Nervous System Infection Flashcards
What are the common symptoms of acute bacterial meningitis?
Fever, headache, photophobia, neck stiffness (meningism), altered consciousness, increased sensitivity to light and sound.
What physical exam findings suggest meningitis?
Positive neck stiffness (meningism), no papilledema (if no increased intracranial pressure), no focal neurological deficit.
What are the classic CSF findings in bacterial meningitis?
- High WBC count (neutrophil predominant) → turbid CSF
- High protein (suggestive of pus)
- Low sugar (bacteria consume glucose; compare with serum glucose)
- Gram stain: Streptococcus pneumoniae (Gram-positive cocci in chains, lancet-shaped)
What are common Gram-negative and Gram-positive pathogens in bacterial meningitis?
- Gram-negative: Haemophilus influenzae, Neisseria meningitidis
- Gram-positive: Streptococcus pneumoniae (elderly), Streptococcus agalactiae (Group B, in children)
Why is a lumbar puncture sometimes contraindicated in bacterial meningitis?
Increased intracranial pressure may lead to brain herniation.
What is the significance of low CSF glucose in bacterial meningitis?
Indicates bacterial metabolism of glucose; CSF glucose <50% of serum glucose suggests bacterial infection.
What is the chief complaint in the chronic meningitis case?
AIDS, fever & headache for 2 weeks
The patient was recently diagnosed with AIDS.
What were the findings in the CSF analysis for the chronic meningitis case?
High WBC, high protein, low sugar
Macrophage predominant WBC.
What organism was identified in the CSF culture?
Cryptococcus neoformans
Takes 1-2 days for culture results.
What test is used to detect cryptococcal antigen in the CSF?
CSF cryptococcal antigen test
What is the significance of the mucicarmine stain?
Stains capsular antigen
What complication can arise from cryptococcal infection?
Cryptococcoma - hydrocephalus
What is a common pulmonary infection associated with cryptococcal meningitis?
Pulmonary infection
What type of meningitis occurs at the base of the brain?
TB meningitis
What is the chief complaint in the encephalitis case?
DM & HT, fever & headache for 3 days
Symptoms were acute.
What behavioral symptoms were observed in the encephalitis case?
Behavioral changes & hallucinations
What was the mental status change in the encephalitis case?
Declined mental status
Fill in the blank: The CSF analysis showed high _______ predominant WBC.
macrophage
True or False: Cryptococcus neoformans is a yeast with a larger capsule.
True
What special bacteria can be found in CSF analysis for chronic meningitis?
Mycobacterium tuberculosis
What parasite is associated with increased eosinophils in CSF?
Angiostrongylus cantonensis
What is the purpose of the CrAg lateral flow assay?
To detect cryptococcal antigen
What antifungal treatment is likely considered for cryptococcal meningitis?
Antifungal therapy
What are the vesicle lesions observed in the physical exam?
Lower lip lesions
Vesicle lesions can indicate a viral infection, particularly herpes simplex virus (HSV).
What were the findings in the cerebrospinal fluid analysis?
Higher RBC (1000 cells/mm3), slightly high protein, normal sugar levels
These findings may suggest viral or traumatic causes of meningitis.
What is the treatment for HSV identified in the cerebrospinal fluid?
Acyclovir IV for 21 days
Acyclovir is an antiviral medication used to treat infections caused by certain types of viruses.
What is the etiology of the viral infection mentioned?
Type 1: oralis, includes genital infections
HSV-1 is commonly associated with oral herpes but can also cause genital infections.
What clinical presentations are associated with the viral infection?
Altered level of consciousness, behavioral change, neurological deficits, hemiparesis, cranial nerve palsies, seizures
These symptoms indicate central nervous system involvement.
What were the symptoms of the young patient with a brain abscess?
Fever, severe headache, weakness in the arm
These symptoms suggest a central nervous system infection or abscess.
What imaging study was performed for the brain abscess?
CT brain with contrast
CT scans help visualize brain lesions and assess for abscesses.
What type of bacteria was identified in the Gram stain of the brain abscess?
Gram-negative coccobacilli
Examples include Haemophilus influenzae, which can cause severe infections.
What is a significant risk factor for developing infections like mucormycosis?
Immunocompromised status
Conditions such as severe diabetes mellitus and hematological disorders increase susceptibility.
What is the treatment for infections associated with the cavernous sinus?
Drainage
Surgical intervention may be necessary to relieve pressure and remove infected material.
What is a medical emergency related to eye and ENT infections?
Orbital cellulitis
This condition can lead to vision loss and requires prompt treatment.
What is the common percentage associated with ear infections?
37%
This statistic reflects the prevalence of ear infections in certain populations.
What is keratitis?
Inflammation/infection of lens
Often very painful condition.
What are the common etiologies of keratitis?
- Gram negative bacteria (e.g. pseudomonas)
- Virus (e.g. HSV)
- Fungal
- Parasite/protozoa (e.g. acanthamoeba)
These pathogens can lead to serious eye infections.
What is endophthalmitis?
Inflammation/infection of vitreous chamber
A serious condition that can follow keratitis.
What are the causes of endophthalmitis?
- Outside in:
- Cellulitis → endophthalmitis
- Bacteremia
These pathways indicate how infections can spread.
What does rhinitis refer to?
Inflammation/infection of nose tissue
Antibiotics are not usually needed for this condition.
What is sinusitis?
Inflammation/infection of the sinuses
Commonly associated with upper respiratory infections.
What are common causes of ear infections?
- Streptococcus pneumoniae
- Haemophilus influenzae
These bacteria are frequently involved in otitis media.
Fill in the blank: Keratitis can be caused by _______.
[Gram negative bacteria, virus, fungal, parasite/protozoa]
True or False: Antibiotics are necessary for treating rhinitis.
False
Rhinitis typically resolves without the need for antibiotics.
What percentage of keratitis cases are attributed to a specific cause mentioned?
37%
This statistic highlights the prevalence of the condition.
What is a common protozoan cause of keratitis?
Acanthamoeba
This organism is particularly associated with contact lens wearers.
