Lesser Known Disorders
Each issue of this series contains at least three lesser known disorders. Some of these disorders may contain subtypes which will also be presented. You will also notice that each disorder has a code. These codes represent the coding system for all disabilities and disorders listed in the Educator’s Diagnostic Manual(EDM) Wiley Publications.
Disorders in this issue:
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Muscle Tension Dysphonia
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Mental Retardation due to Fragile-X Syndrome
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Nonverbal Learning Disabilities (Nonverbal Learning Disorders or NLD)
SL 5.01 – Muscle Tension Dysphonia
Disability Category – Speech and Language Impairment
Definition
A type of voice disorder specifically associated with strained, effortful phonation usually causing vocal fatigue if used extensively (Columbia University College of Physicians and Surgeons, 2005)
Explanation
Muscle tension dysphonia is characterized by the vocal folds typically failing to come completely together because two muscles are pulling in opposite directions simultaneously. The vocal folds have the capacity and ability to assume the correct position for a task, but do not because they are pulling against one another in an inefficient fashion. This is most likely a learned behavior (Thomas, 2004).
SL 5.01a-Primary Muscle Tension Dysphonia
A type of vocalizing or speaking in which the muscles in the neck are tense and when no other lesion or paralysis is seen (Columbia University College of Physicians and Surgeons, 2005).
SL 5.01b-Secondary Muscle Tension Dysphonia
A compensatory method of vocalizing due either to a paralysis, paresis or muscular weakness causing the person to squeeze other parts of the larynx to help produce sound (Columbia University College of Physicians and Surgeons, 2005).
MR 1.04-Mental Retardation due to Fragile-X Syndrome
Disability Category-Mental Retardation
Definition
A genetic condition involving changes in which the bottom of the X chromosome in the twenty-third pair of chromosomes is “pinched off”, which can result in a number of physical anomalies as well as mental retardation (Hallahan & Kauffman, 2006; Taylor, Richards, & Brady, 2005; National Library of Medicine, 2005b). Sometimes referred to as Martin-Bell Syndrome, Fragile-X develops when a mutation occurs in one of the genes of the X chromosome (Beirne-Smith, Patton & Kim,2006). The mutation, occurring when a gene segment that is repeated in most people about 30 times is repeated 55 to 200 times, causes the gene to turn off, that is, to stop producing a chemical present in the cells of people who do not have this disorder (Fast, 2003, cited in Friend, 2005, p.290).
Explanation
Fragile X syndrome (also called Fragile X) is the most common inherited form of mental retardation (Taylor, Richards, & Brady, 2005). It results from a change, or mutation, in a single gene, which can be passed from one generation to the next (National Institute of Child Health and Human Development, 2005b). In association with mental retardation, it occurs in 1 in 4,000 males and at least half as many females (Turner, Webb, Wake, & Robinson, 1996).
Symptoms of Fragile X syndrome occur because the mutated gene cannot produce enough of a protein that is needed by the body’s cells, especially cells in the brain, to develop and function normally. The amount and usability of this protein, in part, determine how severe the effects of Fragile X are in the individual (National Institute of Child Health and Human Development, 2005b).
The most noticeable and consistent effect of Fragile X is on intelligence. More than 80 percent of males with Fragile X have an IQ (intelligence quotient) of 75 or less. The effect of Fragile X on intelligence is more variable in females. Some females have mental impairment, some have learning disabilities, and some have a normal IQ (Dykens, Hodapp, & Finucane, 2000). Fragile X occurs less often in females because they have an extra X chromosome, giving them better protection if one of their X chromosomes is damaged (Hallhan & Kauffman, 2006).
People with Fragile X syndrome also share certain medical problems as well as many common physical characteristics, such as large ears, large head, narrow face, prominent forehead, broad nose, square chin, large testicles, large hands and a long face (Dykens, Hodapp, & Finucane, 2000). In addition, having Fragile X is often associated with problems with sensation, emotion, and behavior. Students with this syndrome also are likely to become anxious when routines are changed, and they often have poor social skills (Symons, Clark, Roberts, & Bailey, 2001).
LD 8.00 Nonverbal Learning Disabilities (Nonverbal Learning Disorders or NLD)
Disability Category – Learning Disabilities
Definition
Nonverbal Learning Disorder, also known as NLD, is a neurophysiological disorder originating in the right hemisphere of the brain. Reception of nonverbal or performance-based information governed by this hemisphere is impaired in varying degrees, including problems with visual-spatial, intuitive, organizational, evaluative, and holistic processing functions (Nonverbal Learning Disorders Association, 2004).
Diagnostic Symptoms
BecauseDiagnostic symptoms for non verbal learning disabilities include:
- Deficits in the areas of nonverbal problem solving, concept formation, hypothesis testing
- Difficulty dealing with negative feedback in novel or complex situations
- Difficulties in dealing with cause-effect relationships
- Difficulties in the appreciation of incongruities
- Well-developed rote verbal capacities and rote verbal memory skills
- Over-reliance on prosaic rote, and consequently inappropriate, behaviors in unfamiliar situations
- Relative deficiencies in mechanical arithmetic as compared to proficiencies in reading (word recognition) and spelling
- Rote and repetitive verbosity
- Content disorders of language
- Poor psycholinguistic pragmatics (cocktail party speech)
- Poor speech prosody
- Reliance on language for social relating, information gathering, and relief from anxiety
- Misspelling almost exclusively of the phonetically accurate variety
- Significant deficits in social perception, social judgment, and social interaction skills
- Marked tendency for social withdrawal and isolation as age increases
- High risk for social-emotional disturbance if no appropriate intervention is undertaken (Nonverbal Learning Disorders Association, 2004).
Further KeyPoints
The interpersonal and social aspects of NLD have great significance for a student’s life. The individual who does not attend to or accurately interpret the nonverbal communication of others cannot receive a clear message. Our concept of self is shaped in large measure by the reflection of how others view us. The person who has NLD, then, may not receive feedback from others and may suffer from a less clear concept of self. The diminished ability to engage with others greatly limits the possibility of defining himself based on such feedback.
Because of their verbal strengths, many individuals with NLD succeed in formal educational situations. However, if their social competence has not developed commensurately, they may not find and keep employment at the level for which their education has prepared them. On a positive note, individuals with NLD make considerable progress in areas of weakness when instruction is appropriate, accurate diagnosis and appropriate instruction can have great benefit for their lives (Foss, 2001).
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