Encephalitis and Meningitis Health Article

Symptoms

Symptoms of encephalitis include sudden fever, headache, vomiting, heightened sensitivity to light, stiff neck and back, confusion and impaired judgment, drowsiness, weak muscles, a clumsy and unsteady gait (manner of walking), bulging in the soft spots (fontanels) of the skull in infants, and irritability. More severe or late symptoms include loss of consciousness, seizures, muscle weakness, or sudden severe dementia.

Symptoms of meningitis, which may appear suddenly, often include high fever, severe and persistent headache, stiff neck, nausea, and vomiting. Changes in behavior such as confusion, sleepiness, and difficulty waking up are extremely important symptoms and may require emergency treatment.

In infants, symptoms of meningitis may include high-pitched cry, moaning cry, whimpering, dislike of being handled, fretfulness, arching of the back, neck retraction, blank, staring expression, difficulty in waking, lethargia, fever, cold hands and feet, refusing to feed or vomiting, pale, blotchy skin color. In adults, symptoms of meningitis may include vomiting, headache, drowsiness, seizures, high temperature, joint pain, stiff neck, and aversion to light.

Arboviral infections may be asymptomatic or may result in illnesses of variable severity. Arboviral meningitis is characterized by fever, headache, and stiff neck. Arboviral encephalitis is characterized by fever, headache, and altered mental status that ranges from confusion to coma. Signs of brain dysfunction such as numbness or paralysis, cranial nerve palsies, visual or hearing deficits, abnormal reflexes, and generalized seizures may also be present.

Diagnosis

Encephalitis or meningitis is suspected by a physician when the symptoms described above are present. The physician diagnoses encephalitis or meningitis after a careful examination and testing. The examination includes special maneuvers to detect signs of inflammation of the membranes that surround the brain and spinal cord (meninges). Tests that are used in the evaluation of individuals suspected of having encephalitis or meningitis include blood counts, blood cultures, coagulation studies, bacterial antigen studies of urine and serum, brain scanning, and spinal fluid analysis.

The most common method of diagnosing encephalitis and meningitis is to analyze the cerebrospinal fluid surrounding the brain and spinal cord. A needle inserted into lower spine extracts a sample of fluid for laboratory analysis, which may reveal the presence of an infection or an increased white blood cell count, a signal that the immune system is fighting an infection. The cerebrospinal fluid may also be slightly bloody if small hemorrhages have occurred. Diagnosis of herpes simplex encephalitis can be difficult, but advances using sensitive DNA methods have allowed detection of the virus in spinal fluid.

Electroencephalography (EEG) measures the waves of electrical activity produced by the brain. It is often used

to diagnose and manage seizure disorders. A number of small electrodes are attached to the scalp. The patient remains still during the test and at times may be asked to breathe deeply and steadily for several minutes or to stare at a patterned board. At times, a light may be flashed into eyes. These actions are meant to stimulate the brain. The electrodes pick up the electrical impulses from brain and send them to the EEG machine, which records the brain waves on a moving sheet of paper. An abnormal EEG result may suggest some of diseases, but a normal result does not rule them out.

Brain imaging, using computed tomography (CT) or magnetic resonance imaging (MRI) may reveal swelling of brain. These techniques may reveal another condition with signs and symptoms that are similar to encephalitis, such as a concussion.

Rarely, if diagnosis of herpes simplex encephalitis isn't possible using DNA methods or by CT or MRI scans, a physician may take a small sample of the brain tissue, or biopsy, for analysis to determine if the virus is present. Physicians usually attempt treatment with antiviral medications before suggesting brain biopsy.

Blood testing can confirm the presence of West Nile virus in the body by drawing a sample of blood for laboratory analysis. When infected with West Nile virus, an analysis of blood sample may show a rising level of an antibody against the virus, a positive DNA test for the virus or a positive virus culture.

Treatment team

The treatment team may include a pediatrician or a general practitioner, an infectious disease specialist and/or a critical care specialist, a neurosurgeon, a neurologist or a neonatologist. Others professionals may give support during hospitalization for intravenous antibiotics or other specific procedures.