Definition of crus cerebri in US English:

crus cerebri


  • Either of two symmetrical tracts of nerve fibers at the base of the midbrain, linking the pons and the cerebral hemispheres.

    • ‘Descending fibers course through the massive cerebral peduncles (crura cerebri), the most ventral parts of the midbrain (mesencephalon).’
    • ‘The DWI-trace maps and the ADC-maps were analyzed in 10 regions of interest bilaterally: centrum semiovale, ventral, occipital and temporal white matter, dorsal limb of internal capsule, globus pallidus, thalamus, crus cerebri, pons and white and grey matter of cerebellum.’
    • ‘The Posterior Perforated Space corresponds to a whitish-grey substance, placed between the corpora albicantia in front, the pons Varolii behind, and the crura cerebri on either side.’
    • ‘This intersecting and mingling is characteristic of association bundles, and contrasts with the orderly formation of projection tracts found in the internal capsule and crus cerebri.’
    • ‘Lateral pressure on the midbrain can, however, compress the opposite crus cerebri against the free edge of the tentorium, forming an indentation in the crus known as Kernohan's notch.’


Early 18th century: from Latin, literally ‘leg of the brain’.


crus cerebri