Dysphagia

Overview

Definition

Dysphagia is a condition in which there is a disruption of the swallowing process, typically interfering with the ability to eat and drink.

Normal physiology

Swallowing consists of 3 phases:

1. Oral preparatory and transport phase:
   • Voluntary control of mastication
   • Food bolus is chewed and directed to the posterior tongue.
2. Pharyngeal phase:
   • Involuntary swallow response
   • Food bolus is advanced through the pharynx.
3. Esophageal phase:
   • Involuntary esophageal peristalsis
   • Food bolus is advanced through the esophagus.

Classification

There are 2 categories of dysphagia:

• Oropharyngeal dysphagia:
  • Difficulty initiating a swallow due to a disorder in the oral or pharyngeal phase
  • Patients have difficulty transferring food from the mouth through the pharynx.
• Esophageal dysphagia: 
  • Disorder in the esophageal phase of swallowing
  • Difficulty swallowing that presents several seconds after initiating a swallow
  • May be accompanied by the feeling of food getting “stuck”
  • Broken into 2 sub-categories: 
    • Functional and motility disorders 
    • Mechanical and obstructive disorders

Oropharyngeal Dysphagia

Epidemiology

• Prevalence in those ≥ 65 years of age:
  • 14%–33% in the community
  • Approximately 40% in hospitalized patients
• Occurs in ⅓ of patients with Parkinson’s disease

Etiology

• Disorders of the oral phase:
  • Poor dentition
  • Decreased salivary gland production:
    • Sjogren’s syndrome
    • From head and neck radiation
    • Medications (anticholinergics, antihistamines)
  • Disruptions in the oropharyngeal mucosa:
    • Mucositis
    • Aphthous ulcers
    • Herpetic lesions
    • Trauma
  • Disruption in the neuromuscular response:
    • Stroke
    • Late-stage Parkinson’s disease
• Disorders of the pharyngeal phase:
  • Structural abnormalities within the oropharynx:
    • Malignancy (most common)
    • Crycopharyngeal bar
    • Pharyngoesophageal diverticulum (Zenker’s diverticulum)
  • Disruptions in the involuntary swallow response coordination:
    • Stroke
    • Amyotrophic lateral sclerosis
    • Myasthenia gravis
    • Polio and post-polio syndrome
    • Parkinson’s disease
    • Multiple sclerosis
    • Muscular dystrophy
    • Dermatomyositis

Clinical presentation

• Symptoms:
  • Feeling of an obstruction in the neck
  • Coughing
  • Choking
  • Drooling
  • Regurgitation when swallowing solids and liquids
• Relevant history and associated symptoms:
  • Recurrent aspiration pneumonia
  • Suggestions of malignancy:
    • Weight loss
    • Alcohol or tobacco abuse 
    • Blood in the mouth 
    • Otalgia 
  • Inadequate salivary production:
    • Dry mouth or eyes
    • Radiation therapy
  • Neuromuscular dysfunction:
    • Weak cough
    • Dysarthria, dysphonia, or nasal speech
    • Incoordination
    • Hoarseness
  • Structural abnormalities:
    • Halitosis (Zenker’s diverticulum)
    • Fullness in the neck
• Physical exam:
  • Head and neck abnormalities to look for:
    • Lymphadenopathy
    • Poor dentition
    • Masses
    • Facial muscle weakness
  • Neurologic abnormalities to test for:
    • Sensory cranial nerves (V, IX, X)
    • Motor cranial nerves (V, VII, X, XII)
    • Loss of gag reflex
    • Muscle strength
    • Cogwheel rigidity
    • Shuffling gait

Diagnosis

• Based on the patient’s history and symptoms, an appropriate workup should be initiated to diagnose an underlying etiology (e.g., Sjogren’s, dermatomyositis, stroke, myasthenia gravis, Parkinson’s disease).
• Next, the following are used to determine the severity and mechanism of swallowing dysfunction:
  • Video fluoroscopy with modified barium swallow:
    • Can test the effects of different barium consistencies
    • Analyzes the movement of anatomic structures
    • Detects oropharyngeal dysfunction and determines severity
    • Assesses for aspiration
  • Manometry: evaluates the pressure with pharyngeal contraction and in the upper esophageal sphincter (UES function)
• If no systemic process is suspected, or found, as an etiology:
  • Nasopharyngeal laryngoscopy:
    • Can evaluate for a structural lesion (tumors, Zenker’s diverticulum)
    • Visualizes the oropharynx, hypopharynx, and larynx
  • Fiberoptic endoscopic evaluation of swallowing (FEES):
    • Similar to nasopharyngeal laryngoscopy, but can also assess function
    • Directly visualizes food and liquids as they are swallowed
    • Sensory testing can also be performed.

