Introduction

Sensorineural hearing loss (SNHL) is a kind of loss of hearing originating from the inner ear sensory organ (cochlea as well as related structures) [1—3].

Sensorineural hearing loss occurs due to damage to the tiny cell of the hair within the cochlea. In adults, sensorineural hearing loss is usually a result of head trauma, exposure to loud noises, aging, or other conditions. The most prevalent causes of sensorineural hearing loss in kids are inner ear anomalies, genetic variations, jaundice, and viral infections from the mother throughout gestation [4—6].

Symptoms of sensorineural hearing loss may involve steady or sudden loss of hearing, muffled hearing, difficulty understanding speech, a full or “stuffy” ear sensation, ear ringing, in addition to dizziness [7].

SNHL occurs due to damage to the tiny cells of the hair of the cochlea and/or the auditory nerve. Sound enters the cochlea; however, hair cells that have been damaged cannot change sound waves into neural signals that traverse the auditory nerve to the brain. Abnormalities of the auditory nerve would additionally result in SNHL [8, 9].

SNHL can arise from malformations of the inner ear (either genetic or environmental abnormalities ), acoustic trauma from exposure to loud noises (such as industrial machinery or gunfire/explosions near the ear), sudden hearing loss potentially induced by viral infections, age-related degeneration of the cochlea or related inner ear structures and auditory nerves, head trauma or abrupt alteration in air pressure, autoimmune inner ear illnesses where in the immune system attacks the inner ear leading to progressive loss of hearing in both ears, Meniere’s disease (MD) distinguished by fluctuating loss of hearing, dizziness, sensation of fullness in the ear, and tinnitus, central nervous system illness resulting from conditions like multiple sclerosis, cochlear otosclerosis, and benign tumors such as vestibular schwannoma that compress the auditory nerve connecting the inner ear to the brain, leading to SNHL.

The diagnosis of SNHL frequently starts with a careful history, physical exam, and investigations such as viral studies, audiological studies such as pure tone audiometry (PTA), and imaging studies such as MRI or CT brain. A physical exam may look for proof of an infection with viruses or head trauma. A careful history illustrates probable ototoxic drugs [10—16].

Treatment options can include medical treatments with corticosteroids (oral or intratympanic injection) that can be utilized to decrease cochlear hair cell inflammation and swelling, platelet-rich plasma (PRP), hearing aid(s) fitting, and operation to correct the etiology of the hearing loss as an implantable hearing device [17—19].

Idiopathic sudden sensorineural hearing loss (ISSNHL) is frequently characterized as SNHL of thirty decibels or more over at minimum three contiguous audiometric frequencies, happening within a seventy-two-hour duration. The cause of ISSNHL is still unclear. The pathogenesis is frequently attributed to infection and disrupted microcirculation [20—22].

Hearing loss correlated with age, or presbycusis, is a symmetrical, progressive, bilateral SNHL due to cochlea degeneration or related auditory nerves structures or inner ear. The loss of hearing is most apparent at greater frequencies. Presbycusis is caused by a combination of genetics, cumulative environmental exposures, in addition to age-related physiological alterations [23].

MD is an inner ear illness distinguished by possibly severe and incapacitating episodes of tinnitus, vertigo, a sensation of ear fullness, and hearing loss. Initially, often just one ear is influenced; however, both ears might become affected with time. Episodes often last from twenty minutes to a few hours in duration. The interval among episodes differs. Ringing and loss of hearing may become persistent over time. The etiology of MD remains unknown; however, it probably includes both environmental and genetic factors. Several theories are present for why it happens, like autoimmune reactions, constrictions in blood vessels, as well as infection with virus [24—27].

Acoustic trauma, which is caused by exposure to loud noises (e.g., machinery/industrial or gunfire/explosion close to the ear). The severity might range from pain to hearing loss. Acute acoustic damage might be managed by a combination of hyperbaric oxygen treatment and corticosteroids (either orally or via intratympanic injection), whereas chronic acoustic trauma can be managed with hearing aids or PRP [28, 29].

