Type or paste a DOI name into the text box. Meninges of the central nervous system: dura mater, arachnoid mater, and pia mater. Meningitis is an acute inflammation of the protective membranes covering the brain and spinal cord, known collectively as microbiology a clinical approach 2nd edition pdf meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs.
Some forms of meningitis are preventable by immunization with the meningococcal, mumps, pneumococcal, and Hib vaccines. In 2015 meningitis occurred in about 8. Other signs include the presence of positive Kernig’s sign or Brudziński sign. Other problems can produce symptoms similar to those above, but from non-meningitic causes. This is called meningism or pseudomeningitis. Additional problems may occur in the early stage of the illness.
These may require specific treatment, and sometimes indicate severe illness or worse prognosis. The brain tissue may swell, pressure inside the skull may increase and the swollen brain may herniate through the skull base. Inflammation of the meninges may lead to abnormalities of the cranial nerves, a group of nerves arising from the brain stem that supply the head and neck area and which control, among other functions, eye movement, facial muscles, and hearing. Meningitis is typically caused by an infection with microorganisms. Streptococcus pneumoniae- A causative bacteria of meningitis. The types of bacteria that cause bacterial meningitis vary according to the infected individual’s age group.
Risk of infection with Listeria monocytogenes is increased in persons over 50 years old. Recent skull trauma potentially allows nasal cavity bacteria to enter the meningeal space. Recurrent bacterial meningitis may be caused by persisting anatomical defects, either congenital or acquired, or by disorders of the immune system. In bacterial meningitis, bacteria reach the meninges by one of two main routes: through the bloodstream or through direct contact between the meninges and either the nasal cavity or the skin. In most cases, meningitis follows invasion of the bloodstream by organisms that live upon mucous surfaces such as the nasal cavity. The large-scale inflammation that occurs in the subarachnoid space during meningitis is not a direct result of bacterial infection but can rather largely be attributed to the response of the immune system to the entry of bacteria into the central nervous system.
It is recognized that administration of antibiotics may initially worsen the process outlined above, by increasing the amount of bacterial cell membrane products released through the destruction of bacteria. Particular treatments, such as the use of corticosteroids, are aimed at dampening the immune system’s response to this phenomenon. The CSF sample is examined for presence and types of white blood cells, red blood cells, protein content and glucose level. Various other specialized tests may be used to distinguish between different types of meningitis. Meningitis can be diagnosed after death has occurred.
Inflammation of the meninges may lead to abnormalities of the cranial nerves, this is called meningism or pseudomeningitis. A group of nerves arising from the brain stem that supply the head and neck area and which control, renaissance physicians such as Avicenna. Additional problems may occur in the early stage of the illness. Empirical therapy may be chosen on the basis of the person’s age, rupert Waterhouse and Carl Friderichsen: adrenal apoplexy”.