Spth 365 Dysphagia and Related Disorders: Diagnosis

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Spth 365 Dysphagia and Related Disorders
Diagnosis

• Lecture One
• Introduction, Neurophysiology

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Dysphagia

• Swallowing disorder characterized by difficulty
  in oral preparation for the swallow or in moving
  material from the mouth to the stomach. Subsumed
  in this definition are problems in positioning
  food in the mouth and in the oral manipulation
  preceding the swallow including suckling, sucking
  and mastication.

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Important point.

• Dysphagia is not a disease itself, rather a
  symptom or effect of another pathologic condition.

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Incidence Prevalence

• Prevalence number of cases of a disease at a
  specific time compared to the number of persons
  in the population at that specific time.
• Incidence number of cases of disease occurring
  at a specific time period compared to the number
  of persons exposed to the risk during that time
  period.

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• Incidence of reported dysphagia as primary or
  secondary diagnosis in Maryland (Kuhlemeier,
  1994)
• 3/1000 in 1979
• increased to 10/1000 in 1989.
• Is this a true increase in incidence or an
  improvement in reported/heightened awareness?

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• 6-10 million Americans with swallowing disorder
  in 1989.
• Increased to 15 million by 1991 study increase
  due to improvements in life-support systems and
  increased survival. (ASHA)

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In specific settings.

• Groher and Bukatman (1986)
• 59 nursing home incidence tends to be higher as
  population is more elderly and with increased
  neuro disease
• 25 rehab, 50 acute in the head injury
  population
• 25, 28 acute neuro/CVA by chart review
• 42 of neurogenic disorders in rehab by chart
  review and physical exam
• 30 of head and neck resections
• 12-13 of general acute hospital beds
• Of interest when methodology of study relied on
  report of nursing impression, incidence figure
  much lower (6), indicating lack of training or
  awareness.

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• Young (1990)
• Chart review of 225 patients with CVA in acute
  hospital. 28 with documented evidence of
  dysphagia.
• Teasall, etal (1994)
• Chart review of 255 patients with CVA admitted to
  rehab.
• 21 had MBS. 78 of those with aspiration on
  MBS.
• 9.9 of unilateral right CVA
• 12.1 of unilateral left CVA
• 24 of bilateral hemispheric CVA
• 39.5 of brainstem CVA

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Speech Therapy role How did we get here?

• Logemann (1974) shared common morphological
  structures and involvement of some common
  neurological pathways between speech and
  swallowing. SL(t)P involved to control for
  potential positive and negative crossover
  effects of therapy.

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How much dysphagia do we do?

• 1985 ASHA omnibus survey
• 35 of all respondents serve patients with
  dysphagia
• 1988 ASHA omnibus survey
• 42.5 of all respondents serve patients with
  dysphagia
• 1995 ASHA omnibus survey
• 51.5 of all respondents serve patients with
  dysphagia
• dysphagia consists of 14 of caseload across
  settings
• 1997 ASHA omnibus survery
• 51 of all respondents serve patients with
  dysphagia
• comprises up to 38.3 of their clinical caseload.
  
• Specific to medical settings,
• 97.4 of reporting speech pathologists in
  residential health care and
• 95.4 of those in hospitals, declare that they
  work with patients with swallowing disorders

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ASHA omnibus surveys
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What are the controversies

• High Liability Area.
• Can we adequately educate ourselves to address
  the issues?
• Many older clinicians are self-taughtgreat for
  skill development but lacking in knowledge base.
  
• Can universities keep up with this?
• How invasive is too invasive?
• Endoscopy?
• Now e-stim?
• What will this do to our relationship with
  physicians?
• We are differentiated from PT and OT at this
  point in that we are not a prescriptive service.
• Will this change if we continue to venture into
  high risk areas, thus resulting in decreased
  autonomy?

