Head and neck disorders affecting swallowing
Neurogenic and Neuromuscular Dysphagia
Cranial Nerves
Neural control, including both sensory input and motor function, plays an integral role in swallowing. Sensory stimuli provide information with regard to bolus location and aspiration prevention, whereas neuromotor func-tion assists in pressure formation that is required for bolus propulsion during all phases of swallowing. Either sensory or motor neural deficits can lead to oropharyngeal dysphagia. Isolated cranial nerve (CN) deficits can include the facial nerve (CN VII), glossopharyngeal nerve (CN IX), vagus nerve (CN X), and hypoglossal nerve (CN XII). Cranial nerve conduction problems can result from a number of causes including direct trauma to nerves, tumor infiltration or compression, or postviral illness. Dysfunction of the facial nerve leads to poor oral commissure control and limitations of bolus manipulation within the oral cavity during mastication. Hypoglossal nerve deficits affect bolus manipulation within the oral cavity and interfere with bolus delivery into the oropharynx. The glossopharyngeal nerve has both a sensory and motor division. The areas innervated include the tongue base and lateral pharyngeal walls, which are important in triggering the reflexive portion of the pharyngeal swallow. This nerve also contributes to the pharyngeal plexus, which controls the motion of the constrictor muscles utilized in bolus propulsion and clearance. Isolated glossopharyngeal nerve weakness is rare; in most cases it is found in combination with vagal nerve or polynerve dysfunction (Figure 8). The vagus nerve also has both motor and sensory components. The sensory component is primarily represented by the superior laryngeal nerve, which provides sensation across the epiglottis, false vocal folds, and portions of the pyriform sinus. Sensory deficits in these areas lead to poor initiation of swallow reflex, primarily with liquid boluses, which often pool in the pyriform sinuses prior to swallowing. The motor division of the vagus is re-sponsible for true vocal cord motion and contributes to the pharyngeal plexus. The complex clinical problems created by vagal nerve injury are discussed below.
Vagal Nerve Injury and Vocal Cord Paralysis
The primary motor division of the vagus nerve is the recurrent laryngeal nerve, which is responsible for the motion of the intrinsic laryngeal musculature. Its primary importance in swallowing is its ability to produce vocal cord adduction during the bolus passage, and to allow appropriate glottic closure during the cough reflex. Injury to the recurrent nerve leads to ipsilateral vocal cord paralysis. Symptoms often include dysphagia, pri-marily with liquid, weak voice, and poor cough. Of more significance is vagal nerve injury at or near the skull base. This adds a component of pharyngeal motor weakness and a laryngopharyngeal sensory deficit signifi-cantly compounding the aspiration risk. Tabaee et al.45 in 2005 reported a 35% aspiration incidence in their patients with unilateral paralysis. The same group of patients had a documented sensory deficit 80% of the time and an absent laryngeal adductor reflex in 34% of the group. High vagal nerve injuries often include injury to adjacent nerves at the skull base, including the glossopharyngeal and hypoglossal nerves. The combined insult produces unilateral pharyngeal sensory and motor deficits, which involve all the muscles used in bolus transfer. This produces severe and frequently unrecoverable dysphagia in most patients, and compensatory strategies are rarely successful.
Surgical interventions to improve glottic closure are well described.46, 47 Vocal cord injection procedures re-store bulk to the atrophic and lateralized vocalis muscle.
Atrophic - Medicine (of body tissue or an organ) having atrophied. 'the lower leg muscles were atrophic'.
Atrophied - (of body tissue or an organ) wasted away or rudimentary. 'atrophied muscles'
Atrophy the partial or complete wasting away of a part of the body
Atrophy of Swallowing Muscles Is Associated With Severity of Dysphagia and Age in Patients With Acute Stroke https://pubmed.ncbi.nlm.nih.gov/28363443/
Nøgleordene: Glottic closure - glottic muscles - swallowing and airway protection determined by glottic muscles - og så har jeg faktisk egentlig svar på en detalje omkring tandlæge behandlingens mange tvivlsomme glæder. Jeg er ret sikker på at stort set alle lukkemekanismer i kroppen er muskelstyret og at disse bliver indeffektive ved muskelsvækkelse, ved sygdom såvel som af ældning - snart sagt en hel naturlov. What goes up must come down.
Patients also may have reduced pharyngeal strength and poor airway protection.
Dentistry considerations for the dysphagic patient: Recognition of condition and management
https://journals.sagepub.com/doi/full/10.1177/2010105819868252
Det kan godt være jeg ikke forstår alle ord og vendinger, og noget af det er læger siger er lidt "sort snak" men jeg får stadig en god overordnet fornemnmelse (og brugbar indsigt) for disse ting.
Respiratory Complications of the
Muscular Dystrophies https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.624.8880&rep=rep1&type=pdf
COUGH EFFICACY - An effective cough has 4 components: An intact sensory pathway to detect airway irritation and secretions. The ability to generate a deep inspiration (which is impaired by inspiratory muscle weakness). Glottic closure. Expiratory muscle contraction against a closed airway (limited by expiratory muscle involvement).
Pulmonary Issues in Patients with Chronic Neuromuscular Disease https://www.atsjournals.org/doi/10.1164/rccm.201210-1804CI
The respiratory physician, nurse, or therapist is often called on for therapeutic management of the patient with neuromuscular disease. One helpful way to think about the functional neuromuscular respiratory system is to divide it into three main areas of function (Figure 1) (66, 67): (1) Ventilatory function determined predominantly by the inspiratory muscles; (2) cough function, which is determined by inspiratory, expiratory, and glottic function; and (3) swallowing and airway protection determined by glottic muscles.