PRP is an autologous treatment derived from the case’s blood. It has been observed to have beneficial properties for nerve regeneration and is therefore used in the field of ear, nose, and throat for several uses [30—33].

Material and methods

Study design

This is a cross-sectional research.

Study subjects

150 cases who had SNHL. All patients received 4 intratympanic injections of PRP with one-week intervals between them. This study was performed at the Al Azhar Faculty of Medicine, New Damietta, from 2021 to 2023.

Patient selection

Inclusion criteria: patients with SNHL:

1) are age eighteen years or older;

2) had a SNHL due to acoustic trauma, presbycusis, ISSNHL, and MD;

3) had no retrocochlear pathology as illustrated by a negative magnetic resonance imaging.

Exclusion criteria: cases with a history of cancer who have recently had chemotherapy or radiation treatment, those with autoimmune illnesses, congenital cochlear malformations, acute otitis media exhibiting aberrant tympanometry, neurological disorders, current utilization of ototoxic drugs, severe hepatic or kidney dysfunction, and pregnancy.

Procedure. The intratympanic PRP injection treatment has been conducted using an endoscope while the case was in a supine position. Following the surgeon’s confirmation of a middle ear state and intact tympanic membrane, local anesthesia has been administered using a cotton ball saturated utilizing a pump spray containing ten percent Lidocaine (Xylocaine), applied to the tympanic membrane for a duration of twenty minutes. As the case tilted the head at 45 degrees towards the unaffected side, a 25-gauge spinal needle has been inserted into the posteroinferior region of the membrane, and half a milliliter of PRP was administered through this location, as seen in Fig. 1. The case has been instructed to prevent eating or movement for thirty minutes while maintaining the same position. It has been conducted four times with one-week periods between them [34, 35].

Fig. 1. Sites of injection.

Statistical analysis and data interpretation

Data analysis has been carried out utilizing SPSS software, version 25 (SPSS Inc., PASW Statistics for Windows version 25). Chicago: SPSS Inc. Qualitative information has been represented by percentages and numbers. Quantitative data have been characterized by Mean±SD for information that are normally distributed, following normality assessment by the Kolmogorov-Smirnov test. The significance of the outcomes attained has been assessed at the (≤0.05) level. Monte Carlo test have been utilized to compare qualitative information among groups where suitable. One-way ANOVA has been utilized to compare across two separate groups, with the post hoc Tukey test utilized for pairwise comparisons (Figs. 2—4).

Fig. 2. Before IT PRP injections (acoustic trauma).

Fig. 3. After IT PRP injections (acoustic trauma).

Fig. 4. Before IT PRP injections (ISSNHL).

Results

In our study, 150 cases with SNHL diseases, such as acoustic trauma, presbycusis, MD, and ISSNHL (68 (46.3%) males and 82 (54.6%) females), with age ranges from 18 to 78 years, received intratympanic injections of PRP. 50 patients with ISSNHL: 39 of them showed hearing improvement, with an average of 28 dB in PTA and 26% in speech discrimination. In acoustic trauma, 18 patients, 12 of them, showed hearing improvement, averaging 30 dB in PTA and 28% in speech discrimination. In presbycusis, 58 patients, 42 of them, showed an improvement in hearing of an average of 25 dB and 24% in speech discrimination. In MD, 24 patients, 16 of them, showed an improvement in hearing of an average of 15 dB and 5% in speech discrimination.

Table 1. Age and sex of all patients

Table 2. Age of the studied groups

Table 3. Hearing improvement frequency among studied groups

Table 4. Comparison of PTA between studied groups

Discussion

SNHL is a prevalent otolaryngologic condition marked by cochlear injury, leading to diminished or complete hearing loss [1—3].

PRP is an autologous treatment obtained from a case’s blood and has demonstrated pro-nerve regeneration characteristics. We administered 0.5 milliliters of PRP into the posteroinferior region of the tympanic membrane, and the case has been instructed to avoid eating or movement for thirty minutes, maintaining a stationary position. It has been conducted four times at one-week intervals [30, 31].

