Signs and symptoms
Viral meningitis characteristically presents with fever, headache and neck stiffness. Fever is the result of cytokines released that affect the thermoregulatory (temperature control) neurons of the hypothalamus. Cytokines and increased intracranial pressure stimulate nociceptors in the brain that lead to headaches. Neck stiffness is the result of inflamed meninges stretching due to flexion of the spine. The various layers of meninges act form a separation between the brain and the skull. In contrast to bacterial meningitis, symptoms associated with viral meningitis are often less severe and do not progress as quickly. Nausea, vomiting and photophobia (light sensitivity) also commonly occur, as do general signs of a viral infection, such as muscle aches and malaise. Increased cranial pressure from viral meningitis stimulates the area postrema, which causes nausea and vomiting. Widened pulse pressure (systolic - diastolic blood pressure), bradycardia, and irregular respiration would be alarming for Cushings reflex, a sign of acutely elevated intracranial pressure. Photophobia is due to meningeal irritation. In severe cases, people may experience concomitant encephalitis (meningoencephalitis), which is suggested by symptoms such as altered mental status, seizures or focal neurologic deficits.Babies with viral meningitis may only appear irritable, sleepy or have trouble eating. Infection in the neonatal period may be the result of infection during pregnancy. In severe cases, people may experience concomitant encephalitis (meningoencephalitis), which is suggested by symptoms such as altered mental status, seizures or focal neurologic deficits. The pediatric population may show some additional signs and symptoms that include jaundice and bulging fontanelles.
Viral meningitis, also known as aseptic meningitis, is a type of meningitis due to a viral infection. It results in inflammation of the meninges (the membranes covering the brain and spinal cord). Symptoms commonly include headache, fever, sensitivity to light and neck stiffness.Viruses are the most common cause of aseptic meningitis. Most cases of viral meningitis are caused by enteroviruses (common stomach viruses). However, other viruses can also cause viral meningitis, such as West Nile virus, mumps, measles, herpes simplex types I and II, varicella and lymphocytic choriomeningitis (LCM) virus. Based on clinical symptoms, viral meningitis cannot be reliably differentiated from bacterial meningitis, although viral meningitis typically follows a more benign clinical course. Viral meningitis has no evidence of bacteria present in cerebral spinal fluid (CSF). Therefore, lumbar puncture with CSF analysis is often needed to identify the disease.In most cases, there is no specific treatment, with efforts generally aimed at relieving symptoms (headache, fever or nausea). A few viral causes, such as HSV, have specific treatments. In the United States, viral meningitis is the cause of more than half of all cases of meningitis. With the prevalence of bacterial meningitis in decline, the viral disease is garnering more and more attention. The estimated incidence has a considerable range, from 0.26 to 17 cases per 100,000 people. For enteroviral meningitis, the most common cause of viral meningitis, there are up to 75,000 cases annually in the United States alone. While the disease can occur in both children and adults, it is more common in children.