Otogenic cerebellar abscess: causes, symptoms, diagnosis, treatment

According to summary statistics of the second half of the 20th century, 98% of purulent diseases of the cerebellum occur in the otogenous abscess of the cerebellum.

In the pathogenesis of the disease, the following ways of infection spread:

1. The labyrinthine pathway (60%) is most frequent, due to the focus of purulent infection in the posterior semicircular canal; less often the infection spreads along the water pipeline of the vestibule and through the endolymphatic sac, even less often - through the VSP and the facial canal;
2. hematogenous pathway takes the second place in the onset of the otogenous abscess of the cerebellum; most often the infection spreads through veins related to sigmoid and stony sines; the arterial path of infection is extremely rare;
3. by extension (per continuitatem); this pathway is formed when the chronic purulent process in the middle ear develops in the cells of the mastoid process, deep inter-sinus-facial and retro-labyrinth cells, with the involvement of the cerebral membranes of the posterior cranial fossa into the pathological process.

Pathological anatomy. The otogenous abscess of the cerebellum can be located inside the cerebellum without damaging its cortex; with superficial localization of the abscess, it is located in the gray and partly in the white matter of the cerebellum, while, as a rule, it is communicated with the primary focus of infection with the help of a "fistula-foot". The otogenous abscess of the cerebellum can be solitary or multiple, ranging from forest to walnut. The density of its capsule is determined by the prescription of the disease - from weakly differentiated and unstable in fresh cases to a sharply thickened and strong one with old abscesses.

Symptoms of otognnogo abscess of the cerebellum. The initial period of the otogenous abscess of the cerebellum is masked by the clinical picture of the underlying disease and lasts approximately between the end of the first week of exacerbation of the purulent process in the middle ear and can last up to 8 weeks, showing only common signs of the infectious process. In this period, it is not easy to suspect the onset of an otogenic abscess of the cerebellum, and only in the second half of the period it becomes possible with a careful examination of the patient by an experienced neurologist.

The period of the "light" gap creates the illusion of recovery, it can last several weeks. At this time, the patient's condition is satisfactory, there may be only a few disorders of movement on the side of the abscess.

The peak period is characterized by general toxic, hydrocephalic and focal syndromes. The earliest and most pronounced signs are increased intracranial pressure. Headache is localized in the occipital region, often there is vomiting, dizziness, loss of consciousness; bradycardia and congestive optic discs are observed in 20-25% of cases. Focal symptoms are characterized by impaired swallowing, dysarthria, the appearance of pathological reflexes, hemiplegia, paralysis of the cranial nerves, spontaneous cerebellar nystagmus. Cerebellar symptoms are often associated with:

1. signs of gait disorder ("drunk walk" - erratic vacillations with a tendency to fall back and toward the lesion focus);
2. violations of voluntary movements (intentional jitter at index tests, hypermetria, adiadochokinesis, chanted speech, etc.);
3. Vestibular disorders may manifest as peripheral and central symptoms.

Peripheral symptoms occur when the primary focus of infection is located in the ear maze (posterior semicircular canal), then they precede the otogenic cervical abscess and manifest spontaneous vertical nystagmus upward in the initial stage of the serous labyrinthitis, with purulent labyrinthite down either diagonal or horizontally rotary (circular) spontaneous nystagmus towards a healthy labyrinth. When the labyrinth is turned off, the caloric test (a bithermal caloric test) on it does not cause any changes in the spontaneous nystagmus, while the same sample, if cold, leads to a decrease in the intensity of spontaneous nystagmus, with a thermal sample it increases. These changes in spontaneous nystagmus indicate a peripheral, i.e. Labyrinthine, genesis. At the same time, there are harmonic disturbances of the samples for coordination of movements, systemic dizziness, consistent with the direction and components of the spontaneous nystagmus, vestibulo-vegetative reactions. Central vestibular disorders (absence of labyrinthitis!) Arise when the brainstem is compressed in the area in which the vestibular nuclei are located, i.e., due to increased pressure in the posterior cranial fossa, which may be due to occlusion of the liquor-conducting pathways and pressure of the cerebellum on medulla. In this case, the spontaneous nystagmus is central in nature and changes when the ear maze is irrigation only with cold or thermal caloric stimuli (changes in spontaneous nystagmus in the direction).

