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Questions and Answers
Which condition specifically refers to inflammation of the meninges surrounding the brain?
What characterizes viral meningitis compared to bacterial meningitis?
Which of the following organisms is most commonly associated with acute meningitis?
What type of CNS infection involves both inflammation of the meninges and the brain parenchyma?
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Which method of pathogen spread is common for CNS infections?
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What is the primary mechanism through which the rabies virus spreads from muscle cells to the brain?
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What role does the rabies virus play in the presence of neurological effects like foaming at the mouth?
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Why is it critical to treat a rabies bite immediately after potential exposure?
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What is the purpose of rabies immunoglobulin (RIG) in rabies post-exposure treatment?
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What is the typical onset period for rabies symptoms after exposure?
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What is the primary indication of Kernig’s sign in a patient?
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Which organism is NOT part of the 'big 6' causative organisms for bacterial meningitis?
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What differentiates acute meningitis from chronic meningitis?
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Which symptom is NOT typically associated with acute meningitis?
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What is a distinguishing feature of viral meningitis compared to bacterial meningitis?
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Which of the following viruses is most commonly associated with viral meningitis?
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What symptom might be observed if Brudzinski’s sign is positive?
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Which pathogen is a common cause of fungal meningitis?
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What is the typical appearance of cerebrospinal fluid (CSF) in bacterial meningitis?
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What effect does a bacterial meningitis infection have on glucose levels in the CSF?
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Which of the following conditions is NOT associated with meningitis symptoms?
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What type of pathogens is Naegleria fowleri classified as?
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Which type of white blood cells predominantly infiltrate the CSF during bacterial meningitis?
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What characterizes chronic meningitis?
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Which characteristic typically distinguishes the CSF appearance in bacterial meningitis?
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Which intervention is typically NOT needed for viral meningitis?
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What is the immediate action taken for a patient suspected of having bacterial meningitis?
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In viral meningitis, why do glucose levels typically remain the same?
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In which population is listeria particularly concerning?
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What supportive therapies are essential in managing viral meningitis?
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What would a high level of neutrophils in the CSF most likely indicate?
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Which feature is not typical of viral meningitis compared to bacterial meningitis?
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What is a challenge in diagnosing fungal or TB meningitis?
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What is the main goal of care in encephalitis?
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What is a common method for a pathogen to breach the blood-brain barrier?
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Which symptom is typically associated with meningitis but not with encephalitis?
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How can pathogens in the blood utilize a 'trojan horse' mechanism to enter the central nervous system?
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What type of barrier protects the brain and central nervous system from pathogens?
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Which of the following is a key symptom of encephalitis?
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What is a common symptom of chronic meningitis?
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What diagnostic procedure is most commonly used to analyze CSF for signs of infection?
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What recent technological advancement aids in the diagnosis of CNS infections using a single CSF sample?
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Which pathogen is NOT associated with causing chronic meningitis?
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Which sign is characteristic of meningeal irritation in a patient with meningitis?
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What is a definitive test for diagnosing Cryptococcus neoformans in the CSF?
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Increased permeability of the blood-brain barrier may occur due to which condition?
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What finding in CSF analysis is typical for Mycobacterium tuberculosis meningitis?
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Which of the following clinical features differentiates viral meningitis from bacterial meningitis?
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Which of the following can act as a portal of entry for pathogens to the central nervous system?
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Which of the following methods can pathogens use to cross the blood-CSF barrier to cause meningitis?
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What is the primary mode of transmission for Coxsackie virus?
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What is the primary mode of transmission for Streptococcus pneumoniae in crowded environments?
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What finding in cerebrospinal fluid (CSF) would indicate meningitis?
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Which statement about chronic meningitis is accurate?
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Which patient population is most at risk for severe complications from Listeria monocytogenes infection?
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What is the typical treatment for fungal meningitis due to Cryptococcus neoformans?
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Which CNS infection is characterized by focal neurological defects?
