Nervous System & Special Senses

Bacterial meningitis: CCS-style management and empiric therapy

Clinical Overview and When to Suspect Bacterial Meningitis

— Neonates (<1 mo): GBS, E. coli, Listeria monocytogenes

— 1 mo–2 yr: S. pneumoniae, N. meningitidis, GBS, H. influenzae (if unvaccinated)

— 2–50 yr: S. pneumoniae, N. meningitidis

— >50 yr, alcohol use, immunocompromise, pregnancy: add Listeria

— Post-neurosurgery, CSF shunt, penetrating trauma: S. aureus, coagulase-negative staph, gram-negative rods (incl. Pseudomonas)

— College dorm, military barracks outbreak → meningococcus

— Recent otitis/sinusitis/CSF leak → pneumococcus

— Pregnant or immunosuppressed eating soft cheeses/deli meats → Listeria

— Tick exposure, rash, recent travel → broaden differential (Lyme, RMSF, viral)

CCS pearl: On a CCS case, the moment you suspect bacterial meningitis, order empiric antibiotics + dexamethasone BEFORE LP and BEFORE CT if there will be any delay. Do not wait for imaging or CSF results — blood cultures first, then antibiotics, then LP when safe. Delaying treatment to "get the tap clean" is a classic CCS scoring trap.

Definition: Acute pyogenic infection of the leptomeninges and subarachnoid CSF, most often bacterial seeding from nasopharyngeal colonization, contiguous spread (sinusitis, otitis, mastoiditis), or hematogenous dissemination.

Epidemiology by age (US, post-conjugate vaccine era):

When to suspect in the ED: Any patient with fever + headache + altered mental status or neck stiffness; the classic triad is present in only ~44% — absence does not rule out meningitis. Low threshold in elderly (may present only with confusion), neonates (poor feeding, lethargy, bulging fontanelle), and post-splenectomy or complement-deficient patients.

Red-flag clinical contexts:

Mortality clock: Untreated pneumococcal meningitis mortality ~20–30%; each hour of antibiotic delay increases mortality. Door-to-antibiotic target <60 minutes.

Presentation Patterns and Key History

— Headache (~85%) — usually severe, generalized, worst-of-life quality

— Fever (~75%)

— Neck stiffness (~70%)

— Altered mental status (~70%) — ranges from lethargy to coma

— Nausea/vomiting, photophobia, seizures (~5–25%)

— Vaccination status (MenACWY, MenB, PCV13/PCV20, Hib) — unvaccinated college freshman in dorm = meningococcus

— Recent URI, otitis media, sinusitis, dental procedure, endocarditis → pneumococcus

— Head trauma, basilar skull fracture, CSF rhinorrhea → recurrent pneumococcal meningitis

— Splenectomy or sickle cell → encapsulated organisms (S. pneumo, N. meningitidis, H. influenzae)

— HIV/CD4, transplant, steroids, biologics (eculizumab → meningococcus risk ↑↑)

— Pregnancy, age >50, alcohol use → cover Listeria

— Sick contacts, travel, exposure to TB or rodents

Board pearl: A patient on eculizumab (e.g., for PNH or aHUS) with fever has meningococcal meningitis until proven otherwise — these patients are required to receive meningococcal vaccination prior to therapy, and often chronic penicillin prophylaxis. This is a recurring USMLE Step 3 distractor.

Classic adult symptoms (in descending frequency):

Time course: Bacterial meningitis evolves over hours to 1–2 days; subacute progression (days to weeks) suggests TB, fungal, or partially treated bacterial meningitis.

Key history to elicit on CCS/MCQ stems:

Pediatric/neonatal red flags: Irritability, paradoxical irritability (worse when held), poor feeding, bulging fontanelle, hypothermia (not always febrile), apnea, seizures. Petechial/purpuric rash in a febrile child = meningococcemia until proven otherwise.

Atypical elderly presentation: May lack fever and meningismus; new confusion or behavioral change + leukocytosis warrants LP.

Physical Exam Findings and Hemodynamic Assessment

— Nuchal rigidity: Resistance to passive neck flexion

— Kernig sign: Pain/resistance with knee extension while hip flexed at 90°

— Brudzinski sign: Involuntary hip/knee flexion on passive neck flexion

— Jolt accentuation: Worsening headache with horizontal head rotation 2–3×/sec — more sensitive but not specific

— Mental status / GCS — trend it

— Focal deficits → suggest abscess, empyema, venous sinus thrombosis, or pneumococcal cerebritis

— Cranial nerve palsies (CN VI most common from ↑ICP; CN VII/VIII in basal meningitis, TB, Lyme)

— Papilledema → defer LP, image first

— Seizures (~25% pneumococcal)

— Petechiae on trunk/extremities, palms/soles → meningococcemia

— Purpura fulminans + hypotension → Waterhouse-Friderichsen syndrome (bilateral adrenal hemorrhage)

— Splinter hemorrhages, Janeway lesions, Osler nodes → endocarditis seeding meninges

— Septic shock physiology common with meningococcemia and pneumococcal bacteremia

— Check MAP, lactate, capillary refill, mottling

— Cushing reflex (hypertension + bradycardia + irregular respirations) → impending herniation

— Pulsus, JVD, new murmur → IE workup

Step 3 management: If you see petechiae + fever + hypotension, initiate the sepsis bundle in parallel with meningitis empiric therapy — IV crystalloid 30 mL/kg, blood cultures ×2, lactate, ceftriaxone + vancomycin, and dexamethasone. Do not delay antibiotics for LP in a hemodynamically unstable patient; image and tap once stabilized.

