In case of tetanus what will be most characteristic finding

Ans is 'b' ie Masseter spasm (Ref Harrison, 16/e, p 840 (15/e, p 918) Park, 16/e, p 237)Tetanus is a neurological disorder, characterized by increased muscle tone and spasms, caused by tetanospasmin*, a powerful toxin elaborated by Clostridium tetani*.Masseter spasm or risus sardonicus is the first manifestation of tetanic spasms.Incubation period is usually 6 to 10 day*. However it may be as short as one day or as long as several months.Wounds should be cultured in suspected cases. But C. tetani can be isolated from wounds of pts. without tetanus and frequently cannot be recovered from wounds of those with tetanus.CSF examination yield normal result.