sentences:  There is evidence that high intensities of worms in the intestines can affect mental performance, but a systematic review in 2000 and a 2009 update found that there was insufficient evidence to show that deworming treatments improve cognitive performance or school performance in children.HIV infection in children in sub-Saharan Africa affects their motor development, but there is insufficient evidence to show a slowing of language development.There are numerous diseases affecting the central nervous system which can cause cognitive impairment.