The Relationship Between Meningitis, Brain Abscess, and Middle Ear

Meningitis and brain abscesses, which are pathologies of the brain membranes and tissue, are conditions that pose significant health risks. Meningitis is an infectious inflammation of the brain membranes. A brain abscess is an abscess formation following localized infectious inflammation in the brain. The emergence of these abscesses can be based on various reasons. However, middle ear infection is the leading cause of meningitis and brain abscess development.

Symptoms of middle ear infection, whether acute or chronic, involve different tissues within the bone we call the temporal, surrounding soft tissues, and tissues related to the brain within the skull. Complications developing within the temporal bone include petrositis, mastoiditis, labyrinthitis, facial paralysis, and fistula. Complications occurring in the surrounding adjacent soft tissues are epidural abscess, mastoid subperiosteal abscess, and neck abscess. There are also complications that develop inside the skull. These include epidural abscess, meningitis, brain abscess, subdural abscess, hydrocephalus, and sinus thrombosis. These listed complications are serious and can lead to life-threatening results.

In the process of middle ear infection, direct spread is seen with the destruction of bone walls. Additionally, the inflammation develops by following natural spaces and channels, seeping through membranes, or by creating thrombus-thromboembolism in small veins.

Relationship with the Middle Ear and Common Features

In acute middle ear infections, intraosseous (within the bone) complications are frequently seen. These are petrositis, mastoiditis, facial paralysis, and labyrinthitis. Furthermore, tissue abscess development is notable in acute otitis. The most common intracranial complication is meningitis. In chronic otitis, soft tissue, intraosseous, and intracranial complications are more frequently observed.

Bacteria are generally the biggest factor in middle ear complications. Respiratory pathogens consist of 3 microorganisms: Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis. Additionally, various anaerobic bacteria play an active role within the skull in both chronic and acute cases.

What are the Complications?

Inflammation in the part we call mastoiditis covers the inflammation of the bone behind the ear called the mastoid. Bone resorption has developed, and therefore the cells inside the mastoid have merged to form a large cavity. Excessive inflammation in the environment is the cause of this erosion. Symptoms such as redness, pain, and swelling are seen in the area. Generally, discharge is observed. Additionally, in children, general condition deterioration, fever, and edema following inflammation, along with the ear being pushed forward, are seen. In the treatment process, if the disease shows resistance or a second complication is seen, mastoidectomy should be applied as quickly as possible. Along with this, antibiotic treatment is continued.

Furthermore, if an acute or coalescent mastoiditis complication develops during chronic otitis, surgical intervention will be required. In this case, tympanomastoid surgery is performed, and cholesteatoma-granulation tissues and other inflammatory lesions are cleaned. With the surgical application to be performed, a definite recovery is seen except in exceptional cases. Other complications and their treatments can be listed as follows;

Petrositis (Apex of the Ear Inflammation)

Petrositis, namely acute petrositis, is the state of inflammation of the petrous apex bone accompanied by symptoms. Petrositis, just like mastoiditis, can manifest itself as both an acute and chronic otitis complication. The reason petrositis shows itself less than mastoiditis is related to the fact that the petrous bone does not always contain air cells and mostly consists of a solid bone structure. Here too, bone resorption called coalescent petrositis can manifest itself. The most common symptom of acute and coalescent petrositis is pain felt deep in the back of the eye. Additionally, strabismus (squinting) or drooping of the eyelid can rarely occur when looking outwards. Treatment methods include intensive antibiotics, mastoidectomy, myringotomy if the membrane is intact, and petrous drainage via subcochlear or alternative routes. If neuropathy is present, cortisol treatment is added. The medical-surgical treatment to be performed here aims to prevent the development and permanence of vital or functional complications.

Facial Paralysis

Facial paralysis occurs as a result of pathology of the facial nerve. Facial paralysis can manifest itself in both acute and chronic otitis complications. In acute otitis, it is assumed that there is a neurotoxic or inflammatory effect due to the infection. In chronic otitis, except for exceptional cases, the direct effect of cholesteatoma on the nerve or the contribution of infection can cause this pathology suddenly. In case of facial paralysis, the eyelid on the paralyzed side cannot close. While the eyebrow does not rise, it shows a shift towards the opposite side due to the condition of the paralyzed side.

In treatment, myringotomy can be applied if the membrane is intact. In addition, intensive antibiotics and close follow-up are among the treatment methods. In facial paralysis due to chronic otitis, the treatments to be applied are the cleaning of the cholesteatoma, surgical treatment, and decompression of the areas where the nerves in the face need it. This means opening the nerve channels and relieving the nerve. The result of the treatment applied for acute (partial) facial paralysis is quite successful. In chronic otitis, the result may vary according to the degree of facial paralysis and the method to be applied in the surgical treatment.

