WK9: Deficits in Attention: Apraxia & AHS

• What is apraxia?

  Inability to carry out skilled actions
• Why is apraxia not considered an elemental motor disorder?

  It is likely a problem in motor planning
• What usually causes apraxia?

  Brain damage to the left hemisphere
• What conditions can lead to apraxia?

  Stroke, Parkinson’s, Alzheimer’s disease
• What is the prevalence rate of apraxia after left hemisphere stroke damage?

  At least 33%
• Who first used the term apraxia?

  Steinthal in 1871
• How did Steinthal define apraxia?

  As a deficit in voluntary actions
• What distinction did Steinthal fail to make regarding apraxia?

  Between agnosia and actions with objects
• What was the case study of patient MT about?

  Unable to imitate hand positions
• What could patient MT do with their left hand?

  Perform tasks fine with the left hand
• What errors did the patient in Pick's case study make?

  Errors when using objects in sequence
• What happened when the patient in Pick's study tried to light a candle?

  Made three incorrect attempts
• What difficulties did patient MJC face in Osiurak et al.'s study?

  Problems pantomiming and imitating actions
• How did the presence of a screw affect MJC's performance?

  More problems without a screw present
• What are the six main types of apraxia according to Wheaton & Hallett (2007)?

  1. Limb-Kinetic Apraxia
  2. Conceptual Apraxia
  3. Ideational Apraxia
  4. Verbal-Motor Dissociation Apraxia
  5. Tactile Apraxia
  6. Ideomotor Apraxia
• What characterizes Limb-Kinetic Apraxia?

  Problems in basic motor coordination
• What is an example of Limb-Kinetic Apraxia?

  Difficulties in picking up a paper clip
• What defines Conceptual Apraxia?

  Loss of knowledge of how to use objects
• What is Ideational Apraxia characterized by?

  Difficulty executing correct action sequences
• What is Verbal-Motor Dissociation Apraxia?

  Failure to respond to verbal movement commands
• What does Tactile Apraxia involve?

  Inability to use hand as a sense organ
• What is Ideomotor Apraxia (IMA)?


  Motor problem not due to other disorders
• What are some deficits associated with IMA?

  Orientation, spatial, and temporal errors
• What is a common error in IMA?

  Holding a comb upside down
• What is the TOLA test used for?

  To assess oral and limb apraxia
• What are transitive tasks in the TOLA test?

  Gestures involving tool use
• What are proximal gestures in the TOLA test?

  Gestures involving upper limbs
• What is the challenge with the TOLA test?

  It does not assess tool usage
• What are the theories of Ideomotor Apraxia?

  • Disconnection Hypothesis
  • Damage to motor representations
  • Different brain damage leads to different apraxias
• What is Alien Hand Syndrome (AHS)?

  Hand acts of 'own free will'
• What brain areas are involved in AHS?

  Medial frontal lobe and corpus callosum
• What happens when the corpus callosum is disconnected?

  Hemispheres act independently
• What is a common symptom of AHS?

  Interference between hands during tasks
• What did Parkin & Barry (1991) report about patient MP?

  Hands acted in opposition during tasks
• What did Biran et al. (2006) find in their case study of patient JC?

  Alien hand would not carry out actions
• What are the three components needed to produce AHS?

  Limb disinhibition, purposeful movements, awareness
• What does the Supplementary Motor Area (SMA) do?

  Plans complex movements
• What happens when there is no inhibition from the SMA?

  Alien hand may interfere with tasks
• What are the symptoms of Alien Hand Syndrome (AHS)?

  • Unresponsiveness of the alien hand
  • Uncontrolled actions
  • Intermanual conflict
  • Subjective reactions to the hand