Saturday, January 30, 2010

CPD II: esophageal disorders

this is the first lecture for diagnosis of gastrointestinal disorders in CPD II. we started with a discussion on the importance of "food hygiene"-- the manner in which one eats (not only the type of food, but when, how, how fast, etc.). the section that followed was a review of normal esophageal function, in particular the three phases of swallowing: oral, pharyngeal, and esophageal. the oral phase involves the formation of the bolus via mechanical and chemical breakdown of food, and propelling of food into the oropharynx. this phase can take anywhere from 1-2 seconds for liquid to 20 seconds for food (depending on the food hygiene of the chewer) and is mediated by cranial nerves V (trigeminal), VII (facial), and XII (hypoglossal). the next phase is the pharyngeal phase, a reflexive phase mediated by CN IX (glossopharyngeal) and X (vagus) in which the UES relaxes and is pulled open by the forward motion of the hyoid and larynx, letting the bolus into the esophagus. the final phase is the esophageal phase, in which the bolus is moved via peristalsis to the lower esophageal sphincter and released into the stomach upon relaxation of the LES. this phase is controlled by the medulla and may take 8-20 seconds.

dysphagia is the phenomenon of having difficulty swallowing and can occur either in the pharynx or the esophagus, with a variety of etiologies. the pre-esophageal dysphagias are generally neurological or involving skeletal muscle dysfunction, such as stroke, motor neuron disease (ALS, MS), myopathy, myasthenia gravis. esophageal dysphagias are categorized as obstructive (carcinoma, lower esophageal ring) or due to a motor disorder-- motor disorders are generally more severe and restrict passage of both liquid and food while obstructive might let liquid through. symptoms are somewhat similar for both esophageal and pre-esophageal dysphagia and center around difficulty swallowing, coughing, choking, drooling, regurgitation, change in dietary habits / weight loss, but the esophageal dysphagia will result in an obstructive sensation lower down in the chest as compared to the upper throat for pre-esophageal dysphagia.

achalasia is a debilitating disorder of the esophagus that results from neuronal damage of the inhibitory neurons that innervate the esophagus (more commonly afflicting the lower esophagus and LES), resulting in constriction and decreased peristalsis. severe cases can result in a near complete constriction of the LES, prohibiting passage of most solids and resulting in buildup of a fermenting bolus. besides the dysphagia, symptoms are regurgitation of food, chest pain, and possible recurrent bronchopneumonia. a chest xray would show the esophageal beak dilation and esophageal manometry would show decreased relaxation and reduced peristalsis.

DES is a rarer esophageal dysfunction with symptoms just as severe, if not more severe than achalasia. in fact, patients with DES are difficult to manage because their symptoms might be mistaken for a myocardial infarction, the treatment of which (vasodilators for occluded coronary artery) might relieve DES symptoms as well. patients with DES might suffer from acute, substernal chest pain radiating to the back that may be triggered by swallowing, which may be accompanied by paleness or perspiration. chest xray might show a "corkscrew" shape to the esophagus and manometry will reveal an abnormal pressure distribution as well as uncoordinated contractions.

the symptoms of DES are somewhat similar to nutcracker esophagus, another esophageal disorder which contrasts with achalasia and DES in that the peristaltic waves are orderly but simply high in amplitude. nutcracker esophagus can result in prolonged chest pain and intermittent nocturnal dysphagia, but less so than DES.

the last esophageal disorder covered in this lecture is scleroderma, which is a widespread connective tissue and smooth muscle disorder that can manifest in fibrosis of esophageal tissue, leading to decreased motility and a weakened LES. dysphagia, regurgitation, barrett's esophagus, and extreme pain upon pressure can result, along with acid reflux so severe that patients might refuse to pick things up off the ground or lie down while sleeping.

questions
normal esophageal function...
1. what are the three phases of swallowing?
2. what is involved in the oral phase of swallowing?
3. which cranial nerves are involved in the oral phase of swallowing?
4. in the pharyngeal phase, the UES is pulled forward by...
5. which cranial nerves are involved in the pharyngeal phase of swallowing?
6. what is involved in the esophageal phase of swallowing?
7. what part of the brain is involved in the esophageal phase of swallowing?
8. describe the general timescale for each of the three phases of swallowing.

dysphagia...
9. what is dysphagia?
10. dysphagia is often seen in patients with what condition?
11. what are the signs and symptoms of oral dysphagia?
12. what are the signs and symptoms of esophageal dysphagia?
13. what are some pre-esophageal etiologies of dysphagia?
14. what are some esophageal etiologies of dysphagia?
15. what is the difference in severity of dysfunction between dysphagia with a motor vs. obstructive etiology?
16. what is involved in the physical exam for dysphagia?
17. differential diagnoses for oropharyngeal dysphagia include...
18. differential diagnoses for esophageal dysphagia include...

