The phrase "severe handicaps" refers to serious physical or mental disabilities that make it difficult for a person to do certain things that others can do easily. Full definition
Projects on brain development mainly focus on perinatal asphyxia as this remains a major cause of (severe) brain damage in newborn infants leading to developmental delay or even severe handicaps. (grow-um.nl)
Note that playing with cursor keys, or even a pad is good for curiosity and severe handicapping only. (pcgamer.com)
They have come under criticism for enrolling a lower percentage of special education students than traditional schools, especially students with more severe handicaps, for whom the cost of schooling is two to three times as high as for other students. (articles.latimes.com)