Modulation of somatosensory abilities and the feeling of ear fullness in patients with acute sensorineural hearing loss

Objective: Patients with acute sensorineural hearing loss (ASNHL) often complain of a feeling of ear fullness (FEF) that is similar to the sensation experienced during barometric pressure changes. This suggests that modulation of somatosensory abilities may relate to the manifestation of FEF, whereas it cannot simply be assumed that somatosensory abilities would be directly affected by ASNHL. To examine this possible relationship, we estimated somatosensory abilities of the tympanic membrane, and investigated the relationship between them and the manifestation of FEF. Methods: To estimate somatosensory abilities of the tympanic membrane, 83 new patients demonstrating unilateral sudden deafness were studied. The air pressure was loaded through an exclusive device on the external auditory canals in order to measure the minimum change in air pressure sensed by the subjects. The minimum pressure was defined as the minimum sensory threshold for air pressure loading (MSTAP; daPa). We estimated patient's somatosensory abilities and inquired about their experiences with FEF at the first medical examination (point 1) and at the time a steady audiogram was obtained (point 2). We also estimated MSTAP in 65 volunteers (130 ears) with no history of ear diseases and compared their MSTAP with that of sudden deafness patients. Results: MSTAP values (-64.0 ± 32.2. daPa, 60.5 ± 26.0. daPa) on the affected side with both negative pressure and positive pressure measured at point 1 were significantly higher than those (-40.7 ± 15.0. daPa, 40.0 ± 12.7. daPa) obtained at point 2 in all sudden deafness patients (p= 0.0001, p= 0.0001). There was no difference between MSTAP values (-39.6 ± 10.7. daPa, 39.9 ± 11.4. daPa) in normal subjects and those obtained at point 2 in all sudden deafness patients. On the other hand, significant differences of MSTAP with negative pressures between the affected and unaffected sides at point 1 were seen in 32 patients, and manifestation of FEF showed an insignificant association in these 32 patients (p< 0.05). Conclusion: Modulation of somatosensory abilities in ASNHL seemed to be the best possible explanation for results, suggesting that a rise in MSTAP may somehow be associated with FEF. Although it cannot be verified by result of the current study, consideration of the previous literature suggests that the phenomenon may be caused by cross-modality of hearing and somatosensory abilities.