Brain Injury, March 2010; 24(3): 525–532 Relationship between severity of traumatic brain injury (TBI) and extent of auditory dysfunction SANJAY KUMAR MUNJAL 1 , NARESH K. PANDA 1 , & ASHIS PATHAK 2 1 Department of Otolaryngology, Head and Neck Surgery and 2 Department of Neurosurgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India (Received 4 June 2009; revised 25 November 2009; accepted 26 November 2009) Abstract Objective: To find out the relationship between severity of traumatic brain injury (TBI) and extent of auditory dysfunction Background: Most of the studies have taken the subjects with TBI as one group without taking into account the extent of head injury viz. mild, moderate and severe. Combining all the three groups has resulted in presenting an incomplete picture of auditory deficits following TBI. Methods and procedures: The sample population consisted of 290 subjects with TBI (study group) and 50 otologically normal subjects as controls. The subjects in the study group were further sub-divided into mild (n ¼ 150), moderate (n ¼ 100) and severe (n ¼ 40) TBI. The audiological assessment consisted of pure tone audiometry, speech audiometry, tympanometry, acoustic reflex testing, auditory brainstem response and middle latency response audiometry. Results and conclusions: An association was observed between the extent of auditory dysfunction and severity of TBI. This association was more pronounced for hearing status at high frequencies and ABR/MLR components. ABR Wave V absolute latency and I–V interpeak latency increased with severity of TBI. Amplitude of MLR wave Na and Pa decreased with increasing severity. It is suggested that subjects should be evaluated for hearing difficulties based on their severity of TBI. Keywords: Audiological assessment, head injury, auditory brainstem responses Introduction The incidence of head injury (HI) is steadily increasing with urbanization and the growth of the vehicular population [1]. An awareness of the magnitude of this problem and its far-reaching consequences are causes of concern among medical and behavioural scientists. Damage to the peripheral auditory structures has long been recognized as common sequelae of head-injury. It is estimated that a majority of subjects with skull trauma have resultant hear- ing impairment. The otologic changes are varied, and depend on the type, magnitude and direction of trauma. Traditionally, differentiation and descrip- tion of temporal bone fracture have been stressed in reports of peripheral otologic trauma. Auditory dysfunction, which typically is a component of temporal bone fractures, may also occur in subjects without evidence of fracture. Middle ear pathology is not uncommon in either condition [2]. Traumatic brain injury (TBI) is the essence of the problem of accidents, since it produces not only widespread damage but also lesions that vary from neuronal stretch to brain laceration and massive haemorrhage. It makes a clear contribution to chronic neurologic morbidity and is the most Correspondence: Naresh K. Panda, MS DNB, FRCS (Edin), Professor and Head, Department of Otolaryngology, Head and Neck Surgery, Post Graduate Institute of Medical Education and Research, Chandigarh, India 160012. Tel: þ91-172-2756760. Fax: þ91-172-2744401, 2745078. E-mail: npanda59@yahoo.co.in ISSN 0269–9052 print/ISSN 1362–301X online ß 2010 Informa Healthcare Ltd. DOI: 10.3109/02699050903516872 Brain Inj Downloaded from informahealthcare.com by HINARI on 04/17/12 For personal use only.