Loss of Proprioception
August 19th, 2017
Overview
Proprioception is the sense of position and movement of the body in the absence of vision.
How to Elicit
- Ask the patient to observe as you demonstrate upward and downward movement of the great toe.
- With their eyes closed, slowly move the joint over one to two seconds to the upward or downward position.
- Ask the patient to report whether the toe has been moved up or down.
- Repeat several times, and then repeat on the other side.
Hold the medial and lateral sides of the interphalangeal joint of the great toe, in order to avoid giving away tactile clues.
If proprioception is impaired at the great toe, repeat at the foot (Chopart's joint). If also impaired, repeat at the ankle, knee and then hip.
Causes of Isolated Vibration and Proprioceptive Loss
- Demyelination - proprioceptive and vibration fibres are myelinated while pain sensation fibres are not.
- Brainstem lesions involving the medial lemniscus
- Dorsal spinal artery occlusion (unilateral impairment)
Dorsal Column Pathway
Cortical Centre
Primary sensory cortex (postcentral gyrus)
Primary sensory cortex (postcentral gyrus)
3rd Order Nuclei
Ventral posterolateral (VPL) nucleus of thalamus
Ventral posterolateral (VPL) nucleus of thalamus
Central Pathway
Medial lemniscus
Medial lemniscus
Decussation
Medulla
Medulla
2nd Order Nuclei
Lower medulla - nucleus cuneatus (UL) / gracilis (LL)
Lower medulla - nucleus cuneatus (UL) / gracilis (LL)
Spinal Pathway
Dorsal column - fasciculus cuneatus (UL) / gracilis (LL)
Dorsal column - fasciculus cuneatus (UL) / gracilis (LL)
1st Order Nuclei
Dorsal root ganglion
Dorsal root ganglion
Receptors
Pacinian corpuscles / Merkel disc receptors / Meisner's corpuscles (vibration)
Neuromuscular spindles (proprioception)
Pacinian corpuscles / Merkel disc receptors / Meisner's corpuscles (vibration)
Neuromuscular spindles (proprioception)
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