Meningeal signs (low sensitivity but high specificity):

Neurologic exam essentials:

Skin exam — do not skip:

Hemodynamic assessment:

HEENT: Examine TMs, sinuses, mastoid for primary source.

Diagnostic Workup — Initial Labs, Imaging, and Decision to LP

— CBC with differential, CMP, coagulation panel (PT/PTT/INR, platelets — needed for LP safety)

— Blood cultures ×2 BEFORE antibiotics (yield 50–90% in bacterial meningitis)

— Lactate, procalcitonin, CRP

— HIV test, glucose (paired with CSF glucose)

— Type & screen if surgical drainage anticipated

— Pregnancy test in women of reproductive age

— Age ≥60

— Immunocompromised state

— History of CNS disease (mass, stroke, focal infection)

— New-onset seizure within 1 week

— Papilledema

— Abnormal level of consciousness

— Focal neurologic deficit

— Mass effect / midline shift on CT

— Platelets <50k or INR >1.5 (correct first)

— Therapeutic anticoagulation (hold/reverse)

— Skin infection over LP site

— Hemodynamic instability not yet resuscitated

Board pearl: A normal CT does not exclude elevated ICP, but it is sensitive enough to detect mass lesions that would make LP dangerous. Never withhold antibiotics waiting for CT — antibiotics first, image second, tap third.

Order set on ED arrival (CCS sequencing):

When to obtain CT head BEFORE LP (IDSA criteria):

If none of the above → proceed directly to LP without CT.

CRITICAL sequencing if CT needed: Blood cultures → empiric antibiotics + dexamethasone → CT → LP. Antibiotic pretreatment may reduce CSF culture yield by ~20% within 4 hours but rarely changes CSF cell count, protein, glucose, or Gram stain within the first 1–2 hours.

LP contraindications:

Opening pressure: Measure routinely; markedly elevated (>40 cm H₂O) suggests cryptococcal, TB, or severe pyogenic meningitis.

Diagnostic Workup — CSF Analysis and Confirmatory Studies

• Standard CSF tube allocation (4 tubes):
— Tube 1: Cell count + differential
— Tube 2: Glucose, protein
— Tube 3: Gram stain, bacterial culture
— Tube 4: Cell count (repeat, to assess traumatic tap) + hold for additional studies
• Classic CSF profiles:
Parameter	Normal	Bacterial	Viral	TB/Fungal
Opening pressure	10–20	↑↑ (>25)	Normal/↑	↑↑
WBC/μL	<5	1,000–5,000 PMN	50–500 lymph	100–500 lymph
Glucose (CSF:serum)	>0.6	<0.4	Normal	<0.4
Protein (mg/dL)	<45	>200	<150	100–500
Gram stain	Neg	+ in 60–90%	Neg	Neg (AFB)
• Adjunct CSF studies:
— Bacterial PCR multiplex panel (BioFire ME) — detects S. pneumo, N. meningitidis, H. flu, GBS, Listeria, E. coli K1, HSV, VZV, enterovirus, cryptococcus
— Latex agglutination antigen testing (lower sensitivity, useful if pretreated)
— Cryptococcal antigen if immunocompromised
— AFB smear/culture + TB PCR if subacute course
— Lactate >3.5 mmol/L favors bacterial over viral
• Traumatic tap correction: Subtract 1 WBC per 500–700 RBCs.
• Confirmatory in special contexts:
— MRI with contrast: leptomeningeal enhancement, complications (abscess, ventriculitis, infarct, hydrocephalus)
— EEG if persistent altered mental status — nonconvulsive status epilepticus common
Key distinction: Listeria often produces a mixed CSF pleocytosis with lymphocyte predominance and lower PMN counts — mimicking viral or TB meningitis. Gram-positive rods on CSF Gram stain in a >50yo, pregnant, or immunocompromised patient = Listeria; add ampicillin.

