Nonverbal Learning Disorder

Overview

Nonverbal learning disability (NLD) refers to a learning disorder that is characterized by deficits in visual-spatial organization and processing that significantly interferes with academic and social functioning (1).  A specific neuropsychological profile of strengths and weaknesses typically associated with NLD has been identified. While the presence of certain subgroups within NLD has been recently proposed, there is debate surrounding their clinical use.  Research on the presentation and underlying etiology of NLD is ongoing.

Diagnosis and Symptoms

While the exact prevalence of NLD is unknown, it is considered to be a relatively uncommon condition (1).  Similar to other learning disorders, NLD is commonly diagnosed in childhood.  NLD is not currently included in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5); however, tentative diagnostic criteria based on frequently observed strengths and weaknesses have been proposed (2). Given the lack of formal diagnostic criteria and potential overlap with other disorders, diagnosis of NLD requires careful neuropsychological consideration.

Individuals with NLD often show strengths within auditory perception, rote verbal information, and simple motor skills.  Sometimes these patients show strengths in reading abilities.  On the other hand, primary deficits are observed in tactile and visual perception, complex psychomotor abilities, and processing novel information.  These primary deficits in turn lead to difficulties in other areas, such as attention and memory for tactile and visual information, concept formation, and problem-solving. Specific academic deficits include trouble with reading comprehension (especially complex material), mathematics, and science.  Social and emotional deficits are also characteristic of NLD, and may present as disturbed social perception, social judgment, and/or social interaction (3).

 

In a relatively recent review paper, researchers developed working diagnostic criteria based on the examination of various criteria used in previous NLD studies (4). This study concluded that a marked discrepancy between weak visual and strong verbal performance on neuropsychological tests was strongly associated with NLD.  Similarly, poor academic math abilities in the context of relatively good reading ability was indicative of NLD.  Other markers of NLD include fine motor impairment, visual-constructional difficulty, and deficits in spatial working memory.

While social and emotional difficulties are often present, they are not generally considered essential to an NLD diagnosis. However, some researchers have noted similarities between NLD and Asperger’s syndrome and their distinction is debated in the literature (2, 5).  Additionally, individuals with NLD are commonly diagnosed with attention deficit-hyperactivity disorder (2, 5).

Subtypes

Due to the heterogeneity of NLD and associated differences in clinical presentation, the utility of establishing specific subgroups of patients within the disorder has been proposed. Although controversial and not yet universally accepted, awareness of these subgroups highlights the various clinical manifestations of NLD.  In an exploratory study by Grodzinsky et al. (2010), clinicians categorized children with NLD via a diagnostic sorting strategy into three subgroups: Processing Efficiency (PROC-EFF), Concept Integration (CONC-INT), and Social Adaptation (SOC-ADAP) (6). Patients in the PROC-EFF subgroup present with a primary deficit in the processing, including the selection and organization, of relevant information in order to produce meaningful response.  As the name suggests, patients in the CONC-INT subgroup are characterized by primary deficits in integrating concepts and piecing together individual elements into a whole.  SOC-ADAP patients present with difficulty in ongoing processing of complex information which manifests as deficits in social adaptation and difficulty in flexible problem-solving.  Research on possible NLD subtypes is ongoing (8).

Byron Rourke developed a detailed theoretical model of nonverbal learning disabilities, which the more recent research has often built upon (7).  To simplify this, he points out that a deficient the right parietal area of the brain and the white matter associated with this and other parts of the brain appears to account for math, reasoning and social perception weaknesses.  His book Nonverbal learning disabilities:  The syndrome and the model (7) is an interesting read, even at 30 years old (1989)s.

Etiology

While the exact cause of NLD is unknown, a common hypothesis of its underlying pathology is termed the “white matter model.”  This model postulates that disruption in subcortical white matter (the fatty sheath surrounding parts of the neuron), which is essential to inter- and intra-hemispheric communication is the primary cause of NLD symptoms. Although more detailed information (such as a specified affected brain region) is missing from this hypothesis, researchers contend that NLD, like many other disorders, originates from a combination of environmental, genetic, and biological factors. NLD symptoms may be present in a variety of other disorders, many of which are also linked to white matter disruptions such as hydrocephalus, agenesis of the corpus callosum, Turner’s syndrome, Fragile X syndrome, and congenital hypothyroidism (8).

Treatment

As with many learning disorders, academic support for those with NLD is critical. Reading comprehension, writing, mathematics, and overall executive function/organization are generally targeted as academic treatment goals.  Additionally, occupational and speech therapy are commonly recommended.  Various forms of psychotherapy is often used to treat psychosocial deficits such as cognitive-behavioral therapy, dialectical behavior therapy, mindfulness based stress reduction, and relational therapy. College counseling and vocational rehabilitation programs may be useful to support individuals with NLD in their transition to independent adulthood (8).  As Broitman and Davis indicate in their book which includes suggestions for interventions of various professionals, special considerations need to be taken into account with NVLD students.  Another worthwhile book for diagnosing and treating NLD is the Carnoldi etal book Nonverbal learning disabilities (10).

I (Dr. Thomas) have had some success in treating NLD with neurofeedback.  I did a QEEG on a patient who had trouble with nonverbal processing, and the goal of the neurofeedback was to improve this cognitive processing.  I combined giving him visual puzzles while training his right parietal are (reinforcing beta), and after about 40 sessions, this and several other abilities improved.

—  S Jacobs & J. Thomas

 

References

  1. Spreen, O (2011). Nonverbal learning disabilities: A critical review. Child Neuropsychology17(5), 418-443.
  2. Casey, J (2012). A model to guide the conceptualization, assessment, and diagnosis of nonverbal learning disorder. Canadian Journal of School Psychology27(1), 35-57.
  3. Rourke, BP & Finlayson, MAN (1978). Neuropsychological significance of variations in patterns of academic performance: Verbal and visual-spatial abilities. Journal of Abnormal Child Psychology6(1), 121-133.
  4. Mammarella, IC, & Cornoldi, C (2014). An analysis of the criteria used to diagnose children with Nonverbal Learning Disability (NLD). Child Neuropsychology20(3), 255-280.
  5. Fine, JG, Semrud-Clikeman, M, Bledsoe, J & Musielak, KA (2013). A critical review of the literature on NLD as a developmental disorder. Child Neuropsychology19(2), 190-223.
  6. Grodzinsky, GM, Forbes, PW, & Bernstein, J (2010). A practice-based approach to group identification in nonverbal learning disorders. Child Neuropsychology16(5), 433-460.
  7. Rourke, B (1989) Nonverbal learning disabilities: The syndrome and the model.  NY: Guilford.
  8. Broitman, J & Davis, J (2013). Overview of NVLD. In Treating NVLD in Children(pp. 9-27). Springer, New York, NY.
  9. Broitman, J, & Davis, J (2013). Treating NVLD Children. New York: Springer.
  10.  Cornoldi, C, Mammarella, C & Fine, J (2016) Nonverbal learning disabilities. NY: Guilford.