The Neuroradiology Journal 20: 194-195, 2007
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‘Eiffel-by-Night’: A New MR Sign Demonstrating Reactivation in Idiopathic Hypertrophic Pachymeningitis B. THOMAS, K. THAMBURAJ, C. KESAVADAS Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology; Trivandrum, Kerala, India
Key words: idiopathic, hypertrophic, pachymeningitis, MRI, sign
SUMMARY – A forty- seven-year-old man presented with chronic headache with lower cranial nerve palsies of ten year duration with recent aggravation of symptoms. MRI revealed hypointensity - predominantly of the posterior falx cerebri and the tentorium cerebelli - on all sequences with intense peripheral contrast enhancement on CE SE T1, which on coronal images mimicked the illuminated Eiffel tower by night.
Case Report A forty-seven-year-old man presented with chronic headache with lower cranial nerve palsies of ten year duration. MRI done ten and nine years earlier respectively had shown progressive pachymeningeal thickening (hypointense on T1 and T2 with uniform contrast enhancement). Meningeal biopsy showed nonspecific inflammatory infiltration with lymphocytes and plasma cells. Other investigations for specific etiology were negative. He was treated with oral steroids and was on follow-up. Recently he presented with an aggravation of symptoms. MR examination of the brain was repeated. Imaging Findings The present MRI revealed hypointensity predominantly of the posterior falx cerebri and the tentorium cerebelli - on all sequences with intense peripheral contrast enhancement on CE SE T1, suggesting central fibrosis and peripheral active inflammation respectively, 194
which on coronal images mimicked the illuminated Eiffel tower by night (figure 1). Discussion Idiopathic hypertrophic pachymeningitis (IHP) is a fibrosing inflammatory process that involves the dura mater especially the posterior part of the falx cerebri and the tentorium cerebelli 1. Pathologically diffuse thickening of the dura with dense fibrosis and inflammatory cell infiltration (marked at the surface), mainly of lymphocytes and plasmacytes is noted 1,2. The fibrosis is seen as a hypointense signal on all sequences and the site of active inflammation on the surface is marked by contrast enhancement. This new sign illustrates these features and should be specifically looked for in all cases of IHP. Potential differential diagnosis may include other causes of pachymeningitis like rheumatoid arthritis, syphilis, Wegener’s granulomatosis, tuberculosis, sarcoidosis and malignancy, which were ruled out in the present case 3.
B. Thomas
A
‘Eiffel-by-Night’: a New Sign Demonstrating Reactivation in Idiopathic Hypertrophic Pachymeningitis
B
C
Figure 1 A) T2-w coronal FSE image through the posterior falx and tentorium demonstrating the thick hypointense dura (thin arrow). B) Post contrast fat saturated T1-w SE image through the same plane shows thickened dura with hypointense center (thin arrow) suggesting fibrosis and enhancing periphery (thick arrow) depicting areas of active inflammation. Together they mimic the illuminated Eiffel tower by night (C).
References 1 Riku S, Kato S: Idiopathic hypertrophic pachymeningitis. Neuropathology 23: 335-44, 2003. 2 Lee Y C, Chueng Y C, Hsu S W et Al: Idiopathic hypertrophic cranial pachymeningitis: case report with 7 years of imaging follow-up. AJNR Am J Neuroradiol 4: 119-23, 2003. 3 Kupersmith M J, Martin V, Heller G et Al: Idiopathic hypertrophic pachymeningitis. Neurology 62: 686-694, 2004.
Dr Bejoy Thomas, Dept of Imaging Sciences and Interventional Radiology Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India - 695011 Tel: 0091 471 2524114 E mail: [email protected]
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www. centauro. it
‘Eiffel-by-Night’: A New MR Sign Demonstrating Reactivation in Idiopathic Hypertrophic Pachymeningitis B. THOMAS, K. THAMBURAJ, C. KESAVADAS Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology; Trivandrum, Kerala, India
Key words: idiopathic, hypertrophic, pachymeningitis, MRI, sign
SUMMARY – A forty- seven-year-old man presented with chronic headache with lower cranial nerve palsies of ten year duration with recent aggravation of symptoms. MRI revealed hypointensity - predominantly of the posterior falx cerebri and the tentorium cerebelli - on all sequences with intense peripheral contrast enhancement on CE SE T1, which on coronal images mimicked the illuminated Eiffel tower by night.
Case Report A forty-seven-year-old man presented with chronic headache with lower cranial nerve palsies of ten year duration. MRI done ten and nine years earlier respectively had shown progressive pachymeningeal thickening (hypointense on T1 and T2 with uniform contrast enhancement). Meningeal biopsy showed nonspecific inflammatory infiltration with lymphocytes and plasma cells. Other investigations for specific etiology were negative. He was treated with oral steroids and was on follow-up. Recently he presented with an aggravation of symptoms. MR examination of the brain was repeated. Imaging Findings The present MRI revealed hypointensity predominantly of the posterior falx cerebri and the tentorium cerebelli - on all sequences with intense peripheral contrast enhancement on CE SE T1, suggesting central fibrosis and peripheral active inflammation respectively, 194
which on coronal images mimicked the illuminated Eiffel tower by night (figure 1). Discussion Idiopathic hypertrophic pachymeningitis (IHP) is a fibrosing inflammatory process that involves the dura mater especially the posterior part of the falx cerebri and the tentorium cerebelli 1. Pathologically diffuse thickening of the dura with dense fibrosis and inflammatory cell infiltration (marked at the surface), mainly of lymphocytes and plasmacytes is noted 1,2. The fibrosis is seen as a hypointense signal on all sequences and the site of active inflammation on the surface is marked by contrast enhancement. This new sign illustrates these features and should be specifically looked for in all cases of IHP. Potential differential diagnosis may include other causes of pachymeningitis like rheumatoid arthritis, syphilis, Wegener’s granulomatosis, tuberculosis, sarcoidosis and malignancy, which were ruled out in the present case 3.
B. Thomas
A
‘Eiffel-by-Night’: a New Sign Demonstrating Reactivation in Idiopathic Hypertrophic Pachymeningitis
B
C
Figure 1 A) T2-w coronal FSE image through the posterior falx and tentorium demonstrating the thick hypointense dura (thin arrow). B) Post contrast fat saturated T1-w SE image through the same plane shows thickened dura with hypointense center (thin arrow) suggesting fibrosis and enhancing periphery (thick arrow) depicting areas of active inflammation. Together they mimic the illuminated Eiffel tower by night (C).
References 1 Riku S, Kato S: Idiopathic hypertrophic pachymeningitis. Neuropathology 23: 335-44, 2003. 2 Lee Y C, Chueng Y C, Hsu S W et Al: Idiopathic hypertrophic cranial pachymeningitis: case report with 7 years of imaging follow-up. AJNR Am J Neuroradiol 4: 119-23, 2003. 3 Kupersmith M J, Martin V, Heller G et Al: Idiopathic hypertrophic pachymeningitis. Neurology 62: 686-694, 2004.
Dr Bejoy Thomas, Dept of Imaging Sciences and Interventional Radiology Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India - 695011 Tel: 0091 471 2524114 E mail: [email protected]
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