Agraphia
Agraphia is the gross disorganization of written speech, leading to the impossibility of implementing the act of writing. It is accompanied by the disintegration of the graphic image of sound, rough agrammatism, the inability to write spontaneously, dictation or independently, to copy the text. Diagnostics include neurological examination, instrumental studies (MRI, electroencephalography), neuropsychological and speech therapy testing. Correction of agraphia is carried out with speech therapy means against the background of drug therapy, physiotherapy.
General information about Agraphia
Agraphia (“a” – absence, “grapho” – I write) – complete lack of formation or loss of writing skills. It is more common in the clinic of aphasia and agnosia. The term “agraphia” was introduced by the British ophthalmologist D. Ginshelwood, who described it at the beginning of the twentieth century. cases of writing disorder in children with an intellectual norm. Currently, in practical speech therapy, it is customary to distinguish a partial violation of writing – dysgraphia and a complete loss of skill – agraphia. The decay of written language always accompanies the loss of oral speech.
Classification of Agraphia
Agraphs are classified based on the mechanism of writing violations. Given the area of local brain damage, neuropsychologist L.S. Tsvetkova distinguishes the following forms of agraphia:
1. Speech (corresponding to a certain form of aphasia):
- kinetic motor;
- kinesthetic motor;
- sensory (acoustic-gnostic and acoustic-mnestic);
- dynamic;
2. Non-verbal (gnostic):
- optical;
- optical-spatial;
- optical-mnestic;
- apracto-agnostic.
In foreign neuropsychology, it is customary to divide agraphies into primary (when the prerequisites for writing are not formed) and secondary (resulting from aphasia). Some experts subdivide agraphies into the following types:
- aphatic (develops in the structure of acoustic-gnostic and acoustic-mnestic aphasias );
- apracial (associated with constructive or ideational apraxia );
- pure, or isolated (due to the defeat of the posterior parts of the 2nd frontal gyrus, associated with a violation of the organization and control of purposeful behavior).
Reasons for agraphia
Gross writing disorder is rarely an isolated disorder. As a rule, it acts as part of a symptom complex that includes the decay of oral speech – aphasia, as well as reading – alexia. The clinic of agraphia is found in the structure of the following syndromes:
- Aphatic disorders: sensory, afferent, and efferent motor, dynamic, semantic, acoustic-mnestic, total aphasia.
- General speech underdevelopment: motor and sensory alalia.
- Optical-spatial agnosia.
- Congenital hearing loss.
- Neurodegenerative diseases: Pick’s disease, Schilder’s leukoencephalitis , Gerstmann-Straussler-Scheinker syndrome, etc.
Risk factors of Agraphia
The pathomorphological substrate of writing disorders is damage to certain areas of the brain involved in providing the act of writing. The factors provoking such violations may be:
- perinatal lesions of the central nervous system;
- ischemia and hemorrhages of the brain ;
- neuroinfection ;
- traumatic brain injury ;
- neurotoxicosis;
- cerebral tumors ;
- neurosurgical operations.
Pathogenesis of Agraphia
Unlike oral speech, which is formed by imitation, writing develops later in the learning process. The writing operation consists of a series of sequential actions: sound analysis of a word, correlating phonemes with the visual image of a letter, drawing graphemes. In its implementation, speech-auditory, speech-motor, visual, motor analyzers are involved.
Writing is realized with the participation of the lower frontal, temporal, lower parietal, occipital cortex of the left hemisphere of the brain. The defeat of any of these areas leads to the loss of a certain link in the written operation, and full-fledged writing becomes impossible.
So, with upper temporal agraphia, the letter disintegrates as a result of the loss of the ability to sound-letter analysis of the word, which loses its constancy of sound. If the focus is located in the middle and posterior parts of the temporal zone, the volume of auditory perception and auditory-speech memory decreases, as a result of which it becomes impossible to write by ear.
The interest of the lower parietal departments leads to a violation of speech kinesthesia, the inability to pronounce sounds and their translation into the corresponding letter. Afferent motor agraphia occurs, in which the ability to write dictation and independently is lost. When the premotor speech zone is damaged, the dynamic scheme of the word is disrupted. In this case, the patient is able to write individual letters, but cannot combine them into a syllable or word.
With pathology of the prefrontal and upper temporal cortex, writing is disrupted at the level of programming, semantic and grammatical aspects. The involvement of the occipital and parieto-occipital structures of the left hemisphere causes the decay of the optical scheme of letters, a violation of the arrangement of graphic elements in space.
Agraphia symptoms
Kinesthetic agraphia
The writing function is grossly impaired in severe and moderate afferent motor aphasia due to the disintegration of the “phoneme-articule-grapheme” connection. Patients on their own can only write their own surname (ideogram letter). In some cases, cheating is available. Patients cannot cope with dictation. The sound-letter analysis is either not available or is performing with errors. In milder cases, the writing contains a large number of omissions of letters and syllables, literal paragraphs.
