Méningite virale et encéphalite

Introduction

• The document discusses viral meningitis and encephalitis.
• This subject is related to various pathogens, including viruses, parasites, bacteria, and fungi.
• The introduction section highlights the different routes of virus entry into the body.

Porte d'entrée

• Viral entry occurs through inoculation (e.g., bites, injections, blood transfusions).
• Respiratory transmission is possible through aerosols or saliva.
• Digestive transmission can happen through ingestion.
• Genital transmission can be seen with HSV, CMV, and HIV during initial infections.

Diffusion au SNC

• Viral replication begins in a primary site.
• Dissemination to the central nervous system (CNS) can occur through the bloodstream (hematogenous) or along neuronal pathways (axonal transport).
• Hematogenous spread involves the blood carrying the virus.
• Neuronal spread follows axonal pathways for certain types of viruses.
• This is a key pathway for herpes viruses' spread.

Manifestations cliniques de l’entrée du virus dans le SNC

• Symptoms from viral entry into the CNS include inflammation of the meninges (meningitis) and/or the brain tissue (encephalitis).
• Viral meningitis is often caused by enteroviruses.

Ponction lombaire (PL)

• Lumbar puncture (LP) is the standard diagnostic procedure for determining the presence of viruses in the CNS.
• It's a sample of cerebrospinal fluid (CSF).
• Analysis of CSF can help differentiate between viral and bacterial meningitis.

Méningites virales

• Viral meningitis is one particular form of meningitis caused by viral infections.
• This section outlines common etiologies of viral meningitis.
• It includes diagnostic methods and the clinical presentation of the condition.

Clinique

• Typical symptoms include headaches, nausea, photophobia, and phonophobia.
• It may involve nuchal rigidity (stiff neck).
• Children under two often present with atypical signs.
• Variations in presentation depending on age.

Prélèvements

• Methods for confirming a diagnosis, such as collecting cerebrospinal fluid (CSF) for testing.

Diagnostic

• Diagnostic approach using polymerase chain reaction (PCR) for rapid and accurate virus identification.
• Various diagnostic tools are available, depending on the suspected virus.

Principales étiologies

• Several viruses are linked to viral meningitis, including enteroviruses.
• Other responsible viruses are listed in the document.

Classification

• Overview of how viral encephalitis and meningitis are distinguished based on their symptoms and causes.

Physiopathologie

• Mechanisms by which viruses cause harm to the nervous system (i.e., replication within nervous tissues, causing inflammatory responses).

Encéphalites herpétiques

• Herpes viruses can cause encephalitis.
• This section details clinical presentation, diagnostic tools, and treatment options.

Virus de la rage

• Rabies virus is a notorious cause of encephalitis transmitted by animal bites.
• This outlines the transmission, clinical signs, diagnosis, and prognosis of rabies.

LEMP

• Leukoencephalomyelopathy is included as a type of encephalitis, and the associated etiology, diagnostics, and outcome.

Conclusion

• The study notes summarize the aspects of viral meningitis and encephalitis.
• The complex relationship between viruses and the nervous system (NS) is addressed.
• The clinical approaches of confirmation and treatment are reviewed.
• This subject is an important part of neurological medicine.