Risk Stratification and First-Line Management Logic

1. Recognize → IV access, labs, blood cultures ×2

2. Decide on CT before LP (see Chunk 4)

3. Dexamethasone 10 mg IV + empiric antibiotics — give together or steroids first, then antibiotics within minutes

4. CT → LP if not contraindicated

5. ICU disposition for unstable, altered, or seizing patients

— <1 month: ampicillin + cefotaxime (or gentamicin)

— 1 mo–50 yr: ceftriaxone + vancomycin

— >50 yr, alcoholic, immunocompromised, pregnant: ceftriaxone + vancomycin + ampicillin (Listeria)

— Post-neurosurgery / shunt / trauma: vancomycin + cefepime (or meropenem or ceftazidime) — covers MRSA + Pseudomonas

— Severe beta-lactam allergy: vancomycin + moxifloxacin + TMP-SMX (for Listeria)

— Adults with suspected pneumococcal meningitis → reduces mortality and hearing loss

— Give 0.15 mg/kg (≈10 mg) IV q6h × 4 days

— Must be given before or with the first dose of antibiotics; little benefit if given after

— Continue only if CSF Gram stain or culture confirms pneumococcus; discontinue if other pathogen

— In children: clearly beneficial for H. influenzae meningitis; pneumococcal benefit less robust

CCS pearl: On CCS, the order "dexamethasone IV" must appear before or simultaneous with "ceftriaxone IV + vancomycin IV" to score the steroid benefit. Adding it after CSF results is too late.

Time-critical algorithm (door-to-antibiotic <60 min):

Empiric coverage based on age/host:

Dexamethasone indications and timing:

Source control considerations: ENT consult for mastoiditis/otitis with intracranial extension; neurosurgery for abscess, empyema, hydrocephalus.

Pharmacotherapy — First-Line Empiric and Pathogen-Directed Regimens

— Ceftriaxone 2 g IV q12h (meningeal dosing)

— Vancomycin 15–20 mg/kg IV q8–12h, target trough 15–20 or AUC 400–600

— Ampicillin 2 g IV q4h (Listeria coverage, >50yo/immunocompromised/pregnant)

— Dexamethasone 0.15 mg/kg IV q6h × 4 days

— Add acyclovir 10 mg/kg IV q8h if HSV encephalitis is in the differential (temporal signs, focal seizures, lymphocytic CSF)

— S. pneumoniae, PCN-susceptible: penicillin G or ceftriaxone × 10–14 days

— S. pneumoniae, ceftriaxone-resistant: vancomycin + ceftriaxone (± rifampin)

— N. meningitidis: ceftriaxone × 7 days; PCN G if susceptible

— H. influenzae: ceftriaxone × 7 days

— Listeria: ampicillin + gentamicin × ≥21 days

— GBS: penicillin G × 14–21 days

— Gram-negative bacilli (e.g., E. coli, Pseudomonas): cefepime or meropenem × 21 days

— S. aureus (MSSA): nafcillin or cefazolin; MRSA: vancomycin ± rifampin × 14–21 days

— Meningococcus, H. flu: 7 days

— Pneumococcus: 10–14 days

— GBS: 14–21 days

— Listeria, GNR: 21 days

— Staph, ventriculitis, shunt: ≥21 days + hardware removal

Step 3 management: Repeat LP at 24–48 hours is indicated for ceftriaxone-resistant pneumococcus or if patient fails to clinically improve — a recurring board question on monitoring therapeutic response.

Empiric dosing (normal renal function, adult):

Pathogen-directed therapy after culture/sensitivity:

Duration cheat sheet:

Beta-lactam allergy management: True anaphylaxis to PCN/cephalosporins → moxifloxacin + vancomycin ± TMP-SMX (Listeria). Cross-reactivity between PCN and ceftriaxone <1%; most "PCN allergy" patients tolerate ceftriaxone safely.

Procedures, Source Control, and ICP Management

— Patient in lateral decubitus or sitting flexed position

— L3–L4 or L4–L5 interspace (below conus medullaris ~L1–L2)

— Measure opening pressure in lateral decubitus only

— Collect 8–15 mL across 4 tubes

— Post-LP headache: atraumatic (pencil-point) needle reduces risk; bedrest does NOT prevent it; treat with caffeine, fluids, epidural blood patch if persistent

— Ventriculostomy / EVD for obstructive hydrocephalus or to monitor ICP

— Surgical drainage of subdural empyema, brain abscess, mastoiditis, sinusitis with intracranial extension

— Shunt removal/externalization in shunt-related meningitis

— Cochlear implant infection → device removal

— Head of bed 30°, midline

— Avoid hypotonic fluids; maintain euvolemia

— Hypertonic saline 3% bolus or mannitol 0.25–1 g/kg for herniation

— Mild hyperventilation (PaCO₂ 30–35) as bridge only

— Treat fever aggressively (acetaminophen, cooling)

— Seizure prophylaxis not routine; treat seizures with levetiracetam

— Household, daycare, intimate, healthcare with respiratory secretion exposure

— Rifampin 600 mg PO q12h × 2 days, OR ciprofloxacin 500 mg PO ×1, OR ceftriaxone 250 mg IM ×1 (preferred in pregnancy)

— For H. influenzae type b: rifampin for unvaccinated close contacts <4 yr

Board pearl: A nursing home roommate of a patient with meningococcal meningitis needs prophylaxis; the ED physician who intubated the patient without a mask does; the physician who only examined the patient does not unless they performed mouth-to-mouth or close airway management.

