Spth 365 Dysphagia and Related Disorders: Diagnosis

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Spth 365 Dysphagia and Related Disorders
Diagnosis

• Lecture Seven
• Other Diagnostic Examinations

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The Diagnostic Dysphagia Exam

• In general the modified barium swallow or
  videofluoroscopic swallowing study, is considered
  the 'gold standard' in swallowing evaluation.
  This is in part due to it's longevity and it's
  availability. However there are several other
  diagnostic techniques available that provide very
  valuable, and sometimes quite different,
  information.

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Manometry

• Definition
• Assessment of pressure dynamics of pharynx, UES
  and esophagus.
• Provides information about
• pharyngeal or esophageal pressure or tone
• contraction of pharyngeal constrictors and their
  functional approximation to anterior pharyngeal
  structures
• UES tone
• the relationship between these events.
• Can be paired with videofluoroscopy.....manofluoro
  scopy
• Greater anatomical interpretation of analog
  manometry signal.

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Manometry

• Technique
• Transnasal insertion of catheter housing
  transducers.
• Exam is usually done by gastroenterologist
  Typically with some topical anesthesia.
• Water perfusion manometry vs solid state
  manometry
• Strengths
• No radiation exposure,
• Lower costs
• Provides information about functional effects of
  observed physiology
• Weakness
• Provides information on very few parameters of
  swallowing.
• Cannot evaluate the physiology directly.

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Scintigraphy

• Definition
• Radionuclide scanning to assess distribution and
  quantity of radioisotope
• Provides information about
• Distribution of ingested materials amount of
  aspirate.
• Technique
• Radionuclide scanning during and after ingestion
  of a radioactive bolus Technetium Sulphus
  Colloid 99.
• Place radioactive markers on the skin to identify
  anatomical boundaries, have patient ingest bolus,
  then take an xray.
• The radioactive isotope is displayed, indicating
  bolus volume and flow.

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Scintigraphy

• Strengths
• Quantifies amount of radioactive tracer which you
  are unable to do with other instruments.
• Most precise technique for documenting amount of
  aspirate.
• Therefore it is gaining in popularity as a tool
  for nursing home/geriatric patients.
• Weakness
• Expensive
• Requires specialized nuclear medicine expertise.
• Equipment is not frequently available

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Scintigraphic image of aspirate into right lung.
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Electroglottography EGG

• Definition
• device which measures the variable resistance to
  current flow between two electrodes placed over
  the larynx.
• Provides information about
• laryngeal excursion, vocal fold closure.
• Can be used as a therapeutic biofeedback device.
• Technique
• Place transducers on either side of thyroid.
• Signal is transmitted between the two with
  changes in impedence reflecting absence of or
  intervening laryngeal structures.
• Thus when larynx elevates during swallowing, the
  EGG signal is displaced.
• Primarily used in research.

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Electroglottography

• Strengths
• Non-invasive, inexpensive exam
• Weaknesses
• Provides limited information

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Electromyography

• Definition
• Examination of electrical impulses produced by a
  muscle
• Provides information about
• Onset and termination of muscle contraction
• useful in determining resting tone of muscles
  (ie....UES hypertonicity, dennervation patterns,
  relative strength/symmetry)
• Technique
• Subcutaneous placement of electrodes directly
  into muscle tissue.
• Measurements taken during functional activities.
  
• Primarily used in swallowing research.
• May be used to diagnose certain disease
  processes or plan surgical interventions.

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Electromyography

• Strengths
• Provides very precise, analog information.
• Only way to assess direct innervation.
• Weaknesses
• Invasive.
• Difficulty in electrode placement of small
  muscles
• IMPORTANT POINT
• Surface EMG IS NOT A DIAGNOSTIC TOOL. Much more
  readily available but not diagnostic.

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Ultrasound

• Definition
• Use of high frequency sound waves emitted into
  body and reflected back.
• Density of tissue modulates sound wave reflection
• Provides information about
• Structure and functional location of soft
  tissues, particularly tongue surface/configuration
  and hyoid excursion.
• With alternate transducer placement can visualize
  lateral pharyngeal wall displacement during
  swallowing.
• Some information about speech articulation.

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Ultrasound

• Technique
• Crystal transducer placed under the chin and
  physiology observed on screen during swallowing
• Strengths
• Noninvasive, no radiation
• good application in pediatric population
• Weaknesses
• Very subjective interpretation
• image is not clear,
• expensive equipment with limited use.

