Three membranes, called the meninges, lie between the brain and the skull and cover the spinal cord. Infection of the meninges is called meningitis. Viral meningitis is usually self-limiting and rarely leads to complications. Bacterial meningitis is a serious condition requiring prompt aggressive treatment with antibiotics. Irritability, stiff neck, headache, high fever, chills, vomiting, delirium, sensitivity to light and a blotchy red rash are symptomatic. Infants may have a bulging soft spot, refuse to eat, cry inconsolably or be lethargic. Illness may come on suddenly or over 24 to 48 hours.
Brain Damage
Permanent neurological damage can result from meningitis, ranging from minor problems with coordination and movement, to epilepsy, paralysis, palsy and severe mental impairment. Toxins produced by bacteria, particularly pneumococcal organisms, may damage brain cells despite treatment with antibiotics. When treatment is delayed, the risk of brain damage increases. Bacteria invade the subarachnoid space, a channel for fluid which flows through the meninges and helps cushion the brain. Infection can gain entry directly from the ear or a skull fracture, or because an untreated infection elsewhere in the body invades the bloodstream and spreads to the brain.
Hearing Loss
Deafness is the most frequent severe after-effect of meningitis, and bacterial meningitis is the most common cause of acquired hearing loss. According to researchers at the Baylor College of Medicine in Houston, Texas, both Streptococcus pneumoniae and Neisseria meningitidis cause hearing loss, although the incidence is greater with pneumococcal infection. The researchers also found that predictors such as seizures and longer hospitalizations were most applicable to meningitis that is caused by Streptococcus pneumoniae.
Learning Disabilities
According to the Meningitis Foundation, approximately 30 percent of survivors of bacterial meningitis sustain a loss of neurons in the hippocampus that can result in impaired learning, ranging from mild difficulties to profound mental retardation. Chemicals in infected cerbrospinal fluid are destructive to brain cells and trigger enzymes leading to inflammation and swelling of brain tissue. New treatments designed to inhibit these chemicals are the focus of research.
Death
Listeria is a particularly virulent form of meningitis. According to the Mayo Clinic, sources of Listeria monocytogenes (listeria) infection include contaminated foods such as soft cheeses and processed cold meats. Animals can also carry the bacteria. Elderly people, infants and pregnant women are the most susceptible. Listeria can cross the placenta in late pregnancy, resulting in stillbirth or neonatal death.
References
- "Archives of Otolaryngol-Head & Neck Surgery"; Senorineural Hearing Loss Is Common in Children With Bacterial Meningitis; Sept, 2006, 132
- Mayo Clinic: Meningitis Complications
- Meningitis Research Foundation: A Study of Brain Cell Damage in Bacterial Meningitis to Find New Treatment Strategies; January, 2001
