Agraphy

Agraphy is a gross disorganization of written speech, which leads to the impossibility of implementing the act of writing. It is accompanied by the disintegration of the graphic image of sound, gross agrammatism, inability to write spontaneously, under dictation or independently, to copy the text. Diagnostics includes neurological examination, instrumental examinations (MRI, electroencephalography), neuropsychological and speech therapy testing. Correction of agraphy is carried out by speech therapy against the background of drug therapy, physiotherapy treatment.

ICD 10

R48.8 Other and unspecified violations of recognition and understanding of symbols and signs. Agraphy

General information

Agraphy is a complete lack of formation or loss of writing skills. It is more common in the clinic of aphasia and agnosia. The term “agraphy” was introduced by the British optometrist D. Ginshelwood, who described in the early twentieth century cases of writing disorders in children with intellectual norm. Currently, in practical speech therapy, it is customary to distinguish a partial violation of writing – dysgraphy and a complete loss of skill – agraphy. The disintegration of written speech always accompanies the loss of oral speech.

Causes of agraphy

Gross violation of writing is rarely an isolated disorder. As a rule, it acts as part of a symptom complex, including the breakdown of oral speech – aphasia, as well as reading – alexia. The clinic of agraphy is found in the structure of the following syndromes:

1. Aphatic disorders: sensory, afferent and efferent motor, dynamic, semantic, acoustic-mnestic, total aphasia.
2. General underdevelopment of speech: motor and sensory alalia.
3. Optical-spatial agnosia.
4. Congenital hearing loss.
5. Neurodegenerative diseases: Pick’s disease, Schilder’s leukoencephalitis, Gerstmann–Straussler–Scheinker syndrome, etc.

Risk factors

The pathomorphological substrate of writing disorders is damage to certain areas of the brain involved in ensuring the act of writing. The factors provoking such violations can be:

• perinatal CNS lesions;
• ischemia and hemorrhage of the brain;
• neuroinfections;
• traumatic brain injuries;
• neurotoxicosis;
• cerebral tumors;
• neurosurgical operations.

Pathogenesis

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 the word, correlation of phonemes with the visual image of the letter, grapheme outlines. Speech-hearing, speech-motor, visual, motor analyzers are involved in its implementation.

Writing is realized with the participation of the inferior frontal, temporal, inferior 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 of the written operation, and a full-fledged letter becomes impossible.

Thus, with upper-hand agraphy, the letter disintegrates as a result of the loss of the ability to sound-letter analysis of the word, which loses the 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 divisions leads to a violation of speech kinesthesia, the inability to pronounce sounds and translate them into the appropriate letter. Afferent motor agraphy occurs, in which the ability to write under dictation and independently is lost. When the premotor speech zone is affected, 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 a 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 parietal-occipital structures of the left hemisphere causes the disintegration of the optical scheme of letters, a violation of the location of graphic elements in space.

Classification

Agraphs are classified based on the mechanism of writing violations. Considering the area of local brain damage, neuropsychologist L.S. Tsvetkova identifies the following forms of agraphy:

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 agraphy into primary (when the prerequisites of writing are not formed) and secondary (resulting from aphasias). Some experts divide agraphy into the following types:

• aphatic (develops in the structure of acoustic-gnostic and acoustic-mnestic aphasias);
• apractic (associated with constructive or ideatory apraxia);
• clean, or isolated (caused by damage to the posterior sections of the 2nd frontal gyrus, associated with a violation of the organization and control of purposeful behavior).

Symptoms of agraphy

Kinesthetic agraphy

The function of writing is grossly impaired in severe and moderate afferent motor aphasia due to the breakdown of the phoneme-articuleme-grapheme connection. Independently, patients can only write their own surname (an ideogram letter). In some cases, cheating is available. Patients cannot cope with a letter dictated by dictation. Sound-letter analysis is either unavailable or is performed with errors. In lighter cases, a large number of omissions of letters and syllables, literal paragraphs are found on the letter.

