DYSPHAGIA: CAUSES AND INVESTIGATIONS

MS ENT University Examination Answer (20 Marks)

DEFINITION

CLASSIFICATION

PHASES OF SWALLOWING

1. Oral preparatory phase - mastication and bolus formation
2. Oral transit phase - tongue propels bolus to oropharynx
3. Pharyngeal phase - triggering of swallowing reflex, elevation of larynx, closure of glottis
4. Oesophageal phase - peristaltic transport to stomach

CAUSES OF DYSPHAGIA

A. Congenital Causes

1. Cleft lip and palate - Inability to form adequate oral seal; nasal regurgitation; impaired suckling
2. Cerebral palsy - Oral muscular incoordination; food pools in floor of mouth; failure to trigger pharyngeal phase; drooling and aspiration
3. Vascular rings - Aberrant subclavian artery, double aortic arch, or anomalous left pulmonary artery cause extrinsic oesophageal compression
4. Oesophageal atresia and tracheo-oesophageal fistula - Present with dysphagia and airway difficulties from birth
5. Laryngeal clefts - Varying degrees of laryngo-oesophageal separation failure
6. Congenital vocal cord palsy - Unilateral or bilateral; impairs glottic closure during swallow

B. Neurological Causes

1. Stroke (CVA) - Most common cause of oropharyngeal dysphagia; affects cortical/brainstem centres; may be part of pseudobulbar or bulbar palsy
2. Parkinson's disease - Tremor, rigidity, and bradykinesia affect oral and pharyngeal phases; delay in triggering swallow
3. Motor neuron disease (ALS) - Progressive bulbar and pseudobulbar palsy
4. Multiple sclerosis - Demyelination of brainstem pathways
5. Myasthenia gravis - Fatigable weakness of pharyngeal muscles; dysphagia worsens with eating
6. Bell's palsy and VII nerve palsy - Impairs oral phase (lip seal, buccal muscle)
7. Brainstem tumours - Affect swallowing centres in medulla
8. Head injury / post-surgical neurological deficit
9. Oculopharyngeal muscular dystrophy - Progressive ptosis + pharyngeal muscle weakness

C. Structural / Mechanical Causes

Luminal / Intrinsic

1. Carcinoma of the pharynx or oesophagus - Progressive dysphagia for solids, then liquids; weight loss; the most feared cause
2. Benign strictures - Peptic (secondary to GORD), post-caustic, post-radiotherapy
3. Pharyngeal pouch (Zenker's diverticulum) - Posterior herniation through Killian's dehiscence between thyropharyngeus and cricopharyngeus; regurgitation of undigested food; halitosis; gurgling; aspiration
4. Webs - Patterson-Brown-Kelly (Plummer-Vinson) syndrome: post-cricoid web + iron deficiency anaemia + koilonychia; pre-malignant
5. Schatzki's ring - Lower oesophageal mucosal ring; episodic dysphagia for solids at start of meals; symptoms begin when lumen <13 mm; associated with GORD
6. Foreign body - Sudden onset; complete dysphagia
7. Achalasia - Dysphagia for both solids and liquids from outset; regurgitation of undigested food; nocturnal aspiration; due to failure of LES relaxation (loss of inhibitory neurons of myenteric plexus); "bird's beak" appearance on barium swallow
8. Diffuse oesophageal spasm - Intermittent dysphagia + chest pain; "corkscrew" oesophagus on barium study

Extrinsic Compression

1. Retrosternal goitre
2. Aortic aneurysm / dysphagia lusoria (aberrant right subclavian artery)
3. Mediastinal lymphadenopathy (TB, lymphoma)
4. Bronchogenic carcinoma
5. Left atrial enlargement (mitral stenosis)
6. Cervical osteophytes / Diffuse Idiopathic Skeletal Hyperostosis (DISH) - Most common at C5-6; mechanical obstruction; aspiration of retained secretions; diagnosis on MBS or endoscopy
7. Mediastinal fibrosis

