MeningitisSymptoms:Symptoms indicative of meningitis include headaches, neck stiffness, and fever. Patients will often feel pain in the neck if it is flexed forward (as when you put your chin on your chest), a sign called meningismus. Other possible symptoms include nausea, vomiting, sensitivity to light, lethargy, confusion and seizures. Other symptoms of infection (cough, rash, urinary symptoms, nasal congestion) may also be present and may point to a specific source of the infection. What is meningitis?Meningitis refers to inflammation and swelling of the tissue that covers the brain (the meninges). The most common and worrisome cause of this is an infection within the cerebrospinal fluid (the fluid enclosed by the meninges) from a virus or bacteria. Sometimes the infection is within the substance of the brain too (meningoencephalitis). Bacterial meningitis can be fulminant, meaning, the infection can escalate within a few hours to rapidly become life threatening. If the cause is a virus it is generally much less severe and rarely life-threatening. There are chronic forms of meningeal infection that are not as immediately dangerous but that still require evaluation and treatment.
How is it diagnosed?A lumbar puncture is required for the diagnosis. This involves placing a needle between the bones of the low back in order to obtain cerebrospinal fluid (the fluid that surrounds the brain and spinal cord). The cerebrospinal fluid is then sent for laboratory analysis, to look for evidence of infection and to attempt to identify any organisms. Typically a head CT scan is performed before the lumbar puncture, to make sure there isn't a mass in the brain, since such a mass could make the lumbar puncture dangerous to perform.What are some organisms that cause this?Common bacteria that cause acute meningitis include Neisseria meningitidis (often in young adults), Streptococcus pneumoniae, Group B strep. (newborns), Haemophilus influenzae (in those not vaccinated), and Listeria monocytogenes (in the immunocompromised). In the case of a viral infection, the specific virus is often not identified. There is a specific test for herpes simplex virus, which is important because this viral infection is treatable and can cause a severe brain infection (encephalitis) resulting in seizures. While other viruses can be identified, the testing for these is often not performed since they are not treatable.How is it treated?Acute meningitis (symptoms that have started within the last few hours or days) is a medical emergency and therefore requires immediate emergency room evaluation. Typically meningitis is treated presumptively, meaning, intravenous antibiotics are started the moment the diagnosis is entertained, even before the necessary testing has been carried out. The initial antibiotics are chosen to cover the most likely organisms, while taking into consideration the immune status of the patient. The antibiotic regimen is later modified based on organism identification. Because the source of infection is often somewhere else in the body, cultures are typically obtained from many locations (sputum, nose, blood) to attempt to identify the causative organism. For bacterial infections, steroids may also be added to reduce inflammation and subsequently reduce long-term damage from the infection.If viral meningitis is certain, then patients do not need to be placed on antibiotics, since this would not be helpful. It is often difficult, though, to be certain, early in the coarse of evaluation, that the infection is viral. If there is a concomitant encephalitis, then antibiotic coverage for herpes simplex virus (with intravenous acyclovir) is often wise until the virus-specific test result (HSV-PCR) is known. There are many potential complications of this infection, including seizures, strokes, and hydrocephalus. For more information regarding this topic, please refer to this excellent and more comprehensive Wikipedia page. Return from MENINGITIS to WORRISOME HEADACHE SYMPTOMS
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