Understanding Meningitis: Causes, Symptoms, Diagnosis, and Management

What is Meningitis

Meningitis is an infection of the meninges, the membranes that surround the brain and spinal cord.

Predisposing factors of Meningitis

• Chronic medical disorders (renal failure, diabetes, adrenal insufficiency, cystic fibrosis)
• Extremes of age
• Undervaccination
• Alcohol use disorder
• Presence of ventriculoperitoneal (VP) shunt
• Presence of external ventricular drain
• Penetrating head injury
• Lumbar puncture
• Cranial or spinal surgeries involving the opening of the dura
• Bacterial endocarditis
• Malignancy
• Being Immunosuppressed
• Exposure to endemic areas
• Certain kind of IV drug use
• Sickle cell anemia
• Splenectomy

Types of Meningitis

Viral Meningitis

This is less severe form of meningitis and more common as compared to bacterial meningitis. Individuals with good immune system who get viral meningitis usually gets better on their own after sometime. There are vaccines to prevent some kinds of viral meningitis

Some group of viruses associated with viral meningitis are;

• Enterovirus

• Herpes virus (HSV)
• Paramyoxo virus
• Tagovirus
• Flavivirus
• Bunyavirus
• Alphavirus
• Retrovirus
• Rhabdovirus
• Reovirus
• Arenavirus

Bacterial Meningitis

This is a more severe form types of meningitis. It is caused by bacteria can be deadly which requires immediate medical attention. Vaccines are available to help protect against some kinds of bacterial meningitis.

Some of the bacteria organism associated with bacterial meningitis include;

Pneumococcal meningitis:this is the most serious form of bacterial meningitis and the most common form of all meningitis. The disease is caused by the bacterium Streptococcus pneumoniae, which also causes pneumonia. People who have had pneumococcal meningitis often suffer neurological damage ranging from deafness to severe brain damage. Immunizations are available for certain strains of the pneumococcal bacteria.

Meningococcal meningitis:This is caused by the bacterium Neisseria meningitides and is very contagious. Individuals at most risk include children under the age of 1 year, immunnocompromised individuals, traveling to places where the disease is endemic.

Other forms include;

• Staphylococcus aureus
• Coagulase negative Staphylococcus
• Streptococcus pyogenes
• Streptococcus agalactiae
• Viridans streptococci
• Enterococcus spp
• Haemophilus influenza
• Listeria monocytogens
• Cutibacterium acnes
• Escherichia coli
• Klebsiella pneumoniae
• Pseudomonas aeruginosa
• Salmonella spp
• Acinetobacter spp
• Stenotrophomonas maltophilia
• Fusobacterium necrophorum
• Pasteurella multocida
• Capnocytophaga canimorsus

Fungal Meningitis

Meningitis caused by fungi. It`s much less common than bacterial and viral meningitis. The most common form of fungal meningitis is caused by the fungus cryptococcus neoformans - found mainly in dirt and bird droppings. Individuals do get it by inhaling fungal spores from the environment and its rare form of meningitis. Individuals with certain medical conditions, such as HIV, neoplasm, diabetes, are at a greater risk of fungal meningitis.

Parasitic Meningitis

It`s a rare form of meningitis that usually affect animals and caused by eating from animals such as fish or poultry, snails, slugs, snakes that are infected by parasites or their eggs. The incidence is higher with raw or undercooked foods. It can affect the nervous system. It`s also less common than viral and bacterial meningitis. Parasitic meningitis can be pass on to other people.

Amoebic meningitis

Amoebic meningitis is a rare, usually fatal and devastating infection of the brain caused by a single-celled bug called Naegleria fowleri. Naegleria fowleri is a free-living microscopic amoeba that lives in soil or warm, fresh water. Individuals contract this organism from swimming in water bodies of the amoebic organism.

Non-infectious meningitis

It`s a non-contagious form of meningitis caused by diseases such as cancer, lupus, or conditions like brain surgery, head injury or certain medications.

Chronic meningitis

Chronic meningitis is caused by fungal and some kind of bacterial organisms such as mycobacterium tuberculosis. These organisms get access into the tissue and fluid surrounding the meninges of the brain causing meningitis. It usually results from certain conditions like respiratory disorders.

Pathophysiology of Meningitis

Understanding the pathophysiology of meningitis, it is crucial to consider both bacterial and viral etiologies separately. Bacterial meningitis typically begins when pathogens breach natural defense mechanisms (such as physical barriers) and gain access to the central nervous system (CNS). This invasion often occurs through respiratory droplets (nasopharyngeal colonization by a new organism), or bloodstream dissemination.
Once inside the CNS, bacteria trigger an immune response characterized by activation of resident microglial cells and infiltration of neutrophils from systemic circulation. These immune cells release pro-inflammatory cytokines and chemokines in an attempt to eliminate the invading pathogens. However, this robust inflammatory response can also lead to collateral damage within neuronal tissues.

