What is Ventriculitis?
Ventriculitis is a medical condition that happens when the lining of the chambers in your brain, known as the cerebral ventricles, become inflamed, usually because of an infection. It has other names like ependymitis, ventricular empyema, pyocephalus, and pyogenic ventriculitis. Even though ventriculitis tends to develop slowly, it’s a serious and potentially deadly infection that can linger even after treatment for meningitis. This is why diagnosing ventriculitis early is important for starting the right treatment. Ventriculitis is especially worrisome for patients who have external ventricular drains (EVDs) or intraventricular shunts—these are special tubes that doctors use to remove excess fluid from the brain.
What Causes Ventriculitis?
Ventriculitis, a condition where the brain’s fluid-filled cavities called ventricles become inflamed, can occur due to various reasons. These include:
1. Meningitis: This is an infection of the protective membranes of the brain and spinal cord, caused by bacteria or viruses.
2. Cerebral abscess with a minute tear reaching to the ventricles: A cerebral abscess is a pus-filled swelling in the brain. If it ruptures, it can lead to ventriculitis.
3. Catheter-related issues: This could be due to a ‘shunt’ or an ‘External Ventricular Drain (EVD)’. A shunt is a tube used to move fluid from one part of the body to another, while an EVD is a device used to release pressure from the brain.
4. Trauma: Physical injury to the brain can potentially lead to ventriculitis.
5. Cerebrospinal fluid (CSF) leak: This happens when the fluid that surrounds your brain and spinal cord escapes.
6. Complication after a brain surgery: Sometimes, surgery on the brain may lead to ventriculitis as a side effect.
7. Complications from intrathecal chemotherapy: This is a treatment where chemotherapy is injected directly into the spinal canal.
It’s important to identify the cause to treat ventriculitis effectively.
Risk Factors and Frequency for Ventriculitis
Ventriculitis, or infection of the ventricles in the brain, can be a little tricky to understand because there isn’t a unanimously agreed-upon definition for it. This confusion makes it hard to estimate how frequently it occurs. It’s often difficult to distinguish between a true infection, contamination, mere colonization, or a suspected infection related to a ventriculostomy procedure, which is why it’s challenging to quantify the occurrence of this condition.
An instance of ventriculitis that arises as a result of meningitis, often referred to as pyogenic ventriculitis, is more common in infants. The likelihood of you getting it could increase if you have a weaker immune system due to conditions like cancer, HIV, diabetes, or alcoholism. It’s also linked to the aggressiveness of the causing agent. This condition is usually considered when meningitis doesn’t improve with antibiotics or keeps coming back.
Several bacterias, especially gram-negative species followed by Staphylococcus species, are common culprits. Hospital-acquired meningitis caused by gram-negative bacilli is on the rise. This kind of meningitis is particularly challenging because it tends to be slow-progressing and recurrent.
The likelihood of getting ventriculitis due to a ventricular catheter varies depending on the insertion technique and overall medical management. This varies significantly but is typically less than 10%. Instances of infection from other procedures involving the brain and spinal cord, such as CSF shunt, EVD ventriculitis, and lumbar drain meningitis also vary.
- Infection due to CSF shunt is usually between 4 to 17%.
- Infection due to EVD ventriculitis ranges between 0 and 22%.
- Lumbar drain meningitis rates go up to 5%.
The wide range of rates can be attributed to our lack of clear definitions and understanding of the condition, contamination of the procedure site by skin bacteria, the possible induction of a condition known as CSF pleocytosis by the catheter, and the overall severity of the illness.
Ventriculitis related to catheters can cause serious health problems and even death in some cases, particularly when caused by gram-negative bacteria. In most situations, 50 to 60% of infections are due to types of bacteria that normally live on our skin, including Staphylococcus and Bacillus species. Their prevalence has been on the rise, partly due to the use of antibiotics that primarily target gram-positive bacteria and prolonged stays in the hospital.
In cases of ventriculitis following a head injury, Streptococcus pneumoniae and gram-negative rods are typically the most common pathogens. Some bacteria that normally inhabit our mouth and throat can also cause infection in patients who have fractures at the base of the skull or who have chronic leaks of cerebrospinal fluid.
Signs and Symptoms of Ventriculitis
The symptoms of meningism, which is inflammation of the protective layers around the brain and spinal cord, can include fever, neck stiffness, headache, sensitivity to light, altered mental state, seizures, or a severe general illness. These symptoms can be subtle and less intense in patients who have ventriculitis, an inflammation of brain fluid spaces, typically due to catheters, trauma, or neurosurgery. This more subtle presentation is often seen in patients with weakened immune systems. These patients can also have fever from causes unrelated to the infection itself, such as a centralized fever inside the body or a drug-induced fever. Infection may also be indicated by redness or soreness over the tubing of a subcutaneous shunt, a treatment used to alleviate brain fluid buildup. Patients, especially infants, may also show signs of obstructive hydrocephalus, a condition characterized by excessive fluid in the brain due to blockage or inflammation.
- Fever
- Neck stiffness
- Headache
- Sensitivity to light
- Altered mental state
- Seizures or severe general illness
- Subtle or reduced symptoms in ventriculitis patients
- Redness or soreness over subcutaneous shunt tubing
- Signs of obstructive hydrocephalus
Testing for Ventriculitis
When doctors suspect ventriculitis, which is inflammation of the ventricles in the brain, they often conduct tests and imaging.
One of these tests is obtaining a sample of the cerebrospinal fluid (CSF), the clear liquid that surrounds and protects the brain and spinal cord. This sample can show high levels of protein and low levels of sugar, signs that point to ventriculitis. It can also reveal an increase of certain types of cells that typically show up when the body is fighting an infection. Even after starting on antibiotics, the disease can still be active even if the cultures are negative. However, it can take several days or weeks for the cultures to grow, indicating an infection.
