What Is a Speech Impediment?

Speech disorders are abnormalities in the application or understanding of spoken words, words, or gestures. This disease refers here to speech disorders caused by localized brain or peripheral neuropathy, including dysphonia and aphasia.

Speech disorders are abnormalities in the application or understanding of spoken words, words, or gestures. This disease refers here to speech disorders caused by localized brain or peripheral neuropathy, including dysphonia and aphasia.

Causes of Speech Disorders

The language disorder caused by developmental delay is not caused by hearing impairment, organic damage to the central nervous system, and severe mental retardation. It is called developmental language disorder. In addition, there are 7 million deaf people in China, the vast majority of whom are pre-speech deaf. The speech disorders discussed here mainly refer to speech disorders caused by localized brain or peripheral neuropathy, including dysphonia and aphasia. The incidence of brain disorders, especially speech disorders [dysphonia and / or aphasia] caused by cerebrovascular disease, is quite high. According to the epidemiological survey of cerebrovascular disease in six cities in 1982, the annual domestic incidence of cerebrovascular disease is 182 per 100,000 population, and the prevalence of medical consultation is 620 per 100,000 population. Data in recent years show that cerebrovascular disease is the number one cause of death among adults. In the statistics of cerebral hemorrhage sites, hemisphere hemorrhage (inner sac and basal nucleus) that can affect the language area accounts for 80%; in the statistics of ischemic cerebrovascular disease, the location of middle cerebral artery thrombosis that can involve the language area To 60% to 80%. Common vertebral-basal artery thrombosis, post-brain neuropathy and certain myopathy caused by various causes can cause difficulty in articulation.

Clinical manifestations of speech disorders

Difficulty in articulation

It is called dysphonia due to the damage of various organizational structures included in the speech expression stage, or the disorder of speech expression caused by the imbalance of physiological processes. If speech is impossible, it is called articulation inability.

This group of symptoms is characterized by dysarthria (ie, the movement of speech in the brain into sound, the motor function that makes up speech). Therefore it does not include obstacles to the correct understanding and use of word meaning or speech. But it is difficult to form the sound of spoken language, and in severe cases, it is impossible to pronounce.

(1) Difficulty in articulation of upper motor neuron damage One side of the articulation organ is controlled and dominated by bilateral upper motor neurons, including the central anterior gyrus facial area of the primary motor cortex and its cones. So unilateral upper motor neuron damage does not cause permanent articulation difficulties.

Dysphonia can occur when bilateral superior motor neuron damage, such as pseudobulbar palsy, amyotrophic lateral sclerosis, and tumors or vascular disease in the midbrain, invades the soles of both sides of the brain.

Symptoms of this kind of dysphonia include paralysis of the dysarthria, and the tongue is smaller and harder than normal. Speech is ambiguous, especially lip and tooth sounds are severely affected. Sexual Dysphonia on Upper Motor Neurons.

(2) Dysphagia due to inferior motor neuron damage The dysarthria caused by nuclear damage are usually preceded by lingual muscle paralysis, limited tongue movement, slow and obscure pronunciation, followed by soft palate paralysis with nasal sound, When the function is lost due to the complete damage of the suspected nucleus, there is no complete articulation.

Dysphonia caused by subnuclear palsy often has localized soft palate damage, difficulty in articulation, and nasal sound. Such as recurrent laryngeal nerve palsy, vocal cord muscle paralysis occurs, and glottal closure paralysis occurs early. When bilateral vocal cords are paralyzed, the vocal cords are in a fixed position, at this time there is difficulty breathing and choking (glottic closure). When the glottis atresia is paralyzed, the glottis opens, although there is no dyspnea but there is no pronunciation.

Infective polyradiculitis (Gullain-Barre syndrome) can occur facial nerve paralysis, bulbar paralysis, often accompanied by soft palate, pharyngeal paralysis, and vocal cord paralysis. Paralysis of the tongue muscle is rare. Therefore, it is often manifested as weak pronunciation and significant larynx disturbance.