Management

Management is guided by the diagnostic workup, and is focused on improving food transfer and preventing aspiration:

• Treatment of any underlying disorder
• Swallowing rehabilitation:
  • Motor exercises
  • Head placement while eating
• Dietary modifications:
  • Thickened liquids
  • Smaller bites of food
  • Alternating solids and liquids when eating
• Nutrition supplementation 
• Enteral nutrition may need to be considered for severe dysfunction and aspiration risk.
• Surgery (Zenker’s diverticulum)

Esophageal Dysphagia: Functional and Motility Disorders

Esophageal functional and motility disorders typically occur due to pathology of the muscles of the esophagus, causing a disruption in peristalsis. All functional and motility disorders exhibit dysphagia with liquids and solids at the onset.

Diffuse esophageal spasm (DES)

An esophageal motility disorder characterized by hyperdynamic and non-propulsive contractions:

• Etiology: idiopathic
• Pathophysiology: 
  • Not fully understood
  • Impaired inhibitory innervation of the muscles of the esophagus and ↓ endogenous nitric oxide synthesis → frequent, high-pressure, non-peristaltic contractions occurring spontaneously with normal peristalsis
• Clinical presentation:
  • May be asymptomatic
  • Intermittent, non-progressive dysphagia
  • Non-cardiac chest pain
  • Can be aggravated with hot or cold liquids
  • Some patients may have associated gastroesophageal reflux disease (GERD).
• Diagnosis:
  • Manometry: simultaneous multi-peak, high-pressure contractions with intermittent normal peristalsis
  • Barium esophagram: severe, non-peristaltic contractions with a “corkscrew” pattern
• Management:
  • Goal of therapy is symptomatic relief. 
  • Peppermint oil to relax the esophageal smooth muscle
  • Calcium channel blockers
  • Proton pump inhibitors (PPIs) for GERD symptoms
  • Botulinum toxin injection into the lower esophageal sphincter (LES) for refractory cases

Scleroderma

Scleroderma is an autoimmune disorder that can cause atrophy and sclerosis of the distal esophagus, resulting in diminished (or absent) peristalsis and LES pressure.

• Pathophysiology: 
  • Atrophy and fibrosis of the smooth muscle in the distal ⅔ of the esophagus →  ↓ peristalsis and loss of LES tone 
  • GERD, Barrett’s esophagus, reflux esophagitis, and subsequent strictures may develop.
• Clinical presentation:
  • Acid reflux
  • Possible associated systemic symptoms:
    • Skin thickening, sclerodactyly, calcinosis, telangiectases
    • Raynaud’s phenomenon
    • Interstitial lung disease or fibrosis
    • Pulmonary hypertension, pericarditis
    • Renal disease
• Diagnosis:
  • Diagnosis of scleroderma is based on the clinical features and detection of anti-Scl-70 (anti-topoisomerase), anticentromere, or anti-RNA polymerase III antibodies.
  • Manometry: ↓ LES tone and absence of peristalsis in the body of the esophagus
  • Endoscopy: reflux esophagitis, Barrett’s esophagus, or esophageal stricture
• Management:
  • PPIs
  • Endoscopic dilation for strictures
  • Gastroplasty or fundoplication for refractory GERD

Achalasia

A neurogenic esophageal motility disorder resulting in impaired LES relaxation and diminished peristalsis:

