Page 12 - Portuguese Journal - SPORL - Vol 61. Nº1

Figure 6 significance (p=0.206). In general, tinnitus
Audiometric improvement according to Siegel’s improved regardless of the auditory gain.
criteria
These results are in line with those of some
previous studies that indicated that HOT
has a significant role in the improvement of
tinnitus associated with SSNHL 14,16,22 . However,
based on the natural history of SSNHL, it
rarely shows spontaneous recovery after 14
days of progression 1,2,15,23 , and a significant
spontaneous improvement in tinnitus and
PTA is therefore unlikely in this interval of time
(considering that all the included cases were
refractory to previous corticosteroid therapy).
Further studies are necessary to assess the
natural course of tinnitus in patients with
sudden hearing loss and to evaluate the
spontaneous improvement in tinnitus over
time, in particular in patients with no auditory
gain. In the most recent meta-analysis on this
topic, which was published in January 2022 ,
15
it was concluded that HOT, combined with
Table 6 corticosteroid therapy, increased auditory gain
THI score before and after HOT
by approximately 15 dB, which was the most
THI Score Pre-HOT Post-HOT significant at frequencies of 250, 500, 1000, and
4000 and in patients aged less than 50 years .
2
Grade 1 – Very mild 10% 40%
The mean improvement in auditory acuity was
Grade 2 – Mild 12% 37% 17 dB, which is within the intervals described in
Grade 3 – Moderate 39% 12% the literature (12.9-50 dB 2,22 ). There is a trend in
the literature to consider that the patients with
Grade 4 – Severe 32% 5% a greater initial hearing loss (higher PTA) have

Grade 5 - Catastrophic 7% 5% a worse prognosis and are less likely to recover
spontaneously in audiometric terms 2,15,22 . In
Abbreviations: HOT, Hyperbaric oxygen therapy, THI,
Tinnitus Handicap Inventory the present study, the patients with initial PTA

Figure 7
Improvement in Tinnitus (mean THI score) according to the Auditory Gain. THI, Tinnitus Handicap Inventory

12 Portuguese Journal of Otorhinolaryngology - Head and Neck Surgery