Pyramidal signs

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Pyramidal signs indicate that the pyramidal tract is affected at some point in its course. Pyramidal tract dysfunction can lead to various clinical presentations such as spasticity, weakness, slowing of rapid alternating movements, hyperreflexia, and a positive Babinski sign. [1]

Contents

The pyramidal tract completes development and myelinization between 2 and 3 years of age. [2] Pyramidal signs occur as a normal phenomena until the age of 2, when the myelinization is finished, and so under this age they aren't considered pathological.

Pathophysiology

The upper motor neurons from the central nervous system descend through the pyramidal tracts (i.e., corticospinal tracts), connecting the brain and spinal cord and help in controlling voluntary movement of muscles. [3]

Irritative phenomena on the upper extremity

Babinski sign Babinski's sign (de).png
Babinski sign

The irritative phenomena are present if there is visible flection of the thumb, which goes to opposition:

Irritative phenomena on the lower extremity

Extension

Extension phenomena are positive if the great toe dorsiflexes (goes up) following the stimulus:

Flexion

These phenomena are positive if the toes of the foot flex:

Clinical significance

Pyramidal signs can be a result from different types of damage to the brain or spinal cord, such as strokes, infections, tumors, hemorrhagic events, multiple sclerosis, or trauma. [4]

Parkinsonian-Pyramidal syndrome (PPS) is a combination of both pyramidal and parkinsonian signs that manifest in various neurodegenerative diseases. [5]

See also

References

  1. Grant, Gerald A.; Xu, Linda; Ellenbogen, Richard G. (2018). "3 - Clinical Evaluation of the Nervous System". Principles of Neurological Surgery (Fourth ed.). doi:10.1016/B978-0-323-43140-8.00003-2. ISBN   978-0-323-43140-8.
  2. Lohia, Akash; McKenzie, Juanette (2024), "Neuroanatomy, Pyramidal Tract Lesions", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   31082020 , retrieved 2024-02-16
  3. Rogers, Laura; Wong, Eric. "Cerebral palsy". www.pathophys.org. McMaster Pathophysiology Review. Retrieved 9 September 2020.
  4. Lohia, Akash; McKenzie, Juanette (2024), "Neuroanatomy, Pyramidal Tract Lesions", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   31082020 , retrieved 2024-02-16
  5. Tranchant, Christine; Koob, Meriam; Anheim, Mathieu (June 2017). "Parkinsonian-Pyramidal syndromes: A systematic review". Parkinsonism & Related Disorders. 39: 4–16. doi:10.1016/j.parkreldis.2017.02.025. PMID   28256436.

Further reading