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Normal Tongue Sagittal View
Ultrasound images courtesy of Dr. Barbara Sonies,
N.I.H.
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Normal Tongue Coronal View
Ultrasound images courtesy of Dr. Barbara Sonies,
N.I.H.
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Asymmetrical Tongue Coronal View
Ultrasound images courtesy of Dr. Barbara Sonies,
N.I.H.
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Fiberoptic Endoscopic Evaluation of Swallowing

• Definition
• use of flexible endoscope to evaluate pharyngeal
  and laryngeal anatomy and physiology.
• Provides information about

• pharyngeal retention post swallow
• asymmetry of bolus passage through pharynx
• aspiration before the swallow
• aspiration after the swallow
• pharyngeal sensitivity

• laryngeal and pharyngeal anatomy
• laryngeal valving mechanisms
• delayed pharyngeal swallow or premature spillage
• isolated velopharyngeal closure

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FEES/T

• Technique
• Transnasal placement of endoscope into pharynx to
  view pharynx and larynx.
• Can be done at bedside or in office with any food
  substance.
• Usually done by ENT with SLP or SLP
  independently.
• Very highly correlated with detection of
  dysphagic symptoms and aspiration 90 agreement
  for detection of aspiration.
• Significant controversy regarding this as a tool
  for swallowing.

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Endoscopic View of Compensatory Techniques
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FEES/T

• Strengths
• Extraordinary view of laryngeal valving
  mechanisms
• can be done bedside with portable equipment,
• less expensive than MBS
• Weaknesses
• Lose visualization of oral cavity, functional
  palatal elevation and pharyngeal dynamics at the
  peak of the swallow
• Invasiveness/comfort
• Training issues

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FEES/T

• Leder SB Ross DA Briskin KB Sasaki CT (1997)
• Using a prospective, double-blind, randomized
  design
• 152 consecutive patients were randomly assigned
  to receive a topical anesthetic (N 54),
  vasoconstrictor (N 50), or placebo (N 48).
• No significant differences were found among the
  three variables.
• An additional 50 consecutive patients had
  endoscopy performed without administration of any
  substance to the nares, and no significant
  differences were found among the four variables
  (N 202).

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FEES/T

• Aviv JE Sacco RL Mohr JP Thompson JL Levin B
  Sunshine S Thomson J Close LG (1997)
• Compared false negative rate of predicting
  aspiration pneumonia in dysphagic stroke patients
  using modified barium swallow (MBS) alone and MBS
  combined with laryngopharyngeal sensory
  discrimination testing (MBS LPSDT).
• MBS and LPSDT were performed within 4 weeks of
  stroke in 20 subjects followed for at least 2
  years to identify aspiration pneumonia
• MBS identified 10 patients as not at risk based
  on the finding of no aspiration on initial MBS
• four of these patients developed AP (FNR 40).
• MBS LPSDT identified five patients as not at
  risk based on the findings of neither aspiration
  nor bilateral sensory deficits
• none of these patients developed AP (FNR 0).

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FEES/T

• Leder SB Sasaki CT Burrell MI (1998)
• Assessed aspiration in 400 consecutive, at risk
  subjects by fiberoptic endoscopic evaluation of
  swallowing (FEES).
• 175 of 400 (44) subjects were without
  aspiration,
• 115 of 400 (29) exhibited aspiration with a
  cough reflex
• 110 of 400 (28) aspirated silently.

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VFSS vs FEES

• Langmore SE Schatz K Olson N (1991)
• 21 subjects were given both examinations within a
  48-hour period.
• Good agreement was found, especially for the
  finding of aspiration (90 agreement).
• Sensitivity was 0.88 or greater for three of the
  four parameters measured.
• Specificity was lower overall, but was still 0.92
  for detection of aspiration.

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VFSS vs FEES

• Wu CH Hsiao TY Chen JC Chang YC Lee SY (1997)
• 28 chronic dysphagic patients underwent both
  videofluoroscopy and FEES in 2 weeks.
• Comparison of the results revealed that
  disagreements in premature oral leakage to the
  pharynx (39.3), pharyngeal stasis (10.7),
  laryngeal penetration (14.3), aspiration
  (14.3), effective cough reflex (39.3), and
  velopharyngeal incompetence (32.1)
• FEES was found to be more sensitive in detecting
  these risky features of swallowing, except with
  respect to premature leakage

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VFSS vs FEES

• Périé S Laccourreye L Flahault A Hazebroucq V
  Chaussade S St Guily JL (1998)
• 34 patients underwent videoendoscopy, manometry
  and videofluoroscopy
• A total agreement between videoendoscopy and
  videofluoroscopy was found in 76.4 of cases for
  pharyngeal propulsion and in 82.3 for
  aspiration.
• Videoendoscopy detected nearly 90 of impaired
  pharyngeal propulsion.
• 70 of aspiration events detected by
  videoendoscopy were also observed on
  videofluoroscopy.