In the terminal period, bulbar symptoms intensify, manifested by violations of cardiac and respiratory activity, dysphagia, dysarthria, lesions of the nerves of the caudal group and the nerves of MMU, including paralysis of the facial nerve, hyperesthesia of the face, disappearance of corneal and pupillary reflexes on the affected side. Death comes from the paralysis of the vasomotor and respiratory centers, caused by the edema of the brain and the obliquity of the medulla oblongata in the large occipital orifice.

The prognosis is determined by the same criteria as in the otogenous abscess of the temporal parietal region, but it is more serious due to the fact that the otogenic cerebellar abscess is formed near the vital centers of the brainstem and, if not detected correctly, can cause sudden occlusion of the medulla oblongata and sudden death from stopping breathing and stopping heart activity.

Diagnosis of the otogenous cerebellar abscess is difficult in the initial stage, when the cerebellar symptoms are not expressed, and the general condition of the patient and local inflammatory phenomena in the temporal bone mask the signs of the beginning otogennogo abscess of the cerebellum. As a rule, the diagnosis of an otogenous cerebellar abscess is established during the climax on the basis of the presence of a triad - dizziness, spontaneous nystagmus, strabismus in combination with characteristic cerebellar symptoms.

Currently, the main instrumental methods for diagnosing cerebral abscess are MRI and CT, which have a high resolution in determining the location, size and structure of the abscess, for example, the density of its capsule or the contents of its cavity. In the absence of these methods, a survey and tomographic X-ray study of the skull and brain, X-ray of the temporal bones according to Schuller, Mayer and Stenvers are used, as well as some axial projections that allow assessing the condition of the basal sections of the skull and brain. It is possible to use other methods of brain research, such as EEG, ultrasound, rheoencephalography, angiography, ventriculography, but with the introduction of MRI and CT, these methods retained only auxiliary functions.

Differential diagnosis is performed between the abscess of the temporal lobe, labyrinthitis, empyema endolymphatic sac (the so-called retro-labyrinth abscess and otogennoy hydrocephalus:

• with labyrinthitis, there are no signs of increased intracranial pressure and changes in cerebrospinal fluid, but there are vivid signs of peripheral lesion of the vestibular apparatus (spontaneous nystagmus, harmonic infringement of index samples, laterulopia, etc.) and cochlea (pronounced hearing loss or deafness);
• Retrolabirintny abscess, in fact, is an intermediate stage between the labyrinthitis and otogennym abscess of the cerebellum, so it can be present and signs of labyrinthitis, and the initial stage of the otogenous abscess of the cerebellum;
• otogennaya hydrocephalus is characterized by a combination of chronic purulent inflammation of the middle ear, usually complicated by cholesteatoma and caries of bone, with paroxysmal or persistent severe headaches accompanied by severe congestion on the fundus; from an abscess of the cerebellum, otogenic hydrocephalus is distinguished by the absence of a forced position of the head (tilting of the head), meningeal symptoms, impaired consciousness, characteristic cerebellar symptoms; when otogennoy hydrocephalus observed high liquor pressure (up to 600 mm Hg), the protein content in the cerebrospinal fluid is normal or slightly lowered (0.33-0.44 g / l), the number of cells is normal.

Treatment of otogenous abscess of the cerebellum. If symptoms of an ostogenous cerebellar abscess are observed, but there is not enough convincing evidence of its presence, obtained at CT or MRI, first one-stage extended RD is performed with removal of all affected bone and mastoid cells, perisinus and perilabyrinth cells, dissecting the posterior cranial fossa and exposing the sigmoid sinus , evaluate its state and state of TMO. When a posterior cranial fossa is found in this area, it is removed and resorted to expectant management for 24-48 hours. During this time, the ear wound is conducted openly with massive antibiotic therapy, carrying out activities aimed at stabilizing intracranial pressure and the functions of vital organs. If during this time in the general state of the patient there is no improvement, and the cerebral and cerebellar symptoms increase, then they start to search for the otogenous abscess of the cerebellum and, when it is found, to remove it. If an abscess is detected with CT or MRT, wait-and-see tactics are not used and after the general-cavity RO begin to search for the abscess and remove it. The postoperative cavity of the otogenous abscess of the cerebellum and middle ear for 48 hours is constantly washed with solutions of antibiotics and drained with gauze turundas.

When thrombosis of the sigmoid sinus, its pathologically altered part is removed and the otogenic cervical abscess is opened through the space left after removal of the sine part. When the labyrinth is damaged, it is removed.

[1], [2], [3], [4], [5], [6],