What is meningoencephalitis?

From the Guidelines

Meningoencephalitis is an inflammatory process that affects both the brain and the meninges, leading to a combination of symptoms of encephalitis and meningitis.

Key Features

• Meningoencephalitis is characterized by the presence of fever, headache, altered level of consciousness, and signs of meningeal irritation, such as neck stiffness and photophobia 1.
• The condition can present with a range of symptoms, including seizures, focal neurologic signs, and behavioral changes 1.
• The diagnosis of meningoencephalitis is often made based on a combination of clinical features, laboratory tests, and imaging studies, such as MRI or CT scans 1.

Causes and Associations

• Meningoencephalitis can be caused by a variety of infectious agents, including viruses, bacteria, and fungi 1.
• The condition can also be associated with non-infectious causes, such as autoimmune disorders and post-infectious or post-immunization encephalitis 1.
• Certain viruses, such as herpes simplex virus (HSV) and enteroviruses, are commonly associated with meningoencephalitis 1.

Diagnostic Approach

• The diagnostic approach to meningoencephalitis typically involves a combination of clinical evaluation, laboratory tests, and imaging studies 1.
• Lumbar puncture (LP) is an essential investigation in the management of patients with suspected meningoencephalitis, as it can help to confirm the diagnosis and identify the underlying cause 1.
• EEG and MRI may also be useful in the diagnosis and management of meningoencephalitis, particularly in cases where the diagnosis is unclear or the patient is not responding to treatment 1.

From the Research

Definition and Characteristics of Meningoencephalitis

• Meningoencephalitis is a critical medical condition characterized by inflammation in both the meninges and brain parenchyma 2.
• It can be caused by bacterial, viral, or fungal infections, as well as noninfectious factors such as autoimmune causes 2, 3, 4.
• The condition is associated with a range of symptoms, including headache, fever, nausea, vomiting, meningism, and qualitative or quantitative disturbances of consciousness 4.

Diagnosis and Treatment

• Diagnosis of meningoencephalitis typically involves lumbar puncture, cell count, and cell picture to differentiate between various forms of inflammation 3.
• Early selective treatment is extremely important, with immediate antibiotic treatment required for bacterial meningoencephalitis and acyclovir administration for suspected herpes encephalitis 3.
• New diagnostic methods, including multiplex PCR and next-generation sequencing techniques, allow for faster differential diagnosis of infectious causes 5.

Outcomes and Prognosis

• Meningoencephalitis is associated with a severe prognosis, including mortality rates ranging from 11 to 25% and functional disability in 15-25% of survivors 2.
• Variables independently associated with poor functional outcome include age > 60 years, immunodepression, delayed ICU admission, and presence of respiratory or cardiovascular failure 6.
• Early administration of antimicrobials, such as third-generation cephalosporin and acyclovir, can be protective against poor outcomes 6.