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Cervical Auscultation (CA)

• Definition
• Defined as listening to the sounds of swallowing
  with a stethoscope (stethoscope or other
  measurement device) at or around the level of the
  larynx to gain information about the pharyngeal
  phase of swallowing and adjacent respirations.
• Described as consisting of two distinct
  components (bursts or clunks), with or
  without a smaller third component or puff.

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Cervical Auscultation

• May provide information about
• Perceived crispness of the signal
• Bolus transit
• Sound quality of adjacent respirations
• Penetration/aspiration (coughing, throat clear,
  stridor)
• Number of swallows
• Presence of usually inaudible spontaneous
  vocalisations
• Timing of the swallow
• Relative strength of the swallow
• Clinicians make perceptual judgements as to the
  functioning of swallowing based on
• Abnormal noisy breath sounds rattly rapid
  components obscured, non-rhythmical.
• Normal rhythmical, crisp clunks expiration
  predictable dry sounds.

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Cervical Auscultation

• Technique
• In dysphagia practice, CA is usually conducted
  with the use of a stethoscope hand held over the
  lateral lamina of the thyroid cartilage.
• Takahashi et al. (1994) lateral border of
  trachea immediately inferior to the cricoid
  cartilage (site showed greatest averaged
  magnitude of the signal to noise ratio with the
  smallest variance).
• The sounds of swallow, distortions of swallow and
  respiration may be tape recorded from a
  microphone or accelerometer held over the larynx.
  The samples can then be relayed for further
  auditory analysis, for demonstration to others,
  and for comparison with CA later in the care of
  the patient.

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Cervical Auscultation

• Theoretical Causes of the Swallowing Signal
• First component
• hyolaryngeal excursion and bolus flow through the
  pharynx (Hamlet, Patterson, Fleming Jones,
  1992).
• Generated as the bolus under pressure bursts
  through the UES (Selley et al., 1994).
• Caused by vibrations resulting from simultaneous
  movement of laryngeal valving and BOT-PPW
  approximation (Chichero Murdoch, 1998).

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Cervical Auscultation

• Theoretical Causes of the Swallowing Signal,
  cont..
• Second component
• Bolus flow though the hyopharynx and UES pharynx
  (Hamlet et al., 1992).
• Generated by the final stages of pharyngeal
  clearance (Selley et al., 1994).
• Opening of the UES and the pharyngeal peristaltic
  wave to clear the pharynx (Chichero Murdoch,
  1998).

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Cervical Auscultation

• Theoretical Causes of the Swallowing Signal,
  cont..
• Third component
• Laryngeal descent post swallow pharynx (Hamlet et
  al., 1992).
• Motion of the epiglottis or lower esophageal
  activity (Mackowiak, Brenman Friedman, 1967).
• Vibrations generated by airway reopening (i.e.
  mechanical movement of epiglottis, vocal folds
  (true/false), arytenoid cartilages and release of
  subglottic air) (Chichero Murdoch, 1998).

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Cervical Auscultation

• Strengths
• Easy
• Available and portable
• Non-invasive
• Cost efficient
• No radiation exposure
• Can sample swallow repeatedly and for prolonged
  periods of time
• No contrast required - uses real food/liquid
• More appropriate referrals to VFS

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Cervical Ogulation

• Weaknesses
• No definitive data correlating the sounds heard
  with specific physiologic events and
  abnormalities
• Experience dependent
• Does not view swallowing mechanism directly
• Dependent on perceptual skills of listener
• Acoustic characteristics of stethoscopes are not
  well defined
• Noisy breath sounds in patients with Asthma,
  COAD/COPD may obscure post aspiration respiratory
  changes
• Stubble and clothing may interfere with sounds

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Cervical Australia

• Hamlet, Nelson Patterson (1990) on the basis
  of clinical experience it seems that the sound of
  a normal swallow may be distinguished from the
  sounds of a dysphagic swallow (pp.749).
• Clinical impressions suggesting that the sound of
  a normal swallow may be distinguished from the
  sound of a dysphagic swallow have been validated
  by efficacy studies

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Cervical Auscultation

• Zenner, Losinski, Mills (1995)
• Incorporated CA with stethoscope into the CSE to
  enhance the ability to detect aspiration and to
  determine specialised diet management for
  patients in long term care.
• Subjects 50 patients (males, 23-103yrs) referred
  for assessment of suspected dysphagia.
• Conducted CSE, with CA, on each patient, followed
  by VFS.

