What is dysphagia?

Dysphagia is a disease that causes swallowing disorders, meaning that people cannot swallow liquids or solids correctly.

  • Very little is known about dysphagia but it is a cause of a significant number of deaths  and greatly affects quality of life.
  • Dysphagia can be treated and is frequently cured, but at the very least, quality of life can be improved.
  • Dysphagia  affects three main groups of patients: patients with neurological diseases (stroke, Parkinson, Alzheimer), the elderly, and patients with otorhinolaryngological diseases.

Some facts and figures

Dysphagia incidence in the population is growing.

Dysphagia affects 25% of people over 70 years old.

Between 30 and 40 million Europeans have swallowing difficulties.

 

Of patients who have had a stroke:

  • Nearly half (45.06%) will experience dysphagia affecting the mouth and pharynx.
  • Between 40% and 50% of people with dysphagia will develop chronic dysphagia.
  • Nearly all (91.7%) patients with post-stroke respiratory infections develop dysphagia.
  • Aspiration pneumonia is the main cause of mortality one year after stroke.

Around 80% of patients with Alzheimer, Parkinson or senile dementia are likely to develop dysphagia:

  • Nearly half (47%) of elderly people hospitalized for any reason have dysphagia.
  • Up to 60% of elderly people living in nursing homes have dysphagia.
  • Specific mortality is unknown, because many deaths related to or deriving from dysphagia are attributed to other causes.

Why dysphagia develops:

  • The muscles that help swallowing do not function properly because they fail to receive motor impulses from the brain correctly. Sensitivity mechanisms in the mouth, pharynx and larynx become impaired, delaying brain commands transmitted in the nerves.
  • Liquids and solids, when swallowed, instead of going to the stomach, enter the respiratory system, causing the patient to gag and to eventually develop respiratory infections.

How dysphagia occurs:

Swallowing takes place in three phases:

1. Oral phase. Food and drink is prepared for swallowing by chewing and salivation, resulting  in what is called a bolus.

2. Pharyngeal phase. The bolus travels down the throat to the point where two tubes branch off: the esophagus leading to the stomach and the trachea leading to the lungs. If the muscles do not do their job properly, the bolus will enter the lungs instead of the stomach.

3. Esophageal phase. The bolus, when there is no swallowing disorder, passes through the esophagus and enters the stomach.

This website mainly covers disorders produced in the first two phases.

The consequences:

  • Lung infections.
  • Asphyxia.
  • Malnutrition.
  • Death (in the absence of proper treatment).
  • Poor quality of life. People who can swallow a little can only eat liquefied food, which tends to lack flavour. People who cannot swallow at all need to be fed directly to the stomach via a gastrostomy tube or to the esophagus via a nasogastric tube.
  • Hospital re-admission.

Early symptoms:

  • Coughing while eating or drinking.
  • Food falling out of the mouth and drooling.
  • A sensation of residual food in the mouth or throat and having to swallow several times.
  • A sensation of cervical obstruction.
  • Sometimes the only symptom is malnutrition, unexplained weight loss or pneumonia.
  • Very often the patients themselves are unaware of symptoms.

Research:

Studies are taking several directions:

1. Diagnosis

  • Systematic screening of at-risk populations (stroke, elderly, etc).
  • Stroke protocols (clinical practice guidelines).
  • Clinical diagnostic methods for primary care doctors.
  • Evaluation instruments and equipment.

2. Nutrition

Development of specific foods, with textures that allow easy swallowing and avoid aspiration, that provide the necessary calories and proteins and that are attractive in terms of taste, smell and colour. In Japan such foods are already widely available in supermarkets.

3. Treatment

  • Muscle and peripheral nerve stimulating equipment.
  • Strategies to directly stimulate areas of the brain that control swallowing.
  • Drugs to treat dysphagia (not as yet authorized for marketing).

4. Neurology

Neurorehabilitation strategies aimed at early disease treatment (electrical or magnetic brain stimulation techniques).