Patterns of Ossification in Patients with Labyrinthitis Ossificans! Karen Buch MD, Alexander Gutierrez, Akifumi Fujita MD, Anand Devaiah MD, Osamu Sakai MD PhD!

•  Labyrinthitis ossifcans(LO) is a pathological process involving the ossification of structures within the membranous labyrinth of the inner ear leading to sensorineural hearing loss.1-4 !

•  Infectious, inflammatory, traumatic, surgical, and hematologic etiologies have all been linked to LO.2-6 !

•  At 34 patients, this is one the largest studies regarding LO to date.!•  No prior studies describe an etiology-specific pattern of ossification

in the labyrinthine structures. !!Purpose: The purpose of this study was to identify potential etiology-specific ossification patterns using CT scans of patients with LO.!

Introduction!

•  Temporal bone CT scans from November 2005-January 2012 were reviewed.!

•  34 patients with LO were identified!•  19 had chronic mastoiditis/inflammation or surgery, 7 had meningitis,

5 had sickle cell disease, 2 had trauma, 1 had an unknown etiology!•  The following membranous labyrinthine structures were evaluated for

ossification: !•  basal, middle, and apical turns of the cochlea!•  lateral, posterior and superior semicircular canals (SCs)!•  vestibule!

•  The membranous labyrinthine structures were assigned a grading score of 0-4 based on the degree of ossification.!

•  Statistical analysis was performed using a t-test.!•  Exclusion criteria: severely motion! limited studies and subjects with ! insufficient clinical data were ! excluded.!

Materials and Methods!

25-50%250-75%3>75%4

< 25%1None0

Ossification AssessmentGrading Score

25-50%250-75%3>75%4

< 25%1None0

Ossification AssessmentGrading Score

Discussion •   Local infection and inflammatory disease cases: had the most

severe involvement overall and the most severe hearing loss.!• ! Prior studies describe the meningitis etiology of LO with the

most profound sensorineural hearing loss. 1-3,7-9!• ! Both the semicircular canals and cochlear turns were severely

affected in cases of local infection and inflammation.!•  Meningitis cases: were the 2nd most severely affected. !

• ! Semicircular canals were more frequently affected than cochlea.!• ! Lateral semicircular canals were most severely involved.!

•  SCD cases: there was much less frequent ossification affecting the cochlea compared to the semicircular canals.!

Results!•  The semicircular canals were the most frequently and severely

affected structure in all etiologies.!•  The lateral semicircular canals were most often affected.!•  The apical, middle, and basal cochlear turns were affected with

nearly equal frequency.!•  The vestibule was least affected in all etiologies.!Local infection and inflammation cases:!•  Apical turn of cochlea was more severely involved than patients

with meningitis (p=.048).!•  Vestibule has significantly decreased ossification grade

compared to SCs. Compared to lateral SC (p=.002), posterior SC (p=.005), superior SC (p=.007).!

•  Vestibule was more severely affected compared to patients with meningitis (p=.04).!

Meningitis Cases:!•  Cochlea was more severely involved than vestibule within the

meningitis grouping (p=.01).!Sickle Cell Disease Cases:!•  No statistically significant difference in ossification of the

membranous labyrinth structures.!•  Cochlear Involvement was less frequent compared to infectious

etiologies.!Hearing Loss Findings:!•  Patients with local infection/inflammation presented with the

most severe hearing loss. 16 of 19(84%) had profound sensorineural hearing loss(SNHL). !

•  Patients with meningitis presented with the second most severe hearing loss. 3 of 7(43%) had profound SNHL. !

•  Patients with Sickle Cell Disease had the least severe hearing loss. 1 of 5(20%) had profound SNHL.

Images of Basal Cochlea Grading!

Grade 0 Grade 1 !

Grade 2 Grade 3 Grade 4!

Images of Lateral Semicircular Canal Grading!

Grade 2 ! Grade 3 Grade 4!

Grade 0 Grade 1!

0.0

0.5

1.0

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3.0

A Coch M Coch B Coch Vest Lat SC Post SC Sup SC

Membranous Labyrinthine Structures

Avera

ge O

ssif

icati

on

Gra

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LocalInfection/Inflammation/SurgeryMeningitis

SCD

Other

Conclusion!•  These findings suggest an etiology-specific ossification pattern for

LO.!•  Personalized screening and treatment plans based on underlying

LO etiology are a future possibility. !! References and Acknowledgements!

Results!

I would like to thank Dr. Buch and Dr. Sakai for their mentorship.!1. Liu BP, Saito N, Wang JJ, Mian AZ, Sakai O. Labyrinthitis ossificans in a child with sickle cell disease: CT and MRI findings. Pediatr Radiol. 2009; 39:999-1001. 2. Hoffman RA, Brookler KH, Bergeron RT Radiologic diagnosis of labyrinthitis ossificans.Ann Otol Rhinol Laryngol. 1979;88:253-7. !3. Swartz JD, Mandell DM, Faerber EN, Popky GL, Ardito JM, Steinberg SB, Rojer CL. Labyrinthine ossification: etiologies and CT findings.Radiology. 1985 Nov;157(2):395-8. 4. Saito N, Nadgir RN, Flower EN, Sakai O. Clinical and radiologic manifestations of sickle cell disease in the head and neck. Radiographics. 2010; 30:1021-34. !5. Xu HX, Joglekar SS, Paparella MM. Labyrinthitis ossificans.Otol Neurotol. 2009;30:579-80. !6. deSouza C, Paparella MM, Schachern P, Yoon TH. Pathology of labyrinthine ossification. J Laryngol Otol. 1991;105:621-4. !7. Chan CC, Saunders DE, Chong WK, Hartley BE, Raglan E, Rajput K. Advancement in post-meningitic lateral semicircular canal labyrinthitis ossificans.J Laryngol Otol. 2007;121:105-9. !8. El-Kashlan, Ashbaugh C, Zwolan T, Telian SA. Cochlear implantation in prelingually deaf children with ossified cochleae. Otol Neurotol. 2003;24:596-600. !9. Philippon D, Bergeron F, Ferron P, Bussières R. Cochlear implantation in postmeningitic deafness. Otol Neurotol. 2010;31:83-7. !

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