This document discusses apraxia of speech (AOS), which is a neurologic disorder characterized by a deficit in the ability to accurately sequence movements needed to produce speech sounds. It is caused by damage to areas involved in motor planning and programming of speech, particularly in the left frontal lobe near Broca's area. The document outlines different types of apraxia, including ideational apraxia which affects object use due to loss of knowledge, and ideomotor apraxia which disrupts voluntary movements. AOS is a subtype of ideomotor apraxia that specifically impacts phoneme production. Common causes of AOS include strokes, degenerative diseases, and traumatic brain injuries affecting the left perisylvian region

1. Apraxia of speech

2. • A neurologic deficit in the production of speech sounds.
• Errors are not caused by muscle weakness, abnormal muscle tone,
reduced range of movement, or decreased muscle steadiness.
• Errors are caused by a deficit in the ability to accurately sequence the
movements needed to produce speech sounds
• Greek word praxis – performance of action
• Apraxia – without action
• Dyspraxia – disordered actions

3. • Indl with apraxia – not without movement
• Problem with selecting and sequencing of movements needed to
produce speech
• Several types of aparaxia, of which AOS is only one of the
subcategories
• Main two types – Ideational apraxia
- Ideomotor apraxia

4. • Ideational – inability to make use of an object or gesture bc the indl
has lost the knowledge (idea) of the objects or gestures function
• Means cannot make proper use an object or gesture bc they no
longer know its purpose
• Uncommon disorder – result from damage to the left parietal lobe
• Usually symptoms can be masked easily by accompanying disorder
like aphasia
• Sometimes it resolves quickly when caused by a stroke

5. • Ideomotor apraxia – disturbance in the performance of the
movements needed to use an object, make a gesture, or complete a
sequence of individual movements
• AOS – one of the ideomotor apraxia
• Not lost their knowledge of an object or gesture
• They have a deficit in the ability to carry out the motor plan needed
to use an object or make a gesture

6. • Ideomotor apraxia typically affects voluntary movements more often
than spontaneous or automatic movements
• Movement sequencing is easier when actually manipulating a real
object compared with only pantomiming its use
• Completing a movement sequence is easier when given gestural
command (imitation)
• Movement sequencing errors can be sometimes inconsistent on
repeated attempts of the same action

7. • 3 subcategories of ideomotor apraxia
• Limb apraxia – inability to sequence the movements of the arms, legs,
hands, or feet during a voluntary action
• Most often the result of left hemisphere damage
• Nonverbal oral apraxia – buccofacial apraxia, facial apraxia, orofacial
praxia, lingual apraxia
• Deficit in the inability to sequence non verbal voluntary movements
of the tongue, lips, jaw and other associated oral structures

8. • Difficulty protruding tongue, whistling, biting the lower lip, puffing
out the cheeks
• Seen in indl with left hemisphere damage, often co-oocurwith
aphasia
• Able to perform automatic oral movements without difficulty- little
clinical significance
• Third category - AOS

9. AOS
• A deficit in the ability to select and sequence the motor commas
needed to correctly position the articulators during the voluntary
production of phonemes.
• It can co-occur with limb or non-verbal apraxia
• Caused by damage to lt frontal lobe, especially near Broca’s area
• Majority of cases – AOS co-occurs with Broca’s aphasia
• Common to co-occur with UUMN dysarthria (Duffy, 2005)

10. Neurologic basis

11. Causes of AOS
• Disorders that damage the MSP
• most common site – damage to left perisylvian area
• Injuries to insula and basal ganglia
• A retrospective study at the Mayo Clinic – 155 quasirandomly
selected cases – Duffy (2005)
- 49% of cases – stroke
Strokes affecting the perisylvian area of lt hemisphere, primarly frontal
and parietal lobes

12. - second most common – 27% - degenerative disease-
Alzheimer’s disease, PPA, Creutzfeldt-Jakob disease
Usually associated with diffuse brain damage
- third- 14%- Trauma
Surgical trauma – aneurysm repair, removal of a tumor, hemorrhage
evacuation
Closed head injury – very few
Remaining cases – tumors in lt frontal lobe, seizure d/o, undetermined
etiology or multiple causes like lt hemisphere stroke and dementia