GI related chest pain...
19. what is heart burn?
20. what are some differential diagnoses for heart burn?
21. what is odynophagia and what is the most common cause?

achalasia...
22. what is achalasia?
23. what are the symptoms of achalasia?
24. what might one find in a PE of a patient with achalasia?
25. what would a chest xray of a patient with achalasia show?
26. what is the standard imaging technique of a patient with achalasia and what would it show?

diffuse esophageal spasm...
27. what is DES?
28. what is a DDX that might interfere with the diagnosis of DES?
29. what are the signs and symptoms of patients with DES?
30. the EKG of a patient with DES will look like...
31. barium swallow of a patient with DES will look like...
32. esophageal manometry of DES patients might reveal...
33. what is the classic definition of DES according to esophageal manometry?

nutcracker esophagus...
34. what is nutcracker esophagus?
35. symptoms of nutcracker esophagus can be distinguished from DES by...
36. what are the symptoms of nutcracker esophagus?
37. manometry of nutcracker esophagus reveals...

scleroderma...
38. what is scleroderma and how does it manifest in the esophagus?
39. in scleroderma patients, where is motility preserved in the esophagus?
40. what are the signs and symptoms of scleroderma?
41. describe the severity of acid reflux in patients with scleroderma.
42. what are some PE findings of patients with scleroderma?
43. xray of scleroderma patients shows...

answers
1. oral phase, pharyngeal phase, esophageal.
2. mechanical breakdown, mixing with saliva and enzymes, propelling of food into the oropharynx.
3. V (trigeminal), VII (facial), XII (hypoglossal).
4. hyoid bone and larynx.
5. IX (glossopharyngeal) and X (vagus).
6. propelling of bolus down esophagus and relaxation of LES.
7. the medulla.
8. oral: 1 second liquid, 5-10 seconds solid. pharyngeal: 1 second. esophageal: 8-20 seconds.

9. difficulty swallowing.
10. myasthenia gravis.
11. coughing, choking, difficulty initiating swallowing, drooling, weight loss, nasal regurgitation.
12. sensation of food sticking in chest/throat, regurgitation, change in dietary habits.
13. usually neurological, involving skeletal muscle: stroke, motor neuron disease such as ALS, MS, myopathy, laryngectomy, pharyngectomy, myasthenia gravis, cerebral palsy.
14. either obstructive (carcinoma, lower esophageal ring), or motor disorder.
15. obstructive can still allow liquids but motor disorder oftentimes does not allow either solid or liquid.
16. examining the soft palate / tongue / teeth, testing cranial nerves (V / VII / XII), watching for dysphonia or dysarthria, examining while swallowing, and assessing respiratory function, among other things. [exam test dys swallow breathe] [test dis exam: swallow! breathe!]
17. cerebrovascular accident, parkinson's, brainstem tumor, degenerative diseases, poliomyelitis, peripheral neuropathy, myasthenia gravis. [CV, park, stem, DJ, pole, neuron, gravity] [DJ went to the park to do a CV workout but due to gravity crashed into a pole that was the huge stem of a neuron]
18. achalasia, DES, nutcracker esophagus, scleroderma, obstructive lesions. [des achy nuts are obstructing my skin]

19. substernal burning pain that usually occurs after meals from reflux of acid into esophagus.
20. panic attack, costochondritis, skin conditions (such as herpes zoster, shingles), pulmonary disorders, MI.
21. pain upon swallowing, from sore throat.

22. nerve degeneration of inhibitory neurons of esophagus causes increased esophageal tone and constriction.
23. progressive dysphagia of solids and foods, regurgitation (especially at night), chest pain, possible recurrent bronchopneumonia.
24. normal findings, or halitosis, or weight loss.
25. esophageal "beak" dilation.
26. esophageal manometry, would show incomplete esophageal relaxation, high resting pressure, reduced peristalsis.

27. uncommon disorder that results in abnormal, non functional peristalsis.
28. an MI, because symptom are similar and the vasodilators given to treat MI might also relieve DES symptoms.
29. substernal chest pain upon swallowing that radiates to back or scapulas, maybe paleness or perspiration.
30. NI.
31. corkscrew esophagus.
32. abnormal pressure distribution, uncoordinated contractions.
33. at least 2 uncoordinated contractions for 10 wet swallows.

34. an esophageal disorder with normal LES function but twice the amplitude of contraction and an abnormally long peristaltic wave.
35. motility study.
36. prolonged chest pain, nocturnal intermittent dysphagia (less than DES),
37. orderly contractions with abnormally high amplitude.

38. widespread disorder of smooth muscle and connective tissue, fibrosis of esophageal tissue leads to dysmotility and weakened LES.
39. in the proximal striated portion.
40. dysphagia, regurgitation, acid reflux, barrett's esophagus, extreme pain upon pressure.
41. so severe that patients often can not bend down or lie down.
42. thickening of skin, joint structures, internal organs.
43. loss of peristalsis.

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