Dysphagia overview

# Overview
Dysphagia derives from the Greek root dys meaning difficulty or disordered, and phagia meaning "to eat". Dysphagia is a medical term defined as "difficulty swallowing."  It is a sensation that suggests difficulty in the passage of solids or liquids from the mouth to the stomach. According to the International Classification of Diseases (ICD-10) which is endorsed by the WHO, dysphagia is a symptom rather than a disease. Dysphagia can result from propulsive failure, motility disorders, structural disorders, intrinsic or extrinsic compression of the oropharynx or esophagus. Dysphagia is distinguished from similar symptoms including odynophagia, which is defined as painful swallowing, and globus, which is the sensation of a lump in the throat. The endoscopy for esophageal dysphagia should be performed when the patient presented with symptoms of difficulty swallowing, painful swallowing, and aspiration. This is the standard test performed when patient has risk of developing pneumonia and diagnosing swallowing difficuties. Video fluoroscopic swallowing study is performed for oropharyngeal dysphagia. It provides information about delay in initiation of pharyngeal swallowing, nasopharyngeal regurgitation, residue of ingestate within the pharyngeal cavity after swallowing, and aspiration of ingestate. The cornerstone of any dysphagia evaluation is a detailed history, and a thorough review of symptoms that can differentiate esophageal from oropharyngeal dysphagia and help predict the specific etiology of dysphagia with an accuracy of approximately 80% confirmed by specific testing. How a patient describes his or her difficulty and its timing, associated symptoms, and other characterizations may specifically denote the anatomic level of swallowing dysfunction.

# Historical Perspective
In 1800, Dr. Patrick Paterson reported a case of gangrenous stomach with dysphagia from lightening. In 1811, Dr. TJ Armiger reported a case of aortic aneurysm causing dysphagia. In 1978, Landres et al reported an isolated case of vigorous achalasia and concluded that this was a variant of eosinophilic gastroenteritis in a patient with marked hypertrophy and eosinophilic infiltration of esophagus. In 1981, Picus and Frank reported a case of a 16-year-old boy with progressive dysphagia for 1.5 years, endoscopic findings were suggestive of multiple 1-mm nodular filling defects in the esophagus in an area of stricture with dilatation above. In 1982, Munch et al and in 1983, Matzinger and Daneman both described isolated cases of esophageal eosinophilia with dysphagia in patients with assumed eosinophilic gastroenteritis. In 1989, Attwood et al described esophageal asthma, an episodic dysphagia with eosinophilic infiltrates. In 1993, Attwood et al reported 12 adults with dysphagia, normal pH monitoring, and dense esophageal eosinophilia. Seven patients had food hypersensitivity, and all required advanced intervention (dilatation and/or steroids in 1 case) for resolution of symptoms. In 1994, Straumann et al described a series of 10 patients with acute recurrent dysphagia seen over a 4-year period.

# Classification
Dysphagia is classified according to location into two groups: oropharyngeal dysphagia or esophageal dysphagia. It may be classified into further six subclasses based on etiology: infectious, metabolic, myopathic, neurological, structural, and iatrogenic.

# Pathophysiology
Dysphagia can result from propulsive failure, motility disorders, structural disorders, intrinsic or extrinsic compression of the oropharynx or esophagus. Propulsive failure can result from dysfunction of the central nervous system control mechanisms, intrinsic musculature, or peripheral nerves. Structural abnormalities may result from surgery, neoplasm, caustic injury, or congenital anomalies.

# Causes
Dysphagia has a couple of categories of causes which can be classified on the basis of location and the organ system involved.

# Differentiating dysphagia from Other Diseases
Dysphagia is distinguished from similar symptoms including odynophagia, which is defined as painful swallowing, and globus, which is the sensation of a lump in the throat. A psychogenic dysphagia is known as phagophobia.

# Epidemiology and Demographics
Dysphagia is a common symptom seen in the elderly poplulation owing to senile physiological changes in the muscles involved in deglutition. It is also seen in other age groups, subsequent to other diseases such as esophageal webs, esophageal cancer, structural damage to the esophagus.

