Although this disorder is not listed in the DSM-IV-TR, it is gaining increasing recognition. It is thought that 1–10 percent of children with learning disorders have NVLD, which affects girls as often as boys. It is believed to be a neurophysiologic disorder originating in the right hemisphere of the brain, the portion of the brain that processes nonverbal information. Some children with NVLD have brain scans that show mild abnormalities of the right cerebral hemisphere. Many have a history of head injury, radiation treatments on the head, treatment for hydrocephalus, or brain tissue removed from their right hemisphere. However, many children with NVLD have no such history and are found to have normal brain scans.
Unlike other learning disorders that can be measured with standardized testing, NVLD is based upon a group of symptoms that together form a disorder. The cluster of symptoms is varied and impacts motor skills, visual-spatial skills, and social skills—the very skills affected by Asperger’s Disorder.
NVLD causes impairment both academically and socially. These children usually have good vocabulary, memory, and verbal skills. They read well, but because they focus excessively on details, they fail to understand the bigger picture. Information is understood at a concrete level, and they miss out on abstract concepts.
The child with NVLD commonly appears awkward and is poorly coordinated in both fine and gross motor skills. She may have difficulty learning to ride a bike or kick a soccer ball. Fine motor skills, such as cutting with scissors or tying shoelaces, are delayed.
In the social arena, children with NVLD miss the nuances of interactions as they fail to recognize nonverbal behavior of body language, facial expression, and tone of voice. They do not adjust to changes easily, may be fearful of new situations, and lack common sense. They are unable to look and learn and generalize from one situation to another. They do not perceive subtle cues in the environment such as when something has gone far enough; the idea of personal space; the facial expressions of others; or when another person is registering pleasure or displeasure. All these symptoms result in difficulty making and keeping friends, which in turn can cause anxiety, depression, and low self esteem.
These symptoms are all the symptoms of Asperger’s Disorder, and there exists a current debate as to whether or not these are actually two different disorders or one disorder with two different names.