensory input at the only levels more primal than the vestibular: smell, taste, and touch. Sometimes balance comes by closing something off. When we close your eyes to process, we are providing ourselves a balance point in two ways; (1) by getting in touch with the inner self, belief, images, and (2) more importantly, from a neuro-developmental level, by blocking out the need to take in and process one set of input--the visual--that the vestibular system deals with, thus immediately reducing the stress. When we look away, similarly we are defocusing visual attention, and relaxing the system. Again, anyone who has experienced stress realizes how while under stress other higher level functions deteriorate. When we are continually under stress, these may seem absent, until brief periods of respite allow us to know we are still capable of speaking, walking, writing, etc.

An Overview to Recovery

Viewing vestibular problems as merely related to balance, which has remained a common misconception, vastly oversimplifies the matter. Assisting the TBI individuals to find and use compensatory techniques (such as closing their eyes, requesting others to eliminate gesturing, etc.) can reduce stress momentarily. However, it does not treat the problem at its root. The TBI client requires a program of individualized vestibular strengthening, in order to return to dynamic and interactive adjustments. Ideally, initial activities should employ no equipment, rather just rely on the body relearning its sense of balance and body in space, on the floor, and be performed for very short periods, gradually increasing the seconds of activity as the system becomes responsive. The brain responds to little bits of challenge on a daily level if it is to be able to deal with them and organize them, and incorporate them into its function. (We call this "gentle enhancement.") When sudden large doses of activity which is irregular to a particular person's systems are introduced, the system goes into shock, just as if there were an overdose of drugs.

The nervous system and brain produce biochemicals in response to need, usually determined by our activity level. Unaccustomed, sudden, or prolonged movement can significantly impact the production of certain biochemicals. Once these have been released into the system, they work their course, and may take much more time to work their way through than it took to introduce them. Numerous other seemingly unrelated functions can thus be effected as a result of over-stimulating and overwhelming the vestibular system. The body provides us signs when it is beginning to be overwhelmed by an activity. When we are on a piece of equipment we cannot control (or cannot control immediately) and when the person who is monitoring us is removed enough so that they cannot see our various signs of state changes (e.g. breathing patterns, muscle tone, dizziness, flushing of the cheeks, etc.) or when their purpose is to measure the degree of our state changes, then our already weak systems are further stressed.

Interhemispheric Integration: Systemic Interactions and TBI

Most people who suffer closed head injuries also suffer some degree of shearing of connective tissue between the two cerebral hemispheres, as well as within each hemisphere. (In the case of stroke, the damage is more localized to one hemisphere, however, any change to a part of an interactive system causes change to the other parts.) Interhemispheric damage frequently causes binocular disturbances, because the coordination of the two eyes is one of the more demanding tasks of interhemispheric integration. Very frequently light sensitivity is one form of visual dysfunction. With regard to the visual disturbances which frequently affect TBI individuals, again, there is a significant vestibular-interhemispheric connection. For us to have three dimensional vision, to be able to track a row of print without losing our place, and to process the various frequencies of light into a unified sensible image, we rely on both of these functions.

Visual disturbance, in turn, puts yet more strain on the vestibular system, because the vestibular system provides support to the muscles that help the eyes team and track. When they do this irregularly and with great strain, the vestibular system needs to work harder to make sense of and to integrate this with the input it is getting proprioceptively about the body's position in space. It can readily become overwhelmed. Conversely, the more we can reduce the visual difficulties, the more readily we can strengthen the vestibular system. The interaction between the vestibular system and interhemispheric functions is not just one way. When we cannot remain open and focused on all the dynamic elements of a situation due to vestibular dysfunctions, then we reduce the amount of input provided for processing to the various areas in the two hemispheres. This may lead to noticeable difficulty in decision making or to impulsive behaviors.

As part of a disorder in interhemispheric integration, many individuals have difficulty word finding or speaking fluently. They may have difficulty comprehending what is said to them, or what they read, and demonstrate a delayed response time, so they appear to have lost intelligence. We have found that these disorders respond very well to the re-establishment of rhythmic integration between the two cerebral hemispheres. The right cerebral hemisphere "houses" our global visual-spatial input in a timeless manner. It is where our creative ideas are born. It is where we "see" what words mean. It is where we store significant parts of our memory. The left cerebral hemisphere usually deals with speech, with making auditory sense of spoken language, with logic and sequence and parts. When we know what we want to say, but stammer or talk around the right words, we are demonstrating a breakdown in interhemispheric integration. When we get stuck on the parts, and cannot see how they fit into the whole picture, we are exhibiting a similar breakdown.

Frequently we see TBI individuals who have been unsuccessful at improving their visual memory, which was tested as being seriously diminished. In most of these instances the problem was not a weakened visual memory, rather an inability to access the information of the right hemisphere by speech or through graphic production of the right hand (both left hemispheric). By working on small amounts of controlled, rhythmic, interhemispheric integration activities, we help speech problems and memory problems. When we work on increasing interhemispheric functions as well as vestibular functions, we discover that TBI individuals can return to such dynamic activities as simultaneously walking and carrying on a conversation. Rhythm is an amazing organizer, and an integrator of interhemispheric functions. Any functions that can be performed to music will usually be more beneficial than the same activity performed without music.

For some individuals, once they are having difficulty with their vestibular functions, and also with rational decision making, another central part of the brain--the limbic system--may function without enough balance or control. When limbic system is not responsive to logical thought (cerebral functions), individuals have great difficulty controlling their emotional responses. In lay terms, having a neurotic or psychotic disorder is "being imbalanced."

Implementation Principles

Because the systems are interactive and interdependent in nature, and because systems tend to shut down when they become overwhelmed, moderation ( "gentle enhancement") is very important. A small amount ( a few seconds) of some vestibular exercise done daily is sufficient. More can stress the system that is dealing with tremendous vestibular demands continually. Simple crossed-arm activities that can be performed mindlessly are better than complex ones for enhancing interhemispheric integration. We want to encourage the development of automatic functions, not those that require a large degree of cognitive monitoring.

Frequently TBI individuals, even more so than the general public, need help in establishing good nutrition to support healing. For many individuals, increasing the amount of omega-3 fatty acids and balancing sodium and potassium levels appear significant in TBI. Depending on the degree and extent of injury, age of onset, etc., individuals will have different needs, and experience different success rates with their recovery from TBI. The purpose of this article is to guide those dealing with TBI (professionals and clients) to examine a few frequently overlooked aspects of interactive and interdependent brain-body function. Anyone interested in learning about specific activities that we have found helpful in treating these interactive functions at their roots may contact us for additional information.
 

Copyright © 1996 The HANDLE Institute