Central Nervous System Infections

Central Nervous System Infections: Causes, Symptoms, and Treatments

Central nervous system infections (CNS infections) are caused by a variety of organisms, including viruses, bacteria, fungi, and protozoa. These infections can affect the brain, spinal cord, and membranes that cover them (the meninges).

Common symptoms of CNS infections include headache, fever, confusion, and changes in mental status, such as hallucinations or seizures. Diagnosis is made based on a person’s symptoms and the results of a physical examination, imaging studies, and laboratory tests. Treatment depends on the cause of the infection and can include antibiotics, antiviral medications, and antifungal medications. In some cases, surgery may be needed.

Causes of CNS Infections

CNS infections can be caused by a variety of organisms, including viruses, bacteria, fungi, and protozoa. Common causes of CNS infections include:

Viruses, including influenza, herpes simplex, Varicella Zoster, poliomyelitis, enteroviruses, and arboviruses (such as West Nile virus).
Bacteria, including Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus), Escherichia coli, and Listeria monocytogenes.
Fungi, including Cryptococcus neoformans, Candida species, and Aspergillus species.
Protozoa, including Toxoplasma gondii.

Infections can also be caused by other organisms, such as parasites and molds.

Symptoms of CNS Infections

Common symptoms of CNS infections include:

Fever.
Headache.
Stiff neck.
Confusion.
Nausea.
Vomiting.
Loss of balance.
Changes in mental status, such as hallucinations or seizures.
Visual disturbances, such as double vision.

In addition, symptoms may vary depending on the type of infection. For example, meningitis (an infection of the meninges) may cause sensitivity to light, headaches, stiff neck, and changes in mental status.

Diagnosis of CNS Infections

CNS infections are diagnosed based on a person’s symptoms, physical examination, imaging studies, and laboratory tests. Common laboratory tests used to diagnose CNS infections include:

Complete blood count (CBC).
Cerebrospinal fluid (CSF) analysis.
Imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI) scans.
Polymerase chain reaction (PCR) testing.

Treatment of CNS Infections

Treatment of CNS infections depends on the cause of the infection. Common treatments include:

Antibiotics, such as penicillins, cephalosporins, and macrolides.
Antiviral medications, such as acyclovir.
Antifungal medications, such as fluconazole.
Surgery, if needed.
Supportive care, such as rest and fluids.

In addition, people who have had a CNS infection may need rehabilitation and physical or occupational therapy to help them regain lost function.