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Visual
loss in infancy and in early childhood can have many causes. Typical
reasons or causes of vision loss in young children include those related
to prematurely (e.g., intracranial hemorrhages), seizure disorders,
genetics abnormalities, birth trauma, accidental head injury, lack of
oxygen and abuse, among others.
In the
scientific literature, it is well established that vision stimulation is
critical for proper and normal development of the visual centers of the
brain. It is also well known that vision and visual perception slowly
develop over the first few years of life. As a consequence, the mainstay
of therapy for visually impaired young children is to engage them in
tasks that stimulate their residual vision in order to maximize vision
development. Early infant stimulation programs as well as early infant
vision stimulation programs are specifically geared toward stimulating
the young patient’s residual vision. Activities in these programs may
include the use of light boxes, various colored lights and patterns,
high contrast targets including checkerboards and gratings (alternating
series of black and white strips) and moving or rotating objects of
various color and brightness. Often, visual stimuli are paired with
tactile stimuli or/and auditory stimuli to try to attract the visually
impaired child’s attention to the object(s) of interest. In school and
rehabilitation centers, where these vision stimulation programs are
undertaken, it may be rather noisy, crowded, and a number of different
activities may be taking place.
While
vision stimulation and early infant stimulation programs are appropriate
for the vast majority of visually impaired infants and young children,
there is a subgroup of visually impaired children that cannot handle
such stimulation. These children often have a medical history of brain
damage or seizure activity. Many of these children are diagnosed as
having "cortical blindness" or "cortical visual impairment" as well as
CP (cerebral palsy). For lack of better terminology, we will refer to
these children as having over-stimulation syndrome (OSS).
An
important characteristic of OSS children is that they appear to better
function, in general, at home than at school or at the rehabilitation
center. OSS children do not like distractions. OSS children will appear
to be more aware of their surroundings, will tend to open their eyes
more, will engage in more visually guided behaviors, etc., when lights
are low, when there are no "distracting" noises or sounds (talking,
radio, fans, background noise) and when they are not held. Some OSS
children do not like to be held, even by a loving parent or grandparent.
If you try to hold their hands they may even pull away from you. OSS
children may even not like having siblings around. Please do not
misunderstand these behaviors of the OSS child; they are not rejecting
you or their siblings, rather, they simply cannot handle the stimulation
or sensory input.
While one
may hypothesize about the reasons why OSS children behave like they do,
it appears as though these children are unable to control the amount of
sensory stimulation impinging upon them. It is as if they cannot ignore
background sounds or lights and are overwhelmed by tactile stimulation.
They appear to be truly overwhelmed by different types of stimuli –
visual, auditory and tactile. As an example, as you read these words,
stop for a minute and listen to the sounds around you. Now feel the
clothes as they hug your body. Feel the watch on your wrist and the
shoes on your feet. Now, as your eyes view these words, pay attention
for a moment to the objects that are impinging on your side or
peripheral vision. Now image, for a moment, that you have no way to
turn-off all of those sensations. You can’t ignore the sounds, you feel
everything touching your skin and you see everything impinging on your
eyes and not just what you want to look at. Now you may have an idea as
to what OSS children might be experiencing.
In
neurology and brain research, it is well established that with any
sensory input, such as with vision, there exists an extensive amount of
inhibition or suppression that takes place to limit, control and refine
the amount of sensory excitation or response. OSS children act as though
this sensory inhibition or suppression is not present or is limited. As
a consequence, the sensory input appears to overwhelm the child and, as
a consequence, the child uses any means available to reduce the sensory
excitation. [This hypothesis is currently under investigation.]
Standard
rehabilitation efforts for OSS children may do just the opposite of
their intended purpose – standard rehabilitation efforts may actually
cause the OSS child to withdraw from the stimulation rather than be
attracted toward it. When confronted with regular infant stimulation or
visual stimulation programs, OSS children may close their eyes, actively
avoid loud, flashy objects or appear to withdraw inside themselves. At
the same time, OSS children may appear more comfortable at home or in
dimly lighted rooms. They may open their eyes and "pay attention" when
the room lights are dim, when there are no sounds and when the parent is
not speaking. They prefer not to be held and not to have other children
around (because of the added stimulation). In a nutshell, OSS children
like it best when they are not over stimulated. And it doesn’t take much
to over stimulate them.
What is a
rehabilitation specialist or parent to do with an OSS child? There is no
easy solution. There needs to be a balancing act between providing the
child with needed and necessary sensory stimulation and, at the same
time, not over doing it. If the objective is to provide vision
stimulation, then stimulation of the other senses (i.e., touch, hearing)
should be kept to a minimum. Multisensory objects; that is, objects that
are visually salient, make noise and touch the child should not be
totally avoided but should be kept to a minimum.
Pay
attention to what the child tells you – not by words but by his or her
behaviors. If the OSS child appears to "like" his or her surroundings
than emphasize such surroundings. If the child appears to withdraw into
himself, try changing the environment by turning down the lights,
turn-off or minimize distractions and even ask other adults and children
to leave the room.
As far as
we can tell, there is no scientific literature available regarding the
specific type of special needs children as outlined in this brief
report; thus the reason for this featured article. Based on personal
experience (Dr. Leguire), it is estimated that about 1 in 100 cortically
visually impaired or cortically blind children may have OSS. As noted
previously, some children with cortical blindness or with cortical
visual impairment may have some of the symptoms that are described in
this report and scientific literature exists about these conditions.
However, by recognizing the OSS child, rehabilitation efforts may be
geared toward maximizing his or her potential |