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Which bacterium is primarily responsible for meningitis in neonates?
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What is a potential consequence of increased intracranial pressure during meningitis?
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What additional condition should be checked in chronic meningitis patients due to potential opportunistic pathogens?
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What type of bacteria is Haemophilus influenzae?
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Which pathogen is the leading cause of adult meningitis in central and southern Africa?
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What clinical feature indicates a medical emergency when associated with Neisseria?
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Which CSF analysis result is indicative of viral meningitis?
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How does viral meningitis typically present compared to bacterial meningitis?
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Which of the following is a common symptom in acute Listeria infection?
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What approach is often required to treat elevated intracranial pressure in viral meningitis?
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When does early onset Group B Streptococcus infection typically occur?
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What is the main complication associated with untreated Streptococcus pneumoniae infections?
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What is the purpose of antibiotic prophylaxis in cases of Streptococcus pneumoniae exposure?
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What symptom profile might indicate a parasitic cause of meningitis such as Angiostrongylus cantonensis?
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How can Listeria monocytogenes enter the bloodstream from the gastrointestinal tract?
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Which bacteria is known for causing meningitis in individuals with a history of alcohol abuse?
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Which characteristic is unique to Neisseria compared to other meningitis-causing organisms?
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Streptococcus pneumoniae is a common pathogen found predominantly in which population?
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What key symptoms form the triad of encephalitis?
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Which viral family is the most common cause of encephalitis?
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What is the primary mode of infection for rabies to enter the CNS?
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What treatment should be initiated immediately upon suspicion of viral encephalitis?
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What is the consequence of untreated herpes simplex virus encephalitis?
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In which part of the brain is hemorrhagic necrosis most commonly observed in herpes simplex encephalitis?
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Which symptom is more pronounced in encephalitis compared to meningitis?
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Which of the following is NOT a viral cause of encephalitis?
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What is the impact of arachnoid membrane damage in viral encephalitis?
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Which virus is associated with high mortality rates in humans when coming from bats via ingestion?
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What is a characteristic of non-viral causes of encephalitis?
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How do herpesviruses typically spread and cause encephalitis?
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What abnormal finding might you expect in the cerebrospinal fluid (CSF) during herpes simplex encephalitis?
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What is a common neurological change seen in individuals recovering from herpes simplex encephalitis?
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What is a potential complication that may arise after treatment with antihelminthic medications like albendazole?
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What distinguishes subdural empyema from other types of CNS infections?
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Which of the following symptoms is NOT typically associated with subdural empyema?
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What is an essential step in the clinical management of acute CNS infections?
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What is the consequence of performing a lumbar puncture in cases of subdural empyema?
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Which of the following risk factors is associated with the development of an epidural abscess?
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In the context of focal CNS infections, why is imaging preferred before performing a lumbar puncture?
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What characterizes an epidural abscess compared to subdural empyema?
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What is a common bacterial cause of epidural abscesses?
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What type of CNS infection is characterized by tissue cysts found in the brain due to egg ingestion?
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What is a common symptom of rabid encephalitis that specifically indicates a fear of water?
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Which method does the West Nile virus use to invade the central nervous system?
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What indicates a likely presence of West Nile virus in the area?
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What is the most common causative agent of brain abscesses?
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In which patient condition is there an increased risk for developing brain abscesses?
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What type of imaging is preferred to diagnose focal CNS infections instead of a lumbar puncture?
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Which symptom is NOT typically associated with a brain abscess?
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Which organism is specifically notorious for causing an intracerebral infection known for its 'starry night presentation'?
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What is a significant predisposing factor for brain abscesses?
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What role do mosquitoes play in the transmission of the West Nile virus?
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What type of organism primarily causes focal infections in the brain parenchyma that may start as cerebritis?
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After a brain abscess is drained, what is the next step in treatment?
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What is a common characteristic of abscesses seen on imaging?
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Which of the following factors can introduce pathogens leading to brain abscess formation?
