title: Clinico-radiological spectrum and outcome in idiopathic hypertrophic pachymeningitis.
abstract: OBJECTIVE
  To elucidate the clinico-radiological features, treatment response and outcome of a large cohort of patients (n=20) with idiopathic hypertrophic pachymeningitis (IHP) and to examine if any of these features could differentiate between IHP and secondary causes of hypertrophic pachymeningitis (SHP).
  
  
  METHODS
  20 patients with IHP diagnosed between 1998 and 2009 formed the study cohort. We adopted a validated clinical score to quantitatively assess and document their neurological disability and to compare their pre- and post-treatment outcomes. Appropriate statistical analysis was done to look for any clinical and/or radiological features to differentiate IHP from SHP.
  
  
  RESULTS
  Out of the twenty eight consecutive patients with pachymeningitis, 20 were having IHP and 8 were having SHP (Tuberculosis-5, Sarcoidosis-2, Wegener's granulomatosis-1). In IHP, headache and visual symptoms dominated the clinical symptomatology (80% and 75%). In MRI, the peripheral pattern of contrast enhancement was more common with IHP (p=0.03). The posterior falx and tentorium showing a hypointense center ("fibrosis") and enhancing periphery ("active inflammation") together mimicking "Eiffel-by-night" sign was found to be more commonly associated with IHP (60% vs 12.5%, p=0.03). Biopsy was done in 9 patients. At a mean follow-up of 51 months (range 24-144 months), the mean pretreatment clinical score improved from 6.55 to 1.80 in 20 patients with IHP (p<0.001).
  
  
  CONCLUSIONS
  Our data on the largest cohort of patients with IHP would shed light into its clinico-radiological spectrum, treatment and outcome. The prognosis is satisfactory if managed appropriately. We have highlighted the role of MRI in differentiating between IHP and other causes of SHP.
authors.affiliation: Department of Neurology and Imaging & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
authors.forename: Gopal Krishna
authors.initials: GK
authors.lastname: Dash
authors.affiliation: Department of Neurology and Imaging & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
authors.forename: Bejoy
authors.initials: B
authors.lastname: Thomas
authors.affiliation: Department of Neurology and Imaging & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
authors.forename: Muralidharan
authors.initials: M
authors.lastname: Nair
authors.affiliation: Department of Neurology and Imaging & Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India. Electronic address: drashalatha@sctimst.ac.in.
authors.forename: Ashalatha
authors.initials: A
authors.lastname: Radhakrishnan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006984:Hypertrophy / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D008581:Meningitis / Q000000981:diagnostic imaging* / Q000628:therapy*; D008875:Middle Aged; D011859:Radiography; D016896:Treatment Outcome
keywords: Clinical features; Hypertrophic pachymeningitis; Outcome; Radiological features; Treatment modalities