Bacterial otogenic meningitis causes
Meningitis - a bacterial or viral inflammation of the pia mater. Meningitis with otitis arises as a result of the spread of infection into the subarachnoid space of the cavities of the middle and inner ear, or is a consequence of other intracranial complications (extra-, subdural brain abscess, sigmoid sinus thrombosis).
The most frequent causes of meningitis with otitis are cocci (strepto-, staphylo-, diplomas and pneumococci), far less - other microbes. But often in the cerebrospinal fluid can not identify any flora.
Most often, infection with otogenic meningitis spreads through contact or labirintogenous. The first time there are usually significant changes up to fracture in the bone separating the middle ear cavity from the meninges. It is sometimes leptomeningitu precedes inflammation of the dura mater (epidural or subdural abscess). When labirintogennom meningitis infection from the affected labyrinth extends through the cochlea and vestibular aqueducts and internal auditory canal. This route of infection in meningitis is more common than in other intracranial complications.
Meningitis usually occurs when mastoiditis complicating acute purulent otitis media and chronic purulent otitis (attic disease), especially the complicated cholesteatoma.
In the initial stage of acute otitis media meningitis is most often a consequence of hematogenous spread of infection (for vascular paths). This so-called fulminant form of meningitis, the most unfavorable. Pathological anatomy. The initial inflammatory changes pia mater (redness, swelling) also apply to the cerebral cortex. Serous exudate in the subarachnoid space during meningitis is later purulent. Simultaneously in the cerebral cortex in meningitis occasionally appear areas of softening and suppuration. Thus, each meningitis is essentially a meningoencephalitis.
The dura in meningitis also becomes hyperemic, tense. Inflammation of the membranes of meningitis often expressed in the base of the brain (basal meningitis), sometimes extends to the hemisphere of the brain or restricted to them. Even more rarely, meningitis is only observed in the cerebellum, sometimes extending to the shell and the spinal cord. In severe cases, purulent inflammation in meningitis is extended to all the subarachnoid space of the cerebrum, cerebellum and spinal cord.
Bacterial otogenic meningitis symptoms and clinical presentation
The headache of meningitis is often intense, nearly constant. Headache in meningitis appear before other symptoms. Initially, the headache of meningitis may be limited to the neck or forehead, then to become diffuse. Very often the headache of meningitis is accompanied by nausea and vomiting.
The temperature of meningitis is increased to 39-40 ° C and above and has the character cpntinua. Pulse is usually accelerated, but sometimes marked bradycardia. The general condition of the patient with severe meningitis, a person is often pale, sallow, haggard, tongue dry.
The patient's consciousness in meningitis confused, passing into delirium. Patient apathetic, often marked motor excitation, increased by extraneous stimuli (sound, light). Salient features of the patient with head thrown back, knees bent legs to eliminate unnecessary tension of the dura mater.
Stiff neck and Kernig's signs and Brudzinski's signs always expressed in a patient with meningitis. Sometimes marked pyramidal signs (pathological reflexes - Babinski, Oppenheim, Gordon and others). Occasionally there are spasms of the limbs. Often with basal meningitis observed abducent paralysis, and sometimes the oculomotor and other cranial nerves. Rarely occur with focal brain symptoms, forcing the resort to an unsuccessful and even unsound puncture the brain.
Cerebrospinal fluid (CSF) is published with the lumbar puncture is usually under significant pressure. It loses its transparency, becomes turbid, sometimes almost pure pus. CSF pleocytosis in CSF varies greatly from moderate increase to the number of cells that can not be counted. Usually dominated by neutrophils, with a further favorable course marked lymphocytic reaction, but such a relation of cellular elements is not constant, especially when treatment with antibiotics. The protein content is usually increased, often significantly. The percentage of sugar and chlorides, on the contrary, reduced.
In blood serum - high leukocytosis, and a significant increase in ESR.
The use of antibiotics has led to significant changes in clinical meningitis. Symptoms become blurred, sometimes unexpressed, another character acquired during meningitis. So, there are cases of meningitis with subfebrile or normal temperature, with mild headache, a little marked meningeal signs, impaired consciousness and other brain symptoms in general, satisfactory or even good condition. Often there are significant modifications in the cerebrospinal fluid (CSF pleocytosis reduction, changes in cellular composition in the direction of lymphocytosis, etc.) and hemogram also mask the true picture of the disease.