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Study Notes
Overview of CNS Infections
- CNS infections can be caused by a variety of pathogens, including bacteria, viruses, fungi, protozoa, and helminths.
- Meningitis is inflammation of the meninges, the membranes surrounding the brain and spinal cord.
- Encephalitis is inflammation of the brain parenchyma.
- Meningoencephalitis involves both the meninges and the brain parenchyma.
- Pathogens can invade the CNS via various routes, including insect bites, animal bites, normal flora, and reactivation of latent viruses.
- The CNS is protected by the blood-brain barrier and the CSF-blood barrier, which prevent pathogens from entering.
Mechanisms of Pathogen Entry
- Pathogens can enter the CNS through anatomical defects, cranial injuries, or skin punctures.
- Pathogens commonly infect the respiratory, gastrointestinal, and genitourinary systems and may then spread hematogenously, cross the blood-CSF barrier or the blood-brain barrier.
- Viruses can travel via retrograde axonal transport along peripheral nerves to reach the CNS.
- Pathogens can infiltrate the CNS through various mechanisms:
- Trojan horse mechanism: Pathogens are engulfed by phagocytes and carried across the blood-brain barrier.
- Transcytosis: Pathogens cross the endothelial layer of the blood-brain barrier by passing through the epithelial cells.
- Breaching tight junctions: Increased permeability of the epithelial cell layer allows pathogens to pass through.
Meningitis and Encephalitis Symptoms
- Symptoms of meningitis and encephalitis can be similar and overlap.
Meningitis
- Fever
- Headache
- Stiff neck (nuchal rigidity)
- Photophobia
- Nausea and vomiting
- Altered mental state
- Kernig's sign
- Brudzinski's sign
- Sometimes rash (characteristic of Neisseria meningitidis infection)
Encephalitis
- Fever
- Headache
- Behavioral changes (hallucinations, speech problems, psychosis)
- Seizures
- Focal neurological deficits (loss of sensation, muscle weakness, paralysis)
Diagnosis of Meningitis and Encephalitis
- Lumbar puncture: CSF analysis for cell counts, protein and glucose levels, and microscopy/culture for pathogen identification.
- Blood cultures: To detect bacteremia or viremia.
- Imaging studies (MRI or CT): Primarily for encephalitis to identify focal lesions.
- Multiplex PCR: Allows for the simultaneous detection of multiple pathogens from a single CSF sample.
Clinical Approach
- Obtain a thorough history, including:
- Headache, fever, intermittent symptoms
- Systemic or febrile features
- Signs of raised intracranial pressure
- Altered mental state
- Neurological symptoms
- Rash
- Infectious contact
- Travel history
- Chronic infections
- Conduct a comprehensive physical exam, including:
- Fever
- Neck stiffness
- Confusion
- Speech
- Motor/sensory function
- Rash
- Fontanelle in infants
Meningitis Signs
- Kernig’s sign: Pain and resistance with passive extension of the leg at 90 degrees.
- Brudzinski’s sign: Flexion of the hips and knees when the patient's neck is flexed.
Types of Meningitis
Bacterial Meningitis
- Medical emergency.
-
Major causative organisms:
- Streptococcus pneumoniae
- Neisseria meningitidis
- Haemophilus influenzae
- Listeria monocytogenes
- Streptococcus agalactiae (Group B Strep - GBS)
- Escherichia coli
- Staphylococcus aureus (less common)
- Characterized by rapid onset and severe symptoms.
- Often results in cloudy CSF with pus and bacterial identification via microscopy and culture.
Viral Meningitis
- Less severe, slower onset (3-10 days).
-
Most common causes:
- Enteroviruses (echoviruses and coxsackieviruses)
- Herpesviridae (HSV, VZV, CMV)
- HIV
- Arboviruses
- Measles, mumps, and rubella
- CSF usually clear with limited neutrophils.
- Often called aseptic meningitis.
Fungal Meningitis
- Common in immunocompromised individuals.
