Sensory Integration Dysfunction Is Controversial Dx - Brief Article - Statistical Data Included

0 Comments | Family Practice News, Feb 1, 2000 | by Carl Sherman

A 3-year-old hates to be hugged and shrieks when her mother brushes her hair.

A first-grader moves awkwardly and is afraid of the swing. He'll only eat bland foods.

Another child seems to crave violent motion. She spins around, literally bouncing off walls and other children.

Such clusters of problem behaviors can be mystifying, particularly in children who otherwise seem developmentally normal. There's a name for these behaviors--sensory integration dysfunction (SID)--although the underlying mechanism, prevalence, and efficacy of treatment remain uncertain.

The term refers to "children who can't regulate sensory input as well as they should developmentally" said Dr. David Steinberg, director of the infancy and early childhood development program at New York University Child Study Center, New York.

"They are understimulated or overstimulated" by the sensory experiences of everyday life, he said.

Whether these behaviors constitute a true disorder, distinct from entities like attention-deficit hyperactivity disorder (ADHD) and mood disorders, remains controversial, said Lucy J. Miller, Ph.D., an occupational therapist in the department of pediatrics at the University of Colorado, Denver, who directs research at the university in this area.

Neither the current Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) or the International Classification of Diseases (ICD-10) includes a code for SID.

Sensory difficulties are, however, often associated with diagnosable conditions, said Dr. Randi Hagerman, professor of pediatrics and head of the developmental and behavioral pediatrics section at the University of Colorado. "I see a lot in kids with severe developmental problems, like fetal alcohol syndrome and fragile X syndrome."

Dr. Steinberg said there is considerable overlap with pervasive developmental disorders and ADHD.

The presence of SID may be evident as early as the first year of life. By the time the child enters school, difficulties are usually impossible to ignore, Dr. Steinberg said.

Such difficulties include dyspraxia: motor planning deficits resulting in poor coordination and clumsiness. But more serious consequences are associated with "sensory modulation disruptions," an inability to respond "adaptively and appropriately" to stimuli, according to Dr. Miller.

Particularly common is tactile hypersensitivity, said Dr. Larry B. Silver, clinical professor of psychiatry at Georgetown University, Washington. The child may constantly complain that clothing is too tight or too rough, and insist on having inside tags removed. "He or she may not like to be held or cuddled."

Other senses are often involved as well. Some children find ordinary sounds intolerably loud. Discomfort with all but the blandest tastes and textures can make diet a dilemma. With vestibular dysfunction, changes of position cause anxiety; in extreme cases, stepping up or down from a curb is all but impossible.

When dysfunction takes the form of hypersensitivity, attempts to compensate become problematic. "If the child is not getting enough stimulation, he or she may move excessively, touch others repeatedly, flap her arms, or spin around," Dr. Silver said.

Almost invariably SID results in difficulties with affect regulation and behavior. "These children often have a fight-or-flight reaction to sensation; they become aggressive or withdraw when they are touched or hear loud sounds," Dr. Miller said.

The cause of SID is uncertain. As with language development problems and learning disabilities, "we suspect that wiring in the cortex is laid down differently," Dr. Silver said. "Here, the faulty wiring has to do with the motor system."

Dr. Hagerman noted that abnormalities in the cerebellum and corpus callosum have been identified in conditions where SID is common, such as fetal alcohol syndrome and ADHD. "There may be problems in interconnection between the hemispheres or in frontal-caudate areas," she said.

A recent physiologic study suggests a defect in central nervous system arousal regulation: Electrodermal responses to stimulation were absent or exaggerated in children with sensory modulation problems, and they habituated to repeated stimulation more slowly than normal controls, Dr. Miller said (Dev. Med. Child Neurol. 41[9]:608-15, 1999).

Sensory integration therapy is administered by a certified occupational therapist and aims to teach children to regulate the specific areas of dysfunction. "Every child is different: A light touch is alerting to one child, calming for another," she said.

Pushing against walls or jumping on a trampoline are helpful for some; weighted backpacks or deep massage "may calm the central nervous system by providing deep proprioceptive input."

Environmental manipulation should be a central part of management, Dr. Miller said. Strategies may include changing the fabric of clothes and sheets, placing the child in a structured, rather than open classroom, and providing a quiet corner where he can seek refuge from stimulation.

The efficacy of treatment remains controversial. "There is little rigorous evidence on either side," Dr. Miller said. Among the 76 studies she has analyzed, most have statistical or design problems.