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• What will this do to the profession itself?
• Some say dysphagia will save the profession in
  times of health care reform.
• Others say we are obliterating speech pathology
  as we know it.
• Contributing to splinter professions.
• Is this true?
• Is this bad?
• What about patients with communication disorders
  only?
• Are they getting lost in the shuffle?
• Should all speech pathologists be required to be
  competent in dysphagia.
• Can it really be a specialty area or elective as
  ASHA now sees it?
• Is this feasible?
• Or will the market not accept that?

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Functional Neuroimaging Studies of Swallowing

• Birn et al (1998)
• fMRI using method relying on magnetic field
  changes, rather than BOLD.
• For both speech and swallowing, maximal magnetic
  field change occurred in inferior cortical
  regions.
• Greater activation noted for speech production of
  word one
• considered by researchers to represent lingual
  artifact

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Functional Neuroimaging Studies of Swallowing

• Mosier et al (1999)
• fMRI using BOLD technique swallow vs finger
• Swallowing with bilateral activation of
• BA 4,
• primary somatosensory cortex (BA 3,2,1),
  supplemental motor area (BA 6),
• prefrontal cortex,
• superior temporal gyrus,
• insular cortex,
• transverse temporal gyrus,
• cingulate gyrus,
• association cortices,
• thalamus
• internal capsule.

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Functional Neuroimaging Studies of Swallowing

• Mosier et al (1999) cont..
• Bilateral activation but with intra-subject
  dominance.
• Dry swallow with greater cortical activation than
  wet swallowbolus injected into posterior oral
  cavity.

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Functional Neuroimaging Studies of Swallowing

• Birn et al (1999)
• single trial, event related paradigm with fMRI
• Averaging of multiple single trials
• swallowing, jaw clenching, tongue movement and
  speech
• localization to the motor cortex inferior to the
  region associated with finger tapping
• finger tapping localized to the motor and
  auditory regions
• authors provide little specificity as to
  localization, but provide significant
  methodological contribution.

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Functional Neuroimaging Studies of Swallowing

• Hamdy et al (1999)
• single trial, event related fMRI
• injected water bolus swallow
• increased signal change observed in
• caudal sensorimotor cortex,
• anterior insula,
• premotor cortex,
• frontal operculum,
• anterior cingulate and prefrontal cortex,
• anterior and posterior parietal cortex, precuneus
  
• superiomedial temporal cortex
• bilateral activation, but with tendency toward
  intra-subject lateralization

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Functional Neuroimaging Studies of Swallowing

• Zald Pardo (1999)
• PET study of repetitive, volitional secretion
  swallowing lateral lingual movement
• localization for swallowing
• bilateral inferior precentral gyrus
• primary somatosensory cortex (BA 43)
• inferior premotor cortex in the right hemisphere
• anterior insula lateralized to the right
• cerebellum, lateralized to the left hemisphere.
• Also, putamen, thalamus, temporal gyrus, right
  inferior parietal lobe

When comparing swallowing to tongue, foci for
swallowing in right anterior insula more
anterior suggest insula specifically associated
with sequential motor task involved in swallowing
(? Sensory)
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Functional Neuroimaging Studies of Swallowing

• Hamdy et al (1999)
• PET study, block design
• water swallow via infusion
• Activation in
• sensorimotor cortices (BA 3, 4, 6)
• cerebellum
• right orbitofrontal cortex
• left mesial premotor cortex and cingulate
• right and left caudolateral sensorimotor cortex
• right and left lateral premotor cortex
• right anterior insula
• left and right temporopolar cortex
• left amygdala
• right prefrontal cortex

• bilateral superiomedial temporal cortex
• bilateal precuneus
• right anterior occipital.

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Functional Neuroimaging Studies of Swallowing
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Weakness of Functional Neuroimaging Studies

• Many techniques lack temporal sensitivity
• requires continuous execution of task
• increases oro-lingual, extra-cranial artifact
• Evaluate entire swallowing process
• motor planning execution
• volitional and non-volitional
• sensory feedback
• therefore lack specificity with and results in
  many undefined cortical sources

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