 According to Swerdlow, "the 'core' TS conundrum" is a lack of consensus about the definition of Tourette syndrome.Since vocal tics result from a "motor event (ie, a contracting diaphragm moving air through the upper airways)", TS could be defined as a disorder of motor tics, eliminating the distinction between TS and the other tic disorders.Individuals who have only tics may not be functionally impaired, raising the question of whether Tourette's as currently defined should be a DSM diagnosis.