【One case of PHILIPS per day】2 cases of Mondini malformation with cerebrospinal fluid otorrhea

Mondini malformation, a common type of congenital inner ear developmental malformation, mainly affects the cochlea, manifests as bone labyrinth and membranous labyrinth hypoplasia of the inner ear, often involving vestibular aqueducts, semicircular canals, and cochlea
.
In developed countries, 10%-20% of children with deafness are congenital, and Mondini malformation accounts for 55%
of congenital inner hearing loss.
This article reported that 2 patients with Mondini malformation, both with cerebrospinal fluid otorrhoea and several misdiagnoses
.

1 Information and methods

1.
1 Clinical data

Case 1, a 16-year-old male, fever, headache with projectile vomiting for 3 days, visited the Department of Neurology of our hospital, the patient had repeated cough, fever, severe headache symptoms, all appeared after cold, outpatient diagnosis of "upper respiratory tract infection" improved after anti-infection treatment
.

Physical examination after admission: apathy, neck resistance, positive kernig sign, positive Brudzinski sign, non-cooperation
of the Masonic movement.

MRI of the head showed no abnormalities in the brain parenchyma; Left middle ear mastoiditis, left maxillary sinus, sphenoid sinusitis, detailed medical history, the patient complained of poor hearing in the left ear since childhood, left ear discharge, nasal discharge symptoms when he was young, no tinnitus and vertigo, no ear pain, no nasal congestion, it is recommended that he undergo high-resolution CT scan of the temporal bone shows that the auditory ossicles in the left middle ear are basically normal, the left cochlea is monocystic, the left internal auditory tract communicates with the vestibule, and the density increases in the bilateral maxillary sinus and ethmoid sinus (Figure 1).

After anti-infection treatment, the fever and headache symptoms improve and then transferred to the Department of Otolaryngology, Head and Neck Surgery, specialized examination: left external auditory canal patency, tympanic membrane intact but turbid, tension part inverted, unclear markers, no redness, swelling and tenderness in the mastoid area; There is no abnormality in
the right ear.
Pure tone audiometry: normal right ear, completely deaf
left ear.
Tympanogram: left type B, right type
A.

Diagnosis: Mondini malformation with cerebrospinal fluid otorrhoea
.

Case 2, a 16-year-old male, had repeated left ear discharge for more than 1 year, worsening for 1 month
.
One year ago, he was diagnosed as "purulent meningitis" by the neurology department due to fever, severe headache and vomiting, and improved after anti-infective treatment, and then the symptoms recurred, which were mostly relieved
after treatment.

After catching a cold 1 month ago, yellow-green liquid began to flow in the left ear, the left ear pain was severe, accompanied by headache, no tinnitus, dizziness, facial movement disorders, and it was ineffective
after self-ear drip treatment.

Specialist examination: the left external auditory canal is filled with yellow-green pus, and after cleaning, the left tympanic membrane tension is perforated, there is fluctuating pus overflow, no redness and swelling in the mastoid area, and mild tenderness; There is no abnormality in
the right ear.
Pure tone audiometry: normal right ear, total deafness
in left ear.
Tympanogram: left type B, right type
A.

CT of temporal bone showed that the structure of the left auditory bone chain was visible, the density of the left tympanic chamber and mastoid air chamber increased, the semicircular canal was fused with the vestibule, the left cochlea only saw the development of the bottom gyrus, the shape increased, the left internal auditory canal was widened, and it was connected with the vestibule; The right ear is structurally normal (Figure 2).

MRI of the head showed no abnormalities in the brain parenchyma; The left middle ear and mastoid cavity showed uneven long T1 long T2 signal shadow, the cochlea showed a round-like long T2 signal shadow, and the inner ear canal was wider than the right side.
No abnormalities were seen in
the right ear.

Diagnosis: Mondini malformation with cerebrospinal fluid otorrhoea
.

1.
2 Surgical methods

There were no contraindications to surgery in the preoperative examination of both patients, and after controlling the infection, tympanic exploration repair was performed under general anesthesia
.
The surgery selects a posterior ear incision, takes several pieces of fascia for backup, separates the external auditory canal flap to reach the tympanic ring, and then provokes the tympanic ring into the tympanic chamber, that is, a large amount of cerebrospinal fluid gushes out
.
Grind off part of the posterior superior wall bone of the ear canal, expose the stapes and round window area, see the vestibular window of cerebrospinal fluid leakage, remove the anvil and stapes, a large amount of cerebrospinal fluid gushes out, fill the prepared fascia into the vestibule, make it form an incarceration at the oval window, close the oval window, reinforce it with fibrin glue, and confirm that there is no cerebrospinal fluid outflow by bilateral neck compression test, tamponade of the external auditory canal, suture of periosteum, subcutaneous tissue and skin
.
After 7 days of postoperative antibiotic treatment, the yarn in the ear was withdrawn, and the stitches were removed and
discharged.

2 Results

Both patients were successfully repaired in one operation, and there were no complications such as dizziness and facial movement disorders after surgery
.
So far, there has been no recurrence
of cerebrospinal fluid otorrhea or meningitis.

3 Discussion

Mondini deformity is characterized by
cochlear malformations.
Some scholars believe that the cochlear development of Mondini malformation stops at the 7-8th week of pregnancy, and the cochlear is only 1 week, 1.
5 weeks or 2 weeks during the development of the cochlea, and there are also cases of normal bone labyrinth development and abnormal membrane labyrinthine, such as patients with recurrent bacterial meningoencephalitis when presenting for treatment, especially children, the possibility of
Mondini malformation with cerebrospinal fluid otorrhoea should be considered.

