Meningitis, an inflammation of the tissues surrounding the brain, is usually caused by infection with viruses or bacteria. The after effects depend on the precise causative agent, as well as the affected person's age and general state of health. Young children, the elderly and immuno-compromised patients, such as those with HIV, are more likely to suffer from complications.
Viral Meningitis
Viral meningitis is generally considered to be a self-limiting disease from which the patient can expect to recover completely. However, as pointed out in a study published in 2006 in the "British Medical Bulletin," viral meningitis can lead to disability and death, especially in infants and those with weak immune systems. HIV meningitis can become chronic and can be complicated by cranial neuropathies, causing, for example, abnormalities of eye movements. West Nile virus can cause a paralysis similar to polio and a movement disorder resembling Parkinson's disease. Children often develop a seizure disorder. Elderly patients and diabetics often suffer from long term neurological and psychiatric impairments, such as memory difficulties.
Haemophilus Meningitis
Haemophilus Influenza used to be the most common cause of meningitis, as the Centers for Disease Control and Prevention explain. Since the introduction of a vaccine, there have been many fewer cases of haemophilus meningitis. In a study published in 1990 in "The New England Journal of Medicine," 14% of affected children had long-term neurological complications. The most common complication was hearing loss in either one or both ears. Other complications included seizure disorder, paralysis and mental retardation.
Meningococcal Meninigitis
Meningococcal meningitis, which is caused by the bacteria Neisseria meningitidis, develops rapidly, can be very severe and despite early treatment is often fatal. As "Adams and Victor's Principles of Neurology" explains, long-term neurological complications are common and include hydrocephalus, meaning an increase in the amount of fluid in the brain's ventricles. This can cause unsteady gait, confusion and incontinence. Other late effects include hearing loss, mental retardation and paralysis.
Pneumococcal Menningitis
Streptococcus pneumonia is a leading cause of meningitis. According to a study published in 2003 in "Brain," about one quarter of patients will die despite receiving the most advanced care. Many of the survivors had complications, including hearing loss, hydrocephalus and paralysis. Blindness may occur. Children may suffer from mental retardation, while adults may develop dementia.
References
- "British Medical Bulletin"; Viral Meningitis; David R. Chadwick; Feb 2006
- "The New England Journal of Medicine"; The Sequelae of Haemophilus Influenzae Meningitis in School-Age Children; H. Gerry Taylor et al.; Dec 1990
- The Centers for Disease Control and Prevention: Meningitis
- "Brain"; Pneumococcal Meningitis in Adults; Stefan Kastenbauer and Hans-Walter Pfister; May 2003
- "Adams and Victor's Principles of Neurology, 7th edition"; Maurice Victor and Allan Ropper; 2001