Kinetic agraphy

Develops in the clinic of efferent motor aphasia. Qualitative defects of writing are the same as in kinesthetic agraphy. Perseverations, omissions of consonants and vowels, permutations of letters, and underwriting of words are also typical. There may be changes in handwriting by type of micro- or macrography.

Temporal agraphy

With a rough degree of acoustic-gnostic agraphy, only the spelling of highly strengthened words, one’s 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 the grossest errors.

With acoustic-mnestic agraphy, dictation writing suffers mainly. Mistakes made (verbal paraphasias, omissions of words) are associated with defects in auditory attention and memory.

Dynamic agraphy

Self-writing and copying of letters and simple words is available. There are omissions and perseverations in the dictation letter. Independent writing and phrase construction is not available in rough form or is limited to stereotypical phrases in moderate-severe cases (speech spontaneity). There are agrammatisms when matching words.

Non – speech agraphy

In optical agraphy, 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 incorrect arrangement of letter elements in space, mirror writing. Optical-mnestic disorders are manifested by the designation of correctly selected phonemes with letters that do not correspond to them. This type of agraphy is characteristic of amnesic aphasia.

Diagnostics

The diagnosis is based on the data of neurological examination, speech therapy and neuropsychological testing. First of all, it is necessary to establish the etiology of agraphy and the leading syndrome within which it developed. For this purpose , the following:

1. Instrumental research. MRI of the brain helps to detect ischemic and hemorrhagic foci, signs of neurodegeneration, 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.
2. Neuropsychological diagnostics. The formation or preservation of prerequisites for written speech is investigated: auditory, visual, somato-spatial gnosis, carpal praxis and other operations. It is important to analyze the arbitrariness of behavior, self-regulation, and the formation of motives for activity. Comprehensive neuropsychological testing allows you to identify the broken links and choose the correct methods of correction of agraphy.
3. Diagnostics of oral and written speech. The examination of a speech pathologist begins with the analysis of oral speech (receptive, expressive), the patient’s ability to analytical and synthetic activity. Then the availability of various types of writing to the patient is determined: ideographic, independent, by ear, cheating. At the same time, safe and broken operations are identified, various types of errors are analyzed.

Correction of agraphy

Rehabilitation training in agraphy is based on replacing the affected analyzer with the most preserved one, creating a new functional system to replace the broken one. The main directions of correctional work in various forms of agraphy:

• With temporal. The reliance on visual, speech-motor, kinesthetic analyzers is used. First, the patient is taught to listen to speech, to isolate sentences and words from the flow. Then they begin to restore the sound distinction and the letter designation of phonemes, conducting an audio-letter analysis. As these skills become stronger, the number of external supports is reduced, including auditory control in the work. The patient is offered to answer questions in writing, make suggestions based on pictures or words, write and dictation with pronunciation.
• With kinesthetic. Visual and auditory analyzers play a leading role in restorative learning. Work is underway on writing 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 the picture, the subject. Then they proceed to pronouncing, restoring the article and writing letters. In parallel, work is underway to eliminate agrammatism 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. To do this, word schemes, split alphabet letters, verbal games are used. First, exercises are introduced for cheating, then for writing from memory and by ear with pronouncing. 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. It is based on kinesthesia (feeling of letter layouts, construction), motor sensations (writing in the air), verbal analysis, 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 make a presentation plan, essays. Analyze the composition of the phrase. Construct compound and compound sentences.

Prognosis and prevention

Correctional training leads to a gradual recovery of writing. However, the results differ significantly depending on the cause and type of agraphy, the age of the patient. Agraphy caused by focal brain lesions has a more favorable prognosis, and the worst prognosis is caused by neurodegenerative pathologies. However, even with a satisfactory result, the automatism of the writing function cannot be brought to a premorbid level.

Prevention of agraphy consists in the prevention of birth injuries, brain catastrophes, cerebral infections. The best response to correctional training is achieved with an integrated approach: pharmacotherapy, physical rehabilitation and logotherapy.