Specific Kinds of Learning Disorders
Most LD’s do not have specific names. Indeed, due to the almost infinite variety of neurodevelopmental weaknesses that can form the basis of an LD, it would be impossible to come up with some system of names that covered all the potential varieties. In most cases, it is best to describe an LD based upon its prominent neurodevelopmental features (e.g. language or memory based, etc.) or upon the affected academic areas (e.g. Reading or Math Disability, etc.).
Certain LD’s are common enough & have had enough written about them to have acquired special names of their own, however. The two oldest names actually pre-date the current LD literature, although we now understand them to be examples thereof. The first of these is Attention Deficit Disorder, which has been known and written about since the earliest years of the 20th century (see separate article). Theoretically and intellectually, ADD (or ADHD) is no different from any other LD except in the fact that we have medications that can help it (by improving the functioning of the brain wiring).
Another LD with “roots” long before the current era is Dyslexia. Dyslexia has been known and written about since the 1800’s. It was a severe Reading Disability characterized by certain distinctive neurodevelopmental weaknesses including visual processing, sequencing, and language issues. Not every Reading Disability is Dyslexia, however.
Other named LD’s have been more recently described. These include Dysgraphia, which is a difficulty performing any pencil/paper types of tasks due to difficulties with fine motor control and visual motor integration. They also include Dysarthria, which is a speech impediment based upon difficulties with oromotor control. The term Dyscalculia is sometimes used to describe a severe Math Disability mirroring Dyslexia in certain ways. Finally, the term “Non-Verbal LD” (NVLD or NLD) has been in fashion lately to describe children who have strong skills when performing work verbally (listening and talking) but have difficulty with all sorts of academic tasks based upon weak visual processing, sequencing, and memory skills combined with difficulties with executive functions and social interactions.
There are also a number of medical/neurologic conditions defined by symptoms unrelated to learning, but which are often accompanied by an LD as well. These include Cerebral Palsy, Traumatic Brain Injury, Epilepsy or Seizure Disorder, Tourette’s Syndrome, Narcolepsy, many Genetic Syndromes, as well as syndromes involving patients who in the past have experienced Head Trauma, Shock, lack of Oxygen, near Drowning, or who have undergone brain surgery or chemotherapy for cancer. Finally, anything that causes hearing loss, (mild or severe), especially early in life, including recurrent/chronic ear infections, can pre-dispose to LD later. This can remain true even if the hearing loss has been corrected if it was present for a significant period of time early enough in life.