Outcome for Meningitis and Ventriculitis in Children

Bacterial Meningitis

• 3–20% mortality rate: Before the advent of antibiotics, bacterial meningitis was uniformly fatal. With modern antibiotic therapy, the mortality rate from bacterial meningitis in children in the United States is now 3–20%, with a higher rate for neonates and adults. The mortality rate for H. influenzae type b meningitis in the United States is only 6%, compared to 20% in the developing world. In the United States, the mortality rate for S. pneumoniae meningitis is about 20% (only 5% for neonates) and for N. meningitidis meningitis is 3%, while the mortality rate for E. coli meningitis is around 20%.
• Neonates with gram-negative meningitis do worst: It appears that neonates with meningitis caused by gram-negative bacteria have worse outcomes, with higher incidence of ventriculitis, hydrocephalus, and brain abscesses (8).
• Serious sequelae possible: [10]In patients surviving bacterial meningitis, serious sequelae, as discussed on the Medical Treatment page, may occur (13, 20).
• Hearing loss: The most common complication of meningitis is sensorineural hearing loss, occurring in about 10 % of patients (25). It is most common in patients with meningitis due to S. pneumoniae (31%), as compared to N. meningitidis (11%) or H. influenzae (6%), and is most closely correlated with initial CSF glucose levels below 20 mg/dl. Hearing loss is usually present in presentation. Children with meningitis should have an initial hearing test before discharge; and if it is normal, no further testing is indicated. If hearing loss is demonstrated, repeat testing should be performed, as up to one-third of patients may improve over 6 months.
• Subdural effusions: Subdural effusions are common in patients with meningitis, occurring in 25% of patients, especially in neonates. In these patients, ultrasound may be used to follow these collections, which generally resolve within a few weeks or months (75).
• Subdural empyema: Subdural empyema may be a complication of bacterial meningitis, occurring most commonly in patients under the age of 5 years. Empyema should be suspected in any child who has focal neurological signs or who appears disproportionally ill compared to the CT or MRI scan, which may demonstrate enhancement of the subdural fluid collection. Subdural empyema requires immediate surgical intervention, most commonly via craniotomy to more thoroughly remove the thick purulent material in the subdural space.
• Hydrocephalus: Hydrocephalus is an uncommon complication of bacterial meningitis in children but is more common in neonates. Communicating hydrocephalus may develop more slowly, but obstructive hydrocephalus or loculated hydrocephalus may develop more rapidly and require urgent surgical intervention.
• Neurological injury: Severe neurological deficits including hemiplegia and mental retardation are relatively uncommon, occurring in only 4% of patients who have had meningitis. However, in neonates with meningitis, the percentage is higher, reflecting the fragility of the developing brain. Any suggestion of focal neurological signs should be investigated with an imaging study, either CT or MRI scans, or cranial ultrasound in infants (33, 75).

Tuberculous Meningitis

• 50% incidence of death or serious disability: Even with timely initiation of antituberculous therapy, there is still a greater than 50% chance of death or significant disability. Administration of corticosteroids decreases the mortality risk (52).
• Vasculitis and infarct: The outcome for patients with tuberculous meningitis is determined mainly by the development of cerebral infarction due to vascular occlusion.
• Hydrocephalus: Hydrocephalus may develop secondary to basal meningitis.
• Worse in children: In one study, only 20% of children with tuberculous meningitis recovered completely, with 80% either dead or with significant disability (37).
• Highest mortality rates in young children and elderly: The mortality rate is highest in children under 5 years of age and in adults over 50 years of age, as well as in those with symptoms of greater than 2-month duration (29).
• 63% mortality rate in HIV-positive patients: In one study, HIV infection has a profound effect on outcome, with a mortality rate of 63% in HIV-positive patients and only 17% in HIV-negative patients (12).
• Significant neurological sequelae in survivors: Significant neurological deficits, including hemiplegia, paraplegia, quadriplegia, aphasia, and visual loss, are common among survivors of tuberculous meningitis.

Viral Meningitis

• Good outcome: The outcome of viral meningitis is in general quite favorable, with infants and children making excellent recovery and experiencing minimal neurocognitive consequences. Sequelae are much rarer in patients with viral meningitis than in those with bacterial meningitis, especially in infants younger than 3 months. Even in patients with more severe neurological signs and symptoms, such as seizures, elevated ICP, or even coma, recovery was rapid and with no longterm sequelae. Infants older than 3 months at the time of infection did slightly worse in contrast to patients with bacterial meningitis.
• Mild cognitive sequelae in infants < 3 months: In infants younger than 3 months of age at time of infection, there is a slightly higher chance of mild neurocognitive deficits, and neuropsychological testing may help to identify children who would benefit from developmental therapies.

Fungal Meningitis

• Complicated infections: Complications of fungal meningitis include focal CNS infection, and refractory infection in the immunocompromised host (65).
• Increased ICP: Increased ICP with or without hydrocephalus may occur with fungal meningitis, and this may require serial lumbar punctures or even shunting,
• Outcome related to reason for susceptibility to infection: The outcome for patients with fungal meningitis is largely dependent on the underlying cause. Neonates who develop Candidal meningitis and are treated promptly may make excellent recoveries. In one recent series, although 35% of infants with Candida meningitis died, in only 12% of the total patients could death be related to the meningitis, as these infants died prior to the initiation of therapy of overwhelming sepsis (26). The remainder died of systemic complications of prematurity or bacterial sepsis, and no evidence of fungal disease was apparent at the time of death. Patients with HIV require lifelong maintenance therapy with fluconazole to prevent relapse.

Ventriculitis

• Cognition: In patients with ventriculitis due to shunt infection, the cognitive consequences can be quite severe, particularly after gram-negative infection.
• Multiloculated hydrocephalus: Multiloculated hydrocephalus is common, requiring multiple surgical procedures to try to maintain communication of the various CSF cavities, often requiring ventriculoscopic procedures, and ultimately multiple shunt catheters.
• See discussion in Shunt Infection and Postoperative Wound Infection chapters