BRAIN ABSCESS: SYMPTOMS, CAUSES AND TREATMENT - NEUROPSYCHOLOGY - 2024

The brain abscess is a type of brain infection Some experts define as a suppurative process wherein an accumulation of pus and dead cells occurs. It is a serious and life-threatening medical condition, despite being rare. Generally, bacterial agents are the most common cause of the development of brain abscesses.

Despite the fact that the diagnosis of this infection is complicated, especially in the early stages of symptoms, new brain imaging methods (magnetic resonance, computed tomography, etc.) have significantly facilitated the accurate and early identification of brain abscesses.

On the other hand, therapeutic interventions for brain abscesses tend to focus on the administration of antibiotic drugs and surgical interventions.

Characteristics of brain abscesses

A cerebral access is defined as a focal infection within the brain parenchyma, that is, in the brain tissue. In addition, it is a form of intracranial suppuration that represents a medical emergency that puts the life of the affected person at risk.

Generally, brain abscesses begin by showing a localized ischemic or necrotic area, with inflammation of the brain tissue. This is followed by the deposition of leukocyte antigens.

Leukocyte antigens fulfill an immune function and, therefore, try to protect the body from the agents that cause infection. At the macroscopic level, the deposit of this type of agent is manifested by the presence of pus.

Pus is a thick liquid with a yellowish or greenish color, which is secreted or suppurated by the inflamed tissues. Generally, this substance is made up of serum, leukocytes, dead cells and other agents.

After these events, the area of ​​the necrotic zone tends to increase and also the suppuration of pus. Next, the affected or purulent area becomes delimited and begins to develop neo-vascularization (formation of new blood vessels) around it.

In the final phase, the affected area is surrounded by a capsule that keeps the infectious process localized.

Statistics

Brain abscesses are a medical condition that has become rare or frequent in more developed countries, especially since the second half of the 20th century, thanks to medical and technological advances.

Statistical data show us that brain abscesses present an incidence that ranges between 0.3-1 cases per 100,000 people / year, in the general population.

Despite the low incidence of this pathology, mainly due to the introduction of new antimicrobial drugs and the development of brain imaging studies, it remains a potentially fatal condition.

When the capsule of a brain abscess ruptures, the person can die in approximately 80%. In addition, of those who survive, between 20-79% will present neurological sequelae after the infectious process.

Regarding sex, some specialists point out that brain abscesses are more frequent in men than in women. On the other hand, in terms of age, brain abscesses are considered a rare disease or pathology in pediatric age.

Studies show that brain abscesses have an estimated incidence of about 4 cases per million population of child age.

Characteristic signs and symptoms

Our central nervous system (CNS) is really susceptible to any damage or injury that affects the nervous tissue. Thus, infectious processes can give rise to a wide variety of neurological symptoms when they affect brain tissue and adjacent structures.

Patients who suffer from this type of localized infection usually present a non-specific clinical picture.

The characteristic signs and symptoms of brain abscesses appear insidiously, evolving over days or weeks, generally, the duration of the symptoms is at least two weeks.

The clinical course of brain abscesses usually includes:

• Intracranial hypertension: increased pressure exerted by cerebrospinal fluid (CSF) within the intracranial vault.
• Intracerebral tumor syndrome: the presence of the purulent capsule can act in the same way as the formation of a tumor mass, leading to compression of the nervous tissues and consequent to the development of various neurological symptoms (epileptic seizures, cognitive deficits, disorders motors, etc.).
• Headaches: headache, usually severe and persistent. Normally, this symptom is present in most of those affected and can be unilateral or bilateral. Headaches usually start progressively.
• Nausea and vomiting: General malaise, nausea, and recurrent vomiting are usually present in more than 50% of affected people.
• Generalized seizures: epileptic seizures or discharges are less frequent, occurring in approximately 30% of cases.
• Papillary edema: process of inflammation of the optic disc, located at the back of the eye through which the optic nerve accesses to reach the brain tissue. Like the previous one, it is a rare symptom, present in approximately 25% of cases.
• Moderate fever: the rise in temperature is usually moderate and occurs in approximately 50% of cases.

On the other hand, it is also possible that brain abscesses debut with other clinical forms;

• S índrome of febrile intracranial hypertension: Development of severe headaches, vomiting, nausea, convulsions, fever, etc. Acute onset in the form of meningitis and acute onset in the form of meningeal hemorrhage.

In addition to this, if the diagnosis is made late, the brain abscess progresses, increasing pus suppuration, cerebral edema and intracranial pressure. Because of this, some serious neurological symptoms may appear such as:

• Confessional state.
• Spatio-temporal disorientation.
• Persistent and frequent seizures.
• Loss of consciousness.
• Coma.

Causes

Brain abscesses develop as a consequence of the existence of an infectious process.

Despite the fact that this medical entity usually presents a diverse etiology, there are risk factors that allow the approximate cause and location of the infection to be identified.

Some of the predisposing factors are:

• Infections of contiguous or adjacent structures.
• Head injuries.
• Neurosurgery.
• Distant source of infection.

In this way, different infectious agents, viruses or bacteria, can reach the brain tissue, leading to the formation of the purulent capsule.

In the case of brain abscesses of bacterial origin, streptococci are the most common pathogens, giving rise to approximately 70% of cases.

Diagnosis

In many cases of brain abscess, the diagnosis is not easy, and since the symptoms are nonspecific. Much of the symptoms resemble those characteristic of other pathologies or diseases of neurological origin.

In the case of brain abscesses, the neurological examination carried out through various brain imaging tests, such as magnetic resonance imaging or computed tomography, is essential.

Neuroimangen tests allow us to determine anatomically the presence of brain lesions, such as abscesses.

On the other hand, it is also common for the medical specialist in charge of the case to request other laboratory tests such as blood cultures or lumbar puncture to determine the presence of an infectious agent.

Treatments

Currently, medical advances have made it possible to develop different therapeutic options. The choice of one of these will depend on the characteristics of the brain abscess and the clinical characteristics of the affected person.

Typically, the most common treatment includes pharmacological and surgical intervention.

Pharmacotherapy

The approach to brain abscesses through pharmacological treatment usually focuses on the use of antibiotic therapies, called antibiotic therapy.

Antibiotics are usually recommended for the treatment of brain abscesses that do not exceed 2.5 centimeters.

In the first weeks, high doses of these drugs are usually used to ensure sufficient penetration and concentration of the antibiotics in the brain tissue.

Normally, this type of treatment lasts approximately 6-8 weeks, and can even reach 3-6 months in severe cases that cannot be operated on.

Surgical treatment

Surgical interventions are used both for the therapeutic approach and for the realization of the diagnosis, they are usually indicated in those abscesses that are larger than 2.5 centimeters.

Various neurosurgery techniques allow a puncture-biopsy to be performed in the affected area. Thus, these procedures allow the evacuation of pus, leading to a decompression of brain tissue.

On the other hand, complete removal of the capsules usually involves a procedure with great risks for the patient, therefore, they are restricted to severe cases in which the other measures have not been effective.

Forecast

When a diagnosis of brain abscess is made, it is essential to carry out a medical approach early, treat secondary neurological complications and, in addition, carry out a follow-up.

Although current therapies help control the progress of this pathology, those affected die in up to 5-10% of cases.

Despite the fact that it is a pathology that puts the life of the person at risk, mortality has been reduced by approximately 25%, in cases of stay in medical intensive care units.

On the other hand, neurological sequelae are prevalent (30-5%), some are mild, while others may involve more significant symptoms such as epilepsy.

References

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