A 69-year-old woman presented to her otolaryngologist (ENT) three months ago with fluid and a constant feeling of blockage in her left ear. She did not have an upper respiratory infection before the onset of these symptoms, she said.
The ENT placed a tube through the patient’s tympanic membrane. Although the patient felt immediate relief, she continued to have fluid draining from her left ear. When she woke up in the morning, her pillowcase was soaked, she said.
His ENT removed the tube, thinking it might have caused an inflammatory reaction.
Drainage continued, however, and the patient is here today. The image on the right shows his ear examination.
Diagnosis: spontaneous CSF leak and encephalocele
Chronic drainage from the ear is nothing unusual; this often happens in patients who have chronic otitis media with perforation.
However, there are a few factors that make this particular case different. First, the patient did not develop any ear problems until the age of 69, which means that she does not have a long history of eustachian tube dysfunction. Second, she developed fluid in her ear without previously having an upper respiratory infection, allergic rhinitis, or related problem. Patients without a history of these conditions are very unlikely to develop fluid in the ear.
Given this lack of past problems, the greatest concern for the patient is that cerebrospinal fluid (CSF) is seeping into the middle ear due to a possible defect in the bone that separates the brain from. the ear, called tegmen tympani.
Another dangerous possibility is nasopharyngeal carcinoma blocking the eustachian tube, causing fluid to collect from the middle ear. Other malignant tumors of the base of the skull could do the same, resulting in destruction or obstruction of the eustachian tube.
Finally, systemic conditions affecting the ear, most commonly Wegener’s granulomatosis or sarcoidosis, could also cause fluid to build up in the middle ear.
Despite this long list of life-threatening problems, the most common causes of uninfected fluid in the ear are Eustachian tube dysfunction due to inflammatory disease or irritative issues, such as allergic rhinitis, laryngopharyngeal reflux or smoking.
In the elderly, it has been found histologically that atrophy of the tensor muscle of the soft palate, which helps open the eustachian tube, may be a probable cause of eustachian tube dysfunction.
Despite the common problems, an adult who presents with unilateral middle ear fluid and unprecedented Eustachian tube dysfunction, allergic rhinitis, or upper respiratory infection requires a more detailed examination and possible examination. complementary assessment.
All of these patients will need a nasopharyngoscopy in order to visualize the opening of the eustachian tube and, in particular, the area behind the eustachian tube where nasopharyngeal carcinomas most often develop – the fossa of Rosenmuller. Carcinomas of the nasopharynx are much more common in Asian patients and smokers, but they can also occur in other patients.
Next, the larynx should be evaluated to make sure that the patient does not have significant acid reflux, which can contribute to the dysfunction of the eustachian tube. The problem tends to occur on the same side that the patient sleeps because more reflux will build up when this Eustachian tube opens at night.
If the exam is normal, a high-resolution CT scan of the temporal bones should be done to assess the bone that separates the ear from the intracranial contents. High resolution coronal and axial images must be obtained. These images are best read by an experienced neuroradiologist.
The clinician should assess the bone separating the brain from the mastoid, middle ear, and petrous apex cells on each slice of the coronal images. Next, axial sections should be studied to examine the bone separating the posterior cranial fossa from the mastoid air cells medial to the sigmoid sinus.
If a bone disturbance is observed, an MRI should be obtained to assess the relationship of the dura mater and brain with the corresponding defect on the CT scan.
In addition, attention should be paid to the path of the eustachian tube to ensure that it is not interrupted or obstructed by a mass at the base of the skull.
If imaging is unremarkable, workup for possible systemic conditions, such as Wegener’s granulomatosis and sarcoidosis, should be considered, depending on the circumstances. A blood test to check the rate of erythrocyte sedimentation, the presence of cytoplasmic antineutrophilic cytoplasmic autoantibodies (cANCA) and the level of angiotensin converting enzyme will usually suffice. Sometimes serum calcium is also controlled. Sarcoidosis is much more common in African Americans than in Caucasians, with a ratio of 10 to 1.
Our patient has a spontaneous CSF leak and an encephalocele. The CT scan shows two defects in the bone that separate the mastoid from the brain, called the tegmen mastoideum (see Figure 1). MRI shows a cerebral hernia in the mastoid through the larger of these defects (see Figure 2).
This condition occurs more often in obese patients because heavy weight around the chest and abdomen causes an increase in central venous pressure, which in turn leads to an increase in intracranial pressure.
The treatment for encephalocele is surgery. If the defects are limited to the mastoid, a postauricular mastoid approach is usually sufficient.
The fascia, in combination with other materials such as cartilage or bone, can be used to reconstruct the defect and the dura. An abdominal fat graft is usually placed to clear the mastoid, and the fascia is used to separate the middle ear from the mastoid in the unlikely event of failure.
As long as the CSF does not communicate with the middle ear, eustachian tube, or ear canal, the risk of meningitis is minimal. However, if CSF communicates with the middle ear, the risk of meningitis increases dramatically.
Patients with a spontaneous CSF leak often have an increase in intracranial pressure after the leak has closed, and they should be monitored for signs of this condition. If the problem is left untreated, these patients are at risk of developing leaks in other areas, such as the opposite ear or nasal sinuses.
Four bonus videos!
IPAD EXCLUSIVE: VISUAL DIAGNOSIS
Read this month’s clinical visit case, then watch accompanying videos from Hamid R. Djalilian, MD, to see three perspectives of the patient’s symptoms, and an example of treatment:
- Video 1 shows the patient’s otoscopy, which showed clear, pulsating fluid.
- Video 2 shows coronal CT images demonstrating mastoid tegmen defects.
- Video 3 includes T2-weighted coronal MRI images showing encephalocele.
- Video 4 shows another patient with a spontaneous cerebrospinal fluid leak during surgical repair.
These exclusive features are only available in the March issue of iPad.
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