Lumbar puncture technique highlights:

Neurosurgical/ENT interventions:

ICP management in fulminant meningitis:

Vasopressors: Norepinephrine first-line for septic shock; target MAP ≥65.

Public health and chemoprophylaxis for close contacts (meningococcus):

Droplet isolation for first 24 hours of effective therapy in suspected meningococcus.

Special Populations — Elderly and Renal/Hepatic Impairment

— Often present without fever or meningismus; new confusion + leukocytosis should prompt LP

— Higher mortality (~30%) due to comorbidities and delayed diagnosis

— Always add ampicillin for Listeria coverage in >50yo regardless of immune status

— Higher rate of pneumococcal serotypes — ensure PCV20 or PCV15+PPSV23 vaccination on discharge

— Increased risk of seizures, stroke (septic vasculitis), and delirium

— Vancomycin: Adjust by CrCl; target trough/AUC monitoring; avoid concurrent nephrotoxins (aminoglycosides, contrast, NSAIDs)

— Ceftriaxone: Predominantly biliary excretion — no renal adjustment in most cases (max 2 g q12h); minor adjustment only in combined hepatic+renal failure

— Cefepime: Reduce dose in CrCl <60; neurotoxicity (encephalopathy, nonconvulsive status, myoclonus) common if not renally adjusted — particularly dangerous in meningitis where mental status is already altered

— Ampicillin: Reduce frequency in CrCl <30

— Acyclovir: Adjust by CrCl; ensure adequate IV hydration to prevent crystal nephropathy

— Ceftriaxone caution in severe hepatic + renal failure — biliary sludging and pseudolithiasis

— Rifampin avoided in severe liver disease

— Moxifloxacin requires no hepatic adjustment generally but monitor for QT

Key distinction: Cefepime neurotoxicity can mimic worsening meningitis — new myoclonus or encephalopathy in a renally impaired patient on cefepime warrants EEG (often shows generalized periodic discharges) and dose reduction or switch to meropenem.

Elderly (>65 yr):

Renal impairment dosing adjustments:

Hepatic impairment:

Polypharmacy traps: Warfarin + ceftriaxone → ↑INR (displaces warfarin from albumin); vancomycin + piperacillin-tazobactam → ↑AKI risk; avoid combining if possible.

Special Populations — Pregnancy, Pediatrics, and Immunocompromised

— ↑ risk of Listeria (17× baseline) — counsel on deli meats, soft cheeses, unpasteurized dairy

— Empiric regimen: ceftriaxone + vancomycin + ampicillin (Category B, safe)

— Avoid moxifloxacin (fluoroquinolones generally avoided), TMP-SMX (1st and 3rd trimester risks), doxycycline

— Dexamethasone: use for indication (pneumococcal); benefits outweigh risks

— Meningococcal exposure prophylaxis: ceftriaxone 250 mg IM ×1 (preferred over cipro or rifampin in pregnancy)

— Pathogens: GBS, E. coli, Listeria

— Empiric: ampicillin + cefotaxime (or gentamicin)

— Avoid ceftriaxone in neonates with hyperbilirubinemia (displaces bilirubin from albumin → kernicterus) and with calcium-containing IV fluids

— LP often deferred until cardiorespiratorily stable, but full sepsis workup including CSF mandatory

— Ceftriaxone + vancomycin

— Dexamethasone before/with first antibiotic dose — strongest evidence for H. influenzae

— Audiology evaluation at discharge and 1 month (sensorineural hearing loss ~10–30%)

— Expand differential: cryptococcus, TB, CMV, toxoplasma, lymphoma

— Add ampicillin for Listeria

— Consider amphotericin + flucytosine if cryptococcal antigen positive

— Eculizumab/ravulizumab → meningococcus despite vaccination; maintain high suspicion

Step 3 management: A pregnant patient with fever, headache, and lymphocytic CSF pleocytosis with gram-positive rods → Listeria. Start ampicillin + gentamicin immediately; ceftriaxone alone is inadequate (cephalosporins have no activity against Listeria).

Pregnancy:

Neonates (<1 month):

Children 1 mo–18 yr:

Immunocompromised (HIV/AIDS, transplant, biologics):

Asplenic/complement deficient: Encapsulated organisms; ensure PCV20, MenACWY, MenB, Hib vaccination; consider daily penicillin prophylaxis in high-risk children.

