Sensory Integration Difficulties
With Arousal Levels

Problems with both hyper vigilance (or hyper arousal) and hypo arousal are seen in many persons with fragile X syndrome. In early development, parents often notice the infant's hypersensitivity to sounds, light, touch, and textures. Many infants and young children with fragile X show difficulties in sleeping, with hypersensitivity to sounds or light. Difficulties in falling asleep or in staying asleep may persist long past when other children are sleeping through the night. Sleep disturbances may be related to a reduction in rapid eye movement sleep and abnormal EEG patterns.

Visually, people with fragile X may be overwhelmed by all the information confronting them: lights, crowds, movement, and other stimuli. High arousal levels to visually complex or crowded environments and unpredictable events may contribute to anxiety in new, unfamiliar situations.  They may not enjoy big screen movies and amusement centers with blinking lights in the way other people might. The difficulty in establishing eye contact may be tied to hyper arousal and anxiety when confronted by too much visual input.

Auditory processing is also affected by sensory integration problems. Sounds may be attended to in a hyper vigilant manner, that is, with too much attention. Or, they may be ignored. The filtering mechanism that most children have with regard to sound seems to work less efficiently for some children with fragile X. Even very young children may become whiny in loud, crowded restaurants or when confronted with fire engine sirens, train whistles, or other overwhelming sounds. A temper tantrum may the result of stimulus overload. Auditory processing problems may also affect areas such as speech and language development. It may be that early ear infections distort auditory input, affecting language development.

The senses of smell and taste may also be altered. Children may mouth or sniff objects in order to receive their smells or tastes. This may reflect the need for additional input to sort out sensory information.

Symptoms of attention deficit hyperactivity disorder (ADHD) include inattention to important incoming information, while paying attention to, or being distracted by, irrelevant sounds, sights, and other inputs. ADHD may be symptomatic of a sensory system with many imbalances. More information about ADHD in persons with fragile X is included in the section on Behavior.

As is true with many characteristics of fragile X syndrome, females with the disorder do not seem to have as many sensory integration problems as do males. Overall, their sensory and fine motor skills seem to be in keeping with their cognitive level. Attention deficit disorders and some stereotypic hand movements are reported for many girls. Many females also have high levels of anxiety, some of which may be connected to hyperarousal.

Gail Harris-Schmidt, Ph.D., CCC-SLP
Saint Xavier University
Chicago, Illinois

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