Total of @ patients with ISSNHL , including @ with hearing loss in low-middle frequencies , @ in middle-high frequencies , @ in all frequencies and @ in total deafness , were randomly divided into two groups , the systemic application group : dexamethasone ( DEX ) was applied by intravenous injection in dose of @ mg@ d followed by @ mg@ d , and the topical injection group : methylprednisolone sodium succinate of @ mg was injected into cortical bone of mastoid region every three days .