Aphasia/PGS/diagnosis

Aphasia is an acquired speech disorder that arises on the basis of focal brain damage, most often cortical areas of the dominant hemisphere. In terms of location, the most common causes of aphasia are cortical lesions, namely perisylvian areas ( Broca's and Wernicke 's areas), lesions in the fasciculus arcuatus, gyrus angularis, inferior gyrus frontalis, gyrus supramarginalis, and lesions in the subcortical areas of the thalamus and basal ganglia.

The most common causes of aphasia are vascular causes (ischemia or hemorrhage in the ACI basin (internal carotid artery)), as well as tumors and head trauma.

Symptoms
Aphasia manifests itself in the impairment of the ability to use language in all its levels. Symptoms of aphasia include '''speech fluency disorders, speech comprehension disorders, paraphasia, anomia, and agrammatism. Echolalia, speech automatisms, perseveration, circumlocution, satiation, reading and writing disorders''' may occur (the above symptoms of aphasia are explained in more detail in Table 1.).

Classification
In our neurology, aphasias are still often divided into "expressive" (motor, more recently nonfluent ), "perceptual" (receptive, sensory, more recently fluent ) and "mixed" (total, global ). "Expressive" aphasias mainly represent anterior involvement of the brain, "perceptual" aphasia posterior involvement (the border is the sulcus centralis ). Patients with an "expressive" phatic disorder more often have hemiparesis or hemiplegia, in patients with a "perceptual" type of phatic disorder, motor impairment is less pronounced. The division of aphasia into "motor" (or "expressive") and "sensory" (or "perceptual") is misleading due to its simplified concept and has already been completely abandoned in world aphasiology (all patients with an "expressive" speech disorder have measures also difficulties with understanding what is spoken - at least at the level of more complex grammatical structures - just as all patients with a "perceptual" disorder naturally produce content-inadequate messages as a result of it, which can act as difficulties with "expression"). Currently, the dichotomous division of aphasia into fluent and non-fluent type and within it into subtypes according to the so-called '''Boston classification is the most widely used in world aphasiology. For a clearer idea of ​​the current division of aphasias, we present the Boston classification in Table 2. However, knowledge of the dichotomous division is sufficient for a doctor's normal clinical practice.''' Explanations: + relatively preserved, − disturbed.

Differential diagnosis
The doctor 's task at the first contact with a neurologically ill patient with a communication disorder is not to classify possible aphasia in more detail, but to diagnose it in general and differentiate it from other possible communication disorders (see differential diagnosis in Table 3). Note: disorders can be combined with each other, relatively common is a combination of aphasia and dysarthria, nonfluent aphasia and speech apraxia, aphasia and dementia...

Investigation
For the correct diagnosis of aphasia, it is important to evaluate the patient's speech in the following areas at least as a guide (for more details, guide examination in Table 4.)

Spontaneous speech production – we evaluate the fluency, informational value of the message, we notice whether the patient's speech does not contain stereotypies, anomia, circumlocution, paraphasia, ... (symptoms of aphasia in Table 1.).

Naming – impaired naming ability is typical for aphasic patients. If the patient does not have a naming disorder, it is necessary to consider other disorders of speech communication , such as speech apraxia or dysarthria (see table 3.). However, the impaired ability to name without a simultaneous, albeit discrete, disability in the other areas listed below is nevertheless not a reason for establishing a diagnosis of aphasia. An isolated naming disorder can be a symptom of the initial stage of the dementia syndrome, but also a symptom of the patient's depression or apathy (see Table 3).

Comprehension - the correct assessment of the patient's ability to understand is not only important for the approximate localization of brain damage in the anterior or posterior cortical area, but also for the course of further communication and treatment with the patient (e.g. the patient cannot be given informed consent to sign if he has a significant impairment of understanding, which, in addition, usually correlates with reading comprehension disorder!).

Repetition – unlike the above areas, repetition may not be impaired in all types of phatic disorders. However, for Broca's, Wernicke's, global and especially for conduction aphasia, impairment of the ability to repeat is typical (see Table 2). We notice not only the accuracy of repetition, but also articulation errors, phonemic paraphasias...

Writing - in most aphasics, writing is impaired to a greater or lesser extent, manifested by substitutions of letters (paragraphs), omission of words, perseverations of words, slippage of words or even the production of completely meaningless words. In the most severe cases, the patient only produces meaningless dashes. Acquired writing disorder (agraphia) can occur in isolation, but very often occurs in conjunction with aphasia.

Reading - is impaired in a large part of aphatics. If reading is not formally impaired, so-called reading comprehension is often impaired (the patient does not assign meaning to the word read, is unable to reproduce the exact content of the read text, answers questions related to the text inaccurately). A reading disorder (alexia) can also occur in isolation without a phatic disorder. Examination of the ability to read aloud with comprehension is essential for the differential diagnosis of pure Wernicke's aphasia and so-called pure verbal deafness. In the first case, reading comprehension is significantly impaired, in the second it is preserved. Note: If the patient already fails to comply with the easy task of the examined area, it is not necessary, for reasons of time, to examine the patient with more demanding tasks.