bacterial meningitis

1. Case presentation
Elisenda Valdez, MD
PGY-2, Internal Medicine
2/15/2023

2. Case
• 67-year-old M, presented to ED from his nursing facility with a 3-day history of
worsening confusion and somnolence. Prior to this, he also complained of
intermittent headaches, subjective fevers and dry cough for 1 week. None of his
friends/contacts at the nursing home have reported any signs or symptoms of
illness, but his 10-year-old grandson who visited last week was recently
diagnosed with pneumonia. He currently denies chest pain, palpitations,
abdominal pain, nausea or vomiting.
• PMH: HTN, HLD, DM.
• Social Hx: denies alcohol/smoking/drugs.
• Allg: NKDA
• Medications: Amlodipine, Lipitor, Metformin.
2/15/2023

3. physical exam
• VS: T 38C, BP 110/73, HR 105, RR 18, 95% SpO2 on 2L nc
• General: ill-appearing, AO x 1, appears uncomfortable.
• HEENT: +Nuchal rigidity with limited movement of neck laterally. Kernig’s sign (–);
(–) Brudzinski’s sign.
• CV: RRR, tachycardic. No murmurs.
• Pulm: R basilar rales, on 2L nc.
• Abd: soft, NT/ND. + BS.
• MSK: unremarkable.
• Neuro: Following simple commands, Sensation/muscle strength intact in all ext.
2/15/2023

4. Labs findings • BMP: NA 135 mmol/L, K 3.3 mmol/L, Creat 0.90 mg/dL, BUN 11 mg/dL,
glucose 120 mg/dL.
• Lactate: 2.5 mmol/L
• LFT’s wnl
• Ammonia wnl
• Thyroid function test: wnl
• UA: unremarkable
• UDS: unremarkable
• Flu/COVID: neg
• Imaging:
CXR: Evidence of LLL infiltrate.
CTH: unremarkable for acute disease.
Admitted for sepsis and acute metabolic encephalopathy secondary to PNA.
Started on Vancomycin/Zosyn.
2/15/2023
Hgb 15 g/dL
RBC 5 T/L
PLT 263 B/L
WBC 16 B/L
Neutrophils % 75%
Eosinophils % 7 %
Basophils 3 %
Lymphocytes 20 %
Monocytes 5 %

5. Day 3
• Persistently febrile, 102.1 F and no improvement on mental status.
• BCx still in process.
• Sputum Cx revealed Strep pneumo
• Repeat CXR: unchanged from prior.
• CT chest: evidence of LLL infiltrate and small L pleural effusion.
• CT A/P: unremarkable.
• Given suspicion for meningitis, antibiotics changed to vanc/Ceftriaxone/Ampicillin
and Acyclovir.
• ID evaluation: Recommends MRI, cont antibiotics and obtain LP.
2/15/2023

6. Day 4
• MRI: minimal diffuse leptomeningeal enhancement, concerning for meningitis.
• BCx : + Strep pneumo
• LP:
• HSV, West Nile virus studies pend.
• Bacterial Pneumococcal meningitis suspected. Acyclovir and Ampicillin discontinued. IV
ceftriaxone 2g was continued and IV dexamethasone started.
• After a few days CSF culture revealed S. pneumoniae.
Opening pressure 23 cm H20
CSF protein 371 mg/dL
CFS glucose 35 mg/dL
CFS RBC 75/uL
CSF cell count 2100 uL
CFS WBC 2700/uL
CSF Neutrophils 77 %
CSF lymphocytes 75%
CSF Eosinophils 5%

7. • His condition clinically improved after a few days and mental status back
to baseline.
• He was discharged after completing IV ceftriaxone for 14 days and IV
dexamethasone for 4 days.
2/15/2023

8. Acute bacterial
meningitis
2/15/2023

9. • Inflammatory disease of the
meninges and is characterized
by an abnormal number of
white blood cells (WBCs) in the
cerebrospinal fluid (CSF) in the
majority of patients.
2/15/2023

10. • Community acquired
o Streptococcus pneumoniae
o Neisseria meningitidis
o Listeria monocytogenes
• Health care associated
o staphylococci and aerobic gram-negative bacilli (occur more commonly after neurosurgical
procedures)
2/15/2023

11. Mechanisms for developing meningitis
• Colonization of the nasopharynx
• Invasion of the CNS following bacteremia due to a localized source
• Direct entry of organisms into the CNS from a contiguous infection
2/15/2023

12. Clinical manifestations
• Classic triad: fever, nuchal rigidity, and a
change in mental status.
• Less common manifestations:
o Seizures
o Aphasia
o Hemi- or monoparesis
o Coma
o Cranial nerve palsy
o Rash
o Papilledema
2/15/2023

13. • The Brudzinski sign refers to
spontaneous flexion of the hips during
attempted passive flexion of the neck.
• The Kernig sign refers to the inability or
reluctance to allow full extension of the
knee when the hip is flexed 90 degrees.
• Low sensitivity and high specificity.
Therefore, a negative test does not
exclude the presence of meningitis.
2/15/2023

14. LABORATORY
• CBC
• BMP
• Coagulation studies
• Blood cultures
• CT scan
o Indications for CT scan prior to LP : Immunocompromised state, H/o CNS disease, New
onset seizure, Papilledema, change in mental status, focal neurologic deficits.
• Lumbar puncture
2/15/2023

15. CSF studies
• CSF cell count is elevated, neutrophilic
predominance.
• Decreased glucose.
• Increased protein.
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16. Treatment
• Most common empiric therapy :
Vancomycin, Ceftriaxone and
Ampicillin. *Acyclovir for HSV ppx.
• Therapy should be directed at the
most likely bacteria based on the
patient's age and host factors.
• IV dexamethasone- associated with a
decrease of neurologic complications
as well as mortality if given before or
at the same time as of antibiotics.
2/15/2023

17. Prognosis
• Life-threatening condition if not treated.
• The mortality rate of bacterial meningitis increases linearly with increasing age specially after ≥65
years of age.
• Associated neurologic complications :
o Seizures
o Focal neurologic deficits (eg, cranial nerve palsy, hemiparesis)
o Cerebrovascular abnormalities
o Sensorineural hearing loss
o Intellectual disability
2/15/2023

18. Thank you
2/15/2023