Nonverbal Learning Disorder (NLD or NVLD) is a relatively newly described condition separate from dyslexia or other forms of learning disabilities. It is characterized typically by a large discrepancy between high verbal and lower performance scales on IQ testing coupled with postulated right hemisphere brain dysfunction. Strengths in youngsters with NLD include early speech and vocabulary development along with early reading and spelling skills; remarkable rote memory; preoccupation with detail; strong auditory learning and retention; and ability to express themselves eloquently, sometimes excessively, for age to name some of these characteristics. Problem areas rest in three general areas-motor, visual-spatial and social. These often surface as awkwardness and poor coordination; difficulty with certain math symbols and handwriting; difficulty with abstract thinking; poor visual recall; faulty spatial perception; difficulty adjusting to new or novel situations; difficulties perceiving non-verbal behavioral or facial clues; and poor social and interactive skills. The overlap between some of these symptoms and Savant Syndrome characteristics and traits, as well as hyperlexia and Asperger’s Disorder, is apparent and important with respect to differential diagnosis and interventions.
There are two excellent websites for much more detailed information about this form of learning disability. One site is www.nldline.com and the other is www.nldontheweb.org. These resources provide in-depth information about clinical characteristics, differential diagnosis, neurobiology, useful intervention techniques and give case examples.
In NLD there are a number of overlapping signs and symptoms of Savant Syndrome traits and behaviors in some youngsters. Of special interest, however, is the observation and debate about the overlap particularly between NLD and the clinical characteristics of Asperger’s Disorder such as high verbal abilities, compromised motor and coordination abilities and unique social and relationship difficulties. Some argue that Asperger’s part of the high functioning autistic spectrum. Others postulate that Asperger’s is in fact a part of the far end spectrum of Nonverbal Learning Disorders sand point out that as high as 80% of Asperger’s Disorder persons have neuro-psychological profiles consistent with NLD. Perhaps Asperger’s Disorder, instead, incorporates both spectrums. A better understanding of both NLD and Asperger’s Disorder can be gleaned from articles that compare and contrast the two conditions. The one website at www.nldline.com has a separate side bar with links to several articles making those comparisons and contrasts. The other website has an article by Dr. David Drinklage entitled “Asperger’s Disorder and Nonverbal Learning Disabilities: How are these two disorders related to each other” at www.nldontheweb.org/nldadvancedreading/aspergersdisordernld.htm.
Nonverbal Learning Disorder is another facet or piece, worthy of exploration of the multi-faced mosaic and puzzle we call Savant Syndrome.