Meningeal inflammation is termed meningitis, and it may be acute or chronic, chronic being arbitrarily defined as lasting for more than 4 weeks . The causes of meningitis may be both infectious and noninfectious. Some authors have a different opinion and have excluded chronic meningeal involvement in association with CNS mass lesions, pre-existing systemic diseases that are known to cause meningitis, and meningitis that may follow neurosurgical interventions from this diagnostic category . However, this exclusion is considered to be too restrictive for clinical practice and is therefore not accepted as such. Chronic meningitis may be associated with cerebritis or encephalitis and involvement of the cerebral parenchyma with granulomatous infection, inflammation, or malignant infiltration. Also, complications such as hydrocephalus, vasculitic infarcts, and raised intracranial pressure may affect cranial nerves and spinal nerve roots and cause dysfunction of these structures too. Chronic meningitis may also affect the adjacent structures such as skull and dural venous sinuses and cause osteomyelitis or cerebral venous sinus thrombosis.
- 9.Tavee JO, Stern BJ. Neurosarcoidosis. Contin Minneap Minn. 2014;20:545–59.Google Scholar
- 14.Marra CM. Neurosyphilis. Contin Minneap Minn. 2015;21:1714–28.Google Scholar
- 17.Erdem H, et al. Diagnosis of chronic brucellar meningitis and meningoencephalitis: the results of the Istanbul-2 study. Clin Microbiol Infect Off Publ Eur Soc Clin Microbiol Infect Dis. 2013;19:E80–6.Google Scholar
- 25.Halperin JJ. Lyme disease: a multisystem infection that affects the nervous system. Contin Minneap Minn. 2012;18:1338–50.Google Scholar