(3) Difficulty in articulation of the basal nucleus of the brain is mainly caused by factors such as increased muscle tone and tremor of the articulatory organs caused by extrapyramidal lesions. Symptoms are characterized by slow speech, slow rhythm, disordered phonology, and inarticulate syllables when speaking, much like mumbling and often with interruptions. More common in hepatolenticular degeneration, hand and foot asthma, chorea, etc. Parkison syndrome is characterized by low speech, fast and incoherent syllables, monotonous speech, and repetitive speech.

(4) Difficulty in articulation of cerebellar system damage, also known as ataxia dysphonia, is mainly caused by uncoordinated or forced movement of the articulation organ muscles. The main manifestations are as follows: Outbreaks of speech are markedly prolonged, with uneven sound intensity, so they are often bursty. The patient's speech intensity is sometimes extremely low, sometimes suddenly extremely high, and a series of syllables or words are issued quickly. Poem-like (or segmented) speech is another feature of speech impairment when the cerebellar system is damaged. It is due to the abnormal configuration of stress when speaking and is evenly divided into many incoherent speech stages, much like recitation of the old The tonal tone of the style poetry. Bard-like speech is most commonly found in cerebellar vermiform lesions and cerebellar degenerative disorders. 10% to 15% of patients with multiple sclerosis experience such articulation difficulties. Bard-like speech, intentional tremor, and nystagmus together form the classic Charcot triad.

(5) Difficulty in articulation caused by muscle lesions Myasthenia gravis The weakness of the lip, tongue, and soft palate muscles is most pronounced , and this weakness improves after rest. Symptoms of speech inconsistency after continuous talking, and then improved after rest. In addition, the extraocular muscles, especially the upper levator muscles, are weak and can be accompanied by chewing and swallowing difficulties. The above symptoms were diagnosed after disappearing by injection of etoflammonium chloride (Tengxilong) or neostigmine. Progressive muscular dystrophy In the face-shoulder-brachial type, orbicularis atrophy may occur, and the tongue muscle may occasionally atrophy, so there are lip and tongue sound dysphonia. Atrophic myotonia includes atrophy of the facial and tongue muscles, paralysis of the soft palate, atrophy of the orbicularis muscle, and dysarthria. Sometimes tongue dysfunction may be one of the symptoms of increased muscle tone.

Aphasia

Aphasia is caused by structural damage or dysfunction involved in the speech stage in the brain. It has nothing to do with hearing impairment (speech sensation stage), and paralysis of speech muscle (speech stage) or other movement disorders. These are the differences between aphasia and dysphonia.

More than 95% of the left brain is the dominant hemisphere for speech and language expression. Right-handed people with the right brain as the dominant hemisphere are extremely rare and have only been reported in the literature. The vast majority of left-handed people show some speech or language barriers due to lesions in the left or right hemisphere, which indicates that, based on the individual situation of the patient, the dominance of the left-handed brain hemisphere Making predictions is more difficult. The most predictable part of speech or language expression disorder is to control the hemisphere area on the side of the hand that often likes to do technical exercises or the lateral cleft edge of the brain. The further away the lesion is from this area, the less likely it is to cause speech or language expression disorders. Impaired speech or language expression due to disease includes a group of diseases collectively known as aphasia.

(1) Speech center Speech function is extremely complicated, and its position on the cerebral cortex cannot be narrowly positioned. It is very difficult to determine the location of the lesion by the symptom of speech disorder clinically, but some areas on the cortex are of major significance for speech function and some aspects, and can still be divided into various speech centers.

There are four main speech centers. The speech sensory center is located at the back of the superior temporal gyrus, the speech movement center is located at the posterior frontal gyrus, the reading center is located at the parietal gyrus, and the writing center is located at the posterior frontal center. The speech centers are related to each other.

