Audiological Findings in Diffused Axonal Injury Secondary to Road Traffic Accident

Abstract

Diffused Axonal Injury (DAI) is a form of mild Traumatic Brain Injury (TBI) that occurs when there are rapid acceleration and deceleration of the head caused by road traffic accidents. It results in the accumulation of Amyloid Precursor Protein (APP) and increased calcium that causes damage to the axonal cytoskeleton and ion channels, hence resulting in degeneration. This report is of 35 year old male patient with DAI secondary to road traffic accident, where a complete audiological test battery was done. Upon multiple Computed Tomography (CT) investigations, the third CT findings revealed a hypodensity at the level of upper brainstem. Upon audiological evaluation, the patient had a moderate sensorineural hearing loss in the left ear and a mild sensorineural hearing loss in the right ear. The speech discrimination scores were poor in both the ears, thus suggesting a presence of a Retrocochlear involvement. On administering Auditory Brainstem Response (ABR), no V peak could be visualised in both ears, thus indicating a lesion at the upper brainstem which correlated with CT findings and on administering various other test batteries, findings revealed a presence of retrocochlear involvement. This study highlights the importance of carrying out both Electrophysiological and Radiological test procedures in diagnosing DAI.

Keywords

• amyloid precursor protein
• auditory evoked potential
• brainstem
• radiology
• traumatic brain injury