• Etiology: 
  • Primary: idiopathic (most common)
  • Secondary: due to malignancy or Chagas disease
• Pathophysiology: 
  • Degeneration of ganglion cells in Auerbach’s plexus → failure of smooth muscle relaxation at the LES → progressive loss of peristaltic function in the distal esophagus
  • ↑ LES pressure → obstruction and secondary esophageal dilation → retention of foods and liquids in the esophagus
• Clinical presentation:
  • Regurgitation of undigested food or saliva, particularly at night
  • Dysphagia symptoms are progressive and insidious.
  • Weight loss
• Diagnosis:
  • Esophageal manometry (preferred test): incomplete relaxation of the LES, ↑ resting LES pressure, and aperistalsis of the distal ⅔ of the esophagus
  • Barium esophagram: suggestive findings of a “bird’s beak” esophagus
  • Endoscopy with biopsy: Rule out secondary causes, such as malignancy and Chagas disease.
• Management: 
  • Treatment is aimed at ↓ LES pressure.
  • Mechanical stretching of muscle fibers: 
    • Pneumatic balloon dilation
    • Surgical myotomy 
  • Chemical reduction of LES pressure: 
    • Botulinum toxin injection into the LES 
    • Oral nitrates
    • Calcium channel blockers

Esophageal Dysphagia: Mechanical and Obstructive Disorders

Esophageal mechanical and obstructive disorders typically occur due to obstruction of the esophageal lumen. All mechanical and obstructive disorders exhibit dysphagia with solids with progression to liquids.

Esophageal rings and webs

Rings and webs are thin mucosal strictures that partially occlude the esophageal lumen:

• Definitions:
  • Esophageal ring:
    • Concentric tissue protruding into the esophageal lumen
    • Most commonly in the distal esophagus
    • Usually mucosal, but can be due to hypertrophy of smooth muscle
  • Esophageal web: 
    • Eccentric membranes that protrude into the esophageal lumen
    • Most commonly occur anteriorly in the proximal esophagus
• Pathophysiology:
  • Etiology is unknown.
  • Rings may be due to chronic damage from GERD.
• Clinical presentation:
  • Usually asymptomatic
  • Dysphagia is intermittent.
• Diagnosis:
  • Barium esophagram: Rings and webs appear as thin, circumferential or eccentric narrowing in the esophagus.
• Specific conditions:
  • Schatzki ring: 
    • Associated with GERD, eosinophilic esophagitis, and hiatal hernia
    • Located in the distal esophagus (proximal to the LES)
    • More common in patients > 40 years of age
    • Treatment: esophageal dilation and PPIs
  • Plummer-Vinson syndrome: 
    • Clinical triad: iron deficiency anemia, dysphagia, and cervical esophageal webs
    • More common in middle-aged women
    • Associated with an increased risk of esophageal squamous cell carcinoma (SCC)
    • Treatment: iron supplementation and esophageal dilation (for significant obstruction)

Esophageal (peptic) strictures

An esophageal stricture is an abnormal narrowing of the esophageal lumen:

• Etiology: 
  • Chronic inflammation from long-standing GERD
  • Direct damage caused by the ingestion of acidic or alkali agents
• Pathophysiology: 
  • Circumferential scarring → reduced lumen of the esophagus → progressive dysphagia of solids
  • Often located in the distal esophagus
• Clinical presentation:
  • Dysphagia is gradually progressive.
  • History of GERD
  • Remote history of ingestion of acid or alkali agents
  • May be associated with weight loss
• Diagnosis:
  • Barium esophagram: can establish the location, length, and number of strictures
  • Confirmed with endoscopy and biopsy (to rule out cancer)
• Management:
  • High-dose PPIs
  • Periodic esophageal dilation

Esophageal cancer

• Etiology:
  • SCC: cancer of the upper ⅔ of the esophagus, commonly seen in:
    • Smokers
    • Alcohol intake 
    • Achalasia
  • Adenocarcinoma: cancer of the distal esophagus, commonly seen in older patients with Barrett’s esophagus
• Pathophysiology: cancer overgrowth → reduced lumen of the esophagus → progressive dysphagia 
• Clinical presentation:
  • Progressive dysphagia
  • Odynophagia (pain with swallowing) in 20% of patients
  • Weight loss (cachexia)
  • Iron deficiency anemia (from chronic upper gastrointestinal blood loss)
  • Cough and hoarseness may be seen due to local tumor spread.
• Diagnosis:
  • Endoscopy with biopsy: for definitive diagnosis
  • Barium esophagram: “apple core” lesion
• Management:
  • Staging:
    • Positron emission tomography (PET)
    • Computed tomography (CT) 
  • Resection is the only curative therapy.
  • Chemoradiation
  • Palliative treatments for advanced disease