Meningitis

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Meningitis Encephalitis

• Presented by
• Donnette O'Neill
• Suzanne Brydges
• Mónica Richardson

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What are Meningitis Encephalitis?

• Meningitis is
• An acute, subacute, or chronic illness that
  causes
• inflammation of the meninges
• Can be caused by a bacterial, viral, or fungal
  infection

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Bacterial Meningitis

• Common pathogens
• Streptococcus pneumoniae (Pneumococcus)
• Haemophilus influenzae B (HiB)
• Neisseria menigitidis (Meningococcus)

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Viral Meningitis

• Common forms include enteroviral viruses such as
• Herpes simplex I
• Epstein-Barr
• Influenza type A B

Herpes simplex I
Epstein-Barr
Influenza
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Fungal Meningitis

• Less common form
• Contracted by persons with a compromised immune
  system
• Histoplasmosis
• Cryptococcosis
• Coccidioidomycosis
• Mucormycosis
• Candidiasis
• Aspergillosis

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What are Meningitis Encephalitis?

• Encephalitis is
• An acute febrile illness that causes an
  inflammation of the
• brain
• Most often caused by viruses such as
• Poliomyelitis
• Rabies
• Mononucleosis
• Rubella/Rubeola

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Pathogenesis

• Meningitis
• Pathogens have two routes into the CNS
• Hematogenous routes (through the bloodstream)
• Neural (along nerve roots)
• Upon entrance to the CNS toxins or
• pathogens produce various results
• including
• Inflammation in the meninges
• Cerebral edema
• Increased intracranial pressure
• Increased CSF viscosity

Inflammatory cells in subarachnoid space
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Purulent exudate in subarachnoid space in
bacterial meningitis
Pathogenesis photos courtesy of
www.neuropathologyweb.org
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Pathogenesis Continued

• Encephalitis
• Pathogen enters CNS via same routes as
  meningitis
• Pathogen (usually viral) enters neural cells
  and causes
• Disruption of cell function
• Perivascular congestion
• Hemorrhage
• Meningitis
• General inflammatory response

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Clinical Manifestations

• Signs of bacterial Meningitis
• Generalized throbbing headache
• Photophobia
• Nuchal rigidity
• Kernig sign (inability to extend leg w/hip
  flexed at 900)
• Brudzinski sign (forceful flexion of neck onto
  chest w/flexion of
• legs thighs

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Infectious Signs

• Systemic infections include
• Chills
• Fever
• Petechial rash
• Tachycardia

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Neurologic Signs

• ? in consciousness
• Hemiparesis
• Hemiplagia
• Ataxia
• Seizures
• Projectile vomiting
• Papilledema (swelling of the optic disk)
• Delirium that progresses to unconsciousness

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Clinical Manifestations

• Signs of viral Meningitis
• Mild generalized throbbing headache
• Mild photophobia
• Mild neck pain
• Stiffness
• Fever
• Malaise

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Clinical Manifestations

• Signs of fungal Meningitis
• Slow development
• First signs are dementia or communicating
  hydrocephalus
• (accumulation of fluid in cerebral ventricles)
• Affected person is usually afebrile (feverless)

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Clinical Manifestations

• Signs of Encephalitis
• Mild to life-threatening
• Fever
• Delirium
• Confusion
• Intracranial pressure

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Evaluation Treatment

• Both infections are evaluated by a CSF culture,
  serology,
• and WBC count
• Lumbar puncture (spinal tap)
• Antibiotics
• Viral Meningitis is treated with antiviral
  drugs (i.e., Acyclovir
• steroids)
• Vaccinations as a preventative measure

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Questions?
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Thank you!