3.
1 Clinical features of Mondini malformation with cerebrospinal fluid otorrhea

Patients with Mondini malformation mainly show severe hearing impairment or total deafness in the affected ear, auditory brainstem response cannot be elicited, vestibular dysfunction shows symptoms of vertigo and semicircular canal paralysis
.
Some children are born without hearing, others develop hearing loss between the ages of 1 and 2 years, and many patients still have residual hearing
in adulthood.
Therefore, especially patients with unilateral deformities, they often neglect to see a doctor
because of normal hearing on the contralateral side.
Patients usually pay attention
when they have recurrent meningitis symptoms.

Mondini malformation with cerebrospinal fluid otorrhea is mainly "meningitis" symptoms, sometimes with it as the first symptom, but also accompanied by ear stuffiness, ear discharge, co-infection manifested as middle ear mastoiditis, cerebrospinal fluid through the leakage along the Eustachian tube into the anterior nostrils as clear discharge, such as retrograde infection can occur repeated respiratory symptoms
.
The leaking cerebrospinal fluid is concentrated in the tympanic chamber, the fluid level is visible in the tympanic chamber during electro-otoscopy, the sound conduction resistance is type B, which is easily misdiagnosed as secretory otitis media, and many clinical cases are found in the earloheg
of cerebrospinal fluid only after tympanic tube placement or myringotomy.
Otorrhea due to perforation of the tympanic membrane with recurrent infections should be differentiated from
chronic purulent otitis media.

Case 1 in this group ignored the patient's history of poor hearing in the left ear since childhood due to the appearance of meningitis symptoms, and the symptoms of multiple central infections did not further clarify the cause, resulting in repeated attacks
.
Case 2 was misdiagnosed as "otogenic meningitis" in the hospital due to deafness and ear discharge.

Therefore, the correct diagnosis is directly determined by the effectiveness of treatment, patients with recurrent meningitis should consider the possibility of congenital inner ear development malformation with cerebrospinal fluid otorrhea, should be asked in detail, if there is leakage fluid, glucose measurement can be performed, to determine whether it is cerebrospinal fluid
.
Imaging tests such as high-resolution CT and MRI examination of the temporal bone can show the morphology of the middle and inner ears and determine the location of the leakage, which is particularly important
to determine the cause.

3.
2 Imaging features of Mondini malformation with cerebrospinal fluid otorrhea

Mondini malformation often appears on imaging as a developed basal periumphery, but hypoplasia in the second and parietal weeks, and the cochlea is small or empty; Cochlear catheters and vestibular catheters may be combined with deformities, cochlear small or empty sac-like semicircular canals may also be absent or of different sizes and two-window malformations, etc.
, and cerebrospinal fluid earloep can be seen in the mastoid cavity
.
The purpose of imaging studies is to determine the type of inner ear deformity and rule out middle ear malformation, locate the leak, and guide the clinician in appropriate management
.

High-resolution CT temporal bone plain scan should carefully observe the internal auditory tract, cochlear canal and mastoid air chamber to determine the location, morphology, and size of the leak, surrounding soft tissues, and hardened bone margins
.
MRI has obvious signal differences between cerebrospinal fluid and bone and air on the long TR sequence, and the location of the leak can be judged even in the absence of
active cerebrospinal fluid otorrhoea.
The use of water imaging technology and three-dimensional stereoscopic imaging can clearly and intuitively display the shape of the inner ear, which has obvious
advantages.

The two cases of Mondini malformation in this group all had cerebrospinal fluid otorrhoea, and the basic morphology of the internal auditory tract, cochlea and vestibule could be displayed on the CT of the thin layer of the temporal bone, which provided a reliable basis
for diagnosing the deformity and finding the location of the leak.

3.
3 Treatment of Mondini malformation with cerebrospinal fluid otorrhoea

Patients with Mondini deformity with residual hearing can wear hearing aids to improve their hearing, and patients with very severe hearing impairment can undergo cochlear implantation
.
Patients with Mondini malformation with cerebrospinal fluid otorrhoea should closely observe the condition and timely surgical repair of the leakage to prevent intracranial infection
.
The surgeon should choose appropriate methods of repair according to the patient's condition, medical conditions, defect site and surgeon's experience, including trans-middle fossa approach, transmastoid approach and transauricular approach
.
Repair and tamponade materials include autologous tissues (temporal myofascia, cartilage, fat, etc.
), hydroxyapatite cement, gelatin sponge and fibrin glue
.

Galbarriatu et al.
point out that tympanic exploration through the retroauricular mastoid approach, a multi-layer closure technique combining autologous tissues and artificial materials, is considered to be the most effective surgical method
。 The operation is carried out under general anesthesia or local anesthesia, during the operation, the stapes floor should be carefully checked for perforation or defect, explore the oval window, round window and its nearby area, determine the source of cerebrospinal fluid, and then remove the stapes, expose the vestibular pool, and stuff the pre-prepared tamponade material into it as soon as possible, so that it can fill the entire vestibular pool and form an incarceration at the oval window, if necessary, fibrin glue can be applied to the tamponade material, and then gently press a small cartilage sheet to strengthen the sealing effect, so that the closed tissue is not easy to come out due to higher cerebrospinal fluid pressure, After tamponade is completed, neck compression test is used to verify cerebrospinal fluid overflow
.

Both patients in this group showed that the stapes floor plate was thin and had a fistula hole
in the center during surgery.
Most scholars believe that the bone of the stapes floor is gradually absorbed in the pulsation of cerebrospinal fluid to form a fistula hole, and secondly, the stapes itself may also have congenital dysplasia, and the fistula hole
is eventually formed under the long-term action of intracranial pressure.
Strict imaging evaluation before surgery, prevention and treatment of complications such as increased intracranial pressure, intracranial infection and facial paralysis after surgery are important guarantees for
the success of surgery.