Harendra Kumar Gautam Ruchika et al. (2022) showed in the article “Role of Platelet-rich Plasma in Sensory Neural Hearing Loss” that intratympanic PRP injection significantly enhanced the status of the hearing in acute mild-to-severe cases of sensory hearing loss without any complication. Consequently, PRP may be a valuable substitute therapy method for SNHL cases. In this article, the number of patients with ISSNHL who recovered by PRP injection was 81.4%. In our study, the number of cases with ISSNHL who recovered by PRP injection was 78%, so there is a similarity in the results of plasma injections between both articles.

Stephy Maria Tom et al. in 2022 showed in the article “Clinicoaudiological evaluation of hearing improvement in patients with sensorineural hearing loss using intratympanic platelet-rich plasma versus steroid injection” that PRP has a greater effect than steroid injection in sudden and gradual SNHL diseases.

Bps Tyagi and Mamatarani Rout in 2019 showed in the article “Platelet Rich Plasma (PRP): A Revolutionary Treatment of Sensorineural Hearing Loss” that the introduction of PRP in otorhinolaryngology, and particularly in SNHL, is carrying revolutionary wonders in management.

Deniz Baklaci et al. in 2023 showed in the article “The Potential Therapeutic and/or Protective Effects of Steroid, PRP, and Melatonin on Noise-Induced Hearing Loss in Rats” an improvement in NIHL through melatonin injection alone and melatonin with PRP.

Plasma is used in many illnesses of the nose, ear, and throat, and this is explained in several studies; for example, Mahmoud Ahmed Shawky and Abdelgawad Mohamed Hadeya in 2023 showed in the article “Platelet-rich plasma in Management of Anosmia (Single versus Double Injections)” that PRP seems safe and efficient for utilization in the management of olfactory loss.

In our research, we found 50 patients with ISSNHL. 39 of them showed hearing improvement, averaging 28 dB in PTA and 26% in speech discrimination, while in acoustic trauma, 18 patients, 12 of them, showed hearing improvement, averaging 30 dB in PTA and 28% in speech discrimination, while in presbycusis, 58 patients, 42 of them, showed an improvement of hearing, averaging 25 dB and 24% in speech discrimination, while in MD, 24 patients, 16 of them, showed an improvement of hearing, averaging 15 dB and 5% in speech discrimination.

In our study, we answered two questions: the first is the number of patients who improved using plasma injection, and the second is the percentage of hearing improvement in various SNHL diseases.

In our study, we find PRP safe and efficient without systemic side effects and low cost, as shown in Figs. 5—12.

Fig. 5. After IT PRP injections (ISSNHL).

Fig. 6. Before IT PRP injections (Meniere’s disease).

Fig. 7. After IT PRP injections (Meniere’s disease).

Fig. 8. Before IT PRP injections (presbycusis).

Fig. 9. After IT PRP injections (presbycusis).

Fig. 10. Sex of the studied cases.

Fig. 11. Hearing improvement among studied groups.

Fig. 12. PTA among studied groups.

Conclusion

Platelet-rich plasma seems effective and safe for the management of sensorineural hearing loss with no systemic side effects as an oral steroid and at low cost.

Declarations

Consent to participate

All cases have provided informed written consent and received an explanation regarding this research.

Consent for publication

The cases provided formal consent for the sharing and publication of their information in this research. Availability of materials as well as data: the data sets utilized and examined in this research are obtainable from the appropriate author upon reasonable request.

Data availability

The datasets generated and analyzed in this research aren’t publically available because of ethical reasons; however, they may be obtained from the corresponding author depending on an adequate request.

Ethical approval. In this research, all procedures, including human participants, followed the IRB’ ethical standards, the 1964 Helsinki Declaration and its later amendments, or similar ethical standards. Institutional Review Board of Damietta Faculty of Medicine, Al Azhar University (IRB00012367). Registration number IRB0001267-23-10-004.

Acknowledgment. Many gratitude and thanks to Mr. Ahmed Shawky Abdel-Ghani for the linguistic review of this investigation paper as well as his continuous support. Many gratitude and thanks to all of those with whom I have had the pleasure to work throughout this dissertation and other associated projects.

The authors declare no conflicts of interest.