This is an old revision of the document!
Vestibulospinal Tract
The vestibulospinal tract is a descending motor pathway involved in the regulation of posture, balance, and extensor muscle tone. It originates in the vestibular nuclei of the brainstem and projects ipsilaterally to the spinal cord.
Origin
- Lateral and medial vestibular nuclei in the pons and medulla (especially Deiters’ nucleus).
Course
- Lateral vestibulospinal tract (LVST) descends uncrossed through the ventral funiculus of the spinal cord. - Medial vestibulospinal tract (MVST) descends bilaterally, primarily within the medial longitudinal fasciculus (MLF), but terminates mostly in cervical spinal cord.
Termination
- Synapses mainly in laminae VII and VIII of the spinal cord. - Influences alpha and gamma motor neurons that innervate axial and proximal limb extensor muscles.
Function
- Facilitates extensor tone, particularly for anti-gravity muscles. - Critical in maintaining balance and upright posture. - Coordinates head and eye movements in conjunction with visual and proprioceptive input.
Clinical relevance
- Lesions result in loss of postural reflexes and balance impairment. - May be overactive in decerebrate rigidity. - Involved in vestibular rehabilitation after stroke or labyrinthine injury.