Timothy C. Hain, MD Page last modified: September 30, 2015
Mastoiditis is an inflammation or infection of the sinus behind the middle ear (Mastoid sinus). This can be often seen on imaging studies such as MRI (see below).
|Right sided mastoiditis (white blotch on the left side of this image). On MRI films, the right side of the head is shown on the left side of the image.||Mastoid fluid on MRI scan (coronal) -- Right side of image corresponding to L mastoid. On the more normal right side, the inner ear can be seen (loops just below temporal lobe of brain).||Mastoid fluid on axial view of CT scan, again right side of image. This is the same patient as the image to the immediate left. On the left side, the more normal right mastoid is full of air (e.g. is black)|
There are several types of Mastoiditis
Severe mastoiditis is characterized by a swollen external auditory canal. Mild mastoiditis, may be silent, and only seen on imaging (as above).
Meredith and Boyev (2008) recently wrote on mastoditis on MRI, and suggested that the term is most often applied to the observation of fluid in the mastoid, which may be clinically insignificant. Neverthless, they note that the literature indicates that only 4/1000 temporal bones have fluid on MRI in the mastoid in asymptomatic volunteers, and in TMJ MRI, only 10 patients had fluid out of 2700. This suggests that fluid in the mastoid is generally rare. It has been our observation that in our dizziness and hearing practice in Chicago, at least 1/100 of our patients has mastoid fluid. This suggests to us that mastoiditis may be an underrecognized cause of dizziness or heaing symptoms. Alternatively, it may be much more common in Chicago than reported in general (seems unlikely to us).
If a mastoidectomy is needed for a severe bacterial mastoid infection, or to treat a cholesteatoma, there can be an opening left in the ear canal, that goes into the mastoid. These "mastoid cavities", left behind by "canal wall up" mastoid surgeries, typically need to be cleaned out periodically with a microscope and suction by an otology doctor.
An acute lower motor neuron facial palsy (Bells palsy) is rare even though dehiscence of the facial canal is very common. When this happens, there should be a myringotomy with PE tube placement, Infectious disease consultation, intravenous antibiotics, and consideration of mastoidectomy. Once the infection resolves, facial nerve function usually recovers over several months.
This comes in several stages.
In patients believed to have labyrinthitis associated with AOM, one should image the brain, obtain a lumbar puncture, place a PE tube, administer IV antibiotics, and consider mastoidectomy.
The symptoms of petrous apicitis include severe frontal headache, eye pain, diplopia, dizziness, nausea, and 6th nerve palsy. There should be otitis media seen on otoscopy. MRI shows inflammation of the petrous apex and mastoids. CT may show bone erosion in the petrous apex.
Treatment is with myringotomy with PE tube, and culture-directed IV antibiotic therapy.