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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LD 2.04 – Developmental Anarithmetria (Incorrect Operation Dyscalculia)
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AL 6.02 – Broca’s Aphasia (Motor Aphasia)
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VI 3.11 – Nystagmus
LD 2.04-Developmental Anarithmetria (Incorrect Operation Dyscalculia)
Disability Category – Learning Disabilities
Definition
A type of dyscalculia specifically associated with difficulties and confusion in performing the correct arithmetic operations (e.g., although addition of numbers was required for a problem, a student subtracted the numbers instead; or multiplying two numbers when division is what was required) (Yisrael, 2000).
Explanation
Students with Developmental Anarithmetria (Incorrect Operation Dyscalculia) will use the incorrect operations when performing math problems. For example, the student states that 5 + 2 = 3. Here, the student performed the operation of subtraction instead of addition. Another example would be the student who states that 30 x 5 = 6. Again, an incorrect operation is performed (the student divided 30 by 5 instead of multiplying the numbers).
SL 6.02-Broca’s Aphasia (Motor Aphasia)
Disability Category- Speech and Language Impaired
Definition
A type of aphasia specifically associated with damage to the frontal lobe of the brain. Individuals with Broca’s Aphasia frequently speak in short, meaningful phrases that are produced with great effort. Broca’s aphasia is thus characterized as a nonfluent aphasia (National Institute of Deafness and Other Communication Disorders, 2002a).
Diagnostic Symptoms
Individuals with Broca’s aphasia (also called motor aphasia) often omit small words such as “is,” “and,” and “the” (Anderson & Shames, 2006). For example, a person with Broca’s aphasia may say, “Walk dog” meaning, “I will take the dog for a walk.” The same sentence could also mean “You take the dog for a walk,” or “The dog walked out of the yard,” depending on the circumstances (National Institute of Deafness and Other Communication Disorders, 2002).
Individuals with Broca’s aphasia may not be able to speak at all. Or they may be able to use single-word statements or full sentences after great effort. They frequently omit words that are conjunctions and articles (and, or, but, the, a), which results in speech that sounds abrupt and choppy. People with Broca’s aphasia can understand and process what others are saying, so they often become depressed and frustrated by their own inability to communicate. They may have difficulty reading, and weakness on the right side of the body may make writing difficult (Penn State-Milton Hershey Medical Center College of Medicine, 2005).
VI 3.11-Nystagmus
Disability Category – Visual Impairment
Definition
Nystagmus is generally described as an involuntary movement of the eyes, which reduces vision. The movement is usually side to side (but can be up and down or circular motion) and can be either jerk or pendular (National Eye Institute, 2005).
Explanation
Nystagmus is neither contagious or infectious, but it is thought to sometimes be hereditary. Nystagmus often seriously reduces vision. Nystagmus affects people in many ways and the effects vary from person to person. Most people who have had the condition since childhood do not suffer from a constantly moving image (known as ‘oscillopsia’) most of the time, as their brains adapt to the movement of the eyes. However, people who acquire Nystagmus in later life are unlikely to adjust so well and will suffer much more from the effects of oscillopsia. People with Nystagmus may be slow readers because of the extra time needed to scan. This should not be taken as a sign of poor reading ability, but students or school children with Nystagmus may need extra time when they are sitting for exams (National Eye Institute, 2005).
VI 3.11a-Acquired nystagmus
Acquired nystagmus occurs later than 6 months of age, and can be due to the effects of a stroke, disease such as multiple sclerosis, or even a heavy blow to the head.
VI 3.11b-Congenital nystagmus
Nystagmus which appears in the first six months of life is called early onset Nystagmus, or congenital or infantile Nystagmus.
VI 3.11c-Jerk nystagmus
Jerk nystagmus consists of two movements: (1) a slow drift of the eyes and (2) a rapid corrective movement back to the point of fixation. This is the most common form of nystagmus.
VI 3.11d-Latent nystagmus
Latent nystagmus is defined clinically as nystagmus which appears on covering one eye and beats towards the uncovered eye.
VI 3.11e Pendular nystagmus
Pendular nystagmus consists of movement which occurs at roughly the same velocity in both directions.
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