What are the symptoms and treatment of meningitis?

Meningitis Symptoms and Treatment

Clinical Presentation

Bacterial meningitis presents with variable and often incomplete symptom patterns, making clinical diagnosis challenging—the classic triad of fever, neck stiffness, and altered mental status appears in only 41-51% of adult cases, so absence of these findings cannot exclude the diagnosis. 1

Common Symptoms in Adults

• Headache: Present in 58-87% of cases 1, 2
• Fever (>38.0°C): Occurs in 77-97% of cases 1, 2
• Neck stiffness: Present in 65-83% of cases 1, 2
• Altered mental status: Reported in 30-69% of cases 1, 2
• Nausea/vomiting: Occurs in 74% of cases 1
• Rash: Identified in 20-52% of adult patients; when present, indicates meningococcal infection in over 90% of cases 1, 2

Critical Diagnostic Considerations

At least 95% of patients will have two or more of these four cardinal symptoms: fever, nuchal rigidity, altered mental status, and headache. 3

• Kernig and Brudzinski signs have extremely poor sensitivity (11% and 9% respectively in adults) and should not be relied upon for diagnosis 1
• The sensitivity of neck stiffness alone is only 31% in adults 1, 2
• Classic symptoms may be completely absent, particularly in elderly patients who are more likely to have altered consciousness and less likely to have neck stiffness or fever 1

Age-Specific Variations

• Neonates present with nonspecific symptoms: irritability, poor feeding, respiratory distress, pale or marble skin, and hyper- or hypotonia; fever is present in only 6-39% of neonatal cases 2
• Children beyond neonatal age: fever is most common (92-93%), with headache in 75% of children older than 5 years 2
• The younger the patient, the more subtle and atypical the symptoms 2

Treatment Approach

Immediate Management

All patients with suspected meningitis require immediate hospital referral via emergency ambulance, with the goal of arrival within one hour of community assessment. 1

Empiric antibiotic therapy must be initiated immediately without waiting for diagnostic confirmation, as mortality remains high in untreated bacterial meningitis. 4

Empiric Antibiotic Regimen

The standard empiric treatment consists of vancomycin plus ceftriaxone plus dexamethasone. 3

• Ceftriaxone dosing for adults: 2 grams IV every 12 hours (total daily dose 4 grams maximum) for meningitis 5
• Ceftriaxone provides coverage for the most common bacterial pathogens: Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae 5
• Vancomycin is added to cover resistant S. pneumoniae 3
• Dexamethasone reduces inflammatory response in the subarachnoid space 6, 3

Special Populations

• Neonates: Ceftriaxone is contraindicated in neonates ≤28 days, especially premature or hyperbilirubinemic infants; if used, administer IV doses over 60 minutes to reduce risk of bilirubin encephalopathy 5
• Elderly and immunocompromised patients: Consider Listeria monocytogenes coverage with ampicillin added to the empiric regimen 1

Diagnostic Workup

Cerebrospinal fluid examination via lumbar puncture is essential for definitive diagnosis when bacterial meningitis is suspected. 2

• Head CT prior to lumbar puncture may not be necessary in most patients 3
• CSF findings in bacterial meningitis: pleocytosis with neutrophil predominance (80-95%), elevated protein, and low glucose with CSF/plasma glucose ratio typically <0.5 2, 7
• Blood cultures should be obtained before antibiotics, but antibiotic administration should never be delayed 1

Duration and Monitoring

• Therapy should continue for at least 2 days after signs and symptoms resolve 5
• Usual duration is 7-14 days; complicated infections may require longer therapy 5
• For Streptococcus pyogenes infections, continue therapy for at least 10 days 5

Common Pitfalls

The most critical error is ruling out meningitis based on absence of classic symptoms—bacterial meningitis should not be excluded solely on the absence of fever, neck stiffness, or altered mental status. 1

• Do not rely on Kernig or Brudzinski signs to exclude meningitis due to their extremely low sensitivity 1
• Never delay antibiotics while awaiting lumbar puncture or imaging studies 4
• Septic shock may be present in approximately 25% of cases, requiring aggressive fluid resuscitation and vasopressor support 2
• Concern from the referring physician or family members should always be taken seriously, even when classic signs are absent 1