Clinical presentation, treatment and outcome of IgG4-related pachymeningitis: From a national case registry and literature review.

Pachymeningitis is rare, either idiopathic or secondary to inflammatory disorders, after tumoral, surgical or infectious causes have been excluded. The fibroinflammatory IgG4-related disease is one of the etiologies of pachymeningitis with only few cases reported yet. From a single referral regional center, we evaluated the frequency of IgG4-related disease as the cause of inflammatory pachymeningitis in 10% of cases. From a National case registry of IgG4-related disease the pachymeningitis frequency was 4.1%. We report eight new cases with cranial, spinal or both involvements and a literature review of 46 pathological proven cases. We observed that IgG4-related pachymeningitis is in most cases not associated to extra-neurological manifestations of the disease. Only 27% of spinal and 40% of cranial IgG4-related pachymeningitis are associated with other disease localizations. First line treatment strategies included surgery and steroids. The use of immunosuppressants or rituximab was necessary in 18% of spinal and 54% of cranial localizations. Some patients remained with sequellae and clinical and/or radiological improvement can be difficult to obtain.