D. Inflammatory / Mucosal Causes

1. Eosinophilic oesophagitis (EoO) - Allergic oesophagitis; food impaction in young males; linear furrows and multiple corrugated rings on endoscopy; >15 eosinophils/HPF on biopsy; managed with dietary elimination and topical steroids (swallowed fluticasone/budesonide)
2. Severe oropharyngeal infections - Peritonsillar abscess, retropharyngeal abscess, Ludwig's angina
3. Tonsillitis/Quinsy - Acute odynodysphagia
4. Oesophageal candidiasis - In immunocompromised; odynodysphagia + dysphagia
5. Radiation mucositis / radiation fibrosis - Post-treatment for head-neck cancers; both acute (mucositis) and late (fibrosis, stricture)

E. Systemic / Autoimmune Causes

1. Scleroderma / CREST syndrome - Smooth muscle replaced by collagen; reduced lower oesophageal peristalsis; severe GORD; Barrett's oesophagus; anti-centromere antibodies positive
2. Systemic Lupus Erythematosus (SLE) - Oesophageal dysmotility; anti-dsDNA antibodies
3. Dermatomyositis / Polymyositis - Inflammatory myopathy of pharyngeal/oesophageal muscles
4. Sjögren's syndrome - Xerostomia impairs bolus formation

F. Functional / Psychogenic Causes

1. Globus pharyngeus - Sensation of a lump/tightness in throat; no actual dysphagia on testing; associated with stress, anxiety; endoscopy normal
2. Conversion disorder / functional dysphagia - Dysphagia in absence of organic cause

INVESTIGATIONS

History-directed Approach (Before Tests)

• Progressive solids → liquids = mechanical obstruction (malignancy, stricture)
• Simultaneous solids and liquids from onset = motility disorder (achalasia, DES) or neurological
• Episodic solids only = Schatzki ring, eosinophilic oesophagitis
• Difficulty initiating swallow + coughing/nasal regurgitation = oropharyngeal/neurological
• Regurgitation of undigested food = pharyngeal pouch or achalasia
• Weight loss, hoarseness, neck lump = malignancy until proven otherwise
• Young male + food impaction = eosinophilic oesophagitis

I. Radiological Investigations

1. Barium Swallow (Oesophagram)

• Standard technique: Patient swallows liquid barium while fluoroscopic images are taken
• Evaluates anatomy of UES, oesophagus, and LES
• Assesses motility, cricopharyngeal function
• Findings:
  • Pharyngeal pouch - posterior pulsion diverticulum at Killian's triangle
  • Achalasia - "bird's beak" tapering at LES with dilated oesophagus
  • Carcinoma - irregular filling defect / shouldering
  • Stricture - smooth (benign) or irregular (malignant) narrowing
  • Schatzki ring - smooth ring at lower end
  • Vascular ring / extrinsic compression - indentation from outside
  • Diffuse oesophageal spasm - "corkscrew" appearance
• Limitation: May give false-positive aspiration; cannot biopsy

2. Modified Barium Swallow (MBS) / Videofluoroscopy

• Gold standard for oropharyngeal dysphagia (especially neurological)
• Smaller sips of barium in multiple consistencies (thin liquid, nectar, honey, puree, solid) under fluoroscopic real-time imaging
• Assesses all phases of swallowing: oral, pharyngeal, oesophageal
• Visualizes structural movement: hyoid excursion, laryngeal elevation, epiglottic tilt
• Detects aspiration (silent or overt), penetration, pooling in valleculae/pyriform sinuses
• Can assess effectiveness of compensatory manoeuvres (chin tuck, head turn)
• Used in cerebral palsy, stroke, post-surgical, neurological patients

3. CT Scan (Neck and Thorax)

• Evaluates extrinsic causes: mediastinal lymphadenopathy, lung malignancy, retrosternal goitre
• Staging of oesophageal/pharyngeal malignancy
• CT angiography for vascular ring diagnosis

4. MRI

• MRI brain: stroke, MS, brainstem tumours, skull base pathology
• MRI neck: soft tissue tumours, neuromuscular disease evaluation
• MRA: vascular anomalies causing extrinsic compression

5. Chest X-ray

• Widened mediastinum, tracheal deviation, air-fluid level in mediastinum (oesophageal perforation)
• Aspiration pneumonia

II. Endoscopic Investigations

1. Upper GI Endoscopy (OGD / Gastroscopy)

• Primary investigation for oesophageal causes
• Direct visualisation of pharynx, oesophagus, stomach
• Permits biopsy of suspicious lesions (carcinoma, EoO - >15 eosinophils/HPF)
• Can diagnose and treat simultaneously: dilation of benign strictures, Schatzki's rings, webs
• Identifies Zenker's diverticulum (requires cautious passage; risk of perforation with blind scope)
• Identifies eosinophilic oesophagitis: linear furrows + corrugated rings
• Barrett's oesophagus

