Anomic aphasia is a variant of an aphasic disorder in which the nominative function of speech disintegrates. It is characterized by visual amnesia, forgetting the names of objects, speech pauses and difficulties in selecting words, verbal paraphasias. Diagnosis involves neurological examination (cerebral MRI, ultrasound of the arteries of the head and neck), neuropsychological and speech therapy testing. Therapeutic and correctional work in aphasia includes etiopathogenetic pharmacotherapy, logotherapy, neurocorrection.
R47.0 Dysphasia and aphasia
Anomic (nominative, anomalous) aphasia is accompanied by difficulties in visual recognition and verbal designation of objects. It was singled out in a separate form by the Soviet neuropsychologist A.R. Luria in 1973, pointing out that in this case the only central defect is the difficulty of naming objects. In the future, Anomic aphasia was excluded from the neuropsychological classification, because in its pure form it is rare, usually acting as a symptom of acoustic-mnestic or semantic aphasia. In modern aphasiology, anomic aphasia is again considered as an independent unit – its frequency among all forms is 4.2-7.5%.
Anomic disorders occur with local lesions of the posterior-inferior temporal cortex and parietal-occipital regions of the left hemisphere (20, 21, 37 and 40 Brodman fields). The causes of anomic aphasia in most cases are:
- cerebral infarction in the basin of the posterior cerebral artery;
- open traumatic brain injury;
- intracerebral hematoma;
- tumors of the large hemispheres (meningioma, astrocytoma, glioblastoma);
- encephalitis of various etiologies;
- progressive dementia (Alzheimer’s disease, Binswanger’s disease, Peak);
- brain surgery.
Predisposing (background) factors are hypertension, cerebral atherosclerosis, hypercholesterolemia, angiopathy, burdened family history, exogenous intoxication.
The pathogenetic mechanism of anomic aphasia remains completely unclear to date. Some researchers note that the 37 cytoarchitectonic field according to Brodman accumulates auditory and visual stimuli (overlap zone), so its defeat leads to dissociation of the visual image of the word and its verbal designation.
There is an opinion linking anomic aphasia with damage to the deep structures of the temporal cortex. In this case, the connection of the cortical auditory analyzer with the hippocampus, which is responsible for the function of memorizing and storing information, is disrupted. From the point of view of the neuropsychological approach (Luria A.R.), nominative aphasia is the result of a violation of the operation of selecting words stored in the patient’s memory.
Anomic aphasia is multifactorial and heterogeneous. Depending on the dominant lesion of the auditory, visual or associative zones, it can occur in three types:
- acoustic-mnestic: the leading defect is the inferiority of auditory-speech memory;
- opto-mnestic: the central defect is optical amnesia and agnosia;
- actually anomic: the main problem is a violation of the naming function.
Symptoms of anomic aphasia
Patients lose the ability to retain in memory an auditory series within 3 or more elements, to perceive an expanded text by ear. Understanding of both situational and other forms of speech suffers. Simple oral instructions are usually available, multi-step ones are not. The patient often asks again, asks to speak more slowly, repeat what he has heard.
Expressive speech is dominated by short sentences, verbal paraphasias. Frequent pauses associated with the search for the right word, perseverations. There are naming difficulties, especially the recall of proper names, geographical names, various dates, phone numbers suffers. Retelling of texts is difficult.
With this type of anomic aphasia, visual recognition of familiar objects is disrupted, and the word perceived by ear does not cause visual images. There are difficulties in depicting objects from memory, in the process of drawing patients miss important characteristic details, do not finish drawing significant details. At the same time, copying and copying is good.
There are also difficulties with sorting items by category: vegetables, clothes, furniture. Written speech is disrupted by the type of literal, verbal or unilateral optical alexia (patients do not see the left half of the text).
The defining violation is forgetting the names of objects. Patients cannot find the right word to denote well-known things, replace the forgotten word with a description of the object or its purpose. So, for example, about a pencil, the patient says “this is … what they draw or write with.” However, when prompted by the first syllable, he manages to remember the word he is looking for.
The phrase is pronounced slowly, interrupted by pauses, during which the patient selects the right word. The time between the question and the answer increases (the latency period). Spontaneous oral speech is replete with verbal paraphasias. Written speech (reading aloud, writing by dictation), as a rule, is preserved. However, cases have been described where anomic aphasia was combined with letter agnosia and optical alexia. Spontaneous writing also suffers, due to the reduction of nouns and the predominance of verbs in oral speech.
With anomic aphasia, speech comprehension, articulation, reading and writing function are preserved, therefore, nominative difficulties are often attributed to age-related “memory problems”. Comprehensive instrumental, psychological and speech therapy examination helps to identify the aphasic nature of disorders:
- Diagnosis of the causes of aphasia. Instrumental studies are designed to find out the etiology of speech disorders and localize the lesion. All patients are shown to perform a cerebral CT or MRI. With cerebrovascular pathology, ultrasound of brachiocephalic vessels, MR angiography is possible. Lumbar puncture and blood tests help in determining the causes.
- Neuropsychological examination. When conducting special diagnostic tests in the neuropsychological status of patients with anomic aphasia, various forms of agnosia (visual-subject, optical-spatial, alphabetic), optical amnesia can be detected. There is a decrease in the volume of memorization and productivity of word reproduction, difficulty in drawing from memory.
- Speech diagnostics. It is carried out by a speech therapist-aphasiologist. It includes the study of expressive and receptive speech, auditory-speech memory, reading, writing. Anomic aphasia is characterized by the search for words when naming objects, verbal paraphasias, weakness of acoustic and visual traces, speech pauses, and sometimes reading difficulties.
Correction of anomic aphasia
Active drug treatment is carried out in the acute period of stroke, TBI, neuroinfections. Patients with neurodegenerative pathologies require constant pharmacological support. Taking into account the main problem against which amnestic aphasia has developed, hypotensive, nootropic, antioxidant, deaggregant, vitamin preparations can be used. Of the methods of physical rehabilitation, darsonvalization of the head and SHVZ, magnetotherapy, electrophoresis, micropolarization are later connected. According to the indications, psychotherapy sessions are recommended.
Correctional classes for anomic aphasia are aimed at restoring the correlation of visual-object images with the word. For this purpose, the categorical and situational connections of objects, as well as their signs, qualities, functions, are updated. Pictures and real objects, articulation and graphic supports, pictograms are used in the classroom. Exercises and techniques used:
- memorization of word series by ear with a gradual increase in the number of words from 3-5 to 10;
- visual memory training (games “What is gone”, “What has changed”);
- reading pictures with captions;
- search for items by name;
- classification of objects;
- comparison of real objects with drawn ones;
- compilation of stories based on plot pictures and retelling of texts;
- solving crosswords.
Regular classes with a speech therapist, conducted against the background of drug treatment, allow you to restore the optical image of various objects, increase the subject vocabulary, expand the volume of auditory-speech memory.
Prognosis and prevention
The rehabilitation prognosis for anomic aphasia depends on the age, premorbid background of the patient, the degree of his interest in restoring speech function. Usually, against the background of drug therapy and neurorehabilitation, the phenomena of visual-objective agnosia, optical amnesia gradually regress. Many patients adapt to the social environment, return to professional activity.
Prevention of any aphatic syndromes is to minimize risk factors: correction of blood pressure, dyslipidemia, hyperglycemia. It is necessary to adhere to the principles of a healthy diet, to include moderate but regular physical and cognitive loads in life.