neurologic disorders
Overview of Meningitis
Diagnosis of Meningitis
Cerebrospinal fluid (CSF) analysis Meningitis is diagnosed mainly by CSF analysis. Because meningitis can be serious and Lumbar Puncture (Spinal Tap) is a safe procedure, lumbar puncture should usually be done if there is any suspicion of meningitis. CSF findings differ by the type of meningitis but can overlap. If patients have signs suggesting increased intracranial pressure or a mass effect (eg, focal neurologic deficits, papilledema, deterioration in consciousness, seizures, especially if patients have HIV infection or are immunocompromised), neuroimaging—typically, contrast-enhanced CT or MRI—is done before lumbar puncture. In patients with increased intracranial pressure, lumbar puncture may cause Brain Herniation , usually within hours of the procedure. Also, if a bleeding disorder is suspected, lumbar puncture is not done until the bleeding disorder is excluded or controlled. When lumbar puncture is deferred, blood cultures should be obtained, followed immediately by empiric treatment with antibiotics. After intracranial pressure has been lowered and if no mass is detected, lumbar puncture can be done. If the skin over the needle insertion site is infected or if a subcutaneous or parameningeal lumbar infection is suspected, the needle is inserted at a different site, usually into the cisterna magna or the upper cervical spine at C2 using radiologic guidance. 