Idiopathic hypertrophic pachymeningitis: clinical, laboratory and neuroradiologic features in China.

Hypertrophic pachymeningitis is a rare chronic inflammatory disorder characterized by marked fibrous thickening of the cerebral and/or spinal dura mater. Clinical, laboratory, neuroradiologic and therapeutic data from 12 patients with idiopathic hypertrophic pachymeningitis (IHP) from our department were retrospectively studied. There were four men and eight women with a mean age of 49±15.3 years, and more than half of the patients (58%) were aged 40-60 years. Headache was the most common symptom, occurring in 92% of patients. Headache improved markedly and rapidly after glucocorticoid treatment. Optic nerve involvement was noted in seven patients (58%). C-reactive protein levels increased in 80% and the erythrocyte sedimentation rate increased in 71% of patients. Three patients were positive for autoantibodies, including antinuclear antibodies (ANA), perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA), anti-cardiolipin antibodies (ACA) and rheumatoid factor (RF). Cerebrospinal fluid showed inflammatory changes, and protein levels were low to moderately elevated. MRI revealed a thickened dura in all patients, and five patients (42%) were diagnosed with sinus stenosis/occlusion. IHP is a chronic inflammatory disorder of the dura with three groups of symptoms, namely headache, cranial nerve palsy and symptoms due to sinus stenosis/occlusion. However, IHP has different features in China in that it predominantly affects women and the age of onset is younger. Sinus stenosis/occlusion is relatively common in IHP patients in China.