Patterns of hearing loss in tympanic membrane perforation resulting from physical blow to the ear: a prospective controlled cohort study

• Published in: Clinical otolaryngology 2009-12, Vol.34 (6), p.526-532
• Main Authors: Orji, F.T., Agu, C.C.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Audiometry, Pure-Tone; Blast Injuries - complications; Bone Conduction - physiology; Child; Cohort Studies; Ear - injuries; Female; Hearing Loss, Conductive - diagnosis; Hearing Loss, Conductive - epidemiology; Hearing Loss, Conductive - etiology; Hearing Loss, Sensorineural - diagnosis; Hearing Loss, Sensorineural - epidemiology; Hearing Loss, Sensorineural - etiology; Humans; Incidence; Male; Middle Aged; Prevalence; Prospective Studies; Severity of Illness Index; Tympanic Membrane Perforation - complications; Tympanic Membrane Perforation - etiology; Young Adult
• ISSN: 1749-4478; 1749-4486
• DOI: 10.1111/j.1749-4486.2009.02035.x

Objectives:  To evaluate the incidence and pattern of hearing loss in non‐explosive blast injury of the ear. Study design:  Prospective clinical study. Setting:  Tertiary referral centre. Participants:  Consecutive patients who suffered physical blow to the ear resulting in tympanic membrane perforations without history of previous middle ear disease. Main outcome measures:  Incidence of conductive and sensorineural hearing loss, extent of air–bone gap versus size and site of perforation, post‐healing hearing loss recovery. Results:  Fifty‐one patients, 31 males (61%) and 20 females (39%) aged 10–56 years, were recruited over a 30 month study period. The prevalence of hearing loss was significantly more in the injured ears than contralateral normal ears (χ2 = 76.26; P = 0.000). Pure conductive hearing loss occurred in 39%, while 28% (14 patients) had mixed hearing loss. Three patterns of sensorineural loss were observed: dip involving several adjacent high frequencies, a dip in a single frequency, and two separate dips involving low and high frequencies. The extent of air–bone gap correlated with the size of perforation (r = 0.33; P = 0.01). Ears that sustained small tympanic membrane perforation showed significantly small average air–bone gap (t = 2.97; P = 0.005). The mean air–bone gap difference between the anterior and posterior perforations was not significant (t = 1.7; P = 0.09). Closure of air bone gap following healing was significant (t = 15.08; P