Furthermore, bacterial toxins released during infection can cause endothelial cell damage in cerebral blood vessels—leading to increased permeability and subsequent leakage of fluid into the subarachnoid space. This results in the formation of cerebral edema, increased intracranial pressure, and alterations of cerebral blood flow.

In contrast, viral meningitis generally follows a milder course compared to its bacterial counterpart. Viruses primarily infect meningeal cells rather than neurons themselves. Consequently, they induce less intense inflammatory responses with fewer infiltrating neutrophils but may still elicit activation of lymphocytes within cerebrospinal fluid (CSF). The exact mechanisms underlying viral-induced inflammation are not fully understood; however viral components directly interacting with host cellular receptors play a significant role in triggering immune responses.

Signs & Symptoms of Meningitis

Classical signs include;

• Nuchal rigidity: The examiner flexes the patient`s neck and the test is positive if there is palpable resistance to passive flexion
• Kernig`s sign: Position the patients` supine with their hips flexed to 90°. This test is positive if there is pain on passive extension of the knee.
• Brudzinski`s sign: Position the patients supine and passively flex their neck. This test is positive if this manoeuvre causes reflex flexion of the hip and knee.

Kernig sign assessment

Among the classical signs include;

• Fever
• Severe Headache
• Confusion
• Seizures
• Double vision
• Anorexia
• Lack of thirst
• Stiffness in the neck
• Crankiness
• Numbness in the face
• Photophobia (Sensitivity to light)
• Vomiting
• Skin rash (with meningococcal meningitis)

Diagnostic Investigations of Meningitis

• Computed Tomograhy (CT Scan)
• Magnetic Resonance Imaging
• CSF Analysis
• Neurological examination
• Laboratory test for blood and urine
• Electroencephalography (EEG)

Medical Management of Meningitis

Appropriate antibiotic treatment for most types of meningitis can greatly reduce the risk of dying from the disease. Anticonvulsants to prevent seizures and corticosteroids to reduce brain inflammation may be prescribed. Lyme disease is treated with antibiotics. Fungal meningitis is treated with intravenous antifungal medications such as IV Amphotericin B and Oral Flucytosine

Medications include;

• IV Ampicillin
• IV Cefotaxime
• IV Gentamicin
• Acyclovir IV
• Ceftriaxone IV
• Vancomycin IV
• IV Moxifloxacin
• Osmotic diuretics such as 25% mannitol or 3% saline
• Chemoprophylaxis: Antibiotic chemoprophylaxis for N. meningitidis includes rifampin, ciprofloxacin, or ceftriaxone, and rifampin for H. influenzae type B. Chemoprophylaxis is indicated patient diagnosed with N. meningitides and H. influenzae type B meningitis.

Nursing Care of Meningitis

The following are the measures to put in place in the care of a hospitalized person recieving treatment

• Monitoring and recording vital signs per hospital protocol.
• Assess and monitor the Glasgow Coma Scale and pay special attention to the motor response.
• Assess the patient's mental status and provide psychological support if the patient is conscious.
• Elevate the head end of the bed 30 degrees with a straight neck to ensure venous drainage from the brain.
• Ensure the patient has a patent IV line for fluids and medications.
• Administer antibiotics as prescribed.
• Monitor and record intake and output.
• Provide oxygenation if the saturation level is low.
• If the intracranial pressure is high, administer mannitol, as prescribed
• Administer phenytoin, as prescribed, if the patient is having seizures.
• Apply side rails as a patient safety measure as the patient may fall down while having seizures.
• Check the patient pupils` dilatation size and responsiveness to light as a result of ICP
• Ensure patient laboratory test such as LFT, RFT and CSF are carried out.
• Change position 2-hourly to prevent bedsore if the patient is bedridden and apply air mattress and thromboembolic deterrent stockings as needed
• Provide adequate and balanced nutrition
• Put a nasogastric tube and start feeding for the unconscious patients, as instructed
• Provide comfort measures.

Complications of Meningitis

If not well managed and treated, meningitis can cause severe complications in both children and adults even resulting to death. Such complications include:

• Shock
• Death
• Seizures
• earning problems
• Paralysis
• Kidney failure
• Brain damage or CVA
• Loss of hearing
• Memory problems