title: Characteristics of the aberrant pyramidal tract in comparison with the pyramidal tract in the human brain.
abstract: BACKGROUND
  The aberrant pyramidal tract (APT) refers to the collateral pathway of the pyramidal tract (PT) through the medial lemniscus in the midbrain and pons. Using diffusion tensor tractography (DTT), we investigated the characteristics of the APT in comparison with the PT in the normal human brain.
  
  
  RESULTS
  In thirty-four (18.3%, right hemisphere: 20, left hemisphere: 14) of the 186 hemispheres, the APTs separated from the PT at the upper midbrain level, descended through the medial lemniscus from the midbrain to the pons, and then rejoined with the PT at the upper medulla. Nine (26.5%) of the 34 APTs were found to originate from the primary somatosensory cortex without a primary motor cortex origin. Values of fractional anisotropy (FA) and tract volume of the APT were lower than those of the PT (P < 0.05); however, no difference in mean diffusivity (MD) value was observed (P > 0.05).
  
  
  CONCLUSIONS
  We found that the APT has different characteristics, including less directionality, fewer neural fibers, and less origin from the primary motor cortex than the PT.
authors: Department of Physical Medicine and Rehabilitation, College of Medicine, Yeungnam University, Daegu, Republic of Korea.
authors: Hyeok Gyu
authors: HG
authors: Kwon
authors: Su Min
authors: SM
authors: Son
authors: Min Cheol
authors: MC
authors: Chang
authors: Saeyoon
authors: S
authors: Kim
authors: Yong Hyun
authors: YH
authors: Kwon
authors: Sung Ho
authors: SH
authors: Jang
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000002:abnormalities* / Q000502:physiology; D056324:Diffusion Tensor Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009421:Nervous System Malformations / Q000473:pathology; D011712:Pyramidal Tracts / Q000002:abnormalities* / Q000502:physiology; D055815:Young Adult