Brain and spinal cord abscesses - Treatment and prognosis

Treatment of brain and spinal cord abscesses

Treatment of brain abscesses can be conservative and surgical. The method of treatment depends primarily on the stage of development of the abscess, its size and localization.

At the stage of formation of the encephalitic focus (the duration of the anamnesis is up to 2 weeks), as well as in case of small (<3 cm in diameter) abscesses, conservative treatment is indicated. Empirical antibacterial therapy becomes the usual tactic. Some surgeons prefer to perform stereotactic biopsy for final verification of the diagnosis and isolation of the pathogen.

Absolute indications for surgical intervention are considered to be abscesses that cause increased intracranial pressure and brain dislocation, as well as those located near the ventricular system (a breakthrough of pus into the ventricular system often becomes fatal). In case of traumatic abscesses located near a foreign body, surgical intervention also becomes the method of choice, since such an inflammatory process cannot be treated conservatively. Fungal abscesses are also considered an indication for surgery, although the prognosis in this situation is extremely unfavorable regardless of the method of treatment.

In case of abscesses located in vital and deep structures (brain stem, thalamus, subcortical nuclei), direct surgical intervention is contraindicated. In such cases, the method of choice may be the stereotaxic method - puncture of the abscess and its emptying with a single or repeated (through a catheter installed for several days) rinsing of the cavity and the introduction of antibacterial drugs.

Severe somatic diseases are not considered an absolute contraindication to surgical intervention, since stereotactic surgery can be performed under local anesthesia.

For patients in extremely serious condition (terminal coma), any surgical intervention is contraindicated.

Principles of drug treatment of brain and spinal cord abscesses

Empirical (before receiving the results of the culture or if it is impossible to identify the pathogen) antibacterial therapy should cover the maximum possible spectrum of pathogens. Therefore, the following algorithm is used.

• Patients without a history of traumatic brain injury or neurosurgical intervention are prescribed the following drugs simultaneously:
  • vancomycin (adults - 1 g 2 times a day intravenously; children - 15 mg/kg 3 times a day);
  • third generation cephalosporin (eg, cefotaxime);
  • metronidazole (adults - 30 mg/kg per day in 2-4 doses; children - 10 mg/kg 3 times per day).
• For patients with post-traumatic abscesses, metronidazole is replaced by rifampicin at a dose of 9 mg per 1 kg of body weight once a day orally.
• In patients with immunodeficiency (except HIV), the most likely causative agent of brain abscess is Cryptococcus neoformans, less often Aspergillus spp. or Candida spp. In this regard, they are prescribed amphotericin B at a dose of 0.5-1.0 mg/kg per day intravenously or liposomal amphotericin B - 3 mg/kg per day intravenously with a gradual increase in the dose to 15 mg/kg per day. If the abscess disappears according to neuroimaging methods, fluconazole is prescribed at 400 mg/day orally for up to 10 weeks, and then patients are transferred to a constant maintenance dose of 200 mg/day.
• In patients with HIV, the most likely causative agent of brain abscess is Toxoplasma gondii, so sulfadiazine with pyrimethamine is used in the empirical treatment of such patients.

If a pathogen culture is obtained, the treatment is changed taking into account the antibiogram. If the culture is sterile, empirical antibacterial therapy is continued.

The duration of intensive antibacterial therapy is at least 6 weeks, after which it is advisable to prescribe oral antibacterial drugs for another 6 weeks.

The use of glucocorticoids leads to a decrease in the severity and faster reverse development of the fibrous capsule of the abscess, which is good with adequate antibacterial therapy, but otherwise can cause the spread of the inflammatory process beyond the primary focus. Therefore, the prescription of glucocorticoids is justified only with increasing edema and dislocation of the brain; in other cases, the issue requires discussion.

Surgical treatment of abscesses of the brain and spinal cord

The main method of treating most intracerebral brain abscesses is currently simple or inflow-outflow drainage. The essence of the method is to install a catheter into the abscess cavity, through which pus is evacuated and antibacterial drugs are administered. If possible, a second catheter of a smaller diameter is installed into the cavity for several days, through which an infusion of a washing solution is carried out (usually 0.9% sodium chloride solution is used, the effectiveness of adding antibacterial drugs to it has not been proven). Abscess drainage implies mandatory antibacterial therapy (first empirical, then taking into account the sensitivity of the isolated pathogen to antibiotics).

An alternative method is stereotactic aspiration of the abscess contents without installing drainage. The advantage of this method is a lower risk of secondary infection and more lenient requirements for the qualifications of medical personnel (control over the functioning of the inflow-outflow system requires special knowledge and close attention). However, when using this method, in approximately 70% of cases there is a need for repeated aspirations.

In case of multiple abscesses, the focus that is most significant in the clinical picture or most dangerous in terms of complications (brain dislocation, pus breakthrough into the ventricular system, etc.) is drained first.

In case of subdural abscesses or empyema, drainage is used; the inflow-outflow system is not used.

Operations of total removal of an abscess together with the capsule, without opening the latter, are not currently used due to high trauma. Exceptions are fungal and nocardiosis (caused by Nocardia asteroides, less often Nocardia brasiliensis) abscesses that develop in immunodeficient patients. Radical removal of abscesses in such situations somewhat improves survival.

Surgical treatment of epidural abscesses is the same as for osteomyelitis.

Forecast

The prognosis for brain abscesses depends on many factors. Of great importance is the ability to determine the pathogen and its sensitivity to antibacterial drugs, which allows for targeted pathogenetic therapy. An important role in the outcome of the disease is played by the reactivity of the body, the number of abscesses, the timeliness and adequacy of treatment measures.

Mortality from brain abscesses is about 10%, disability is about 50%. Almost a third of surviving patients develop epileptic syndrome.

Subdural empyemas are prognostically less favorable than brain abscesses, since the absence of purulent focus boundaries indicates either high virulence of the pathogen or extremely low resistance of the patient. Mortality in subdural empyemas is about 50%. In fungal empyemas in immunodeficient patients, it approaches 100%.

Epidural abscesses and empyemas usually have a favorable prognosis. Infection almost never penetrates through the intact dura mater, and debridement of the osteomyelitic focus allows the epidural empyema to be eliminated.

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