What is the function of the corticospinal (CST) tract?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: February 18, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The primary function of the corticospinal tract (CST) is to transmit motor signals from the brain to the spinal cord, controlling voluntary movements of the body, particularly the limbs 1.

Key Functions

  • It is responsible for regulating the contraction and relaxation of muscles, allowing for precise and coordinated movements.
  • The CST is divided into two main pathways: the lateral corticospinal tract, which controls the limbs, and the anterior corticospinal tract, which controls the trunk and proximal limb muscles.

Clinical Implications

  • Damage to the CST can result in weakness, paralysis, or loss of motor control 1.
  • Measures of CST white matter integrity, such as fractional anisotropy (FA), can predict motor outcome and treatment response in patients with stroke 1.

Diagnostic Biomarkers

  • The presence of a motor evoked potential (MEP) in response to transcranial magnetic stimulation (TMS) is a strong predictor of good motor outcome 1.
  • Combining neuroimaging and neurophysiology biomarkers, such as MRI and TMS, can provide a more accurate prediction of motor outcomes and therapy response 1.

From the Research

Function of the Corticospinal Tract

The corticospinal tract (CST) has several functions, including:

  • Modulation of sensory inputs in the spinal cord [ 2 ]
  • Conveying motor commands to bulbar or spinal motoneurons [ 3 ]
  • Playing a major role in cortical control of spinal cord activity [ 3 ]
  • Being the principal motor pathway for voluntary movements [ 3 ]

Motor Control and Recovery

The CST is also involved in:

  • Motor recovery after spinal cord injury [ 4, 5 ]
  • Enhancing voluntary motor output in motor disorders affecting the CST [ 4 ]
  • Promoting recovery of motor function through sprouting of the CST [ 5 ]

Development and Refinement

The development and refinement of the CST is driven by:

  • Neural activity in the motor cortical areas [ 6 ]
  • Limb motor experience [ 6 ]
  • Competition between developing corticospinal terminals for synaptic space on spinal neurons [ 6 ]

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.