×
MedSchool: Ace Your OSCEsThe Medical Company
 
 
 
 
 
GET - On the App Store
View
Signs
 
 

Vibration Sense

 
Bookmark

Overview

Also known as pallesthesia
  • How to Assess

  • With the patient's eyes closed, place a vibrating 128hz tuning fork over the interphalangeal joint of the great toe. Ask the patient to describe the sensation. If they can feel it vibrating, progressively diminish the vibration until they cannot feel it. If they cannot feel it vibrating, test on the medial / lateral malleolus and then the tibial tuberosity.
This test is best performed on skin overlying bone rather than soft tissue.
  • 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)
 
 
3rd Order Nuclei
Ventral posterolateral (VPL) nucleus of thalamus
 
 
Central Pathway
Medial lemniscus
Decussation
Medulla
 
2nd Order Nuclei
Lower medulla - nucleus cuneatus (UL) / gracilis (LL)
 
 
Spinal Pathway
Dorsal column - fasciculus cuneatus (UL) / gracilis (LL)
 
1st Order Nuclei
Dorsal root ganglion
 
 
Receptors
Pacinian corpuscles / Merkel disc receptors / Meisner's corpuscles (vibration)
Neuromuscular spindles (proprioception)

Overview

  • Note

    Vibration sense is mediated by
  • Merkel disc receptors (low frequencies 5-15 Hz)
  • Meissner’s corpuscles (mid frequencies 20-50 Hz)
  • Pacinian corpuscles (high frequencies 60-400 Hz)
Therefore clinical testing of vibration is mediated by pacinian corpuscles.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now
   
 
 

Snapshot: Initialising...