health Oct 12, 2021
Brain model early 20th century.
Photo by David Matos / Unsplash

Nature’s amazing creation is the Human Brain. This organ differentiates  human beings from other animals, with its capacity to coordinate various activities like movements, memories, moral judgements, balanced thoughts, language, art, etc.,

The cerebrum is the largest part of the human brain. It is divided into two halves namely, right and left.
The left brain contains regions associated with speech and language and mathematical calculation. The Broca's area and Wernicke's areas of cerebrum contain centres that are mainly concerned with language functions and language usage.
The right brain is responsible for visual and auditory processing, spatial skills and artistic ability centres. To carry out normal functions, both halves are used by us all the time.

Acquired reading disability -- ALEXIA

If these functions are temporarily lost, due to brain damage, or abnormal electrical or chemical activity in the brain, it may lead to a loss in the ability to speak sentences and the ability to write.  
Loss of the ability to read or understand the written word is an acquired reading disability. Such an acquired reading disability as a result of an acquired event such as a stroke, is called ALEXIA.
Alexia is a disorder of the central nervous system and it is characterized by the impaired ability to read.

Alexia may be accompanied by communicative aphasia (the ability to speak in sentences), and agraphia (the ability to write). Alexia is different from developmental dyslexia found in children who suffer from difficulties in learning to read.

Pure alexia

Cerebral lesions in restricted regions of brain lead to Pure alexia.
Pure alexia is also known as: "alexia without agraphia"(agnosic alexia), "letter-by-letter dyslexia", or “spelling dyslexia", or “pure word blindness”, or "word-form dyslexia” or “text blindness”, “visual aphasia” or “Dejerine syndrome” (after Joseph Jules Dejerine who described it in 1892).
Individuals with pure alexia suffer from severe reading problems while other language-related skills such as naming, oral repetition, and writing remain undamaged.


The blood vessel that supplies blood to the back outer parts of the brain is the posterior cerebral artery. In the case of alexia patients, they suffer from a stroke to the posterior cerebral artery. This will stop proper blood flow to the area necessary for normal reading abilities.
As a result of this, the patient can write but cannot read, even what they have just written. The patient can still write because the pathways connecting the left-sided language areas to the motor areas remain undamaged.

Any damage to the left brain, particularly, to the left visual cortex area, patients can recognize only such words that are spelled out loud to them. This is because of the normal functioning of the right visual cortex which is able to process visual information, but unable to send this information to the language areas (Broca's area, Wernicke's area, etc.) in the left brain due to the damage in the left brain.

Many people with pure alexia are able to identify and name individual letters over time and also can recognize sequences of letters as words. They adapt to use a style of compensatory reading known as letter-by-letter reading. This style of reading takes longer time and as the number of letters in a word increases, the amount of time also increases. For each letter that is added, they may take an additional three seconds to read the word.

Pure alexia patients exhibit some unexpected outstanding abilities even though they have an inability to read words.
For instance, one patient had conserved calculation capabilities such as deciding which number was greater, and whether a number was odd or even.
Even though the patient cannot read the numbers, the patient is able to calculate simple arithmetic tasks such as addition, subtraction, and division, but not multiplication.
If the patient is given a subtraction with "8 – 6", he or she would read it as "five minus four", but can give the correct answer "two". This shows that they still retain some residual logic processing.

Alexia patients may feel difficulty in,

●Recognizing words

● Identifying and reading synonyms

●Difficulty with reading.

●Double vision when trying to read.

● can read only some words but not others

●Focusing on the left side of the paragraph or page.

● can read larger words, but cannot read tiny words such as “it,” “to,” “and,” etc.

●any combination of some of the above combinations.

There is no sufficient scientific research that identifies the main cause of alexia. A formal diagnosis can be done by a speech-language pathologist. With his experience with alexia, he will be able to find the type of alexia and also can suggest possible treatments and approaches. He may also be aware of the latest studies and treatments available.

Specialized rehabilitation practices have been implemented to a single patient or small patient group. A text-based approach known as multiple oral re-reading (MOR) treatment is implemented to patients seeking rehabilitation.
In this treatment, patients are asked to practice reading words aloud repeatedly. This helps to stimulate the damaged part of the brain.
MOR works by reading out loud the same text repeatedly, until certain norms are reached. Improved reading rate is the main criteria for a pure alexic patient.

Another method that has been followed is the use of kinaesthetic or cross modal therapy.
In this therapy, patients are asked to trace the words in which they are trying to read aloud but it is a more possible approach for those on the slower reading end of the spectrum.

If the problem is mainly due to the damage to the visual field, an ophthalmologist who has experience with alexia, should suggest to undergo a low vision examination and based on the report, he may prescribe corrective lenses or may follow the techniques to improve reading eye movements.

Some Home Remedies

Encourage Silent reading as it is easier than reading out loud.
Learn them to sound out the first letter and it can help in reading the entire word. In such a type of learning i.e., to sound out the first letter or combination, the letters can blend into words.
Learning should start with simple words such as c-a-r or h-a-t. Then move on to longer words such as a-n-i-m-a-l. Then move on to sentences such as l-o-o-k   a-t   t-h-e   a-n-i-m-a-l.


A. Sandhya

M.Sc Zoology

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