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MSU College of Osteopathic Medicine

I. General Principles

C. Locations and Definitions: 

  • Infections tend to be confined by the meninges. Terminology for infections in various compartments of the nervous system are listed below:
  • Epidural Abscess or Empyema: accumulation of pus in the space between dura and skull (perios­teum)
  • Pachymeningitis: inflammation of the dura (rare)
  • Subdural Abscess or Empyema: accumulation of pus in the space between the dura and arachnoid
  • Meningitis/Leptomeningitis: inflammation of the pia and arachnoid, in the subarachnoid space (e.g. meningococcal meningitis)
  • Encephalitis: general­ized inflammation of the brain parenchyma
  • Abscess or Granuloma: localized inflamma­tion in the brain or spinal cord parenchyma
  • Myelitis: general­ized inflammation of the spinal cord parenchyma (e.g. poliomyelitis)
  • Radiculitis: inflammation of the nerve roots
  • Neuritis: inflammation of a peripheral nerve
  • Encephalomyelitis: general­ized inflammation of the brain and spinal cord
  • Ependymitis: inflammation of the ventricles and ventricular lin

Note: the terms neuritis and myelitis are synonymous with neuropathy and myelopathy and can indicate a non-inflammatory process.