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Cervical Auscultation

• Zenner, Losinski, Mills (1995) cont
• Results

• CSE and VFS agreement
• Oral transit delay 72
• Oral residuals 62
• Pharyngeal delay 66
• Pharyngeal residuals 42
• Aspiration 76 (stat. sig.)

• Diet Mgmt
• Restriction of thin liquids 82
• Restriction of bread products 88

Results support the use of CA in detecting
aspiration and in diet recommendations for
patients in long term care. the use of CA as a
highly sensitive and specific method of dysphagia
assessment in long term care
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Cervical Auscultation

• Eicher, Manno, Fox, Kerwin (1994)
• Purpose determine whether a clinical paediatric
  swallowing assessment (incl. CA) can accurately
  predict penetration/aspiration as documented by
  VFS
• Subjects 49 children 1-319 months
• Clinical judgement and VFS agreement re presence
  of penetration and aspiration
• without CA - 76
• with CA - 86 (stat.sig.)
• Authors conclusions
• CA can be used as an effective screening tool for
  penetration/aspiration as well as follow up in
  the treatment of paediatric dysphagia.
• Feel confident when recommend to postpone or
  cancel a VFS study when evaluation with CA
  suggests a completely competent swallow.

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Oxygen Saturation

• Definition
• Non-invasive continuous measure of arterial blood
  oxygenation
• Provides information about
• Oxygenation of peripheral blood flow
• Aspiration event vs overall pulmonary status
• Technique
• Sensor placed on finger, toe, earlobe
• As oxygen content of the blood increases, blood
  colour changes
• Sensors monitor the wavelengths of light emitted
  by small light source as it passes through tissue
• Measures the amount of light absorbed by the
  blood in the tissue
• 95-100 normal range lt90 suggests significant
  problems

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Oxygen Saturation

• Sherman et al (1999)
• Patients with aspiration or penetration without
  clearing had a significant decline in Sp02
  compared to those with penetrated but cleared or
  in whom no penetration was observed.
• Colodny (2000)
• Aspirators had lower Sp02 levels before, during
  and after feeding compared with nonaspirators.
  Those who aspirated solids were most compromised.
  
• Pulse level rose for all patients from before to
  during feeding declined after feeding.
• No relationship found between levels and
  aspiration events.

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Pulse Oximetry

• Sellars, Dunnet and Carter (1998)
• Pulse oximetry was undertaken in six patients
  undergoing videofluoroscopic study of swallow.
• Normal controls also underwent pulse oximetry
  during feeding.
• No clear-cut relationship between changes in
  arterial oxygenation and aspiration.
• However, some support is found for the
  association between altered arterial oxygenation
  and oral feeding in dysphagic individuals.

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Pulse Ox-in-a-tree

• Zaidi and a bunch of other people (1995)
• For 10 weeks all acute stroke admissions were
  seen within 48 hours for oximetry assessment
• Patients swallowed 10ml water while sitting up
  and SaO2 was noted for 2 minutes.
• Two control groups underwent the same assessment.
  
• Subjects underwent independent assessment of
  swallowing by a speech and language therapist
  (SLT).
• Mean (SD) SaO2 fall in subjects 2.6 (2.9)) was
  significantly more than in control 1.1 (0.8)
  or IP 1.1 (0.9).
• Mean (SD) SaO2 fall was significantly more in
  SLT-graded 'aspirators' 4.6 (2.7) than
  'nonaspirators' 1.4 (1.0).
• Conclude that
• (1) a fall in SaO2 on swallowing fluid is common
  in patients with acute stroke (2) the presence
  or absence of desaturation agrees statistically
  with SLT assessment of aspiration (3) SaO2
  measures may aid bedside assessment of
  swallowing.

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Pulse Oximetry

• Collins MJ Bakheit AM (1997)
• Pulse oximetry was performed simultaneously with
  videofluoroscopy in 54 consecutive dysphagic
  stroke patients.
• RESULTS Pulse oximetry reliably predicted
  aspiration or lack of it in 81.5 of cases.
• The predictive value of the test was low in
  patients aged gt or 65 years and possibly those
  with chronic lung disease
• One smoker also had a false-negative pulse
  oximetry result, ie, normal oxygen saturation
  despite radiological evidence of aspiration.