Cortical Deafness Due to Ischaemic Strokes in Both Temporal Lobes

Abstract

Cortical deafness is a clinical rarity whereby a patient is unresponsive to all types of sounds despite the preserved integrity of the peripheral hearing organs. In this study, we present a patient who suddenly lost his hearing following ischaemic infarcts in both temporal lobes with no other neurological deficits. The CT confirmed damage to the primary auditory cortex (Heschl's gyrus) of both hemispheres. Initially, the patient was unresponsive to all sounds, however, he regained some of the auditory abilities during 10 months follow up. Pure tone threshold improvement from complete deafness to the level of moderate hearing loss in the right ear and severe in the left was observed in pure tone audiometry. Otoacoustic emissions, auditory brainstem responses, and acoustic reflex findings showed normal results. The middle and late latency potential results confirmed objectively the improvement of the patient's hearing, however, after 10 months still, they were somewhat compromised on both sides. In speech audiometry, there was no comprehension of spoken words neither at 3 nor at 10 months. The absent mismatch negativity confirmed above mentioned comprehension deficit. The extensive auditory electrophysiological testing presented in this study contributes to the understanding of the neural and functional changes in cortical deafness. It presents the evolution of changes after ischaemic cerebrovascular event expressed as auditory evoked potentials starting from short through middle and long latency and ending with event-related potentials and supported by neuroimaging.

Association of Body Mass Index with Hearing Loss in Korean Adult Population

“…A cross-sectional study of 40 patients with dyslipidemia showed that higher triglyceride levels were associated with a higher average pure-tone threshold [ 29 ]. Suzuki et al showed that low levels of high-density lipoproteins were associated with atherosclerosis-related microcirculatory disturbances of the cochlear vasculature and increased susceptibility of the cochlea to noise, resulting in an increased risk of hearing loss [ 30 , 31 ].…”

Stroke-Associated Cortical Deafness: A Systematic Review of Clinical and Radiological Characteristics

“…A total of 103 manuscripts was selected for a complete text evaluation, after which 44 were included [ 2 , 4 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. The total number of patients included was 46 ( Table 1 ).…”

“…The duration of the follow-up varied from 2 weeks to 15 years. A substantial part of the patients did not improve, and remained with a persistent inability to recognize any sound at all (16/34.8%) [ 2 , 8 , 12 , 15 , 16 , 17 , 18 , 19 , 29 , 33 , 34 , 35 , 37 , 43 , 46 , 48 ], while others evolved to pure word deafness (11/36.6%) [ 7 , 9 , 10 , 11 , 13 , 18 , 21 , 22 , 24 , 31 , 36 , 39 , 41 , 42 ]. Oral conversation was regained in six (20%) of the patients [ 7 , 20 , 25 , 27 , 28 , 32 , 42 , 43 ].…”

A review of the auditory-gut-brain axis

“…Finally, central hearing loss involves disruption to the central auditory system -which begins with the auditory nerve exiting the cochlea and continues through to the auditory cortex of the brain (Zahnert, 2011). Central hearing loss and processing disorders of the central auditory system have many possible causes, including brain lesions (Jerger, 1987), meningitis infections (Kihara et al, 2012), brain injuries (Bergemalm and Lyxell, 2005;Oleksiak et al, 2012), strokes (Bamiou et al, 2012;Fujioka et al, 2020;Lachowska et al, 2021), multiple sclerosis (MS) (Matas et al, 2010;Valadbeigi et al, 2014), heavy metal poisoning (Dutra et al, 2010;Alvarenga et al, 2015;Castellanos, 2016), prenatal hypoxia (Jiang et al, 2008) and can also occur with age (Kim and Chung, 2013).…”