I have discussed a variety of treatments for Autism disorders in prior posts ranging from metal detoxification through nutritional supplementation. Remembering that the basic principles of a healthy nervous system are proper fuel delivery and activation of the sensory systems/receptors. When we look at receptor activation, this includes everything from muscle spindle receptors to visual receptors. Our nervous system is a byproduct of the summative effect of all types of receptors. In understanding this basic principle one can see that stimulating various receptors can be therapeutic and effective for evoking changes within the central nervous system. When these changes amount to new and stronger pathways this is referred to as plasticity.
Visual systems are a very good diagnostic and therapeutic window to the central nervous system. Trained physicians can recognize inappropriate visual compensations and imbalances. These examples are seperate from refractive problems such as correcting near or far sightedness (although correction of ocular balance and reflexes may improve visual acuity). Examples to look for include eyes that cross, diverge or slightly rotate either when focusing straight forward or upon motion. Head tilt or rotation to compensate for visual imbalances. Excessive blinking, squinting or blepherospasms (eyelid twitching). Double vision or blurred vision. Sensitivity to light or moving objects such as driving or ceiling fans. Headaches, nausea, fatigue or irritability especially on prolonged visual exertion.
Trained physicians will utilize this information and correlate it to their exam findings. It should be noted that the visual system is an integral part of the global central integrated state and should not be assessed as an isolated entity. Examination of this system may include visual acuity via Snellen charts, Functional blind spot mapping, optokinetic tests, cover-uncover tests, light reflexes, yolking mechanisms of eye movements including lateral, vertical and angular gaze observation, retinal examination, electronystagmography, dominant eye testing, depth perception and peripheral vision testing.
These findings need to be correlated to the remainder of the motor, sensory and autonomic exam findings to have an accurate assessment of the level of the dysfunction. Once the clinician has a working diagnosis there are many therapies that may be utilized to improve balance and integration of the visual systems. These may include visual evoked potentials such as checkerboard computer programs, eyelights or other light/color stimulation. This may be applied in a hemifield or quadrant pattern or via certain colors for the purpose of varying frequencies (ie. red has a slower frequency than blue-approximately 450THz vs 650THz). Color filters can be used as glasses to change the frequency of visual systems in this same manner. For example, if I wanted to increase the frequency of firing to the right cortex relative to the left I may utilize blue filters over the hemifield pathways to the right occipital lobe (left eye Temporal field, right eye Nasal field). Conversely, I could red filter the opposite visual fields. A good reference is the Eyelights company website. They make a good eyewear product that can be programmed for varying visual patterns.
Eye exercises are also effective in strengthening weak or fatiguing systems. This may include horizontal, vertical or diagonal repetitive movements. Again, this needs to be performed in concert with observed deficits. For example, if I observe saccadic dysmetria and rapid fatigue on right horizontal pursuit I may utilize right horizontal eye exercises to develop improved stamina and plasticity of that pursuit. Patching of the dominant eye can also help balance the workload of the visual pathways.
Since all sensory modalities except smell relay through the thalamus, there are many other sensory based stimulations that may alter the ability for visual pathways to summate at the cortex. If I diagnose a large thalamic blind spot on the right indicating decreased summation I may utilize visual or large diameter afferenation to increase the probability of second and third order neuronal firing. For example, I could program eyelights to flash on the left hemifield or I could adjust the contralateral muscle or joint receptors to increase the sensory barrage of the right thalamus. I will expand on these principles in future posts, but it is important to understand how using these principles can evoke central effects to make the nervous system more efficient and balanced just as one could exercise weak muscles to make them stronger.
These are just some examples of many visually based diagnostics and exercises that can be effective in treating central dysfunction associated with autism or other central neurological disorders. Patients and parents need to be aware of the benefits and many applications of functional neurological rehabilitation. Many board certified chiropractic neurologists and neuroopthamologists are utilizing these parameters to improve neurological balance and function. This is critical when it comes to diagnosing and treating neurofunctional problems such as Autistic Spectrum Disorders.