-
Causes:
- Cryptococcus neoformans
- Coccidiodes immitans
- Chronic presentation with a gradual onset of symptoms over weeks.
Protozoal and Helminthic Meningitis
-
Extremely rare but can be deadly.
-
Naegleria fowleri (amoeba): Enters the CNS through the olfactory bulb, causing rapidly fatal meningoencephalitis.
-
Angiostrongylus cantonensis (rat lungworm): Causes eosinophilic meningitis, often through the ingestion of infected snails or slugs.
Other Causes of Meningitis
-
Chronic meningitis can also be caused by:
- Mycobacterium tuberculosis
- Treponema pallidum (neurosyphilis)
- Borrelia burgdorferi (Lyme disease)
-
Non-infectious causes of meningitis include:
- Cancers
- Drug effects
- Head trauma
Septic vs. Aseptic Meningitis
- Septic meningitis: Usually bacterial, results in cloudy CSF with pus.
- Aseptic meningitis: Usually viral, fungal, or non-infectious, results in clear CSF with few inflammatory cells.
Acute vs. Chronic Meningitis
- Acute meningitis: Rapid onset over hours to days, usually caused by bacteria or viruses.
- Chronic meningitis: Gradual onset over weeks, often associated with immunocompromised individuals, and caused by fungi, mycobacterium tuberculosis, or treponema pallidum.
Key Bacterial Causes of Acute Meningitis
Streptococcus pneumoniae
- Gram-positive cocci.
- Normal URT flora, opportunistic pathogen.
- Can invade CNS via pneumonia, otitis media, mastoiditis, sinusitis, or endocarditis.
- Causes meningitis in all age groups, particularly in elderly and young children.
- Mortality rate varies but can be high.
Neisseria meningitidis
- Gram-negative cocci.
- Normal nasopharyngeal flora, but can be pathogenic.
- Spread through close contact, often seen in outbreaks.
- Can cause rash, fever, and other symptoms.
- High mortality rate if untreated.
Haemophilus influenzae
- Gram-negative coccobacilli.
- Normal URT flora.
- Common cause before Hib vaccine, now less frequent.
- Mortality rate around 3-6%.
Listeria monocytogenes
- Gram-positive rod.
- Foodborne pathogen
- Prevalent in food-processing environments.
- Causes meningitis in immunocompromised individuals, pregnant women, neonates, and elderly adults.
- High mortality rate.
Streptococcus agalactiae (Group B Strep - GBS)
- Gram-positive cocci in short chains.
- Normal GI and vaginal flora.
- Primarily causes meningitis in neonates.
- Can be acquired in utero, during labor, or shortly after birth.
- Treatable with antibiotics.
Protozoa and Helminths
- Naegleria fowleri: Amoeba found in warm, stagnant water that can enter the CNS through the olfactory bulb, causing meningoencephalitis.
- Angiostrongylus cantonensis (Rat lungworm): Nematode larvae that enter the CNS through the ingestion of infected snails or slugs.
Treatment
- Bacterial meningitis: Immediate treatment with antibiotics is required.
- Viral meningitis: Supportive therapy to manage symptoms.
- Fungal meningitis: Antifungal therapy is essential.
- Protozoal and helminthic meningitis: Treatment depends on the specific pathogen.
Prevention
- Vaccination: Hib vaccine for Haemophilus influenzae and vaccines for common serogroups of Neisseria meningitidis.
- Proper sanitation and hygiene: Prevent foodborne exposures to Listeria monocytogenes and other pathogens.
- Prophylactic antibiotics: For close contacts of individuals with Neisseria meningitidis infections.
- Avoid contact with contaminated water: To prevent Naegleria fowleri infection.
Chronic Meningitis
- Gradual onset of neurological symptoms and signs lasting longer than 4 weeks, sometimes for months or years.
- Chronic symptoms include mild fever, headache, altered sensorium, and meningismus.
- Symptoms may fluctuate, improving for a period before returning or worsening.
