Idiopathic hypertrophic cranial pachymeningitis: easy to suspect, difficult to prove.

Idiopathic hypertrophic cranial pachymeningitis (IHCP) is a chronic fibrosing inflammatory condition of dura mater resulting in thickening of dura.1 It has a non specific clinical picture comprising headache, vomiting, cranial nerve palsy, ataxia, raised intracranial pressure and focal neurological deficit. These symptoms and signs in IHCP are due to entrapment of cranial nerves, occulsion of CSF flow, venous sinuses and rarely arteries. The diagnosis of IHCP is based on excluding a large number of causes such as inflammatory (tuberculosis, fungal, Lyme’s disease, syphillis, HTLV), collagen vascular disorders (rheumatoid arthritis, Wegner’s granulomatosis, systemic lupus erythematosus, mixed connective tissue disease), multifocal fibrosclerosis, neoplasia (carcinoma, lymphoma, meningioma en plaque) and miscellaneous disorders such as sarcoidosis, hemodialysis, mucopolysaccharidosis and intrathecal drug administration.1