Sensory issues, sometimes referred to as Sensory Integration or Sensory Processing Disorder, tend to occur along with other issues. These are common in children with emotional dysregulation and in children with autism. Children can be much more sensitive (hypersensitive) or much less sensitive (hyposensitivity) to particular types of sensory input (noise, light, smell, taste, touch, movement). Sensory hypersensitivity also occurs in chronic illness, such as Lyme disease. It is of course important to make sure at an early age that the basic sensory processes (vision, hearing, proprioception) are normal.
Children may also be described as “sensory avoidant” or “sensory seeking.” Sensory hypersensitivity can cause distress, as when an ordinarily tolerable level of noise, for example a vacuum cleaner, causes a child with autism to cover his ears or tantrum. Children with hypersensitivity to touch may be bothered by rough textures – such as the seams, tags or zippers in clothing, and will refuse to wear anything but the softest t-shirts and sweatpants. They may dislike being touched or hugged. Children may be hypersensitive to and intolerant of smells, tastes and even textures of foods, and refuse all but their favorite two or three items. Some children are hypersensitive to heat or cold and wear summer clothes through the winter or winter clothes through the summer.
An apparent insensitivity to pain is not uncommon in children with autism spectrum and other types of conditions. Even after a bad fall or bad bump they may show no reaction, which can make it difficult to know when they are hurt or sick and need medical attention. And many children seem to be particularly sensitive to, upset by or fearful of pain.
Interestingly, children who are hypersensitive to some kinds of sensory input may also be hyposensitive to others. Sensory seeking refers to being overly interested in, attentive to or insistent upon having – even craving – a particular sensory experience.
What we describe as “hyperactive” may be understood as a craving for the experience of movement. We all have a hard-wired need to move (which is how we learn to walk), and tend to feel restless when we have been still for too long, but some of us have more of a need then others. Self-stimulation behaviors in autism, such as rocking and spinning, may be related to this, and physical restlessness can be a sign of distress. Some children seem to crave physical contact – bumping or leaning against others, or hugging, even when this is unwelcome or inappropriate.
Some children seem to not to hear you when you call their name, or seem to not notice things visually in their environment. This is generally an attentional issue related to interest and motivation. Children on the autism spectrum may not look up when you come into the room or respond when you call their name.
Problems with the Motor system are also common in children with other issues. Low muscle tone refers to a lack of the normal degree of tension in the muscles, which includes the muscles of the hands and torso. This is sometimes described as “floppy;” the posture is slumped, the gait (the way they walk) is slow and shuffling, and the arms kind of hang loosely at their sides. Children with low muscle tone may have poor motor coordination, involving fine motor (dressing and feeding) and graphomotor (drawing and writing) control. Gross motor coordination of the large muscles of the trunk and limbs affects walking, running and other sports activities.