Traumatic brain abscess

Introduction to traumatic brain abscess Traumatic brain abscess is more common in open brain injury and craniocerebral firearm injury. Foreign matter entering the skull is important for the occurrence of brain abscess. In addition, it is closely related to whether the wound treatment is timely and completely. basic knowledge The proportion of illness: 0.012% Susceptible people: no special people Mode of infection: non-infectious Complications: purulent meningitis ventriculitis

Causes of traumatic brain abscess

Infection (50%):

Common pathogens are Staphylococcus aureus, followed by hemolytic streptococcus and anaerobic streptococci, and occasionally infection with Clostridium perfringens. In recent years, reports of anaerobic infections have increased.

Direct infection of brain swelling. The tissue bulges outward from the skull defect, which is also called cerebral palsy. Males have a good anterior cerebral bulge, and women have more cerebral bulging in the posterior cranial. Patients with mild neurological symptoms have no obvious neurological symptoms. The severe ones are related to the location and degree of damage. They may show mental retardation, convulsions and varying degrees of paralysis, hyperreflexia, and non-constant pathological reflex.

Other factors (25%):

(such as scalp, gravel, broken bone pieces, metal pieces) directly into the brain tissue is most common. Traumatic brain abscess can be caused by communication between the cranial cavity and the infected area or contaminated area (such as the paranasal sinus and middle ear).

Pathogenesis

Brain abscess after brain trauma is mostly related to the accumulation of broken bone fragments or foreign bodies. In the firearm penetrating injury, the residual shrapnel of the fire is more likely to cause infection than the bullet that is injected at a high speed. The high temperature generated by friction in the flight has reached the peak. The effect of the bacteria, in addition, through the maxillofacial region, paranasal sinus or deafness, mastoid gas chamber, etc., the penetrating injury in the skull, the possibility of infection is significantly increased, especially in patients with nasal paralysis In the case of sinus inflammation, it is more likely to occur, and the onset time of traumatic brain abscess varies greatly, which can be several weeks after the injury or even years later, even decades.

The formation of brain abscess after the bacteria enters the brain is a continuous process. It passes through the acute encephalitis stage, the suppuration stage, and finally the abscess formation. The occurrence of abscess is more than 2 weeks to 3 months after the injury, especially in 1 month. It will gradually decrease after 3 months, and a few can reach several years or even decades.

Abscess sites are associated with bacterial invasion of the intracranial pathway. Abscesses of open brain trauma occur mostly in or near the brain lesions, while firearm injuries often develop along the wound or near the wound. When contaminated foreign bodies enter the brain, there are more abscesses. Centered on or in the vicinity of foreign matter.

Traumatic brain abscess is mostly single, but there may be multiple rooms. The thickness of the pus wall varies with time. Before and after the early 2 weeks of infection, it is in the stage of purulent encephalitis and meningitis. At this time, the brain tissue is necrotic, soft, and inflammatory. Cell infiltration, hyperemia, edema is more obvious, no pus wall formation, to the formation of abscess around 3 weeks, surrounded by granulation tissue, fibrous tissue, reticuloendothelial cells and glial cells proliferating, forming a complete capsule, the thickness of the pus wall In proportion to time, the wall thickness of 1 month is about 1 mm, which is a chronic abscess that can be longer than the diameter of the abscess.

Traumatic brain abscess prevention

After the injury, pay attention to the control of the infection of the scalp, skull and other parts, for the fragments of the penetrating wound, foreign bodies, etc., should be promptly removed by surgery.

Traumatic brain abscess complications Complications, purulent meningitis, ventriculitis

The pus of the abscess flows into the subarachnoid space or the ventricle causing acute suppurative meningitis or ventriculitis.

Traumatic brain abscess symptoms Common symptoms Cerebral palsy Brain parenchymal hemorrhagic encephalitis-like changes Loss coma conscious disorder Increased intracranial pressure Increased brain softening edema Cerebral palsy

The early acute inflammatory reaction of traumatic brain abscess is often concealed by brain trauma. The fever, headache, increased intracranial pressure and localized neurological dysfunction are easily confused with brain trauma, especially in the non-functional area of the brain. Such as the forehead, the tip of the so-called "dumb area", so there are mistakes, when the abscess formation, the clinical manifestations are similar to the intracranial space-occupying lesions, then there is no sign of intracranial infection, only intracranial hypertension In addition to headache, lethargy, pulse slowness, or occasional seizures, there is no other characteristic. If the abscess is located in an important brain function area, there are often signs of local nerve defects that can help locate.

1. Systemic infection symptoms

In the intracranial stage of bacterial invasion, most patients have general malaise, rash, fever, headache, vomiting and other acute encephalitis or meningitis, usually within 2 to 3 weeks, the symptoms are alleviated, a few can last 2 to 3 months, when abscess After the formation of the capsule, the patient's body temperature is mostly normal or low fever, while the symptoms of increased intracranial pressure or brain compression gradually worsen, and the brain abscess enters a limited stage. There may be an incubation period in the clinic, which can be from several days to several months or even years. During the incubation period, the patient may have headache, weight loss, fatigue, memory loss, apathy or unresponsiveness, and extensive use of large doses of antibiotics to accelerate the disappearance of early systemic infection symptoms and prolong the incubation period.

