Idiopathic hypertrophic cranial pachymeningitis.

Idiopathic hypertrophic cranial pachymeningitis is a rare chronic inflammatory process of unknown origin that can cause neurological deficits owing to thickening of the dura. Patients with this condition commonly present with cranial neuropathy accompanied by localized headache. The clinical features, neuroimaging findings, histopathological features and treatment outcomes for three patients with this condition are reported here. The first patient presented with subacute dull headache in the left temporal area followed by left abducens nerve palsy. The second patient suffered from a cranial nerve IX-XII lesion accompanied by an occipital headache and the third patient presented with left optic neuropathy and mild headache in the frontal area. In all patients, MRI of the brain revealed prominent dural thickening, and histopathological study of the dura revealed chronic inflammatory cell infiltration. Combined therapy with corticosteroid and immunosuppressive drugs was effective, resulting in almost complete resolution of the symptoms and signs, except for visual impairment in one patient.