(2) Clinical types of aphasia There are different opinions on the classification of aphasia. At present, the Benson (1979) classification is mostly used, which takes into account the clinical characteristics and localization of the lesions, and has strong scientific and practical features. Peripheral fissure aphasia syndrome It includes motor aphasia, sensory aphasia, and conductive aphasia. The common features are difficulty of oral restatement and the focus is near the lateral fissure of the dominant hemisphere. Motor aphasia is also called Broca aphasia or non-fluent aphasia. The patient was unable to speak, but had no effect on others' speech and understanding of reading the newspapers. He knew what he was going to say, but he couldn't say that. Words are repeated and often wrong, but the patient notices immediately after the mistake, so he is worried that he can't speak well, so this kind of patients are often quiet. Sometimes the patient can recite poems, sing, calculate, and swear, even though he cannot speak. The lesions are concentrated in the posterior cortex or subcortex of the superior frontal gyrus. Sensory aphasia, also known as Wernicke aphasia or fluent aphasia, is characterized by fluent aphasia and comprehension disorders (there must be retelling disorders, and naming difficulties are common). The lesion is located on the left temporal parietal or parietal occipital region. Because the function of understanding speech appears earlier than other speech functions, the sensory speech center is the main speech center. It causes the most severe symptoms when it is damaged, and dysfunction of other speech centers connected to the center can occur at the same time. Although the motor speech center is still preserved, the correctness of speech has been destroyed, and motor aphasia must be merged. The patient not only cannot understand the content of others speaking to him, but also cannot find out that he has spoken wrongly, so he is often distressed that others cannot understand him. Patients also like to speak, but speak incorrectly, use the wrong words, and even create new words, so-called fluent wrong words. Such aphasia generally has a poor prognosis. Conductive aphasia is characterized by fluent and self-speaking speech that is easy to understand and difficult to repeat. The conductive aphasia lesions are localized and have the smallest lesions among all types of aphasia. The lesion may be in the predominant hemisphere arch (connecting the linguistic sensory center and the verbal motor center). There is no change in the routine neurological examination. Most patients have difficulty in naming. The reading examination has serious typos. The prognosis is generally good and can be restored to only the naming disorder. Watershed (marginal zone) aphasia syndrome This type of aphasia is characterized by: aphasia without rehearsal barriers or relatively good rehearsal, and the lesions are in the watershed area. Including transcortical motor aphasia, transcortical sensory aphasia and transcortical mixed aphasia. Percutaneous motor aphasia: Except for accessibility, its characteristics are similar to motor aphasia. Spoken language is well understood, but patients often have severe apraxia, so care must be taken in judging. Naming is impaired and writing is flawed. Most patients have hemiplegia on the right. The lesions are mostly in the front or upper part of Broca, and the most characteristic is the middle or front part of the subfrontal gyrus. Transcortical sensory aphasia: It is similar to sensory aphasia, except that it is well repeated. Naming, reading, and writing are often impaired, with lesions at the left temporal apical watershed. Transcortical mixed aphasia: Coexistence of transcortical motor aphasia and transcortical sensory aphasia. It is characterized by abnormal language functions except spoken paraphrase, and the lesions are large lesions in the dominant hemisphere watershed. Subcortical aphasia syndrome Traditionally, typical aphasia syndrome usually only indicates pure cortical lesions, or cortical and subcortical involvement at the same time, and the thalamus and basal nucleus do not play a role in aphasia. In recent years, through in-depth research on the role of these structures in language and survival cases, it is pointed out that simple subcortical lesions can also cause aphasia syndrome. Many sources indicate that aphasia syndrome caused by subcortical lesions does not correspond to the so-called typical aphasia. The brief description is as follows: Thalamic aphasia: This type of aphasia is characterized by less speech, difficulty in finding words, naming disorders, low-pitched tones, less autonomous speech, incomprehension of complex commands, reading and writing disorders, good recitation, and mostly memory impairment . The prognosis of thalamic aphasia is generally good, and it can be recovered within a few weeks, with naming disorders remaining. Basal aphasia: The lesion is limited to the putamen, caudate nucleus, and pale bulbous area, and often includes the inner capsule. It is characterized by dysarthria, low-pitched tone, and can be misinterpreted. Oral comprehension is relatively good. There are barriers to naming, reading and writing. Basal aphasia is similar to transcortical motor aphasia, and some is similar to transcortical sensory aphasia. This type of aphasia often has symptoms of hemiplegia and has a good prognosis. Naming aphasia refers to aphasia in which the naming disorder is the only or main symptom. It is characterized by fluent spoken language, neurological examination generally does not have positive signs, and may also have mild hemiplegia. Complete aphasia All language functions are severely impaired, and spoken expression is obviously limited, but true silence is also rare. It can usually be pronounced as a single syllable. Oral comprehension is severely impaired. It cannot be repeated, named, read, or written. It has severe neurological signs. The lesion is located in the left middle cerebral artery, and the prognosis is poor. Dyslexia refers to the loss of comprehension of written language, which can be complete or partial, often accompanied by naming aphasia, which is mainly caused by damage to the dominant hemispheric angular gyrus. Aphasia. Almost all aphasia patients have varying degrees of aphasia, so it can be used as a screening test for aphasia. Writing is the most difficult language function to master, and there is still no satisfactory classification.

