Eosinophilic Meningitis - Causes, Symptoms, Treatment And Prevention

What Exactly Is Eosinophilic Meningitis?

Eosinophilic meningitis is a medical condition with inflammation of the meninges, which are the protective membranes surrounding the brain and spinal cord. The condition is typically caused by infection with certain parasites, particularly nematodes such as Angiostrongylus cantonensis and Gnathostoma spinigerum.

Eosinophils, a type of white blood cell in the cerebrospinal fluid, characterize it. Symptoms commonly include severe headaches, neck stiffness, fever, nausea, vomiting, and neurological abnormalities. Diagnosis involves clinical evaluation, analysis of cerebrospinal fluid samples, and serological tests. Treatment usually involves antiparasitic drugs and corticosteroids to control the infection and reduce inflammation.

What Are The Causes of Eosinophilic Meningitis?

Eosinophilic meningitis is also known as EM or eosinophilic meningoencephalitis. Several types of helminth worms cause EM. The most common of them are:

• Gnathostoma spinigerum.

• Angiostrongylus cantonensis (rat lungworm).

• Baylisascaris procyonis (a raccoon roundworm).

These worms are responsible for the following infections that bear their names:

• Angiostrongyliasis.

• Baylisascariasis.

• Gnathostomiasis.

When anyone consumes contaminated water or comes into contact with an infected animal's feces or droppings, these parasites may enter the body. It might eventually get into the brain or spinal cord and cause EM.

Rarer EM causes consist of:

• Rocky Mountain spotted fever.

• Coccidioides fungus.

• Tuberculosis.

• Neurosyphilis.

What Are The Symptoms Associated With Eosinophilic Meningitis?

The symptoms of eosinophilic meningitis can vary in severity and may include:

• Headache.

• Stiff neck.

• Nausea and vomiting.

• Fever.

• Sensitivity to light (photophobia).

• Fatigue.

• Tingling or numbness.

• Visual disturbances.

What Are The Complications of Eosinophilic Meningitis?

The complications resulting from eosinophilic meningitis may vary based on the seriousness of the infection and the underlying cause. Some of the possible complications include:

• Neurological Damage.

• Vision Problems.

• Meningoencephalitis.

• Hydrocephalus.

• Secondary Infections.

How To Diagnose Eosinophilic Meningitis?

Healthcare professionals frequently combine clinical symptoms, medical history, and laboratory investigations to make an eosinophilic meningitis diagnosis. Here are a few of the techniques frequently employed in diagnosis:

• Medical History and Physical Examination: The doctor will ask about the symptoms, recent travel history, exposure to potential risk factors such as raw or undercooked food, and any other relevant information. Additionally, they will perform a comprehensive physical assessment.

• Lumbar Puncture (Spinal Tap): This is crucial in diagnosing meningitis. A needle collects a small amount of cerebrospinal fluid (CSF) from the lower back. The CSF sample is subsequently delivered to a lab for evaluation.

• CSF Analysis: The CSF sample is examined to learn more about its composition and search for any irregularities. Eosinophils are frequently found in greater numbers in the CSF in eosinophilic meningitis. Elevated protein levels and possibly a higher white blood cell count are possible additional findings.

• Blood Tests: Blood testing can be used to look for particular antibodies or infection-related symptoms. For instance, serological tests can find antibodies to Angiostrongylus cantonensis in cases of rat lungworm infection.

• Imaging Studies: Imaging tests such as magnetic resonance imaging (MRI) or computed tomography (CT) scans may be conducted to assess the brain and spinal cord for abnormalities or rule out other potential causes of meningitis.

• Additional Tests: Additional tests could be carried out based on eosinophilic meningitis's likely cause. These could include stool analysis, serological tests for certain parasites, or other specialized laboratory studies.

How To Treat Eosinophilic Meningitis?

It is essential to consult with a healthcare professional for a proper diagnosis and to develop an individualized treatment plan. They will consider the specific cause of eosinophilic meningitis and the severity of symptoms to determine the most appropriate treatment approach. The primary goal of treating eosinophilic meningitis is to treat the underlying condition, which is often a parasite infection. The primary methods for treating eosinophilic meningitis are as follows:

• Antiparasitic Medications: The main course of therapy entails taking drugs designed to destroy or eliminate the parasitic worms inflicting the condition. The specific medicine used may vary depending on the parasite found. For instance:

  • Angiostrongylus Cantonensis: Albendazole or mebendazole may be used with corticosteroids to reduce inflammation.