Complications and Adverse Outcomes

— Cerebral edema and herniation — leading cause of early death

— Seizures (~25% pneumococcal); status epilepticus

— Stroke from septic vasculitis (especially MCA territory in pneumococcus)

— Cerebral venous sinus thrombosis

— Hydrocephalus (communicating from inflammatory exudate or obstructive)

— Subdural empyema, brain abscess, ventriculitis

— Cranial nerve palsies (CN VI, VII, VIII)

— Septic shock, DIC

— Waterhouse-Friderichsen syndrome — bilateral adrenal hemorrhage with meningococcemia → acute adrenal insufficiency; treat with stress-dose hydrocortisone 100 mg IV q8h

— ARDS

— AKI (sepsis, vancomycin)

— SIADH (~30%) — euvolemic hyponatremia; fluid restrict (avoid hypotonic fluids regardless)

— Sensorineural hearing loss (most common, ~14% overall, up to 30% in pneumococcal) — audiology at discharge and 4–6 weeks

— Cognitive impairment, memory deficits, executive dysfunction

— Epilepsy

— Focal motor/sensory deficits

— Behavioral changes in children; learning disabilities

— Vestibular dysfunction

— Pneumococcal: 20–30% adults

— Meningococcal: 10–15%, but >40% if septic shock or purpura fulminans

— Listeria: 15–30%, highest in elderly

— H. flu: 3–7%

Board pearl: Recurrent pneumococcal meningitis = look for a CSF leak (β2-transferrin testing of rhinorrhea/otorrhea, high-resolution CT of skull base). Recurrent meningococcal meningitis = test for terminal complement deficiency (C5–C9) with CH50.

Acute neurologic complications (within hours–days):

Systemic complications:

Long-term sequelae (~30–50% of survivors):

Mortality:

Recurrence: Consider CSF leak (basilar skull fx, dural defect), immunodeficiency (complement, IgG subclass), parameningeal focus (chronic mastoiditis, sinusitis).

When to Escalate — ICU, Consults, and Inpatient Triage

— GCS <12 or rapidly declining mental status

— Seizures

— Hemodynamic instability, septic shock, vasopressor requirement

— Respiratory failure or need for airway protection

— Focal neurologic deficits or signs of ↑ICP

— Purpura fulminans / DIC

— Need for ICP monitoring or EVD

— Infectious Disease — antibiotic stewardship, duration, resistance management

— Neurology — for seizures, focal deficits, EEG interpretation

— Neurosurgery — hydrocephalus, abscess, empyema, EVD, decompression

— ENT — mastoiditis, sinusitis, CSF leak workup

— Critical Care — ICU comanagement

— Audiology — hearing assessment before discharge

— Public Health / Infection Control — meningococcus reporting and contact tracing

— Ophthalmology — endophthalmitis if disseminated infection

CCS pearl: On CCS, even if the case starts in "ED," move location to ICU early once antibiotics, steroids, blood cultures, and LP are ordered. Continued ED location after stabilization is a common scoring miss.

ICU admission criteria — virtually all patients with confirmed/suspected bacterial meningitis initially, especially if:

Step-down/ward criteria: Hemodynamically stable, mentating appropriately, on appropriate antibiotics, no seizures × 24 hr, no progression of neuro findings.

Consultations to place on CCS:

Airway management: Intubate for GCS ≤8, inability to protect airway, refractory seizures, or impending herniation. Use RSI with cerebral protection (etomidate or ketamine + rocuronium); avoid succinylcholine if hyperkalemia or prolonged immobilization.

Transfer considerations: Community ED → tertiary center for neurosurgical capability, ICU bed availability, pediatric specialty care if applicable. Do not delay antibiotics for transfer — give first dose before ambulance leaves.

Key Differentials — Other Infectious Meningitides

— Enterovirus (most common, summer–fall), HSV-2 (recurrent — Mollaret), VZV, HIV (acute seroconversion), arboviruses (West Nile, EEE)

— CSF: lymphocytic pleocytosis (50–500), normal glucose, mildly elevated protein, negative Gram stain

— Generally benign, supportive care; PCR confirms

— Temporal lobe involvement → focal seizures, personality change, aphasia

— MRI: temporal hyperintensity

— CSF: lymphocytic, often RBCs, HSV PCR positive

— Treat acyclovir 10 mg/kg IV q8h × 14–21 days; start empirically if suspected

— Subacute (weeks), basilar meningitis with CN palsies, hydrocephalus, stroke

— CSF: lymphocytic (early may be neutrophilic), very high protein, very low glucose

— AFB smear low sensitivity; MTB PCR (Xpert MTB/RIF), culture; tuberculin/IGRA

— Treat RIPE × 2 months + adjunctive dexamethasone, then continuation phase

— Cryptococcus neoformans in HIV/transplant — indolent headache, fever; CSF: lymphocytic, ↑opening pressure, cryptococcal antigen positive, India ink

— Treat amphotericin B + flucytosine induction × 2 weeks, then fluconazole; serial therapeutic LPs for ICP

— Coccidioides (Southwest US), Histoplasma, Blastomyces

Key distinction: Neutrophilic CSF with low glucose = bacterial (or very early TB). Lymphocytic CSF with low glucose = TB, fungal, Listeria, or partially treated bacterial. Lymphocytic CSF with normal glucose = viral.

Viral (aseptic) meningitis:

HSV encephalitis:

Tuberculous meningitis:

Fungal meningitis:

Lyme meningitis: Bilateral facial palsy, radiculitis; lymphocytic CSF; serology + WB.

