Timothy C. Hain, MD • Page last modified:
March 7, 2021
|CT scan of labyrinthitis ossificans. On the left (right inner ear) is a normal labyrinth. On the right, (left inner ear), is a similar level but the lateral semicircular canal shows no loop.
Labyrinthitis ossificans (LO)
The inner ear contains the labyrinth, which consists of a set of interconnected channels in the bone that contain fluid, membranes, and neural cells that respond to sound and motion. In LO, the labyrinth is replaced by bone, almost always as a result of a bacterial infection. This typically results in profound deafness and loss of vestibular function on the affected side. If there is bilateral LO, patients are completely deaf and have no vestibular sensation.
Little is known as to why some patients develop LO and others don't. Aminpour (2005) suggested that TNF-alpha may play an important role in an animal model of meningitis.
Mineralization in animals is rapid, and begins 3 days after infection (Tinling et al, 2004). Nabili et al (1999) reported that mineralization started at 3 weeks, and continued over a 12 month course.
Frequency of LO:
Labyrinthitis ossificans is rare, occurring in only about 2% of persons who have had mastoidectomy. (Lin et al., 2014).
In our experience, most patients with LO are completely deaf, have no balance function, and developed this as a child as a result of meningitis.
We have encountered only one patient who developed this as a result of otitis media (i.e. middle ear infection). This is likely due to the current propensity for patients with otitis media to get antibiotics.
Causes of LO.
Most of the data comes from case reports.
- Schwartz et al mentioned etiologies of meningitis, middle ear infection and cholesteatoma (Swartz et al., 1985).
- Suga andLindsey reported 2 cases due to chronic otitis media in 1975 (Suga & Lindsay, 1975).
- Khoo and Tan (2015) reported a single case of autoimmune inner ear disease progressing to LO. Benson (2010 reported another case. This would seem rather unusual.
- Dhanjal et al (2014) reported a case due to neurosarcoid.
- Ruiz and Gomez (2013) reported a case with Usher syndrome (this would seem somewhat unlikely as Usher's has nothing to do with inflammation).
- Douglas et al (2008) reported that LO was more likely after meningitis from strep pneuomoniae, but Neisseria has a lower chance of hearing loss.
Diagnosis of LO.
Imaging studies are needed to diagnose LO. The CT scan of the temporal bone is the most straightforward, as it shows bone replacing the labyrinth. MRI scan of the inner ear area can show the loss of fluid in the labyrinth, but cannot distinguish plugging from soft tissue from bone.
Treatment (prevention) of LO.
Hartnick et al (2001) reported that patients treated with steroids had less LO.
There is considerable literature concerning cochlear implant in LO patients. The question is whether or not the electrodes can be threaded into a cochlea that is blcoked by bone.
- Aminpour, S., et al. (2005). "Role of tumor necrosis factor-alpha in sensorineural hearing loss after bacterial meningitis." Otol Neurotol 26(4): 602-609.
- Benson, A. G. (2010). "Labyrinthitis ossificans secondary to autoimmune inner ear disease: a previously unreported condition." Otolaryngol Head Neck Surg 142(5): 772-773.
- Dhanjal, H., et al. (2014). "Bilateral sensorineural hearing loss and labyrinthitis ossificans secondary to neurosarcoidosis." Cochlear Implants Int 15(6): 337-340.
- Douglas, S. A., et al. (2008). "Meningitis resulting in hearing loss and labyrinthitis ossificans - does the causative organism matter?" Cochlear Implants Int 9(2): 90-96.
- Hartnick, C. J., et al. (2001). "Preventing labyrinthitis ossificans: the role of steroids." Arch Otolaryngol Head Neck Surg 127(2): 180-183.
- Khoo, J. N. and T. Y. Tan (2015). "Progression of autoimmune inner ear disease to labyrinthitis ossificans: clinical and radiologic correlation." Ear Nose Throat J 94(3): 108-110.
- Lin, H. Y., Fan, Y. K., Wu, K. C., Shu, M. T., Yang, C. C., & Lin, H. C. (2014). The incidence of tympanogenic labyrinthitis ossificans. J Laryngol Otol, 128(7), 618-620. doi:10.1017/S002221511400111X
- Nabili, V., et al. (1999). "Chronology of labyrinthitis ossificans induced by Streptococcus pneumoniae meningitis." Laryngoscope 109(6): 931-935.
- Ruiz, A. P. and J. M. Garcia Gomez (2013). "Labyrinthitis ossificans in a cochlear implant patient with Usher syndrome." Otol Neurotol 34(3): e10-11.
- Suga, F., & Lindsay, J. R. (1975). Labyrinthitis ossificans due to chronic otitis media. Ann Otol Rhinol Laryngol, 84(1 Pt 1), 37-44.
- Swartz, J. D., Mandell, D. M., Faerber, E. N., Popky, G. L., Ardito, J. M., Steinberg, S. B., & Rojer, C. L. (1985). Labyrinthine ossification: etiologies and CT findings. Radiology, 157(2), 395-398. doi:10.1148/radiology.157.2.3931172
- Tinling, S. P., et al. (2004). "Location and timing of initial osteoid deposition in postmeningitic labyrinthitis ossificans determined by multiple fluorescent labels." Laryngoscope 114(4): 675-680.