  • Gnathostoma Spinigerum: Albendazole, ivermectin, or a combination of both, along with corticosteroids, may be prescribed.

• Corticosteroids: These drugs aid in reducing inflammation and easing meningitis-related symptoms. They are frequently used with antiparasitic medications to regulate the immunological response. One common corticosteroid is prednisone.

• Supportive Care: This includes measures to manage symptoms and provide relief. Treatment may involve pain relievers, antipyretics (fever reducers), fluids to prevent dehydration, and antiemetics (anti-nausea drugs) if necessary.

• Symptomatic Treatment: Various symptoms of eosinophilic meningitis, such as headache, neck stiffness, and nausea, can be managed through symptomatic treatment. Bed rest and maintaining a quiet environment may also be recommended.

How to Prevent Eosinophilic Meningitis?

The primary method of preventing eosinophilic meningitis is to take precautions to avoid the parasites that can cause the disorder. Here are some preventive measures:

• Practice Good Hygiene: Ensure hands are washed thoroughly with soap and clean water before handling food, using the restroom, and touching animals. Teach children the importance of good hygiene practices as well.

• Avoid Contaminated Water: Drink safe, treated water and avoid consuming water from sources that may be contaminated. If clarification about water safety is needed, consider using bottled water or purifying methods such as boiling, filtration, or chemical disinfection.

• Properly Cook and Store Food: Ensure food, particularly seafood and meat, is cooked thoroughly at temperatures that kill potential parasites. Avoid consuming raw or undercooked meats and seafood.

• Wash Produce and Peel Fruits: Thoroughly wash fruits and vegetables with clean water before consuming them. Additionally, consider peeling fruits when possible to minimize the risk of ingestion of parasites.

• Avoid Contact with Snails, Slugs, and Raw Snail Products: If a resident of areas where the rat lungworm (Angiostrongylus cantonensis) is present, avoid direct contact with snails and slugs. Additionally, do not consume raw or undercooked snails or products made from raw snails.

• Prevent Rodent Infestation: Take measures to prevent rodent infestation. Seal any cracks or openings that rodents can use to gain entry. Store food in rodent-proof containers, and keep the living spaces clean and free of food debris that may attract rodents.

• Be Cautious with Unusual Food Sources: If traveling to regions with more prevalent parasitic infections, be cautious with unusual or exotic food sources. Avoid eating raw or undercooked foods from unfamiliar or unreliable sources.

• Educate Self: If living or traveling to regions known for eosinophilic meningitis, self-educate about the specific parasites and their transmission methods. This will help to take appropriate precautions and make informed decisions.

What Is The Prognosis or Outlook of Eosinophilic Meningitis?

The prognosis of eosinophilic meningitis can vary depending on several factors, including the specific parasite involved, the severity of the infection, the timeliness of diagnosis and treatment, and the individual's overall health. In general, eosinophilic meningitis caused by parasites like Angiostrongylus cantonensis or Gnathostoma spinigerum has a relatively good prognosis. With appropriate and timely treatment, most individuals recover fully without long-term complications. Anti-parasitic medications, such as albendazole, help control the infection and eliminate the parasites, while corticosteroids help reduce inflammation and alleviate symptoms.

However, in some cases, complications can arise, mainly if the infection is severe or there are delays in diagnosis and treatment. It is worth noting that individual factors, such as age, overall health, and immune status, can influence the prognosis. For example, individuals who have compromised immune systems or pre-existing medical conditions might be at an increased risk of encountering more severe symptoms or complications.

Conclusion:

In conclusion, eosinophilic meningitis is an inflammatory condition of the meninges caused by parasitic infections, most commonly Angiostrongylus cantonensis and Gnathostoma spinigerum. Although EM usually resolves independently without treatment, it can sometimes cause dangerous complications, including coma and death. Prompt diagnosis, appropriate treatment, and preventive measures are essential in managing this condition and minimizing its impact on affected individuals.