Labyrinthitis (Inner Ear Inflammation)

Labyrinthitis is a type of inner ear inflammation that specialist doctors call the labyrinth. It mostly develops during acute, and rarely during chronic otitis or meningitis. It is possible to mention 2 types of labyrinthitis. These are serous and suppurative labyrinthitis. In serous labyrinthitis, there is the absorption of inflammatory mediators into the inner ear. In suppurative labyrinthitis, bacteria settle in the inner ear and generally require surgical intervention. In both forms, the entry points of the bacteria are the connection channel of the brain with the inner ear and other gaps.

Symptoms in serous labyrinthitis include complications such as imbalance, dizziness, nausea, hearing loss, and vomiting. In suppurative labyrinthitis, intracranial abscesses and secondary complications can additionally be seen. In the treatment of these types of forms, myringotomy if the membrane is intact, intensive antibiotics, and if there is resistance to treatment, mastoidectomy should be applied rapidly. If necessary, labyrinth drainage should be applied to control intracranial complications. Cortisol is applied for the purpose of suppressing inflammation and preventing the development of the labyrinthitis form accompanied by ossification where hearing is completely lost. Recovery of hearing can be achieved with the treatment applied in serous labyrinthitis. However, in hearing losses occurring as a result of suppurative labyrinthitis, except for exceptions, an irreversible situation arises. In both types, dizziness and imbalance complaints will disappear within 2 weeks with the treatments applied.

Labyrinthine Fistula

The situation where the outer wall of the inner ear, called the labyrinth, creates a hole and the combined system of the middle ear and mastoid is in contact is called a labyrinthine fistula. The condition develops with the direct damage caused by the cholesteatoma. The fistula frequently involves the horizontal lateral semicircular canal. However, it can also involve the superior and posterior semicircular canals and the cochlea. In such a case, the symptoms that may arise are dizziness and imbalance that can occur depending on situations such as loud noise, cold air, and pressure changes.

The treatment is surgical. Cleaning of the cholesteatoma is provided with tympanomastoid surgery. This is followed by the protection of the membranous labyrinth and the closure of the fistula. The closure process is done with materials such as bone paste, fascia, and cartilage. The goal of treatment is to stop inner ear type hearing loss and dizziness. The treatment gives results in a very large proportion. However, since the inner ear will be intervened in an inflamed environment, it also carries the risk of hearing loss.

Soft Tissue Abscess

A soft tissue abscess is an abscess condition that occurs when the infection spreads to the subperiosteal area. This abscess condition generally manifests itself in acute otitis, and rarely during chronic otitis. Spreading occurs directly through destruction in the bone walls of the mastoid or by throwing thromboembolism via small veins. These abscesses are located in 3 main places. These are zygomatic root abscess, post-auricular (behind the ear) abscess, and neck abscess. The most common of these is the post-auricular abscess. In this abscess, there is extreme swelling behind the ear, total forward rotation of the ear, pitting with finger pressure, and even in some cases, skin perforation and discharge.

In the zygomatic root abscess, swellings seen in the upper and front region of the ear draw attention. Also, difficulty in opening the jaw is observed. In a neck abscess, swelling is felt along the neck muscle. The treatment for these 3 listed abscesses is performed by applying myringotomy if the membrane is intact, intensive antibiotics, and rapid surgical intervention and abscess drainage. If there are no other complications, recovery is achieved except in exceptional cases with surgical treatment.

Epidural Abscess

An epidural abscess is an abscess formed between the skull bones and the wall forming the outer membrane layer of the brain. The formation occurs through the spread of infection to the adjacent tissue via bone destruction. It can be seen in both acute and chronic otitis forms. Its formation can be in two separate locations. One is in the middle cranial fossa, adjacent to the lobe, and the other is in the posterior cranial fossa, adjacent to the cerebellum.

Epidural abscess symptoms do not include any significant complaints other than mild headache and fever. Some even progress silently. In acute or chronic cases, treatment is intervention directed at the source of infection. Drainage of the abscess includes this. Myringotomy can also be performed if the membrane is intact. Then, intensive antibiotic treatment is applied. However, if other complications are present, surgical intervention may be required. If an exceptional situation does not occur, recovery is fast.

Subdural Abscess

This situation is the formation of an abscess between the dura, which forms the outer membrane layer of the brain, and the arachnoid, which forms the inner membrane layer. The development process of a subdural abscess occurs with the infection reaching the subdural space along with acute or chronic mastoiditis. This situation is rarely seen. It can occur as both an acute and otitis complication.

The manifestation of a subdural abscess is sudden and severe. It shows itself with severe fever, vomiting, headache, and nausea. Paralysis or other neurological symptoms may occur. It can lead to a serious condition such as a coma. In treatment, drainage, mastoidectomy, and myringotomy if the membrane is intact must be performed. Urgent surgical intervention may be required along with intensive antibiotic support. This situation carries high vital risk as well as neurological disability risk.

