This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
The affections of the brain of most anatomical interest are those involving its circulation, the motor areas, and the motor paths. Paralyses may arise from (a) interference with the motor areas in the cortex by hemorrhages, injuries, or tumors; (b) destruction of the motor paths from the cortex to their point of exit from the brain; (c) injury of the nerves at their exit from the brain.
Disturbances of the circulation may be either of the nature of anaemia or ischae-mia, causing softening, or of congestion, causing apoplexy.