Dysphagia

Definition of Dysphagia

Dysphagia is a difficulty in swallowing food or liquids. It results from an abnormality in the oral, pharyngeal, or esophageal phases. It can be due to neurological causes such as strokes, multiple sclerosis, or Parkinson's disease. Mechanical causes include esophageal strictures, tumors, and diverticula. Motor causes involve esophageal motility disorders, such as achalasia. Dysphagia can lead to weight loss and malnutrition. It increases the risk of aspiration pneumonia, requiring thorough evaluation to tailor treatment.

Epidemiology

Dysphagia affects about 3 to 5% of the general population, but its prevalence increases with age. Among the elderly, dysphagia can affect up to 22% of individuals. This increase results from the degeneration of swallowing structures and comorbidities. In long-term care facilities, prevalence often exceeds 50%. This mainly concerns patients with neurological disorders. Dysphagia is common after a stroke (CVA). It affects about 30 to 50% of patients in the first days after the event.

Causes of Dysphagia

The causes of dysphagia are classified into three main categories:

• Motor causes: These involve esophageal motility disorders, such as achalasia (insufficient relaxation of the lower esophageal sphincter) or diffuse esophageal spasms. These dysfunctions lead to abnormal esophageal contractions, hindering the progression of food to the stomach.
• Neurological causes: They affect the coordination of muscles involved in swallowing. The main ones include strokes (CVA), multiple sclerosis, Parkinson's disease, myasthenia, and spinal cord injuries.
• Mechanical causes: They result from an obstruction or narrowing of the esophagus. This includes esophageal strictures (often caused by chronic gastroesophageal reflux), tumors, diverticula (such as Zenker's diverticulum), and the sequelae of radiotherapy.

Risk Factors

The main risk factors for dysphagia include:

• Advanced age: Aging leads to decreased coordination and strength of swallowing muscles.
• Neurological disorders: Strokes, Parkinson's disease, multiple sclerosis, dementia, and head trauma increase the risk of dysphagia.
• Chronic gastroesophageal reflux (GERD): GERD can cause esophageal lesions. These lesions lead to strictures and increase the risk of dysphagia.
• History of radiotherapy or cervical surgery: These interventions can cause scarring or anatomical changes, affecting swallowing.
• Autoimmune diseases: Scleroderma, lupus, and other conditions can lead to esophageal muscle involvement.
• Tobacco and alcohol consumption: These factors increase the risk of head, neck, and esophageal cancers, which can cause dysphagia.
• Muscle diseases: Myopathies, myasthenia, and other muscle disorders can affect the coordination of swallowing muscles.

Symptoms of Dysphagia

The symptoms of dysphagia can vary depending on its cause, but the most common include:

• Sensation of blockage or discomfort during swallowing, especially for solid foods, sometimes also for liquids.
• Painful swallowing (odynophagia), which can occur with food or drinks.
• Regurgitation of undigested food or liquids, often accompanied by a sensation of reflux.
• Coughing or choking during or after swallowing, especially with liquids, suggesting a misdirection.
• Involuntary weight loss and malnutrition, resulting from difficulty ingesting sufficient quantities of food.
• Change in voice or hoarseness after meals, caused by irritation of the airways.
• Excessive salivation or sensation of drooling, often due to difficulty swallowing saliva.
• Chest pain that can be mistaken for cardiac pain, particularly when the cause is esophageal.

Radiological Imaging

Radiological imaging plays an essential role in diagnosing dysphagia, allowing for the localization and identification of the cause of swallowing difficulty. Here are the main modalities used:

1. Barium esophagram: This is the first-line examination. The patient swallows a barium liquid, and radiographs track its passage through the esophagus. This exam allows visualization of strictures, diverticula (such as Zenker's diverticulum), motor abnormalities (such as achalasia), and gastroesophageal reflux.
2. Thoracic CT scan: The CT scan evaluates the surrounding structures of the esophagus and looks for masses, extrinsic compressions, mediastinal abnormalities, or complications, such as perforation. It is often used when a tumor is suspected.
3. Cervical and thoracic MRI: MRI is indicated to explore neurological causes of dysphagia, such as brainstem lesions or spinal cord involvement. It is also useful for evaluating tumors and soft tissue abnormalities.
4. Upper digestive endoscopy: Although not purely radiological, endoscopy is commonly used to complement imaging. It allows direct visualization of the esophageal mucosa and the potential for biopsies in case of suspicious lesions.
5. Cervical ultrasound: It is particularly useful for examining the cervical region, especially in cases of suspected compressive masses (such as thyroid tumors) or lymphadenopathy that could contribute to dysphagia.

These exams help specify the mechanical or functional nature of dysphagia and guide therapeutic decisions.

Prevention of Dysphagia

Prevention of dysphagia is based on measures adapted to its causes and identified risk factors:

• Early treatment of neurological disorders: Prompt management of strokes, Parkinson's disease, and other neurological conditions can reduce the risk of dysphagia.
• Management of gastroesophageal reflux (GERD): Treating GERD with proton pump inhibitors (PPIs) and dietary measures helps prevent esophageal complications.
• Swallowing rehabilitation: In at-risk individuals (such as post-stroke patients), early speech therapy can strengthen swallowing muscles and limit misdirection.
• Modification of diet: Adapting the texture of foods and drinks to make them easier to swallow can help people with swallowing disorders.
• Avoiding tobacco and alcohol: Reducing or eliminating the consumption of these substances decreases the risk of head and neck cancers, which can cause dysphagia.
• Regular medical follow-up: People with a history of radiotherapy, cervical surgery, or autoimmune diseases should receive follow-up to detect early signs of dysphagia.
• Hydration and oral care: Maintaining good hydration and regular oral care can prevent oral infections and reduce the risk of dysphagia, especially in the elderly.

These measures aim to reduce the risk of complications, improve patients' quality of life, and prevent the worsening of dysphagia.

Conclusion

Dysphagia is a complex swallowing disorder that can be caused by neurological, mechanical, or motor factors. Management of dysphagia relies on an accurate diagnosis, often aided by radiological imaging. This allows for the identification of the underlying cause and guides treatment. Prevention includes managing risk factors and regular medical follow-up. This is particularly important for the elderly and those with predisposing conditions. Early and appropriate management improves patients' quality of life. It reduces complications, such as malnutrition and pneumonia, and promotes better rehabilitation.

Finally, if you have symptoms or concerns, consulting a general practitioner allows for an accurate diagnosis and appropriate advice.

Source: UpToDate