Childhood Apraxia for Speech

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Childhood Apraxia for Speech
Cherry Hill Apraxia Support Group February 28,
2008
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Apraxia an SLPs view
Apraxia A motor planning impairment

• Types Ideomotor, Kinetic, and Developmental
  Apraxia for speech
• No questioning
• Assessment no clear distinguishing
  characteristics, using symptom checklists
• Treatment effect
• Uncertainty and parents

Longitudinal studies

• Learning disability - at risk
• So is it really motor planning? Language?
  Cognition?

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• Is it a pure motor planning deficit?
• Could the underlying causes be different
  deficits?

- Could we explain ALL the features observed? -
Can we suggest more effective therapy
approaches?
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Childhood Apraxia of Speech (CAS)

• Currently there is no single validated list of
  diagnostic
• features for CAS
• Difficult to differentiate between CAS and other
  pediatric
• speech-language disorders
• Many children with CAS may be misdiagnosed with a
  neuromuscular
• disorder (dysarthria), phonological delay, or
  even pervasive
• developmental disorder

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CAS - definition
Childhood apraxia of speech (CAS) is a
neurological childhood (pediatric) speech sound
disorder in which the precision and consistency
of movements underlying speech are impaired in
the absence of neuromuscular deficits. CAS may
occur as a result of known neurological
impairment, in association with complex
neurobehavioral disorders of known or unknown
origin, or as an idiopathic neurogenic speech
sound disorder. The core impairment in planning
and/or programming spatiotemporal parameters of
movement sequences results in errors in speech
sound production and prosody.
ASHA Ad Hoc committee on apraxia of speech (2006)
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CAS - definition
Cont.

• Inconsistencies in diagnosis have prevented
  research from moving
• Forward
• Children with CAS are at risk for persistent
  speech, expressive
• language, and literacy problems
• CAS is currently viewed as a motor planning
  problem
• However, we have seen clinically that treating
  CAS as a motor
• problem has not been effective
• CAS could be a language problem involving speech
  sounds (phonology)

ASHA (2007)
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CAS as a language problem

• Phonology how sounds are put together to form
  words in a language
• Problems with the organization and perception of
  sounds
• are linguistic in nature
• Difficulties in both generating and recognizing
• rhymes (Marion et al., 1993)
• Difficulties perceiving and comparing syllables
• (Marquardt et al., 2002)

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CAS Theoretical Perspectives

• Input processing deficit
• Organizational processing deficit
• Representational processes

• Output processing deficit
• Motor programming deficit
• Prearticulatory sequencing deficit.

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(No Transcript)
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Phonological theory

• Every sound in a language is represented in the
  brain as a set of features
• E.g., a /p/ sound would involve activating
  features like labial, plosive
• A /b/ sound would involve activating features
  like labial, plosive and voice
• A dominant theory at present suggests that all
  these features are not active all the time in
  each language, only a few features are needed
• One suggestion has been that, in CAS, too many
  features are active
• This would mean that CAS is primarily a problem
  with the representation of sounds in the brain
• We can test whether this is a good hypothesis by
  examining brain activity in children with CAS as
  they process and produce sounds

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Feature Geometry
A way of indicating the interdependence of
features involved in sound structure
representation
Root
sonorant
laryngeal
consonantal
lateral
voice
continuant
nasal
spread glottis
voice
place
constricted glottis
coronal
labial
dorsal
round
anterior
distributed
high
back
low
labiodental
grooved
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EEG Experiment

• Noninvasive and extremely safe functional brain
  recording
• Measures electrical currents naturally produced
  by the brain
• Recorded by electrodes placed on surface of scalp
• We can observe the brains natural responses to
  specific stimuli

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EEG Experiment

• Consonants such as /p/ and /b/ are distinguished
  by very short bursts of voicing which last only
  around 40 milliseconds
• EEG has a high time resolution allowing us to see
  neurophysiological responses to stimuli just
  milliseconds after their presentation
• Using EEG we can measure the childs automatic
  response to the presentation of a speech sound,
  even if the child is not paying attention to the
  sounds

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What your child will
experience
before the experiment

• Measure head to determine size of sensor net
• 128 channel sensor net soaked in a salt water
  solution
• The Brain Spa seating each of the electrodes
  in the proper position
• Check contacts

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What your child will
experience
during the experiment

• You may be with your child at all times
• Child will be seated comfortably in our
  soundproof room
• Child will watch visually stimulating
  age-appropriate material
• on a computer screen while a series of speech
  sounds are played through headphones
• The experiment will take about
• 15 minutes

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What wed like you to do

• Please ask questions well tell you anything
  you would like to know about our plans for the
  study
• Wed like your organization to support this work
• We need a letter of support from your group
  stating that youre willing for us to recruit
  study participants
• We will obtain approval from our Institutional
  Review Board to carry out the study, with your
  involvement
• Then we will write to each of you, asking again
  for you and your child to participate
• If you agree, please get in touch with us to
  arrange your visit to the lab

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What well do

• Protect your confidentiality at all times
• Make it a fun learning
• experience for your
• children
• Keep you updated with
• progress as we carry out the
• study
• Present our results to you at the
• end of the study
• Present our results at professional conferences,
  and publish in scientific journals, to advocate
  for children with CAS

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Thanks! Questions, comments?

• Neurocognition of Language Lab
• Teachers College, Columbia University
• 212-678 8158 rk2121_at_columbia.edu
• www.tc.edu/neurocog