Syphilitic meningitis: Secondary or neurosyphilis; CSF VDRL; treat IV penicillin G 18–24 MU/day × 10–14 days.

Parasitic: Naegleria fowleri (freshwater, fulminant amoebic meningoencephalitis); cysticercosis.

Brain abscess: Focal deficits, ring-enhancing lesion on MRI; do NOT LP (herniation risk); surgical drainage + prolonged antibiotics.

Key Differentials — Non-Infectious Mimics

— Thunderclap "worst headache of life," meningismus from blood

— CT head sensitivity ~98% within 6 hours; LP shows xanthochromia and persistent RBCs across tubes

— CTA/DSA for aneurysm; neurosurgical/endovascular intervention

— May coexist with infection — don't miss either

— NSAIDs (especially ibuprofen, in SLE patients), TMP-SMX, IVIG, monoclonal antibodies (rituximab, OKT3), intrathecal agents

— CSF: neutrophilic or lymphocytic pleocytosis; resolves with discontinuation

— Neurosarcoidosis — basilar meningitis, CN palsies, hypothalamic dysfunction

— SLE meningitis

— Behçet disease — recurrent meningitis + oral/genital ulcers + uveitis

— Vogt-Koyanagi-Harada — meningitis + uveitis + vitiligo + alopecia

— Breast, lung, melanoma, lymphoma, leukemia

— CSF cytology, flow cytometry; MRI shows leptomeningeal enhancement

— Treat intrathecal chemotherapy ± radiation

Board pearl: A patient with SLE on ibuprofen presenting with fever, headache, and neutrophilic CSF pleocytosis but negative Gram stain and cultures = NSAID-induced aseptic meningitis. Stop the NSAID; symptoms resolve in 1–7 days. Treat empirically for bacterial meningitis until cultures finalize.

Subarachnoid hemorrhage:

Migraine with aura: Recurrent stereotyped headaches, photophobia, nausea — but no fever, no CSF abnormality.

Drug-induced aseptic meningitis:

Autoimmune/inflammatory:

Carcinomatous/lymphomatous meningitis:

Chemical meningitis: Ruptured dermoid/epidermoid cyst, intrathecal contrast, post-spinal anesthesia.

Hypertensive encephalopathy / PRES: Severe hypertension, occipital deficits, posterior white matter edema on MRI.

Sepsis/septic encephalopathy without CNS infection: Altered mentation from systemic infection; CSF normal.

Heat stroke, serotonin syndrome, NMS: Fever + altered mentation + autonomic instability — but rigidity, hyperreflexia, drug history differentiate.

Secondary Prevention, Discharge Medications, and Long-Term Plan

— PCV20 (or PCV15 followed by PPSV23) for all adults post-pneumococcal meningitis and for ≥65 yr, asplenic, immunocompromised, CSF leak

— MenACWY + MenB for post-meningococcal infection, asplenic, complement-deficient, eculizumab users, college freshmen in dorms, military, microbiologists, travelers to meningitis belt

— Hib for unvaccinated children and asplenic patients

— Annual influenza + COVID — reduce upstream respiratory infections

— Meningococcus: rifampin × 2 days, OR ciprofloxacin ×1, OR ceftriaxone IM ×1 (pregnancy)

— Hib: rifampin × 4 days for unvaccinated household contacts <4 yr or immunocompromised

— CSF leak evaluation (β2-transferrin) if recurrent or post-trauma

— Sinus/mastoid CT if otitis or sinusitis was source — ENT follow-up for surgical correction

— Echocardiogram if persistent bacteremia or new murmur → endocarditis seeding

— HIV test, immunoglobulin levels, CH50/complement workup for recurrent cases

— Complete IV antibiotic course (may transition to OPAT via PICC for prolonged regimens)

— Levetiracetam if seizures occurred

— Acetaminophen for residual headache; avoid NSAIDs if drug-induced meningitis suspected

— Vaccines administered before discharge documented

Step 3 management: Every patient discharged after pneumococcal meningitis should leave with PCV20 administered or scheduled, audiology appointment in 4–6 weeks, and ID follow-up for antibiotic completion review. Missing the vaccine on discharge is a classic Step 3 transitions-of-care error.

Vaccination after meningitis (close discharge counseling):

Chemoprophylaxis for close contacts (initiated by ED/inpatient team or public health):

Source workup before discharge:

Discharge medication checklist:

Public health reporting: Bacterial meningitis (especially meningococcus and H. flu) is reportable to local health department — typically within 24 hours.