- Can be caused by infections, cancer, trauma, or medications.
- It's crucial to check for HIV and immune deficiency as it can lead to unusual pathogens.
- Common causes include Mycobacteria, Spirochetes, Fungi, and opportunistic infections.
- Mycobacterium tuberculosis can cause chronic meningitis after a primary TB infection.
- Cryptococcus neoformans is a leading cause of meningitis in HIV patients in central and southern Africa.
- Fungal meningitis requires antifungal treatment.
- Viral meningitis is the most prevalent type of acute meningitis.
- It is less dangerous than bacterial meningitis and often resolves on its own with supportive therapy.
- Enteroviruses, including echoviruses and coxsackievirus, are common causes of viral meningitis.
- Coxsackie virus can cause hand foot and mouth disease.
Encephalitis
- Encephalitis is an acute inflammation and infection of the brain parenchyma.
- Pathogens reach the brain via the bloodstream, crossing the blood-brain barrier, or through peripheral nerves.
- Key triad of symptoms includes fever, headache, and focal neurological signs (e.g., mental state changes, seizures, speech disturbances, hemiparesis).
- Viral encephalitis accounts for 85% of cases globally.
- Herpesviridae (HSV, VZV, CMV, EBV), particularly HSV, are common causes.
- Other causes include rabies, enteroviruses, mumps, HIV, arboviruses (West Nile, Zika, JEV), Hendra, Nipah, and non-viral agents like Listeria, rickettsia, bartonella, toxoplasma, and prions.
- HSV encephalitis is the most common worldwide and presents with acute disease and worsening symptoms over a week.
Herpes Simplex Encephalitis
- HSV-1 usually causes cold sores and HSV-2 is an STI.
- Reactivated HSV can travel from nerve ganglia to the temporal lobe of the brain via retrograde axonal transport.
- This can lead to meningoencephalitis, encephalitis, and haemorrhagic necrosis of the brain.
- If left untreated, there is a 70% mortality rate.
- Treatment with acyclovir, an antiviral, reduces mortality to 20%, but some patients may experience long-term memory impairments.
- MRI/CT scans can reveal temporal lobe involvement.
Rabies
- Rabies is a fatal viral infection spread through animal bites or scratches.
- The virus spreads from muscle cells to peripheral nerves and then to the CNS.
- The onset of symptoms occurs 20-90 days after exposure.
- Prompt treatment with rabies vaccine and rabies immunoglobulin (RIG) injected at the bite site significantly increases survival chances.
Meningitis CSF Results
- CSF analysis is crucial in diagnosing meningitis.
- Increased opening pressure, neutrophils, and protein levels suggest bacterial meningitis.
- Increased T lymphocytes and reduced glucose levels indicate viral, fungal, or TB meningitis.
- Cloudy CSF suggests bacterial infection, while viral meningitis is associated with clear CSF.
- Fungal or TB meningitis can have both clear and cloudy CSF, requiring Indian ink or acid-fast staining to determine the cause.
Clinical Management of Meningitis
- Bacterial meningitis: requires immediate treatment with broad-spectrum bactericidal antibiotics.
- Viral meningitis: managed with supportive therapy, including anti-inflammatories, anti-epileptics, and anti-pyretics.
- Fungal, protozoal, or helminthic meningitis: treated with specific antimicrobials depending on the pathogen.
- Supportive therapies include fever reduction, seizure prevention, and reducing inflammation and intracranial pressure.
Learning Outcomes
- Understand the clinical features, outcomes, and causative agents of encephalitis and focal CNS infections.
- Recognize the diverse range of viruses responsible for encephalitis.
- Relate different types of microbes (bacteria, protozoa, helminths) to focal CNS infections.
- Learn how encephalitis and focal CNS infections are diagnosed and managed.
Rabies
- Rabid encephalitis presents with behavioural changes, hallucinations, hypersexuality, outbursts, excessive salivation, hydrophobia, convulsions, fever, coma, and death.
