The presence and severity of akathisia can be measured using the Barnes Akathisia Scale ,   which assesses both objective and subjective criteria.  Precise assessment of akathisia is problematic, as it is difficult to differentiate from a multitude of disorders with similar symptoms. In a study of movement disorders induced by neuroleptics, akathisia was found in only 26% of patients originally diagnosed with akathisia.  The primary distinguishing features of akathisia in comparison with other syndromes are primarily subjective characteristics, such as the feeling of inner restlessness.  Akathisia can commonly be mistaken for agitation secondary to psychotic symptoms or mood disorder , antipsychotic dysphoria, restless legs syndrome (RLS), anxiety, insomnia , drug withdrawal states, tardive dyskinesia , or other neurological and medical conditions. 
American Charles Osborne had hiccups for 68 years, from 1922 to February 1990,  and was entered in the Guinness World Records as the man with the longest attack of hiccups, an estimated 430 million hiccups.  In 2007, Florida teenager Jennifer Mee gained media fame for hiccuping around 50 times per minute for more than five weeks.   Christopher Sands, a Briton, hiccupped an estimated 10 million times in a 27-month period from February 2007 to May 2009. His condition, which meant that he could hardly eat or sleep, was eventually discovered to be caused by a tumor on his brain stem pushing on nerves causing him to hiccup every two seconds, 12 hours a day. His hiccups stopped in 2009 following surgery.