Abstract
Lightning strike can produce an array of clinical symptoms and injuries. It may damage multiple organs and cause auditory injuries ranging from transient hearing loss and vertigo to complete disruption of the auditory system. Tympanic-membrane rupture is relatively common in patients with lightning injury. The exact pathogenetic mechanisms of auditory lesions in lightning survivors have not been fully elucidated. We report the case of a 45-year-old woman with bilateral profound sensorineural hearing loss caused by a lightning strike, who was successfully rehabilitated after a cochlear implantation.
1
Introduction
Lightning is a phenomenon in which an electric discharge of 40,000 to 50,000 A, and temperature of 20,000°C is generated between the clouds and the earth; it can cause serious injury to humans . Otologic injury by lightning has been occasionally reported, with perforation of the tympanic membrane being the most common injury, accompanied by ossicular disruption, vestibular organ injury with transient vertigo, sensorineural hearing loss, and tinnitus. Tympanic-membrane perforation and hearing loss need to be managed actively because the neurologic sequelae caused by lightning injury is more diverse than those caused by other factors . We report a case of cochlear implantation in a patient with severe sensorineural hearing loss caused by lightning, which was not recovered by medical treatment with review of literature. This manuscript has been approved by the Institutional Review Board of Pusan National Universtiy Yangsan Haspital.
2
Case
A 45-year-old woman visited the emergency department, presenting with hearing loss, dizziness, and burns on the neck and right upper extremities. The lightning struck her right arm, traveled through the whole body, and then reached the earth. The patient showed alert consciousness but was restless. Physical examination showed first-degree burns on the right upper extremity, chest, and neck regions. The left tympanic membrane showed total perforation, whereas the right was intact ( Fig. 1 A ). The patient reported no history of otologic management and operation. There was no evidence of facial palsy. She complained of mild vertigo. The pure-tone audiogram (PTA) showed bilateral severe hearing loss, but the computed tomographic findings for the temporal bone were normal. The results of the auditory brainstem response test were the same as the PTA results. A right behind-the-ear-type hearing aid was used for 3 months, but no improvement was noted. The PTA threshold levels after 8 months were 81 dB (R) and 78 dB (L) ( Fig. 2 ). The size of the perforation in the left tympanic membrane had reduced ( Fig. 1 B). The results of the transitory evoked otoacoustic emission test showed that wave reproducibility was 19% in the left ear and 5% in the right ear; the distortion product otoacoustic emission test showed no evidence of a functioning cochlea. Cochlear implantation was performed 9 months after the lightning injury in the right ear according to the results of the promontory stimulation test with the Cochlea Nucleus CI 24R system. The results of the speech perception test before the operation were as follows: 19 of 50 in the environmental test; and 12 of 20 (3 syllables), 9 of 20 (2 syllables), and 0 of 20 (1 syllable) in the open-set test. Those obtained 6 months after the operation were as follows: 48 of 50 in the environmental test; and 19 of 20 (3 syllables), 9 of 20 (2 syllables), and 13 of 20 (1 syllable) in the open-set cognition test.