Brain Abscess

This is the development of local inflammation and subsequent abscess in the brain tissue. A brain abscess can occur in the form of acute or chronic mastoiditis. A brain abscess can manifest itself in two localization areas. The first is in the middle cranial fossa in the form of a temporal lobe abscess. The other is in the posterior cranial fossa in the form of a cerebellar abscess. Any brain abscess is seen in the form of fever, headache, and general condition deterioration. Although it shows a deceptive state of recovery a few days later, a mature abscess then forms. With the effect of the mass, there is an increase in the pressure within the skull. This is followed by headache, fever, and different neurological symptoms. There is a risk of blockage in the brain stem, and this carries a vital danger.

In its treatment, it is important to start antibiotics effective against aerobic and anaerobic bacteria without delay. In addition, rapid drainage and abscess decompression may be required. Open surgical application of this abscess is rarely applied. When the patient's general condition is good, intervention directed at the source of infection, namely mastoidectomy and myringotomy if the membrane is intact, can be applied. It should not be forgotten that even if a surgical path is followed, it is a situation that includes vital risk.

Sinus Thrombosis

Sinus thrombosis occurs when an infectious thrombus forms in the sinus system, which is located between the dura layers adjacent to the mastoid and transports the venous blood of the brain. It can manifest itself as both an acute and chronic otitis complication. The symptoms arising with sinus thrombosis can be listed as follows; spiking septic fever, pain behind the ear, headache, consciousness changes, and general condition disturbances. Sensitivity in the neck is observed along with inflammatory findings. As the disease progresses or when additional complications occur, different neurological findings are added to the general condition.

Treatment is directed towards myringotomy if the membrane is intact, intensive antibiotic use, mastoidectomy, and cleaning of the granulations formed on the sinus via the mastoid route. In some cases, procedures such as sinus ligation, thrombus removal, and sinus excision can be applied. Also, not making an extra intervention other than mastoidectomy is an option.

If there is a situation like a thrombus being thrown into the circulatory system, internal jugular vein ligation or removal procedure can be applied. Additionally, anticoagulant treatment may be required. This situation carries vital danger even if surgical intervention is resorted to.

Hydrocephalus

This condition, also called otitic hydrocephalus, is a situation that arises with an increase that can occur in the pressure of the cerebrospinal fluid. It generally manifests itself with impairment in cerebrospinal fluid absorption. It can develop as both an acute and chronic otitis complication. Among the symptoms that frequently arise in the case of hydrocephalus are headache, vomiting, and visual disturbance. In the fundus examination to be performed, it is possible to encounter edema also called papilla. Along with this, signs and symptoms of sinus thrombosis can also be detected.

The treatment of hydrocephalus is directed at two purposes. One involves the medical-surgical treatment applied in sinus thrombosis. On the other hand, in order to lower the pressure in the cerebrospinal fluid, diuretic, cortisol, and lumbar drainage applications are made. Even if medical and surgical intervention is made for sinus thrombosis and the accompanying hydrocephalus, it may include significant vital risk. Along with all these, there is also the possibility of hydrocephalus becoming permanent.

Meningitis

Meningitis is the complication formed by acute inflammation of the brain membranes. Ear-based meningitis generally develops as an acute otitis and in some cases as a chronic otitis complication. Meningitis is frequently an intracranial complication of acute otitis. Bacteria reach the brain membranes from the middle ear and mastoid. It does this by following bone destructions, the labyrinth-aqueductus cochlea path, or venous paths. These types of meningitis, unlike meningitis occurring as a result of an epidemic, are not caused by meningococci but by Streptococcus pneumoniae and Haemophilus influenzae, which are the agents of acute otitis.

Increasing streptococcal meningitis carries a vital risk. Also, it has a very high risk of causing hearing loss by creating ossificans labyrinthitis. Symptoms of meningitis frequently include neck stiffness, headache, high fever, and decrease in sugar. In the treatment of meningitis, there is the use of antibiotics that can cross the brain barrier and succeed in affecting the bacteria. Along with this, myringotomy is applied if the membrane is intact. In order to minimize the risk of hearing loss, high-dose cortisol can be resorted to. This is generally dexamethasone.

Although this kind of path is generally followed as a treatment method in meningitis due to acute otitis, if other complications are present, there should be an intervention directed at the source of infection. That is, in this case, there is a need for mastoidectomy.

In meningitis occurring due to chronic otitis, in addition to the treatments above, tympanomastoid surgical treatment is applied aimed at finding and destroying the source of infection when the patient's general health condition allows. Although a large part of ear-centered meningitis can be cured with these treatment methods to be applied, they carry risks such as hearing loss.