Nonverbal learning disorder

# Overview
Nonverbal Learning Disorder (NLD) (also known as NVLD) is a  developmental or learning disorder with manifestations in the following domains: a) somatosensory and motor functions; b) visuospatial and visuoconstructive functions; c) arithmetic; d) social cognition, and e) inferential reasoning. Psychopathologically, externalizing symptoms predominate in the preschool and early school years, often confounding with attention-deficit/hyperactivity and oppositional-defiant disorders. Towards the preadolescent and adolescent years there occurs a gradual shift towards internalizing symptoms related to anxiety and depression. Internalizing symptoms may be best thought of as a consequence of long-term academic and social-interpersonal failure: a reactive disorder. In many people with NLD, social isolation and awkwardness are consequences of long-term social-interpersonal failure. Disorders in the social domain may be best conceptualized as lack of social cognition and, consequently, social abilities. Individuals with NLD have difficulties generalizing from one situation to another and learning from experience. It can be hard for them to interpret the subtleties encountered in social interactions, which may involve, for example, nonverbal gestures and facial cues indicating irony or cynicism.

# Nonverbal learning disorder overview
NLD is a neurological syndrome characterized by the impairment of nonverbal or performance-based information controlled by the right hemisphere of the brain. Difficulties will arise in the areas of gross motor skills, inability to organize visual-spatial relations, or adapt to novel social situations. Frequently, a person with NLD is unable to interpret non-verbal signals and cues, and therefore he or she experiences difficulty interacting with peers in socially normative ways. A person with this neurological condition may frequently excel in areas of verbal ability, as well as have excellent spelling and reading comprehension skills. A diagnosis of a nonverbal learning disorder has no correlation to level of intelligence.
NLD generally presents with specific assets and deficits.  The assets include early speech and vocabulary development, remarkable rote memory skills, attention to detail, early reading skills development and excellent spelling skills.  In addition, these individuals have the verbal ability to express themselves eloquently.  Moreover, persons with NLD have strong auditory retention.
The four major categories of deficits and dysfunction present as follows:
- motoric (lack of coordination, particularly on the left-hand side of the body, severe balance problems, and difficulties with graphomotor skills).
- visual-spatial-organizational (lack of image, poor visual recall, faulty spatial perceptions, difficulties with executive functioning and problems with spatial relations).
- social (lack of ability to comprehend nonverbal communication, difficulties adjusting to transitions and novel situations, and deficits in social judgment and social interaction).
- sensory (sensitivity in any of the sensory modes: visual, auditory, tactile, taste or olfactory).
Persons with NLD are particularly inclined toward developing secondary internalizing disorders such as stress, anxiety and panic, as well as debilitating phobias. Without appropriate intervention, the cumulative effect of ongoing stress can advance to an unmanageable state of anxiety for an NLD person, who is already predisposed to internalizing disorders.
Brain scans of individuals with NLD often confirm mild abnormalities of the right cerebral hemisphere.
Like most disorders, not everyone with NLD will manifest his or her abilities and deficits in the same way and each individual will have his or her own strengths and weaknessess.

# NLD and its relationship to Savant and Asperger's syndromes
NLD 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 eloquence unusual for their age.
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.
In NLD there are a number of over-lapping 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. Clinically, Asperger's is part of the autistic spectrum. It has also been postulated that Asperger's is in fact a part of the far end spectrum of Nonverbal Learning Disorders. Proponents of this analysis point out that as high as 80% of Asperger's Disorder persons have neuro-psychological profiles consistent with NLD. Fitzgerald and Corvin have argued that the diagnosis of Asperger's is more useful clinically, and that NLD is "an example of excessive diagnostic splitting ]

# Notes
-  "Executive Functioning":--Neuropsychological functions including, but perhaps not limited to, decision making, planning, initiative, assigning priority, sequencing, motor control, emotional regulation, inhibition, problem solving, planning, impulse control, establishing goals, monitoring results of action, self-correcting.  In some cases this will mimic ADHD, but a comprehensive neuropsychological examination can generally distinguish between the two