During the meningitis with timely surgery, the absence of other complications, and rational use of antibiotics and sulfonamides mostly favorable, mostly disease after 3-4 weeks ends with recovery. However, there is a prolonged duration (up to several months), usually intermittent nature (the so-called recurrent meningitis). This form of meningitis caused by a number of factors:
- remaining after surgery on the ear purulent foci in the labyrinth or the apex of petrous
- deep epidural abscess
- circumscribed accumulations of pus in the subarachnoid space, not giving due fibrinopurulent plastic osumkovaniya Effects of antibiotics (they can cause focal cerebral symptoms)
With intermittent flow with a number of outbreaks of meningitis and damping progressively increases resistance of bacteria. The prognosis for such a course of meningitis, mostly bad. Fatal properties also hematogenous form of meningitis, in which the symptoms are often so lightning fast growing that the autopsy can not establish a visible (macroscopic) changes in the shells.
Bacterial otogenic meningitis diagnosis
In the presence of typical meningeal symptoms and patterns of cerebrospinal fluid diagnosis is simple. Setting meningitis, need to find a number of circumstances - is it linked to the ear, whether it is epidemic cerebrospinal meningitis or tuberculosis, not whether it is a consequence of the other otogennogo intracranial complications (eg, cerebral abscess or extradurally).
Acute inflammation or exacerbation of chronic suppurative otitis media favors otogennogo nature of meningitis. Being in the cerebrospinal fluid of meningococci or tuberculous mycobacteria reveals the nature of meningitis. However, mycobacteria are sown in tuberculosis is not always the case. For tuberculous meningitis is characterized by a clear liquid, resulting in a puncture at high pressure, lymphocytic reaction liquor falling film of fibrin. Refinement of diagnosis helps to identify the organ tuberculosis. However, this is far from always, and at the same time, the clinical course of tuberculous meningitis may be atypical.
Along with tuberculous meningitis should be differentiated from otogenny meningitis cerebrospinal meningitis. The latter is characterized by sudden onset, the absence of any prodrome, which at otogennom meningitis can be a gradually increasing headache for several days prior to the development pattern of the disease. If at a purulent meningitis has a picture of acute otitis media or exacerbations of chronic suppurative otitis media should not delay the surgery on the ear.
In the vast majority of cases, operational findings confirm the correctness of the decision. At surgery often can be detected and other intracranial complications, meningitis if there was on their soil. In the absence of such findings should be closely monitored for neurological symptoms and the dynamics of changes in cerebrospinal fluid, particularly in view of the possibility of unrecognized brain abscess. Suspicion of brain abscess should arise in the absence of improvement of neurological status with the simultaneous trend toward normalization of CSF and belkovokletochnoy dissociation in the cerebrospinal fluid (elevated protein content with a slight CSF pleocytosis).
Bacterial otogenic meningitis treatment
Operation on the temporal bone (simple or obschepolostnaya depending on the nature of otitis media) with a wide exposure of the dura mater in the middle and posterior fossa. In identifying associated complications (epidural or subdural abscess, brain abscess, sigmoid sinus thrombophlebitis) is an appropriate intervention. Intervention in the maze or the apex of the pyramid, even if complications are optional. Very often, the phenomenon of suppurative labyrinthitis or petrozita eliminated after a routine operation on the temporal bone and medical treatment. However, the lack of success or partial effect of these interventions on the maze or the top of the pyramid should be made.
Postoperative treatment consists of antibiotics and sulfonamides. Treatment must be combined with oral administration of nystatin to avoid the development of candidiasis (500 000 IU, 3-4 times a day) and vitamin therapy (ascorbic acid and vitamin B complex).
To reduce the intracranial pressure is carried out dehydration: 10-15 ml of 25% magnesium sulfate solution IM, 10 ml 2.4% solution of aminophylline IV, infusion, 1-2 ml of 2% solution of Lasix IV or IM or furosemide (1-2 tablets) orally. Produce lumbar puncture (in severe cases, 2-3 days, starting with rehabilitation of cerebrospinal fluid - 4-5 days), and produced a moderate amount of liquor. In marked clinical improvement and normalization of the CSF approach to puncture stopped. In severe cases, after removing the liquid endolyumbalno administered antibiotics.
At the most severe forms of meningitis in a threatening rise in intracranial pressure, beyond the specified treatment, in addition to the transactions carried out an autopsy showed the tank side of the brain. In severe cases of meningoencephalitis is used as the introduction of antibiotics through the lumen of the carotid arteries.