Name The Bug
67-year-old with fever, neck stiffness, and altered mental status has gram-positive lancet-shaped diplococci in CSF. Name the organism.
Streptococcus pneumoniae.
CSF sample has neutrophilic predominance, high protein, and low glucose. What type of meningitis is most likely?
Bacterial meningitis.
Name 2 core antibiotics commonly used for empiric community-acquired bacterial meningitis in U.S. adults.
Vancomycin and ceftriaxone.
What classic triad is associated with bacterial meningitis?
Fever, neck stiffness, and altered mental status.
A patient has confirmed meningococcal meningitis. What type of isolation precautions are required initially?
Droplet precautions, in addition to standard precautions, until at least 24 hours of effective antibiotics.
A college student presents with fever, headache, hypotension, and a rapidly spreading petechial rash. Name the organism
Neisseria meningitidis.
CSF has lymphocytic predominance, mildly elevated protein, and normal glucose. What type of meningitis is most likely
Viral meningitis.
70-year-old presents with suspected bacterial meningitis. What antibiotic should you add?
Ampicillin.
A patient with fever and headache has severe neck stiffness. Passive neck flexion produces involuntary hip and knee flexion. Name this sign.
Brudzinski sign.
A medical resident is exposed to oral secretions while intubating a patient with meningococcal meningitis without appropriate protection. What intervention is required?
Postexposure antibiotic prophylaxis, such as rifampin, ciprofloxacin, or ceftriaxone, per current guidelines.
72-year-old immunocompromised patient develops meningitis. This gram-positive rod must be covered empirically.
Listeria monocytogenes
LP reveals CSF glucose of 25 mg/dL and simultaneous serum glucose of 100 mg/dL. What is the CSF-to-serum glucose ratio?
0.25 (25%). This is abnormally low and raises concern for bacterial, TB, or fungal meningitis.
What edication should be administered with the first antibiotic dose in suspected bacterial meningitis?
Dexamethasone.
A patient develops headache, photophobia, and CSF lymphocytic pleocytosis. CSF enterovirus PCR is positive. What is the treatment strategy?
Supportive care for uncomplicated enteroviral meningitis.
Patient with cryptococcal meningitis has an opening pressure of 42 cm H₂O and severe headache. What is the preferred intervention to reduce intracranial pressure?
Therapeutic lumbar puncture with CSF drainage, repeated as necessary.
Patient with HIV (CD4 35) develops weeks of headache and blurry vision. CSF opening pressure is 38 cm H₂O, Name the organism.
Cryptococcus neoformans.
CSF shows lymphocytic predominance, glucose 28 mg/dL, protein 180 mg/dL, and elevated opening pressure. Name two major infectious categories on the differential.
Tuberculous and fungal meningitis.
30-year-old has fever, headache, altered behavior, and temporal lobe abnormalities on MRI. What medication must be started immediately?
IV acyclovir for suspected HSV encephalitis.
A 34-year-old with meningitis develops a new seizure and focal weakness. Before performing LP, what diagnostic test is indicated?
CT head before LP, while ensuring antibiotics are not delayed.
55-year-old patient with bacterial meningitis develops worsening headache, vomiting, bradycardia, hypertension, and irregular respirations.
What is this classic triad called, and what does it indicate?
Cushing's triad indicates severely elevated ICP with impending brain herniation.
Cushing's triad is a late sign of increased ICP. This is a neurologic emergency requiring immediate intervention, and LP should be avoided when impending herniation is suspected.
Patient develops subacute basilar meningitis with cranial nerve palsies, hydrocephalus, and CSF lymphocytic pleocytosis, high protein, and low glucose, Name the pathogen
Mycobacterium tuberculosis.
Patient with suspected bacterial meningitis received ceftriaxone before LP. CSF Gram stain and cultures are negative. Does a negative CSF culture exclude bacterial meningitis?
No. Prior antibiotics can reduce culture yield. Continue treating based on clinical suspicion and other CSF tests, including PCR.
A patient with HIV has confirmed cryptococcal meningitis. What is the preferred two-drug induction treatment?
Amphotericin B plus flucytosine, typically for 2 weeks.
A patient with untreated HIV and cryptococcal meningitis is starting antifungal induction therapy. Should ART generally start immediately?
Defer ART, generally starting about 4–6 weeks after initiation of effective antifungal therapy, to reduce CNS IRIS-related complications
A patient with bacterial meningitis suddenly develops adrenal hemorrhage, refractory shock, and purpura fulminans. Name the syndrome.
Waterhouse–Friderichsen syndrome, classically associated with meningococcemia.