- All of these symptoms present in dogs and make it more likely for the virus to be transmitted.
- Rabies is endemic in many locations. Vaccinations are recommended before travelling to endemic regions, and immediate treatment is crucial when exposed.
Arboviruses
- West Nile virus is an arbovirus that is transmitted through mosquito injection.
- The virus travels from the lymph nodes to the spleen before crossing the blood-brain barrier to cause encephalitis.
- The virus can enter the brain via macrophages, effectively using them as a "Trojan horse."
- The virus can also cross the blood-brain barrier through tight junctions, causing encephalitis.
- There is no vaccine for West Nile virus.
- Prevention measures include removing sick or dead birds and controlling mosquitoes.
- Common signs of West Nile virus are dead bird sightings. Birds act as reservoir hosts for the virus and can die as a result.
- Personal protection measures against mosquito bites are essential: long sleeves, long pants, and mosquito repellent.
- Once the virus is in the central nervous system (CNS) it infects neurons and causes significant damage, leading to encephalitis symptoms.
Focal CNS Infections
- Focal infections in the brain parenchyma may begin as cerebritis (inflammation of the cerebrum), potentially caused by worms, protozoa, parasites, or other pathogens.
- Brain abscesses develop from cerebritis, usually caused by bacteria, as pus collects at the infection site and becomes surrounded by a well-vascularized capsule.
- Brain abscesses can be observed as circular structures on CT and MRI scans, indicating the location of the pus collection.
- The capsule surrounding the abscess prevents the infection from spreading.
- Brain abscesses carry a high mortality rate (20%) if untreated.
- Imaging is the preferred diagnostic method for suspected brain abscesses, due to the clarity of detection on CT/MRI scans.
- The most common cause of brain abscesses is bacteria, followed by fungal and protozoal/helminth infections.
- Most infections originate from normal flora in the body.
- Brain abscesses can also be caused by surgical procedures or dental work.
- Polymicrobial (multiple bacteria) brain abscesses are possible, often due to normal flora or trauma.
- Significant neurological damage can occur (20% to 70%) leading to sequelae (long-term effects).
Predisposing Factors For Brain Abscesses
- Infections located elsewhere in the body can spread into the bloodstream and reach the brain:
- Otitis media (middle ear infection)
- Sinusitis (inflammation of the sinuses)
- Dental sepsis (infected teeth)
- Lung abscesses
- Bacterial endocarditis (infection of the heart valves)
- Neurosurgical procedures
- Infections of CNS device shunts
- Recent head trauma
- Congenital heart disease
- Immunosuppression (cancer patients, transplant recipients, HIV)
- Low CD4 counts in HIV-infected individuals.
- Example: Rebecca Dalton's case - a tooth abscess was resolved, but a brain abscess developed requiring surgery.
Symptoms of Brain Abscess
- Headache
- Focal neurological deficits – vary depending on the abscess location.
- Seizures
- Stroke syndrome (due to pressure)
Treatment of Brain Abscess
- Initial empirical antibiotic treatment followed by specialization based on blood and drainage cultures and microbial analyses.
- Depending on size and symptoms, corticosteroids may be used to reduce pressure and cerebral edema.
- Drainage procedures are common to remove pus and alleviate pressure.
Focal Infection Caused By Protozoa
- Toxoplasma gondii (also known as "toxo") is a common intracellular parasite.
- Most people have been exposed to Toxoplasma, particularly those who have cats.
- Pregnant women are advised to avoid cleaning cat litter to prevent exposure to oocysts (parasite eggs).
- Toxoplasma gondii can be contracted by ingesting undercooked meat containing cysts that hatch in the digestive system and can travel to the brain.
- The infection can form walled-off areas in the brain.
- Immunocompromised individuals are more susceptible to toxoplasmosis infection.
- Late-stage HIV infections can exhibit "starry night presentation" on brain imaging, indicating multiple walled-off cysts.