Follow-Up, Monitoring, and Rehabilitation

— Daily neurologic exam, GCS trend

— CBC, CMP, vancomycin trough/AUC every 2–3 days

— Repeat LP at 48 hours if: not improving, ceftriaxone-resistant pneumococcus, gram-negative bacilli, or immunocompromised

— Follow-up blood cultures at 48–72 hr to confirm clearance

— Daily fever curve; persistent fever >72 hr → look for complication (abscess, empyema, drug fever, DVT, nosocomial infection)

— Primary care: 1–2 weeks

— Infectious Disease: 2 weeks to confirm antibiotic completion and clinical response

— Audiology: at discharge baseline, and 4–6 weeks (sensorineural hearing loss often delayed)

— Neurology: 4–6 weeks if seizures, focal deficits, or cognitive concerns

— Neuropsych testing at 3–6 months if cognitive complaints

— Pediatric developmental assessment at 1, 3, 6, 12 months for infants/young children

— PT/OT for motor deficits, deconditioning from prolonged ICU stay

— Speech-language pathology for aphasia, dysphagia, cognitive-communication

— Cochlear implant evaluation if profound bilateral hearing loss

— Vocational rehabilitation if cognitive sequelae affect work

— Hearing loss may evolve over weeks; report any auditory change immediately

— Seizure precautions: driving restrictions per state law (typically seizure-free 3–12 months)

— Vaccination of household contacts and updating own vaccines

— Mental health: depression/PTSD common after critical illness; screen at follow-up

CCS pearl: Schedule "audiology in 4 weeks" and "ID follow-up in 2 weeks" as outpatient orders on CCS discharge — these are commonly missed but high-value scoring items.

Inpatient monitoring while on therapy:

Post-discharge follow-up cadence:

Rehabilitation needs:

Counseling topics:

Quality metrics tracked: Door-to-antibiotic time, dexamethasone administered before/with antibiotics, vaccination at discharge, audiology referral, ID follow-up arranged.

Ethical, Legal, and Patient Safety Considerations

— Bacterial meningitis (especially meningococcal and Hib) is legally reportable to state/local health departments, typically within 24 hours

— HIPAA permits disclosure to public health authorities without patient consent for disease surveillance and contact tracing

— Failure to report can result in physician licensure action

— LP in an altered, unconsentable patient → implied/emergency consent applies (treatment necessary to prevent serious harm); document medical decision-making

— Surrogate decision-maker hierarchy (spouse → adult child → parent → sibling) when patient lacks capacity

— Pediatric meningitis with Jehovah's Witness parents refusing blood products → emergent court order if life-threatening; do not delay antibiotics or LP

— Notify close contacts and offer chemoprophylaxis — duty to warn supersedes individual privacy for communicable disease

— School/daycare/dorm/military barracks notification through public health channels

— Antibiotic continuation errors at discharge are a top sentinel event — ensure OPAT setup, PICC care instructions, and pharmacy reconciliation

— Medication reconciliation including new anti-epileptics, vaccines administered, and removal of empiric drugs no longer needed

— Communicate audiology and ID follow-up to PCP via discharge summary within 48 hr

— Document close exposure (intubation, suctioning, mouth-to-mouth) → offer chemoprophylaxis to staff

— Routine bedside care without respiratory secretion contact does not warrant prophylaxis

— Devastating neurologic outcomes (severe anoxic injury, herniation) may prompt goals-of-care discussion; involve palliative care early

— Brain death determination if applicable — follow institutional protocol (apnea test, ancillary studies)

— Door-to-antibiotic <60 min as institutional QI metric

— Dexamethasone before/with antibiotics — pharmacy hard-stop alerts reduce miss rate

Board pearl: A college freshman dies of meningococcal meningitis; the roommate refuses prophylaxis citing autonomy. You must still report to public health for contact tracing, but you cannot force the roommate to take antibiotics — autonomy is preserved, but document the offer and education provided.

Mandatory public health reporting:

Informed consent edge cases:

Vaccination and contact tracing:

Transition-of-care safety:

Healthcare worker exposure:

End-of-life/goals of care:

Patient safety bundles:

High-Yield Associations and Rapid-Fire Clinical Facts

— College dorm, military barracks, petechial rash → N. meningitidis

— Pneumonia, otitis, sinusitis, asplenia, sickle cell → S. pneumoniae

— Pregnant + soft cheese, deli meat, >50yo + alcohol → Listeria

— Unvaccinated child, epiglottitis history → H. influenzae type b

— Neonate, rectovaginal colonization → GBS, E. coli K1

— Post-neurosurgery, shunt → Staph aureus, coag-neg staph, gram negatives

— Freshwater swimming, nasal exposure → Naegleria fowleri

— PMN + low glucose + ↑↑ protein + ↑ opening pressure = bacterial

— Lymph + normal glucose + mild ↑ protein = viral

— Lymph + low glucose + very high protein = TB or fungal

— Lymph + low glucose + gram-positive rods = Listeria

— Dexamethasone before or with first antibiotic — not after

— Ceftriaxone alone misses Listeria; always add ampicillin if >50yo, pregnant, immunocompromised

— Vancomycin added for ceftriaxone-resistant pneumococcus

— Cefepime in renal failure → neurotoxicity

— Ceftriaxone in neonates → bilirubin displacement, calcium precipitation

— Meningococcus → Waterhouse-Friderichsen, purpura fulminans, DIC

— Pneumococcus → hearing loss, hydrocephalus, stroke

— H. flu → subdural effusions in children

— Meningococcus contacts: rifampin, cipro, or ceftriaxone (pregnancy)

— Hib contacts: rifampin

— Eculizumab users: meningococcal vaccine + chronic penicillin

— Classic triad sensitivity ~44% — absence does NOT rule out

— Kernig/Brudzinski sensitivity ~5–30% — low!

