Dysphagia
Introduction[edit | edit source]
Dysphagia is a difficulty in swallowing liquid or solid food due to disruption in swallowing mechanism from mouth to pharynx.[1] Dysphagia leads to severe complications: [1][2]
- Aspiration pneumonia
- Dehydration
- Malnutrition
- Dehydration
Physiology of swallowing[edit | edit source]
Having a thorough knowledge of anatomy and physiology of swallowing and eating is essential while evaluating and treating disorders of eating and swallowing,[3]There are four stages while describing the physiology of swallowing :
- Oral preparatory stage
- Oral propulsive stage
- Pharyngeal stage : Main feature of this stage are: food passage, propelling the food bolus through the pharynx and UES to the esophagus; and airway protection, insulating the larynx and trachea from the pharynx during food passage to prevent the food from entering the airway.
- Esophageal stage
Eating, swallowing and breathing are tightly coordinated during the normal process. Swallowing is dominant to respiration in normal individuals.Breathing ceases briefly during swallowing due to physical closure of the airway by elevation of the soft palate and tilting of the epiglottis and also of neural suppression of respiration in the brainstem. [3]
When drinking a liquid bolus, swallowing usually starts during the expiratory phase of breathing. The respiratory pause continues for 0.5 to 1.5 s during swallowing, and respiration usually resumes with expiration. This resumption is regarded as one of the mechanisms that prevents inhalation of food remaining in the pharynx after swallowing. When performing sequential swallows while drinking from a cup, respiration can resume with inspiration. [3]
Eating solid food also alters the respiratory rhythm. The rhythm is perturbed with onset of mastication. Respiratory cycle duration decreases during mastication, but with swallowing. The “exhale – swallow – exhale” temporal relationship persists during eating. However, respiratory pauses are longer, often beginning substantially before swallow onset.[3]
Causes that affect the normal swallowing physiology[edit | edit source]
There are various causes for alteration in normal swallowing physiology. broadly it can be categories into two heading :
- Structural abnormalities
- Functional abnormalities
Structural abnormalities[edit | edit source]
It can be acquired or congenital. Cleft palate, cervical osteophytes, webs or strictures in the passage are some of the examples of the structural abnormalities. The abnormalities might affect in any stage of the swallowing and alter the normal physiology. [3]
Functional abnormalities[edit | edit source]
Impairments affecting the jaw, lips, tongue, or cheek can hamper the oral phase or food processing. Reduced closing pressure of the lips may lead to drooling. In weakness of the buccal or labial muscles, food can be be trapped in the buccal or labial sulci (between the lower teeth and the cheeks or gums, respectively). Tongue dysfunction produces impaired mastication and bolus formation, and bolus transport. These usually result from tongue weakness or in-coordination, but sensory impairments can produce similar effects, including excessive retention of food in the oral cavity after eating and swallowing.
Loss of teeth reduces masticatory performance. Chewing can be prolonged by missing teeth, and particle size of the triturated bolus becomes larger due to lower efficiency of mastication.
Dysfunction of the pharynx can produce impaired swallow initiation, ineffective bolus propulsion, and retention of a portion of the bolus in the pharynx after swallowing. Insufficient velopharyngeal closure may result in nasal regurgitation and reduce pharyngeal pressure in swallow, hampering transport through the Upper Esophageal Sphincter (UES).
Impaired opening of the UES can cause partial or even total obstruction of the food-way with retention in the piriform sinuses and hypo-pharynx, increasing risk of aspiration after the swallow. Insufficient UES opening can be caused by increased stiffness of the UES, as in fibrosis or inflammation, or failure to relax the sphincter musculature.
Esophageal dysfunction is common and is often asymptomatic. Esophageal motor disorders include conditions of either hyperactivity (e.g., esophageal spasm), hypo-activity (e.g.weakness), or in-coordination of the esophageal musculature.Either of these can lead to ineffective peristalsis with retention of material in the esophagus after swallowing. Retention can result in regurgitation of material from the esophagus back into the pharynx, with risk of aspirating the regurgitated material. Esophageal motor disorders are sometimes provoked by gastroesophageal reflux disease, and in some cases, can respond to treatment with proton pump inhibitors[3].
References[edit | edit source]
- ↑ 1.0 1.1 Balamurali K, Sekar D, Thangaraj M, Kumar MA. Dysphagia in Patients with Stroke: A Prospective Study. available from:https://www.ijcmsr.com/uploads/1/0/2/7/102704056/ijcmsr_96.pdf
- ↑ González-Fernández M, Ottenstein L, Atanelov L, Christian AB. Dysphagia after stroke: an overview. Current physical medicine and rehabilitation reports. 2013 Sep 1;1(3):187-96.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Matsuo K, Palmer JB. Anatomy and physiology of feeding and swallowing: normal and abnormal. Physical medicine and rehabilitation clinics of North America. 2008 Nov 1;19(4):691-707.
