Monday, November 29, 2010

ADHD, NLD, APD, and Vision Problems: Blind Men with An Elephant?

Remember the  childhood story of the blind men and the elephant?  You know, the one that goes:  One Blind Man grabbed the elephant's tail and said, "An elephant is like a snake". 
Another  Blind Man grabbed the elephant's tusk and said, "An elephant is like a spear".  Another Blind Man grabbed the elephant's side and said, "An elephant is like a wall."  Another Blind Man grabbed the elephant's leg and said, "An elephant is like a tree".

Sometimes, I think the various practioners are looking at different aspects of the same mental problem from the vantage and disadvantage point of their respective disciplines.   There is significant overlap between the different diagnosis of conditions that a neuropsychologist would identify as ADHD or Non-Verbal Learning Disorder (NLD); an audiologist would identify as Auditory Processing Disorder (APD); an occupational therapist would see as Motor Apraxia; or Vision Problems that fall under the purview of a developmental optometrist.   All of these things play in the biochemistry of the body.

The overlap amongst these sometimes is so great that specialists have questions as to whether or not some of these conditions are truly separate conditions especially in the case of APD and NLD or APD and ADHD.    In short, if you walk into an audiologist's office, you will get one diagnosis.  If you walk into a neuropsychiatrist's office, you will get another diagnosis.

APD and ADHD can be confused or can coexist. This is an important distinction as APD is not treated with stimulant medication like ADHD.  According to Lori Cochran, both ADHD and APD have similar problems with auditory attention, memory,  and oversensitivity to auditory stimuli.  They both have behavioral problems with motivation, frustration, self-awareness, task avoidance, and distractability.  However, ADHD has problems with aggressive behavior, visual attention, increased motor activity, lower motor coordination, and impulsivity.   APD has a lower verbal IQ and lower verbal abstraction.  People with ADHD are at risk for two types of APD:  Tolerance-Fading Memory (TFM) and Organization types. 

Little research has been done on the relationship between NLD and APD.  According to Tillery, Preliminary reports find about 40% of those with NLD will also exhibit APD, in the Tolerance Fading Memory type. Individuals with TFM often display weak expressive language and reading comprehension abilities, require repetition with directions, and may show more difficulty in remembering the initial instruction verses the final instruction. Those with the Organization category display more reversals than usual. These reversals may be seen during test taking and in their academic performance, and may be related to an attention or learning disorder, rather than APD.
 The group of children with APD and NVLD had significantly lower scores on Verbal IQ, Digit Span, Sentence Memory, Block Design, and Speech Sounds Perception than children without APD. An ancillary finding was that the incidence of attention deficit/hyperactivity disorder was significantly higher in children with NVLD (with and without APD) than in the general population.

Vision and ADHD
Convergence Insufficiency (CI), where your eyes don't turn in enough, can often get misdiagnosed as ADHD.   Dr. Granet and his colleagues at UCSD, did i the first paper published in a medical journal that establishes a direct link between ADHD and CI. In a review of 266 charts of patients with CI, these researchers found a three times greater amount had ADHD than would be expected among patients in general.

It might seem obvious that if a person has difficulty sustaining the use of both eyes together as a team for a period of time when reading, that reading would be stressful. In fact, the way many patients with this condition (CI) handle their difficulty is to frequently re-focus to a distance, look away, take breaks, or avoid the nearpoint task altogether.

For many years, that’s been obvious to us as developmental optometrists. In other words, a substantial number of patients who seek our care have a history of being able to attend very well when someone else is reading, but have a short attention span, or get antsy, when they have to read independently. They appear to have ADHD when in reality, they have visual inattention for a good reason.

The problem is that these patients are usually lumped together, and they end up in special education and are often medicated. While a small set of patients with true ADHD may benefit from medication, precious resources and money would be saved if those with visual problems such as CI were properly evaluated. Not to mention the anguish that many families experience when homework takes hours to accomplish because of visual inattention. Or adults who struggle to keep pace with jobs requiring sustained near performance.

Vision and NLD
Practioners are also noticing the same overlap between Vision and NLD.   A developmental optometrist at VisionHelp noticed that many of the  characteristics of NLD listed by Dr. Rourke (the big daddy of NLD) were the same vision problems he treats in his practice:  visual spatial deficits, visual-motor problems, etc.

People with NLD  are considered to have primary strengths in simple motor function, auditory perception, and rote learning of repetitious acts. Secondary strengths occur in selective attention for verbal material, and rote memory for verbal information. People with NLD tend to spell phonetically.

Primary weakness for the NLD child occur in bilateral coordination of the body and in visual perceptual skills. There is impaired discrimination and recognition of visual detail and visual relationships, as well as deficiencies in visual-spatial-organizational abilities. Visual attention tends to be poor, and there is persistent difficulty in problem solving and complex concept formation. Reading comprehension is much poorer than is single-word reading (decoding). These weaknesses tend to get worse over time.

All too often, children with NLD have their visual weaknesses managed by “accommodations” in school or at home. In other words, the only help offered is to lessen the demand on their visual skills (see the discussion on “Section 504 Accommodations” elsewhere on this site). But parents of children with NLD deserve to know that more can be done.

The Clinical Practice Guidelines of the ICDL (Interdisciplinary Council on Developmental and Learning Disorders), available through, notes that if a child with NLD is taught by optometric techniques to enhance motor awareness, motor memory, and motor integration, and this improvement is transferred to the academic arena, significant benefits can be realized. Vision therapy is one of many interdisciplinary interventions necessary for these individuals (pp. 250-251). In the same volume, a colleague of ours, Dr. Harry Wachs, has a detailed chapter on visual-spatial thinking, which details these optometric techniques used to help NLD children (pp. 517-536).

Marcia Rubenstein, an educational consultant based in West Hartford, CT, recently published a book oriented to parents, entitled: Raising NLD Superstars: What Families with Nonverbal Learning Disabilities Need to Know About Nurturing Confident, Competent Kids. She notes (p.164) that some developmental optometrists examine children who are having problems in school and recommend vision therapy to treat conditions such as deficient eye teaming, tracking problems, or problems with visual memory. She concludes: “Many parents of NLDers attest to the success of vision therapy and to the sustained accomplishments of their children after treatment.”

So, I guess this all depends on what part of the elephant you end up grabbing?  NLD, APD, ADHD, Vision?
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