— Jolt accentuation more sensitive

Key distinction: "Worst headache of life" alone → SAH first. "Worst headache of life" + fever + neck stiffness → bacterial meningitis. Both can coexist; CT then LP for xanthochromia and CSF cell counts will sort them out.

Pathogen ↔ buzzword matching:

CSF profile shortcuts:

Drug pearls:

Complications by pathogen:

Prophylaxis cheats:

Sensitivities to remember:

Board Question Stem Patterns

CCS pearl: When a stem asks "most appropriate next step" in a patient with classic findings, the answer is almost always empiric antibiotics + dexamethasone before LP and CT — not "obtain LP first."

Stem 1 — Classic adult pneumococcal: 58yo with recent otitis media, now fever, confusion, neck stiffness. Next step? → Blood cultures + dexamethasone + ceftriaxone + vancomycin, then CT, then LP.

Stem 2 — Elderly with Listeria risk: 72yo alcoholic, fever, AMS, ataxia. CSF: lymphocytic with gram-positive rods. Best therapy? → Ampicillin + gentamicin (add ceftriaxone for empiric coverage until pathogen confirmed).

Stem 3 — Eculizumab patient: 30yo on eculizumab for aHUS, fever, headache. Most likely organism? → N. meningitidis despite prior vaccination.

Stem 4 — Petechial rash + shock: 19yo college freshman, dorm, petechiae, hypotension. Next step? → Empiric ceftriaxone + vancomycin + dexamethasone + IV fluids + vasopressors; droplet isolation; contact prophylaxis. Adrenal hemorrhage → stress-dose hydrocortisone.

Stem 5 — Recurrent meningitis: 25yo, third episode of pneumococcal meningitis. Workup? → Look for CSF leak: β2-transferrin of any rhinorrhea, high-resolution CT skull base.

Stem 6 — Recurrent meningococcal: 22yo, second meningococcal episode. Workup? → Terminal complement deficiency (CH50, C5–C9).

Stem 7 — Contact prophylaxis: Roommate of meningococcal patient is pregnant. Best prophylaxis? → Ceftriaxone 250 mg IM ×1.

Stem 8 — When to image first: 65yo immunocompromised, papilledema, focal deficits. Next step? → Blood cultures, empiric antibiotics + dexamethasone, THEN CT, THEN LP.

Stem 9 — Drug-induced: 28yo SLE on ibuprofen, neutrophilic CSF, negative cultures. Diagnosis? → NSAID-induced aseptic meningitis.

Stem 10 — Discharge planning: Survivor of pneumococcal meningitis. Best next step pre-discharge? → Audiology evaluation + PCV20 vaccination + ID follow-up.

Stem 11 — Neonatal: 2-week-old, lethargy, fever, bulging fontanelle. Empiric? → Ampicillin + cefotaxime (avoid ceftriaxone in neonates).

Stem 12 — CCS sequencing: Always: blood cultures → dexamethasone + antibiotics → CT (if indicated) → LP → ICU.

One-Line Recap

Bacterial meningitis is a time-critical neurologic emergency where the correct CCS-style sequence — blood cultures, then dexamethasone with empiric ceftriaxone + vancomycin (plus ampicillin in >50yo, pregnant, alcoholic, or immunocompromised), then CT if indicated, then LP, then ICU — saves lives, and missing the steroid timing or the Listeria coverage is the dominant board-failure pattern.

Recap 1 — Door-to-antibiotic <60 min: Never delay antibiotics for CT or LP; cultures and steroids first, then drugs, then imaging, then tap.

Recap 2 — Empiric coverage tiered by age/host: Ceftriaxone + vancomycin for all adults; add ampicillin for >50yo, pregnant, alcoholic, or immunocompromised (Listeria); add cefepime/meropenem + vancomycin for post-neurosurgery (Pseudomonas + MRSA).

Recap 3 — Dexamethasone must precede or coincide with the first antibiotic dose for pneumococcal meningitis; it reduces mortality and hearing loss but is useless if given late. Continue 4 days only if pneumococcus confirmed.

Recap 4 — Discharge transitions: Audiology evaluation, PCV20/MenACWY vaccination, ID follow-up in 2 weeks, contact chemoprophylaxis for meningococcus (rifampin/cipro/ceftriaxone IM in pregnancy), and mandatory public health reporting within 24 hours.

Recap 5 — Recurrence workup: Recurrent pneumococcal = CSF leak (β2-transferrin); recurrent meningococcal = terminal complement deficiency (CH50).

Recap 6 — Highest-yield trap: Cephalosporins do not cover Listeria — forgetting ampicillin in the right host kills the patient and the question.