What is the incidence of seizures in meningitis?

From the Guidelines

Seizures occur in approximately 15% of patients with acute bacterial meningitis. The incidence of seizures in meningitis is a significant concern, as it is associated with a worse outcome 1. The pathophysiology involves direct irritation of the cerebral cortex by inflammatory mediators, cerebral edema, vasculitis, and metabolic disturbances such as hyponatremia.

Key Points to Consider

• The clinical presentation of meningitis can vary, and seizures may be the presenting symptom in some cases, particularly in children.
• Patients with pneumococcal disease are more likely to have seizures, focal neurological symptoms, and a reduced conscious level 1.
• The management of seizures in meningitis involves prompt recognition and treatment, as well as addressing the underlying infection.
• Anticonvulsant treatment should be started promptly even when seizures are suspected but not proven 1.

Important Considerations for Management

• Control of raised intracranial pressure is essential to prevent mortality, although the best approach to achieving this is still unclear 1.
• Measures such as achievement of normal to elevated MAP, control of venous pressure, head elevation, avoidance of hyperthermia and hyponatraemia, and maintenance of normocarbia and normoglycaemia may be considered 1.
• Patients with suspected or proven status epilepticus should have EEG monitoring 1.

From the Research

Incidence of Seizures in Meningitis

• The incidence of seizures in meningitis varies across different studies, with reported frequencies ranging from 13% to 37.4% 2, 3.
• A study published in 1992 found that seizures were a presenting manifestation in 13% of patients with bacterial meningitis 2.
• Another study published in 2005 reported that 27% of adult patients with community-acquired bacterial meningitis experienced seizures during their hospitalization 4.
• A study published in 1985 found that seizures occurred in 27% of patients with acute bacterial meningitis, with most seizures beginning on the first or second day of illness 5.
• A more recent study published in 2021 reported a seizure prevalence of 37.4% in children with acute bacterial meningitis, with the majority of seizures occurring in children under the age of 5 years 3.
• A 2024 study on pneumococcal meningitis found that 24.4% of patients developed acute symptomatic seizures, with more than half of these seizures occurring before admission 6.

Risk Factors and Outcomes

• Seizures in meningitis are associated with a poorer outcome, including increased risk of death, disability, and neurological complications 4, 5, 3.
• Factors such as age, fever, and the presence of neurological complications increase the risk of seizures in meningitis 5, 3.
• The use of antiseizure medication prophylaxis may be effective in preventing seizure development in patients with pneumococcal meningitis, particularly when administered within 4 hours of admission 6.
• Seizure development is associated with increased risks of intensive care unit admission, orotracheal intubation, and longer hospital stays 6.