Kinetic agraphia
Develops in the clinic of efferent motor aphasia. Qualitative writing defects are the same as in kinesthetic agraphia. Also typical are perseverations, omissions of consonants and vowels, permutations of letters, incomplete description of words. Changes in handwriting by the type of micro- or macrographic are possible.
Temporal Agraphia
With a rough degree of acoustical-gnostic agraphism, only the spelling of highly consolidated words, one’s own first and last name, is preserved. When copying from a sample, patients make multiple mistakes. There are verbal and literal paragraphs in the letter by ear. There is no self-control and self-correction. The analysis of the sound-letter composition of the word is made with gross errors.
In acoustical-mnestic agraphics, dictation writing suffers mainly. Errors ( verbal paraphasias, missing words) are associated with defects in auditory attention and memory.
Dynamic agraphia
Self-writing and cheating of letters and simple words are available. There are omissions and perseverations in the dictation letter. Independent writing and phrase building is not available in a rude form or limited to stereotypical phrases in moderate to severe cases (speech spontaneity). There is agrammatism when words are agreed upon.
Non-speech agraphia
In optical agraphics, the letter is accompanied by the replacement of optically similar letters (o-a-e, i-sh-t). The optical-spatial form is accompanied by an irregular arrangement of the elements of letters in space, mirror writing. Optical-mnestic disorders are manifested by the designation of correctly distinguished phonemes with inappropriate letters. This type of agraphia is characteristic of amnestic aphasia.
Diagnostics of Agraphia
The diagnosis is based on data from neurological examination, speech therapy, and neuropsychological testing. First of all, it is necessary to establish the etiology of agraphia and the leading syndrome within which it developed. For this purpose, the following are carried out:
- Instrumental research. MRI of the brain helps to detect ischemic and hemorrhagic foci, signs of neurodegeneration, and cerebral tumors. MR angiography is used to diagnose cerebrovascular pathology. EEG is informative for suspected neurometabolic and neurodegenerative pathologies of the central nervous system. To exclude hearing loss, an audiogram is recorded.
- Neuropsychological diagnostics. The formation or preservation of the prerequisites for written speech is investigated: auditory, visual, somatospatial gnosis, carpal praxis, and other operations. It is important to analyze the arbitrariness of behavior, self-regulation, the formation of the motives of activity. Comprehensive neuropsychological testing allows you to identify impaired links and choose the right methods for correcting agraphia. Agraphia its reasons classification symptoms
- Diagnostics of oral and written speech. The examination of a speech therapist-defectologist begins with an analysis of oral speech (receptive, expressive), the patient’s ability to analytic-synthetic activity. Then the patient’s availability of various types of writing is determined: ideogram, independent, by ear, cheating. At the same time, saved and disturbed operations are identified, various types of errors are analyzed.
Correction of agraphia
Restorative training in agraphia is based on replacing the injured analyzer with the most intact one, creating a new functional system to replace the broken one. The main directions of correctional work in various forms of graphics:
- With the temporal. The support is used on the visual, speech-motor, kinesthetic analyzers. First, the patient is taught to listen to the speech, to isolate sentences and words from the flow. Then they proceed to the restoration of sound recognition and lettering of phonemes, carrying out sound-letter analysis. As these skills are strengthened, the number of external supports is reduced, including auditory control. The patient is asked to answer questions in writing, make sentences using pictures or words, write and dictation with pronunciation.
- With kinesthetic. The leading role in restorative learning is played by visual and auditory analyzers. Work is underway on the writing of whole words available in the active dictionary and their sound-letter analysis (the strategy “from the whole to the particular”). The written words are correlated with a picture, an object. Then they move on to pronouncing, restoring the article, and writing letters. In parallel, work is underway to eliminate the Grammatics in writing, to retain the lexical structure of the phrase in memory.
- With kinesthetic. Work is underway to restore analytical writing, which is based on the analysis of the composition of the word. For this, word schemes, letters of the split alphabet, verbal games are used. First, exercises for cheating are introduced, then for writing from memory and by ear with pronunciation. A separate task is to restore the grammatical structure of the phrase.
- With optical. The task is to restore the visual image of the letter and the correct spatial arrangement of its elements. Reliance is applied on kinesthesia (palpation of letter layouts, construction), motor sensations (writing in the air), verbal analysis, and auditory perception. Numerous dictations of well-established words are carried out. This approach helps to improve the differentiation of optically close letters.
- With dynamic. Patients learn to draw up a presentation plan, composition. The composition of the phrase is analyzed. Complex and complex sentences are constructed.
