We examined the case of a 66-year-old male patient, who was addressed to our clinic with a hearing and balance disorder. The patient described disturbing left-sided hyperacusis with tinnitus and autophonia. He experienced oscillopsia while running but had never presented with the Tullio phenomenon. He also experienced a vertical sensation of self motion while humming. For the past 20 years, he has been incapable of wearing any shoes other than his running shoes, whose thick soles cushioned the vibrations induced by his steps, thus decreasing his symptoms. It was difficult for him to talk aloud and when participating in normal conversations he often found himself having to whisper. There was no family history of hearing impairment.
The patient had a previous unclear history of "round and oval window reinforcement" as a treatment for his hyperacusis, undertaken 20 years prior, which had worsened his hearing and led to disturbing tinnitus. In the clinical workup, we performed an otoscopy and tympanometry, which were normal. The tuning fork examination showed left-sided lateralization on the Weber test combined with a negative left-sided Rinne test. The clinical vestibular workup was normal with the exception of a mixed horizontal (leftbeat)/vertical (downbeat) and torsional nystagmus with the top pole rotating to the left ear during sustained humming. The onset of the nystagmus was immediate (no latency), increasing in amplitude and speed (crescendo) until discontinuation of stimulus, at which point the nystagmus ceased completely. The fistula sign was negative. On the hearing test, there was left-sided low-frequency conductive hearing loss (Figure 1), which was either due to the presence of middle ear scar tissue linked to his prior middle ear surgery or conductive hearing loss associated with the SCC dehiscence. The preoperative vHIT demonstrated hypofunction of the left anterior canal with a gain of 0.64 and with normal gains bilaterally in all other canals (Figure 2). On the oVEMPS, amplitudes were elevated on the left hand side (Figure 3) with significant asymmetry (94%) of the peak-to-peak amplitude. On the Cervical Vestibular Evoked Myogenic Potential (cVEMPs), there were no responses on the left side due to significant conductive hearing loss. A neuroradiological workup was undertaken in our institution; on the thin cut high-resolution temporal bone CT with a slice thickness of 0.6 mm, there was a bony discontinuity along the roof of the left superior SCC with a dehiscence measuring 5.4 mm (Figure 4).
The patient was scheduled for left transmastoidal plugging of the superior SCC dehiscence (Figure 5). We skeletonized and blue-lined the left superior SCC at the ampulated and non-ampulated end without identifying the actual dehiscence. The canal was then opened with an underwater endoscopic technique at either end (ampullary and non-ampullary) and plugged using wet temporal fascia and covered with bone dust, thus leading to its complete occlusion. The patient remained hospitalized for 3 days, during which he received corticosteroids and anti-emetics because of postoperative nausea and vertigo, which resolved over time.
A postoperative checkup was performed after 2 weeks to remove the operative gauze from the ear and after 2 and 5 months. The patient no longer suffered from autophonia, thus enabling him to give speeches/sermons at his local church. He was able to take up sport again with the disappearance of the running-induced oscillopsia. The only residual symptoms were the pre-existing tinnitus and conductive hearing loss, which, after the plugging of the anterior canal, neither improved nor worsened (Figure 1). The video head impulse test (vHIT) showed on the left side (operated side) normal Vestibulo-Ocular reflex (VOR) gain values for the lateral semicircular canal but pathological gains for the posterior and anterior canals (Figure 2). oVEMPs were symmetrical (reduced to 20% asymmetry) in their responses with normal amplitudes. The fremitus nystagmus that had initially been clearly visible during humming completely vanished postoperatively.