Cruz, K. Cruz R. Cudal, I. Dancel, J. Dans, K. Daquilanea, M. HISTORY PHYSICAL EXAM Approach to Diagnosis Signs and Symptoms or Laboratory findings pathognomonic of a disease Signs and Symptoms or Laboratory findings pointing to an organ or part of an organ system Signs and Symptoms or Laboratory findings pointing to a group of diseases Signs and Symptoms or Laboratory findingsn whose mechanism is well understood Signs and Symptoms or Laboratory findings found in the least number of disease Presenting Manifestations MENINGITIS Meningitis is swelling and irritation (inflammation) of the membranes covering the brain and spinal cord. This inflammation causes changes in the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. CAUSES OF MENINGITIS Infection Viral Bacterial Fungi Parasites Chemical irritation Drug allergies Fungi Tumors LUMBAR TAP Lumbar puncture is the most important procedure used in diagnosis of viral meningitis. Other potential procedures intracranial pressure monitoring, brain biopsy, ventricular drainage or shunting. positioning the patient, usually lying on the side, applying local anesthetic and inserting a needle into the dural sac to collect cerebrospinal fluid (CSF). the "opening pressure" of the CSF is measured using a manometer. The pressure is normally between 6 and 18 cm water (cmH 2 O); [ [ The initial appearance of the fluid may prove an indication of the nature of the infection: cloudy CSF indicates higher levels of protein, white and red blood cells and/or bacteria, CSF findings in different forms of meningitis Type of meningitis Glucose ProteinCells Acute bacterial lowhigh PMNs, often > 300/mm Acute viralnormal normal or high mononuclear, < 300/mm Tuberculouslowhigh mononuclear and PMNs, < 300/mm Fungallowhigh< 300/mm Malignantlowhigh usually mononuclear VIRAL MENINGITIS Viral meningitis is inflammation of the leptomeninges as a manifestation of CNS infection. Viral meningitis is also often referred to as aseptic meningitis. PATHOPHYSIOLOGY Viral pathogens may gain access to the CNS via hematogenous Neural REPLICATION virus replicates in the initial organ system (ie, respiratory or gastrointestinal mucosa) and gains access to the bloodstream. If the replication persists despite immunologic defenses, viremia occurs, which is thought to be responsible for seeding of the CNS. Rapid viral replication likely plays a major role in overcoming the host defenses. may cross the BBB directly at the capillary endothelial levelor through natural defects such as the area postrema and other sites that lack a BBB. Signs and Symptoms Clinical features Severe headache Constitutional symptoms Vomiting Diarrhea Cough myalgias Fever Nuchal rigidity Irritability, disorientation, and altered mentation Seizures Other signs of viral infections PRESENT IN OUR PATIENT Severe headache fever, Drowsy Irritable Ill-looking seizures Decrease level of Consciousness brain tissue may swell, with increasing pressure inside the skull and a risk of swollen brain tissue getting trapped Seizures common in the early stages of meningitis (30% of cases) and do not necessarily indicate an underlying cause. result from increased pressure and from areas of inflammation in the brain tissue MANAGEMENT COURSE IN THE WARD REFERENCES Division of Infectious Disease, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.; ADAM Health Illustrated EncyclopediaADAM Health Illustrated Encyclopedia Amir Vokshoor, MD, Staff Neurosurgeon, Department of Neurosurgery, Spine Surgeon, Diagnostic and Interventional Spinal Care, St John's Health Center