Alexia is Loss of the power to perceive the written word, due either to brain injury that disconnects these functions or to temporary condition caused by abnormal electrical or chemical activity within the brain. Alexia is a learning disability, happens once injury to the brain causes a patient to lose the power to scan. It's additionally referred to as Aphasia, text vision defect or alexia.

Patients with "alexia" and "developmental dyslexia" will show same symptoms; however, "alexia" refers to reading incapacity, wherever reading inability had been developed, sometimes occurring in adulthood conditions, whereas "developmental dyslexia" refers to organic process reading incapacity right from birth.

This problem is classified as per the exact location of the brain damage and also presence of other conditions as agraphia and/or aphasia. It may be possible that this disease, agraphia and apasia all occur together or one or more in absence of the other. In absence of aphasia, it is classified as alexia without agrpahia when left occipital lobe in effected andalexia with agraphia in which left angular gyrus is affected.

There are two types of alexia. The first one is that of “the central dyslexia” which is mainly superficial dyslexia, linguistic dyslexia and deep dyslexia. The second group is called “the peripheral dyslexia” which mainly includes attentional dyslexia, neglect dyslexia and pure dyslexia (is a condition known as alexia without agraphia)

Alexia occurs when the left part of dominant hemisphere of the brain is damaged. It can also occur with damage to the parietal and/or occipital lobes of the brain(these parts are reposnible for processing of visual, phonological and auditory processing. In such a condition the information that is gathered from the visual and auditiory means is not able to  be processes in a stimulus thus causing the patient not being able to understand the written word. This situation can also occur if the inferior frontal of the brain is damaged. The problem can also come after stroke.

When Alexia is without agraphia is mainly happens when the communication between left and right brain hemispheres is disturbed. In such a situation the right visual cortex is not able to receive information from the left side of the visual field, thus information could not be passed through the posterior commissure and splenium of the corpus callosum to the part in the left hemisphere where words are formed. In people with alexia without agraphia, this communication of information is disturbed.

Alexia may occur with or without receptive and/ or expressive aphasia It can also occur with agraphia, the condition in which there is loss of ability to write even when there is no other motor inability in functions. Sometimes damage is restricted to areas doing the processing f input information. This result in condition called pure alexia. In such a condition the person is able to produce the written word but not able to understand that.

There are few patients with major damage to areas responsible for visual processing found to have completely regained the 100 % ability back after treatment. The treatment can delay he damage if caused by adulthood and stop further complications is caused by some accident.

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