Infectious CNS Diseases Flashcards
What organisms cause Acute pyogenic (bacterial) meningitis?
- Neisseria meningitides
- Streptococcus pneumoniae
How do you diagnose Bacterial Meningitis?
- CSF cloudy - due to inc #s of nuetrophils
- CSF protein leveles inc.
- [glucose] fall
What is the most common cause of Meningitis?
Aseptic (Viral) Meningitis
What are the causative organisms of Aseptic (Viral) Meningitis?
- Enteroviruses (echoviruses, Coxsackie viruses, polioviruses)
- Mumps virus (paramyxovirus)
How do you diagnose Aseptic (Viral) Meningitis?
- CSF is clear & colorless
- Excess lymphocytes
- Moderately inc. protein
- Normal [glucose]
What are the Etiologys of Brain Absecess? (6)
- Middle Ear Infection (60%) - results in temporal lobe and cerebellar abcesses
- Frontal Sinusitis Infection (20%) - results in frontal lobe abscess
- Bacteriema/Septicemia (10%) - usually results in frontal lobe abscess
- Penetrating Skull Trauma
- Secondary to Meningitis
- Odontogenic Infections
What are the causative organisms of Brain Abscess?
- Streptococcus viridans
- Staphylococcus aureus
- Klebsiella
- May also be caused by fungal infection
What are 4 Complications of Brain Abscess?
- Meningitis
- Intracranial Herniation
- Focal Neurological Deficit
- Epilepsy
- Almost always 2o to TB elsewhere in the body
- Infection usually reaches the CNS via the bloodstream
Tuberculous Meningitis
What is the Pathogenesis of Tuberculosis Meningitis?
- Granulomatus Inflammation affects the:
- Basal Meninges
- Large Arteries
- CNs
What is the causative organism in Chronic Meningitis?
- Neisseria Meningitidis
- Rare condition, in middle aged and elderly
What is the causative organism of Lyme Disease?
- Borrelia burgdorferi
Lyme Disease is a systemic illness characterized by what?
- Skin Lesions
- Neurological features:
- Arthralgia
- Headache
- Neck Stiffness
- Cranial Neuropathy
What is the causative organism of Neurosyphilis?
-
Treponema pallidum
- caused by invasion of the CNS, weeks, months, or years after initial infection
What are the 4 disorders of Arboviruses?
- West Nile Encephalitis
- St. Louis Encephalitis
- Eastern Equine Encephalitis
- Western Equine Encephalitis
What Arbovirus disorder has the highest mortality rate?
Eastern Equine Encephalitis (33%)
What is the most common agent of severe Viral Encephalitis, although an uncommon complication of this infection?
Herpes Simplex (Type 1 or 2)
1% of Poliomyelitis cases result in CNS involement, what is the characterization of this?
- Degeneration and Necrosis of Anterior Horn Cells of the spinal cord
- Leading to muscle weakness and Acute Symmetric Paralysis (mostly legs)
Eosinophilic, sharply outlined, inculsion bodies found in the cytoplasm of certain nerve cells containing Rabies Virus, and are considered to be Pathognomic.
Negri Bodies
What is the causative organism of Subacute Sclerosing Panencephalopathy?
Persistant infection with an altered measles virus
What is the causative organism of Progressive Multifocal Leukoencephalopathy (PML)?
JC Polyoma Type of Papovavirus
What is Progressive Multifocal Leukoencephalopathy (PML) often associated with?
- AIDS
- CLL
- Carcinoma
- SLE
What is the causative organisms of Fungal infections?
-
Cryptococcus neoformans
- can produce ds in the absence of immunosuppression
- Aspergillus fumigatus
- Candida albicans
- Phycomycosis
- commonly affects uncontrolled diabetics
What is the causative organism of Toxoplasmosis?
Toxoplasma gondii
Prion Diseases are anatomically defined by the finding of what?
-
Spongiform Encephalopathy (spongiosis)
- Characterized by clusters of small cysts in CNS gray matter along with a striking absence of inflammatory response
- Long incubation period
- Progressive Course
Name 2 Examples of Prion Diseases?
- Kuru
- Creutzfeldt-Jakob Ds
- Characterized by:
- Ataxia
- Rapidly Progressive Dementia
- Death
- Incubation area of up to 30 years
- Always fatal, usually within 6 months
- Spongiosis is Prominent
Creutfeldt-Jakob Ds (subacute spongifor encephalopathy)
