| Meningism | |
|---|---|
| Other names | Meningismus,[1][2] pseudomeningitis[1][3] |
 | |
| Positive Kernig's sign in cerebrospinal meningitis | |
| Differential diagnosis | Meningitis |
Meningism is a set ofsymptoms similar to those ofmeningitis but not caused by meningitis.[1][3][4] Whereas meningitis isinflammation of themeninges (membranes that cover the central nervous system), meningism is caused by nonmeningitic irritation of the meninges, usually associated with acutefebrile illness,[1][2] especially in children and adolescents.[2] Meningism involves the triad (3-symptomsyndrome) of nuchal rigidity (neck stiffness),photophobia (intolerance of bright light) andheadache. It therefore requiresdifferentiating from other CNS problems with similar symptoms, including meningitis and some types ofintracranial hemorrhage. Related clinical signs includeKernig's sign and three signs all namedBrudzinski's sign.
Althoughnosologic coding systems, such as ICD-10 and MeSH, define meningism/meningismus as meningitis-like but in fact not meningitis, many physicians use the termmeningism in a loose sense clinically to refer to any meningitis-like set of symptomsbefore the cause is definitively known. In this sense, the word implies "suspected meningitis". The wordsmeningeal symptoms can be used instead to avoid ambiguity, thus reserving the termmeningism for its strict sense.
The main clinical signs that indicate meningism are nuchal rigidity, Kernig's sign and Brudzinski's signs. None of the signs are particularly sensitive; in adults with meningitis, nuchal rigidity was present in 30% and Kernig's or Brudzinski's sign only in 5%.[5]
Nuchal rigidity is the inability to flex theneck forward due to rigidity of the neck muscles; if flexion of the neck is painful but full range of motion is present, nuchal rigidity is absent.[citation needed]
Kernig's sign (afterWaldemar Kernig (1840–1917), aRussian neurologist) is positive when the thigh is flexed at the hip and knee at 90 degree angles, and subsequent extension in the knee is painful (leading to resistance).[6] This may indicate subarachnoid hemorrhage or meningitis.[7] Patients may also showopisthotonus—spasm of the whole body that leads to legs and head being bent back and body bowed forward.[citation needed]
Jozef Brudzinski (1874–1917), aPolish pediatrician, is credited with several signs in meningitis. The most commonly used sign (Brudzinski's neck sign) is positive when the forcedflexion of the neck elicits a reflex flexion of the hips, with the patient lyingsupine.[5][8]
Other signs attributed to Brudzinski:[9]