2. FEES - Functional Endoscopic Evaluation of Swallowing

• Flexible nasopharyngoscope passed transnasally to visualise the pharynx
• Patient given food/liquid in different consistencies with or without food colouring
• Performed in office; minimal anaesthesia; portable (bedside use possible)
• Pre-swallow assessment: Secretion level in valleculae/pyriform; pooling; risk for aspiration
• Post-swallow assessment: Detects penetration and aspiration; location of residue (valleculae, pharyngeal wall, pyriform sinuses); effectiveness of cough reflex
• Can be combined with compensatory manoeuvres to test benefit
• Limitation: "White-out" during actual swallow (cannot visualise the swallow moment); cannot assess oral phase or UES function

3. FEESST - Functional Endoscopic Evaluation of Swallowing with Sensory Testing

• FEES + laryngeal sensory testing
• Tests laryngeal adduction reflex triggered by air puffs or touch on aryepiglottic folds
• Useful in neurologically impaired patients; bedridden patients who cannot undergo MBS
• Adjunct to MBS

4. Rigid Oesophagoscopy

• Under general anaesthesia
• For foreign body removal, biopsy of lower pharyngeal/upper oesophageal lesions
• Allows better assessment of post-cricoid and upper oesophageal regions

III. Physiological / Functional Investigations

1. Oesophageal Manometry

• Probes with pressure sensors placed transnasally into oesophagus
• Measures UES, LES pressure and coordination of peristalsis
• Findings:
  • Achalasia: High resting LES pressure + failure to relax + aperistalsis
  • Diffuse oesophageal spasm: Normal peristalsis interspersed with simultaneous high-amplitude contractions
  • Cricopharyngeal dysfunction: UES dysfunction
  • Scleroderma: Low-amplitude or absent peristalsis in lower oesophagus
• High-resolution manometry (HRM) gives more precise data; useful when motility disorder suspected

2. 24-hour Ambulatory pH Monitoring / pH-Impedance

• Diagnoses GORD as a contributing factor
• pH <4 for >4.5% of 24-hour period = abnormal acid exposure
• Useful when peptic stricture or Barrett's is suspected

3. pH-MII (Multichannel Intraluminal Impedance with pH)

• Detects both acid and non-acid reflux events
• Useful in unexplained dysphagia with suspected reflux

IV. Laboratory Investigations

1. Full Blood Count - Anaemia (iron deficiency in Plummer-Vinson syndrome; megaloblastic in vitamin deficiency)
2. Serum iron, TIBC, ferritin - Iron deficiency in post-cricoid web
3. ESR, CRP - Infection, inflammation, malignancy
4. Autoantibody screen - ANA (SLE, scleroderma), anti-centromere (CREST), anti-Jo-1 (polymyositis), ANCA
5. Serum electrolytes and renal function - Baseline before investigations
6. Blood glucose - Diabetic neuropathy causing dysmotility
7. Thyroid function tests - Hypothyroid myopathy; retrosternal goitre
8. Acetylcholine receptor antibodies - Myasthenia gravis

V. Specialist Investigations

1. EMG (Electromyography) - Pharyngeal and laryngeal muscles in suspected neuromuscular disease
2. Nerve conduction studies - Peripheral neuropathy
3. Tensilon (Edrophonium) test - Myasthenia gravis diagnosis
4. Neuroimaging (CT/MRI brain) - For stroke, tumour, MS

SUMMARY FLOW CHART (Approach)

DYSPHAGIA
     |
     ├── Oropharyngeal (difficulty initiating, coughing, nasal regurg)
     │        → Clinical exam + FEES + Modified Barium Swallow + Neuroimaging
     │
     └── Oesophageal (food sticking in chest)
              |
              ├── Mechanical (progressive, solids→liquids)
              │        → Endoscopy (OGD) + Biopsy + CT staging
              │
              └── Motility (intermittent, solids + liquids)
                       → Barium swallow + Oesophageal Manometry + pH study

IMPORTANT SPECIFIC SYNDROMES TO MENTION (Scoring Points)