From Uncommon Infection to Multi-Cranial Palsy: Malignant External Otitis Insights

Salvatore Ferlito; Antonino Maniaci; Milena Di Luca; Calogero Grillo; Lorenzo Mannelli; Marco Salvatore; Ignazio La Mantia; Giacomo Spinato; Salvatore Cocuzza

doi:10.1177/1559325820963910

From Uncommon Infection to Multi-Cranial Palsy: Malignant External Otitis Insights

Dose Response. 2020 Dec 17;18(4):1559325820963910. doi: 10.1177/1559325820963910. eCollection 2020 Oct-Dec.

Authors

Salvatore Ferlito¹, Antonino Maniaci¹, Milena Di Luca¹, Calogero Grillo¹, Lorenzo Mannelli², Marco Salvatore², Ignazio La Mantia¹, Giacomo Spinato^{3

4}, Salvatore Cocuzza¹

Affiliations

¹ Department of Medical and Surgical Sciences and Advanced Technologies "GF Ingrassia," ENT Section, University of Catania, Catania, Italy.
² IRCCS SDN, Naples, Italy.
³ Department of Neurosciences, Section of Otolaryngology and Regional Centre for Head and Neck Cancer, University of Padova, Treviso, Italy.
⁴ Department of Surgery, Oncology and Gastroenterology, Section of Oncology and Immunology, University of Padova, Padova, Italy.

Abstract

Purpose: The progression of the otitic infectious process toward diseases of particular severity is often unpredictable, just as it is challenging to manage the patient over time, even after the apparent resolution of the disease. We aim to define a radiological reading key that allows us to correctly and promptly treat the disease, avoiding the possible severe complications.

Methods: We conducted a retrospective study of 13 cases of basal cranial osteomyelitis (SBO) due to malignant external otitis, by the ENT Department of the University of Catania. Through a standardized approach and following the latest guidelines, we have evaluated all patients performing a standardized and personalized radiological protocol according to the stage of the patient's pathology and modulating the treatment consequently.

Results: Clinical signs have been observed such as otorrhea (100%), otalgia in 13/13 patients (100%), granulations in external auditory canal (100%), preauricular cellulitis in 9/13 patients (69%) headache 6/13 cases (46%), dysphonia 4/13 cases (31%). HRCT of the temporal bone proved useful in identifying even minimal bone lesions in 13/13 (100%) while improving MRI in vascular and nervous involvement, although in 1/13 patient with nerve palsy clinical symptomatology preceded radiological evidence. The 99mTc 3-phase planar bone scintigraphy was positive for SBO in 9/13 cases (69%) during the initial phase and, in 100% of the cases in images delayed to 2-3 hours. Subsequent checks up to 1 year, using the Ga 67 scintigraphy, excluded the presence of recurrences in 100% of patients.

Conclusion: The osteomyelitis of the base of the skull is a severe complication of malignant external otitis, often not always easily diagnosed. Recurrence can occur up to 1 year after stopping therapy. Imaging techniques such as Tc and MRI are relevant for the initial diagnostic approach and the staging of the pathology and its complications. Nuclear medicine imaging plays a fundamental role in the evaluation of related osteoblastic activity, especially in the remission phase of the disease.

Keywords: necrotizing otitis externa; osteomyelitis; radiological findings; skull base.