2. Increased intracranial pressure symptoms

With the formation and enlargement of the capsule of the brain abscess, the intracranial pressure is increased, and the patient is accompanied by different degrees of headache, which may be persistent and paroxysmal. When the morning is heavier or the force is increased, vomiting may occur. In particular, patients with cerebellar abscess are often expiratory vomiting. Patients may be accompanied by varying degrees of mental and conscious disturbances, reflecting the serious condition. Coma is more common in advanced critically ill patients. About half of the patients have optic disc edema. Increased intracranial pressure often causes vital signs. The change is in response to the Cushing.

3. Brain localization symptoms and signs

On the basis of brain dysfunction caused by trauma, the existing symptoms are gradually aggravated or new symptoms and signs appear.

4. Cerebral palsy or abscess ulceration

It is a serious crisis in patients with brain abscess. The former is similar to other cerebral palsy caused by intracranial space-occupying lesions (such as intracranial hematoma); the latter is when the abscess is close to the brain surface or ventricle, because the pressure inside the abscess suddenly changes. The abscess suddenly collapses, the pus flows into the subarachnoid space or the ventricle, causing acute suppurative meningitis or ventriculitis. The patient suddenly has high fever, coma, convulsions, peripheral blood leukocytes, and cerebrospinal fluid often purulent, such as rescue. Timely, often the patient died.

Traumatic brain abscess examination

Lumbar puncture, it is generally believed that lumbar puncture has little value in the diagnosis of brain abscess. On the contrary, it may induce the risk of cerebral palsy and brain abscess rupture. Therefore, it is only careful when differential diagnosis is necessary or obvious meningitis. Early brain abscess The intracranial pressure is usually slightly higher, and the number of white blood cells in the cerebrospinal fluid is increased, generally in the range of (5-10)×108/L. If the suppurative meningitis is higher, when the abscess is formed, the intracranial pressure is increased, and the cerebrospinal fluid is in the cerebrospinal fluid. The number of cells is normal or lymphocytosis is dominant, and the protein content of cerebrospinal fluid is mostly increased to 2 to 4 g/L or higher, and the sugar and chloride contents are approximately normal.

1. X-ray film inspection

It can show intracranial broken bone fragments and metal foreign bodies. Chronic brain abscess can show bone changes with increased intracranial pressure or contralateral displacement of pineal gland, and occasionally calcification of abscess wall.

2. Brain CT scan

The CT findings of brain abscess vary according to the stage of abscess development. In the stage of acute suppurative encephalitis, the lesions appear as low-density areas with blurred borders, no enhancement, suppuration and abscess wall formation, and equal-density abscess walls around low-density areas. The abscess wall can be slightly strengthened, and the thickness of the abscess is uneven. When the abscess is small, it can be nodular-like strengthening, and the thickness of the intensive is uneven. The abscess is small and can be nodular, and there is irregular cerebral edema around the abscess. More significant, CT can not only determine the existence, location, size, number, shape and edema of the surrounding brain tissue, but also help to choose treatment methods and determine the timing of surgery.

3. MRI examination

MRI has its own unique advantages, not only in the period of abscess formation, but also on the T2-weighted image, it can show the characteristic low signal band around the necrotic area, and in the encephalitis period, according to the change of T1 and T2 relaxation time. An early diagnosis is made, that is, a slightly lower signal region in the white matter is visible on the T1-weighted image, and a significantly high signal is present on the T2-weighted image. The central region of the encephalitis is a slightly lower signal and has a placeholder effect. With Gd-DTPA enhancement, irregular diffuse enhancement can be seen on T2-weighted images and contribute to clinical treatment.

Diagnosis and diagnosis of traumatic brain abscess

According to the patient's history of head trauma, the history of acute suppurative encephalitis after injury, as well as the current intracranial pressure and brain limitations, physical signs, combined with the results of various examinations, it is not difficult to make a diagnosis, skull X-ray examination, It is helpful to know whether there are bone fragments or foreign bodies remaining. The appearance of CT scan not only makes most patients diagnose clearly before surgery, but also helps to choose treatment methods and timing. CT scan is the most accurate and quick method. It can not only show the size and location of the abscess, but also the amount of abscess, whether there is separation, gas accumulation and its relationship with important surrounding structures. At the same time, it can also understand the thickness of the pus wall through intensive scanning to estimate the abscess. Age, in order to choose the appropriate treatment, MRI can more accurately identify the condition of the abscess.

Note that the identification of intracranial space-occupying lesions, such as brain tumors, according to the characteristics of infectious lesions of brain abscess, can be distinguished from each other.

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