# Risk Factors
The risk factors for dysphagia are smoking, obesity, pregnancy, hiatal hernia, scleroderma, alcohol consumption, consuming drinks that contain caffeine, and medications. Medications include anticholinergics, beta blockers, bronchodilators, calcium channel blockers, dopamine-active drugs for Parkinson's disease, progestin for abnormal menstrual bleeding or birth control, sedatives for insomnia or anxiety, and tricyclic antidepressants.

# Screening
There is insufficient evidence to recommend routine screening for dysphagia.

# Natural History, Complications, and Prognosis
If left untreated, dysphagia can potentially cause aspiration pneumonia, malnutrition, or dehydration, all of which can be symptoms of dysphagia as well. Prognosis is dependent on the underlying disease. However, prognosis is generally regarded as good.

# Diagnosis

## Diagnostic Criteria
The endoscopy for esophageal dysphagia should be performed when the patient presented with symptoms of difficulty swallowing, painful swallowing, and aspiration. This is the standard test performed when patient has risk of developing pneumonia and diagnosing swallowing difficuties. Video fluoroscopic swallowing study is performed for oropharyngeal dysphagia. It provides information about delay in initiation of pharyngeal swallowing, nasopharyngeal regurgitation, residue of ingestate within the pharyngeal cavity after swallowing, and aspiration of ingestate.

## History and Symptoms
The most important factor in the evaluation of any dysphagia is a detailed history, and a thorough review of symptoms that can differentiate esophageal from oropharyngeal dysphagia and help predict the specific etiology. How a patient describes the symptoms and their timing, associated historical features, and other characterizations may specifically denote the anatomic level of swallowing dysfunction.

## Physical Examination
A speech language pathologist is most often the first person called upon to evaluate a patient with suspected dysphagia. During this informal examination, medical history is obtained, the mini-mental state examination is administered, and oral and facial sensorimotor function, speech, and swallowing are evaluated non-instrumentally.

## Laboratory Findings
There are no diagnostic laboratory findings associated with dysphagia per se. However, in certain diseases leading to dysphagia, laboratory evaluation is done to look for the underlying disease.

## Electrocardiogram
There are no ECG findings associated with dysphagia.

## X-ray
An x-ray may be helpful in the diagnosis of the underlying cause of dysphagia. Findings on an x-ray suggestive of of dysphagia include structural abnormalities, masses, and to rule out causes.

## Ultrasound
Ultrasound may be helpful in the diagnosis of dysphagia. Findings on an ultrasound suggestive of dysphagia muscular function, and hypertrophy of the muscular layer.

## CT scan
CT scan may be helpful in the diagnosis of the underlying cause of dysphagia. Findings on CT scan suggestive of dysphagia include structural abnormalities and central nervous system (CNS) abnormalities.

## MRI
MRI may be helpful in the diagnosis of the underlying cause of dysphagia. Findings on MRI suggestive of dysphagia include structural abnormalities and central nervous system abnormalities.

## Other Imaging Findings
There are no other imaging findings associated with the diagnosis of dysphagia.

## Other Diagnostic Studies
Other diagnostic studies for dysphagia include video fluoroscopic swallowing study and esophageal manometry. Video fluoroscopic swallowing study, also known as modified barium swallow, is used as the initial study for the evaluation of oropharyngeal dysphagia.

# Treatment

## Medical Therapy
The main objective of treating dysphagia is to avoid aspiration of the food and bolus impaction, reduce the morbidity associated with ongoing symptoms. Effective medical management begins with early identification of the underlying cause with a detailed history, physical examination and, judicious use of investigations.

## Surgery
Surgery is not the first-line treatment option for patients with dysphagia. Surgery is usually reserved for patients with either dysphagia leading to life-threatening aspiration and airway protection.

## Primary Prevention
There are no established measures for the primary prevention of dysphagia.

## Secondary Prevention
Effective measures for the secondary prevention of dysphagia include chewing your food thoroughly and eating slowly