Taeniasis (Pork Tapeworm Infection)
- Taeniasis is caused by the pork tapeworm.
- Infection occurs by consuming undercooked pork meat containing oncospheres (parts of the tapeworm's life cycle).
- The scolex (head) of the tapeworm attaches to the small intestine and grows into a large worm.
- Eggs released by the worm are excreted in feces.
- Ingesting these eggs can lead to infection in humans.
- Embryos from the eggs can migrate to muscle tissue and the brain, forming cysts.
Treatment of Taeniasis
- Antihelminthic medications (e.g., albendazole) kill the worms but can trigger a massive immune response that may worsen inflammation in the brain.
- Corticosteroids (e.g., dexamethasone) may be needed to manage inflammation.
- Anticonvulsant medications may be necessary to manage seizures.
- Surgical removal of worms is possible in cases with limited infestation.
Subdural Empyema
- Subdural empyema is a collection of pus in the space between the dura mater and arachnoid mater.
- It can occur in individuals with lung or heart infections.
- Subdural empyemas appear as high-signal regions on CT scans.
- These are not walled-off.
- The most frequent cause (50-80%) is otorhinologic infections (ears or nasopharynx) that spread to the brain.
- Trauma can also introduce microbes and contribute to subdural empyema.
- Lumbar punctures are contraindicated as they might increase the risk of infection spreading.
- Causes include:
- Streptococcus
- Staphylococcus
- Gram-negative bacilli
- Anaerobic bacteria
- Symptoms:
- Fever
- Altered mental state
- Seizures
- Headache
- Hemiparesis
- Vomiting
- Subdural empyemas can be polymicrobial (multiple bacteria).
- High mortality rate even with treatment (10-20%).
Treatment of Subdural Empyema
- Medical emergency, requires prompt intervention.
- Urgent decompression and surgical drainage
- Aggressive antibiotic treatment
Epidural Abscess
- Collection of pus in the epidural space, the area between the dura mater and the vertebral column.
- Typically caused by bacteria, most commonly Staphylococcus aureus, often from normal flora.
- Risk factors: immunocompromised individuals, HIV, recent spinal surgery, or trauma.
- Lumbar punctures are contraindicated due to the risk of spreading infection, as they can push the infection into the cerebrospinal fluid (CSF) and meninges.
- Pressure on the spinal cord can lead to neurological deficits: radiculopathy (nerve compression), paralysis.
- Fatal if left untreated.
Treatment of Epidural Abscess
- Urgent aggressive antibiotic therapy.
- Urgent decompression (surgical intervention to relieve pressure).
Clinical Management Of Encephalitis And Focal CNS Infections
- Immediate assessment and treatment are crucial for the best chance of survival.
- Differentiation between meningitis, encephalitis, and focal CNS infections is essential.
- Focal neurological signs indicate direct brain tissue injury, warranting prompt attention.
- Imaging (CT/MRI) should be performed before lumbar puncture, if applicable.
- Identifying the pathogen responsible is critical: MCS (microbial cultures), drainage analysis, blood cultures, PCR, serology.
- Empiric antimicrobial therapy is initiated immediately, followed by adjustment based on identified pathogens (antibiotics, antivirals, antiparasitics, antifungals).
- Anti-inflammatory and anti-seizure medication may be required to reduce inflammation and protect the patient.
- Surgical intervention (drainage, removal) may be necessary in some cases.
Summary:
- Encephalitis involves inflammation of the brain's white matter.
- Infections can be diffuse (e.g., HSV) or focal due to parasites or worms.
- CT/MRI play a crucial role in diagnosing brain infections.
- Lumbar puncture may be needed but is generally not the first choice.
- Clinician management depends on the infectious agent involved.
- Timely treatment is paramount due to the high risk of mortality.
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Test your knowledge on meningitis, focusing on its causes, symptoms, and distinctions between viral and bacterial forms. This quiz covers key aspects of central nervous system infections and their pathogens. Perfect for students studying neurology or infectious diseases.
