Course of Disease of Meningitis
Bacterial meningitis is characterized by a rapid progression of symptoms that can lead to significant morbidity and mortality, with half of adults developing focal neurological deficits and one-third developing hemodynamic or respiratory insufficiency during the clinical course. 1
Initial Presentation
The classic triad of fever, neck stiffness, and altered mental status is present in less than 50% of bacterial meningitis cases 1, 2
Common presenting symptoms include:
- Fever (77-97%)
- Headache (58-87%)
- Neck stiffness (65-83%)
- Altered mental status (30-69%)
- Nausea/vomiting (45-74%)
- Rash (20-52%, particularly in meningococcal disease)
- Focal neurological deficits (15-34%) 2
Meningococcal disease specifically presents in three main patterns:
- Meningitis (60% of patients)
- Shock/fulminant sepsis with or without meningitis (10-20%)
- Mild disease with fever and rash without meningitis or shock (up to 30%) 1
Disease Progression
Acute Phase (Hours to Days)
- Rapid deterioration can occur within hours of symptom onset
- Neurological complications develop frequently:
- Decreased mental status
- Focal neurological deficits
- Seizures
- Hydrocephalus 1
- Systemic complications include:
- Shock (particularly in meningococcal disease)
- Respiratory insufficiency
- Sepsis 1
Complications During Hospitalization
- Cerebrovascular complications are common:
- Cerebral infarctions
- Subarachnoid hemorrhage
- Intracranial hemorrhage
- Venous sinus thrombosis 1
- Space-occupying lesions may develop:
- Subdural empyema
- Brain abscess
- Hydrocephalus (obstructive or communicating) 1
Mortality and Prognosis
- Overall mortality for bacterial meningitis is approximately 20%, increasing with age 1
- Mortality varies by pathogen:
- Streptococcus pneumoniae: 30-58%
- Neisseria meningitidis: 7%
- Listeria monocytogenes: up to 100% in elderly patients
- Gram-negative bacilli: 83% in elderly patients 2
Long-Term Sequelae
One-third of survivors develop persistent complaints 1
Common sequelae in children (median follow-up 24 months):
Common sequelae in adults:
Specific Considerations for Different Types of Meningitis
Tuberculous Meningitis
- Before effective chemotherapy, it was uniformly fatal
- Remains a devastating disease with high morbidity and mortality despite prompt treatment
- Patients with more severe neurologic impairment (drowsiness, obtundation, coma) have greater risk of sequelae and higher mortality 1
Viral Meningitis
- Generally self-limited with better prognosis than bacterial meningitis
- Still can cause significant morbidity including fatigue, sleep disorders, and emotional difficulties in the weeks and months after discharge 1
Post-Discharge Course
- Follow-up care is essential as many issues only become apparent after discharge
- Patients, family members, and caregivers should be informed about potential sequelae 1
- Hearing evaluation should be performed during admission or within 4 weeks of recovery 1
- Patients may experience:
- Fatigue and sleep disorders
- Emotional difficulties
- Headaches (up to one-third of patients)
- Arthritis, limb pain, muscle pain, and neuropathic pain 1
Key Pitfalls to Avoid
- Delaying antibiotic administration, which worsens outcomes 2
- Failing to recognize atypical presentations, especially in elderly patients 2
- Underestimating severity in young patients 2
- Relying on Kernig's and Brudzinski's signs, which have low sensitivity 2
- Missing the diagnosis in patients without the classic triad of symptoms 2
The course of bacterial meningitis requires vigilant monitoring and prompt intervention to improve outcomes. Early recognition of complications and appropriate management are crucial to reducing mortality and long-term neurological sequelae.