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:
LD 1.05-Auditory Figure Ground Processing Disorder
Disability Category: Learning Disability
Definition
An auditory processing disorder specifically associated with difficulties attending to a designated aural stimulus due to being focused by background sounds (Terry, 2001). It is the inability to attend to one sound against a background of sounds (e.g., hearing the teacher’s voice against classroom noise).
Explanation
A student with Auditory Figure Ground Processing Disorder often experiences difficulties with following oral instructions, as he/she may not be able to separate the instruction from background conversations. For example, a teacher may tell her students to take out their pens and open to page 152. The student with Auditory Figure Ground Processing Disorder may not process this information, not because he is not paying attention, but rather because he is focused on the background noise of a fan in the room or the ticking of a clock. This child may be unable to process that the telephone is ringing when he/she is listening to the radio, or have difficulty hearing someone talking at a party when music is playing (Terry, 2001).
It should be noted that any medical problems associated with this child’s hearing have been ruled out as a primary cause of the child’s difficulties. The difficulties are in the internal processing of information, not due to a hearing impairment.
OHI 1.00-Aicardi Syndrome (Aicardi-Goutieres syndrome)
Disability Category-Other Health Impaired
Definition
Aicardi syndrome is a rare genetic disorder identified by the French Neurologist, Dr. Jean Aicardi in 1965 (Aicardi Syndrome Foundation, 2006). Aicardi Syndrome is a rare genetic disorder characterized by the partial or complete absence of the structure that links the two hemispheres of the brain, the corpus callosum. The disorder affects only girls (National Institute of Neurological Disorders and Stroke, 2005a).
Diagnostic Symptoms
According to the Aicardi Syndrome Foundation (2006), Aicardi syndrome is characterized by the following “markers”:
- Absence of the corpus callosum, either partial or complete (the corpus callosum is the part of the brain which sits between the right and left sides of the brain and allows the right side to communicate with the left.)
- Infantile spasms (a form of seizures)
- Lesions or “lacunae” of the retina of the eye that are very specific to this disorder
- Other types of defects of the brain such as microcephaly, (small brain); enlarged ventricles; or porencephalic cysts (a gap in the brain where there should be healthy brain tissue)
Further Key Points
Children are most commonly identified with Aicardi Syndrome before the age of five months (U.S. National Library of Medicine, 2005). A significant number of these girls are products of normal births and seem to be developing normally until around the age of three months, when they begin to have infantile spasms (Aicardi Syndrome Foundation, 2006). Aicardi Syndrome may be associated with other brain defects such as a smaller than average brain and cavities or gaps in the brain filled with cerebrospinal fluid (National Institute of Neurological Disorders and Stroke, 2005a).
Treatment of Aicardi syndrome primarily involves management of seizures and early/continuing intervention programs for developmental delays. Prognosis for these children varies, though all experience developmental delays, typically moderate to severe mental retardation (Aicardi Syndrome Foundation, 2005).
OI 1.01 Fibrous Dysplasia
Disability Category: Orthopedic Impairment
Definition
Fibrous dysplasia is a chronic disorder in which bone expands due to abnormal development of fibrous tissue, often resulting in one, or more, of the following:
- uneven growth of bones
- pain
- brittle bones
- bone deformity (University of Maryland Medical System 2003)
Some patients have only one bone affected (monostotic), whereas other patients have numerous bones affected (polyostotic) (NIH Osteoporosis and Related Bone Diseases, 2000).
Explanation
The following are the most common symptoms for fibrous dysplasia. However, each individual may experience symptoms differently. Symptoms may include:
- a waddling walk
- bone pain (as a consequence of the expanding fibrous tissue in the bone)
- bone deformity
- bone pain
- bone fractures
- scoliosis—a lateral, or sideways, curvature and rotation of the back bones (vertebrae), giving the appearance that the person is leaning to one side.
The symptoms of fibrous dysplasia may resemble other bone disorders or medical problems. Always consult your physician for a diagnosis (U.S. National Library of Medicine, 2003a; University of Maryland Medical Center, 2003).
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