CNS infections

• Nervous system infections are classified upon the location of the infection into
1. Meningitis(infection of the meninges)
2. Encephalitis(infection of the parenchyma of the brain)
3. Brain abscess and subdural empyema

• The meningitic syndrome is simple triad: headache, neck stiffness and fever. Photophobia and vomiting are often present. In acute bacterial infection there is usually intense malaise, fever, rigors, severe headache, photophobia and vomiting. This develops within hours or minutes. The patient is irritable and often prefers to lie still. Neck stiffness and positive Kernig s sign usually appear within hours.



VIRAL MENINGITIS

• Viral infection is the most common cause of meningitis, and usually results in a benign and self-limiting illness requiring no specific therapy.

• A number of viruses can cause meningitis the most common being enteroviruses.

• The condition occurs mainly in children or young adults.

• Characterized by acute onset of headache and irritability and the rapid development of meningism.

• The CSF usually contains an excess of lymphocytes, normal glucose and the protein level may be raised.

• Treatment is symptomatic; the condition is usually benign and self-limiting. Recovery usually occurs within days.