Apraxia!
The disorder of motor cognition
Hugo Karl Liepmann (1863 - 1925)
2) Definition
“Inability to perform a higher motor task”
It can’t be explained by weakness, sensory loss, or lack of understanding
3) Apraxia assessment
Pantomime
Meaningful hand gestures
Buccofacial apraxia
Meaningless hand gesture
Luria 3-steps task
*Describe the body part and the impaired movement
*Consider mistake, if persist after correction
4) Meaningless hand gesture
5) Luria (3-steps task)
- working memory and executive function
6) Pathophysiology
L-side parietal lobe is related to space-time form picture
7) Liepmann's forms
Ideational
- conceptual
Ideomotor
- action production
- inability to map motor engrams
Limb- kinetic
- action production
- fine-motor/ clumsy
8) Localization
Poor localization value
Inf parietal lobe - ideational
Sup parietal lobe - ideomotor
9) Ideational
- no comprehension of appropriate use for a tool
> omit steps or steps out of order
- can do the task if demonstrated
10) Ideomotor
- error in scaling, timing, or orientation of mov
- body-part-as-object error
> highlight right use for patients
- only limb apraxia 2/2 sparing bundle of Turck (sup temp; temporopontine tract)
- sympathetic apraxia in the nonparetic limb 2/2 lost connection R&L
11) Limb-kinetic
- melo-kinetic (melody)
- pure dexterity problem
- Test: playing cards, picking up coin from table
12) Speech
- shape, ordering and timing of syllables
- L-side inferior frontal gyrus & L-side anterior insular
- speech apraxia versus aphasia?
- speech apraxia versus dysarthria
> single syllable magnifies dysarthria
> 2 or more syllables magnifies both disorders
13) Buccofacial
- ventral premotor cortex
14) Other forms of apraxia (not true apraxia?)
Constructional
- inability to copy drawings or 3D pictures
- no motor problem
- Rey-Osterrieth complex figure
15) Dressing apraxia
- turn one sleeve of the hospital gown inside out, and then ask the patient to put it on
- inability to represent the spatial, kinesthetic components of visually guiding her hands to her clothes
- dorsal (sup) visual association cortex and pathways in the parietal lobe
16) Eyelid opening
- automatic and not skilled
- co-contraction agonist-antagonist; dystonia?
PD and has developed EOA following DBS
- sensory trick (similar to dystonia)
- help of fingers to open
- PSP
- misnomer
- velocity of opening (slow)
- frontalis muscle (contraction)
- buccinator (no contraction)
17) Oculomotor
- inability of voluntary saccades to a visual target
- post parietal region
- not higher motor control
Congenital Ocular Motor Apraxia
- failure to initiate horizontal saccades to the right and left
- head thrusts to fixate on a target
Ocular Motor Apraxia - compensatory mechanisms
- head thrust (VOR)
- blinking (turn off the omnipause neurons in the pons)
- simulta eye & head mov (suppress VOR)
- VOR for confirm EOM amplitude
- normal VOR
18) Gait
- not higher level, usually associated with global impairment
- rare, true apraxia