The CSF sample can also be tested for the presence of specific proteins that can help make an early diagnosis. An increase in certain proteins suggests a more likely bacterial infection than a viral one although this can be less accurate if antibiotics are given before the sample is taken.
Ultrasounds (imaging using sound waves) can also be helpful, particularly for newborns. It is done using a device that sends high-frequency sound waves into the body through the soft spot on the baby’s head. The sound waves bounce off structures in the body and create an image. Ventriculitis can cause changes in the thickness and texture of the ventricles, and can even lead to blockages and fluid buildup in the brain. It can also show inflammation in certain brain structures, like the choroid plexus, a network of blood vessels in the brain that produces CSF.
A CT scan (a type of X-ray that takes detailed images) without contrast (a substance that helps doctors see the images better) can also show signs of ventriculitis. These include a buildup of debris, fluid, or low density around the ventricles. Once contrast is added, the lining of the ventricles becomes more visible.
MRI, another imaging technique that uses magnetic fields and radio waves, can help further. For ventriculitis, the debris in the ventricles may look brighter or darker in MRI images. There can also be intense restriction of water molecules movement in the debris. FLAIR images, a type of MRI scan, can indicate subtle changes around the ventricles.
Finally, doctors may use a technique called radionuclide brain scintigraphy. In this test, they inject a harmless radioactive substance into your veins. This substance can accumulate in the ventricles indicating ventriculitis.
While these test results can vary from patient to patient and may not provide a definitive diagnosis for every individual, they offer valuable information to help physicians better understand and manage each case of suspected ventriculitis.
Treatment Options for Ventriculitis
To treat brain inflammation caused by infections, known as ventriculitis, it’s crucial to use antibiotics that can reach the brain’s fluid (also known as the cerebrospinal fluid, or CSF). This is particularly important for patients with a weakened immune system who may need more aggressive treatment.
Initially, doctors provide antibiotics based on the patient’s age and the suspected cause of infection. In some cases, like when ventriculitis happens related to a medical device like a catheter, stronger antibiotics are used.
Deciding on specific antibiotics depends on laboratory tests indicating which antibiotics the bacteria are likely to respond to. Also, the type of antibiotics can be chosen based on how well they can reach the brain fluid when there is inflammation.
The duration of antibiotic treatment depends on the type of bacteria causing the infection and how a patient responds to treatment. Generally, antibiotics are given for a period between 10 and 21 days.
In some cases, if the ventriculitis is not responding to usual treatment, antibiotics can be given directly into the brain fluid. Commonly used antibiotics for this method include vancomycin or gentamicin. These antibiotics can reach higher levels in the brain fluid than when they are given into the vein.
When infection happens specifically due to devices like a catheter, it is recommended to remove all parts of the infected device along with giving antibiotics. This is because even with antibiotic treatment, some bacteria can stick to these devices and continue to live. The choice to replace the device will depend on the patient, the type of bacteria causing infection, how severe the infection is, and findings in the brain’s fluid.
What else can Ventriculitis be?
The enhancement or brightening of the ependymal lining, which is a membrane that lines the central channels of the brain, can be seen in various conditions. These include:
- Primary CNS lymphoma, which is a rare form of non-Hodgkin lymphoma that starts in the brain.
- Ependymal spread of glioblastoma, which means that a type of brain tumor called a glioblastoma is spreading along this lining.
- Metastases, which refers to cancer that has spread to the brain from another place in the body.
- Germinoma, which is a rare type of brain tumor.
What to expect with Ventriculitis
Ventriculitis, when left untreated, can lead to serious health issues like poor brain function, a condition called hydrocephalus (which is an accumulation of too much cerebrospinal fluid in the brain), and even death. Therefore, it’s crucial to recognize and treat ventriculitis as early as possible. However, it’s important to note that high-quality studies examining the likely course or outcome of the disease are currently insufficient.
Possible Complications When Diagnosed with Ventriculitis
Doctors suggest long-term medical check-ups due to the possibility of the infection returning and causing hydrocephalus, which is a condition that leads to an accumulation of fluid in the brain. Even if tests like lumbar puncture do not show any sign of infection, it is important to note that some parts of the brain like the ventricles and choroid plexus can still hold hidden infection.
Preventing Ventriculitis
There isn’t a clear consensus in medical research about using preventive antibiotics for patients with ventriculostomies, a procedure where a doctor inserts a drain into the brain to relieve pressure. Yet, it’s generally suggested that patients receiving a different type of brain drain or shunt should receive antibiotics around the time of the procedure.
Research comparing the use of antibiotics only around the time of surgery to longer-term antibiotics show that they can lower the risk of serious brain infections. However, long-term antibiotics may also lead to the growth of hard-to-treat organisms, including certain types of fungus and bacteria resistant to common antibiotics such as MRSA.
Improving the manner in which the catheter is cared for has been shown to help lower the chance of infections. Experience and the use of clean methods can help lower the risk of inflammation due to the catheter, highlighting the importance of proper training. Interestingly, the way the procedure is carried out also plays a role. Fewer infections occur when the device is positioned under the skin with a lower skin puncture.
Healthcare professionals are increasingly using packages of care tactics to reduce infections associated with brain drains. These tactics include things like education, careful handling, testing only when required, and using preventive antibiotics before surgery, which have all shown positive results.
In contrast, preventive antibiotics have not been effective in patients with brain fluid leaks following a head injury. While these antibiotics can help prevent infections at the surgical site in patients undergoing brain surgery (craniotomies), they do not help in preventing meningitis, a type of brain infection. Furthermore, these antibiotics may make the patient more prone to resistant organisms.
