Speech communication disorders and swallowing disorders/PGS

Speech communication disorders and swallowing disorders in adults with neurological disabilities

When a doctor meets a patient, he should always evaluate his speech, both formally and content-wise, as well as his ability to swallow. Speech disorders and swallowing disorders can be the first symptom of a serious neurological disease, and their detection can help to correctly diagnose the underlying disease. It is essential for practice to be able to differentiate between aphasia, speech apraxia, dysarthria, oral apraxia and communication disorder in dementia. More detailed diagnosis and therapy of speech and swallowing disorders is then in the hands of a clinical speech therapist.

Dysarthria and swallowing disorders
Dysarthria is neurogenic disorder  motor motor production of speech sounds at the non-symbolic level. Dysarthria is a speech disorder, not of language as a system. Unlike aphasia, there are no impairments in understanding, naming, syntax, or grammar… (differential diagnosis given in the table 3). Dysarthria results from paresis, impaired muscle tone or impaired coordination of the muscles involved in speech production. Damage to the motor system that leads to dysarthria, can occur anywhere along the pathway from the brain to the muscle itself.

Dysarthria is often accompanied by dysphagia (swallowing disorder), which is why we also mention it in this chapter.

Symptoms and classification
Among the symptoms of dysarthria are disturbances respiration, articulation, phonation, nasal resonance, and prosody. Dysarthria is divided into six types according to the place of origin, namely central (spastic), peripheral (weak), cerebellar (atactic), extrapyramidal-hypokinetic, exprapyramidal-hyperkinetic, mixed (see Table 5 for details). Some authors also mention cortical dysarthria, but this is currently considered a speech apraxia (differential diagnosis of dysarthria and other communication disorders in Table 3).

Mixed dysarthria is caused by lesions of more than one system, e.g. central-peripheral type (in ALS), cerebellar-central (in multiple sclerosis), cerebellar-central-hyperkinetic (in Wilson's disease), cerebellar-central-peripheral (in olivopontocerebellar atrophy), hypokinetic-central-cerebellar (in progressive supranuclear palsy).

Examination
For the diagnosis of dysarthria, at least an indicative assessment of the patient's speech in the areas ofrespiration, articulation, phonation, nasal resonance and prosody is essential. Because dysarthria is often associated with a swallowing disorder (however, it often occurs in combination with aphasia!!), it is also necessary to roughly examine swallowing (more detailed examination in Table 6). The detected symptoms will help us to more accurately determine the location of the lesion and thus to diagnose the underlying disease (see table 5).

Respiration – we evaluate in silence and during speech. We note the frequency of breaths, their depth, the regularity of breath, the method of breaths (through the nose, mouth) and possible stridor. We evaluate the length of the phrase uttered in one breath.

Articulation – we evaluate not only the symmetry and primary mobility and strength of the articulatory organs (lips, tongue, jaw, soft palate), but also the ability of diadochokinesis and the articulation of continuous speech (we also note facial expressions, facial symmetry).

Phonation – we evaluate the ability to put on and hold the voice and control its pitch and strength. In case of uncertainty regarding the etiology of dysphonia or aphonia, we recommend consulting with an ENT doctor. It is not only a diagnosis of possible paresis of one or both vocal cords or dysphonia of another etiology (tumor, trauma, psychogenic origin, etc.), but also a differential diagnosis of spastic dysphonia as focal dystonia from a more serious neurological disease.

Resonance – increased nasal resonance („open mumbling“), which often occurs in dysarthria, means a pathological leakage of air through the nose during the articulation of non-nasal sounds (Czech nasals are only M, N, Ň). It is usually caused by insufficiency of the oropharyngeal closure, for example, in paresis of the soft palate (central, peripheral) or in other neurological diseases (myasthenia gravis, extrapyramidal disease, etc.).

Prosody – by prosody we mean dynamics (the ability to change the pitch of the voice in speech), rhythm (observing the length of syllables), phrasing (dividing the speech into sentence sections using pauses and melody), stress (differentiating the force of the syllable of a word or beat) and tempo.

Swallowing – incorrect evaluation of the swallowing state can lead to an immediate threat to the patient's life due to aspiration or to a significant deterioration of his health status due to malnutrition or dehydration. The cranial nerves V., VII., IX., X., XI., a XII. are involved in the correct course of the complex act of swallowing. Therefore, damage to any of the above nerves can cause a swallowing disorder. It has been repeatedly proven that neurologically ill patients are at a very high risk of so-called silent aspiration (the patient aspirates without coughing or other visible signs of inhaling a mouthful) due, among other things, to impaired sensitivity in the upper part of the aerodigestive tract.In a large proportion of patients who aspirate, aspiration is not diagnosed during routine clinical examination! If a swallowing disorder is suspected, it is therefore advisable to initiate a videofluoroscopic examination (i.e. a special fluoroscopic examination of the act of swallowing, which from the analysis of the dynamic recording enables a detailed analysis of the preparatory, oral and pharyngeal phases of swallowing, allows 100% exclusion of aspiration, subject to compliance with certain standards, and further enables the quantification of some symptoms; the results of the examination are essential for planning subsequent swallowing rehabilitation). If X-ray workplaces lack this technical equipment, it is necessary to carry out a routine X-ray examination of the act of swallowing, which at least excludes or confirms the imminent risk of aspiration. A possible alternative to videofluoroscopy is a videoendoscopic examination of the act of swallowing, which is performed at some ENT departments.

Thanks
The author would like to thank MUDr. Eva Krasulová, PhDr. Milena Košťálová, Mgr. Kateřina Lísalová a PaedDr. Jaroslava Roubíčková for professional consultation.

Thank you Mrs. Hanneke Kalf, MSc, speech therapist from Sint Radboud University Medical Centre Nijmegen, for providing consultation regarding the tests Swallowing Speed Test a Swallowing Volume Test.

Thanks also go to colleagues from the neurology clinic 1. LF a VFN, who are the authors of the videos no. 17–22.