The following are three case studies with different reasons for cortical deafness. A case published in 2001 describes the patient as 20-year-old man referred for cochlear implants because of bilateral deafness following a motorcycle accident two years earlier. His CT shows hemorrhagic lesions involving both internal capsules. He was comatose for several weeks and awoke quadriparetic, cognitively impaired and completely deaf. He exhibited a response towards the occasional sudden, loud sound, however, by turning his head. Reading and writing capabilities were maintained, and he was able to communicate by lip-reading. His own speech was dysarthric, but comprehensible. Normal tympanograms and stapedial reflexes imply that the middle and inner ear remained functioning and the auditory nerve was intact. His auditory nerve was tested by evoking responses with normal auditory nerve potentials at 10 dB bilaterally. The results of the BAER waves were normal, but an abnormal complex IV-V suggested that the pathways were functioning through the brainstem, but there was a lesion present in the mid-brain. With these findings, it was determined the patient had cortical deafness due to bilateral interruption of the ascending auditory pathway associated with hemorrhagic lesions of both internal capsules. Therefore, cochlear implantation was not performed. Published in 1994, this patient was monitored over the course of almost 20 years after exhibiting signs of hearing impairment as an infant. Audiologic and related test results in concurrence with MRI confirmed bilateral absence of considerable portions of her temporal lobes resulting in cortical deafness.
Otoscopic examination revealed normal-appearing external auditory canals, intact tympanic membranes bilaterally, and normal middle ear anatomy. Audiogram at that time showed bilateral profound hearing loss with no responses to pure-tone or speech testing. Treatment
Auditory perception can improve with time. There seems to be a level of neuroplasticity that allows patients to recover the ability to perceive environmental and certain musical sounds. Patients presenting with cortical hearing loss and no other associated symptoms recover to a variable degree, depending on the size and type of the cerebral lesion. Patients whose symptoms include both motor deficits and aphasias often have larger lesions with an associated poorer prognosis in regard to functional status and recovery.Cochlear or auditory brainstem implantation could also be treatment options. Electrical stimulation of the peripheral auditory system may result in improved sound perception or cortical remapping in patients with cortical deafness. However, hearing aids are an inappropriate answer for cases like these. Any auditory signal, regardless if has been amplified to normal or high intensities, is useless to a system unable to complete its processing. Ideally, patients should be directed toward resources to aid them in lip-reading, learning American Sign Language, as well as speech and occupational therapy. Patients should follow-up regularly to evaluate for any long-term recovery. History
Early reports, published in the late 19th century, describe patients with acute onset of deafness after experiencing symptoms described as apoplexy. The only means of definitive diagnosis in these reports were postmortem dissections.