Speech impairment test

Laboratory inspection

Necessary and selective tests are selected based on possible causes. Blood routine, blood biochemistry, electrolytes: pay attention to specific changes that have diagnostic value for the primary disease. Examination of blood glucose, immunization items, and cerebrospinal fluid has abnormal diagnostic significance.

2. Other auxiliary inspections

If the following inspection items are abnormal, it has a differential diagnosis significance. CT, MRI examination; EEG, fundus examination; skull base radiograph; ENT examination.

The advent and application of CT have greatly improved people's understanding of aphasia location.

Kertesz et al. Found that patients with conductive aphasia have injuries related to the anterior and posterior diameters; patients with named aphasia have parietal lobe damage; and most cases with complete aphasia have damage to more than one lobe. Some people have studied the relationship between aphasia and the lesions shown on CT and found that the cortical areas related to aphasia are Broca, Wernicke, superior marginal and angular gyrus, which are located in Brodman 44, 22, 40 and 39, respectively. Before the lateral fissure, below the anterior angle of the lateral ventricle; Wernicke's representative area is located after the left lateral fissure to the left of the left ventricle triangle; the superior marginal gyrus and the angular gyrus are located at the posterior part of the left ventricle body of the parietal lobe.

It is generally believed that minor injuries can cause mild aphasia. The location of the lesions seen on CT for all types of aphasia is relatively consistent and reliable. The type of aphasia may indicate the location of the injury, but in turn, it is difficult to determine the type of aphasia from the location of the lesion. It shows that the problem is not consistent. At present, it is thought that it may be related to CT shooting at different times of the lesion, or it may be related to the existence of different cerebrovascular collateral circulation supply in patients, resulting in varying degrees of compensation.

Speech disorder diagnosis

Diagnosis can be made based on the cause, clinical manifestations, and laboratory tests.

Speech disorder treatment

Speech disorders in adults caused by localized brain or peripheral neuropathy are mainly treated for the primary disease. In the rehabilitation period, language training is performed. For language disorders caused by delayed development, there are two types of expressive and sensory language disorders. For people with sensory language impairment, the emphasis is on training in speech understanding, auditory memory, and auditory perception. For people with expressive language impairment, the focus is on training children to imitate other people's speech. Parents are also encouraged to participate in the training. People with expressive language impairment have a good prognosis. They can gradually gain language ability with age without treatment. However, learning may be difficult. The prognosis of those with language impairment is poor, and the language ability may be recovered to varying degrees after special training. Mild children recover better and worse, and severe cases with partial hearing impairment are almost impossible to cure.