Idiopathic hypereosinophilic syndrome: a new cause of vasculitis of the central nervous system

• Published in: Journal of neurology Vol. 262; no. 5; pp. 1354 - 1359
• Main Authors: Rice, C. M., Kurian, K. M., Renowden, S., Whiteway, A., Price, C., Scolding, N. J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2015; Springer Nature B.V
• Subjects: Abdomen; Adrenal Cortex Hormones - therapeutic use; Adult; Ataxia; Biopsy; Bone marrow; Cyclophosphamide - therapeutic use; Eosinophilia - pathology; Epilepsy; Hematology; Humans; Hypereosinophilic Syndrome - complications; Hypereosinophilic Syndrome - drug therapy; Immunosuppressive Agents - therapeutic use; Kidney diseases; Male; Medicine; Medicine & Public Health; Nervous system; Neurology; Neuroradiology; Neurosciences; Original Communication; Steroids; Vasculitis, Central Nervous System - etiology; United Kingdom > UK; CNS vasculitis; Idiopathic hypereosinophilic syndrome
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-015-7720-9

Idiopathic hypereosinophilic syndrome (IHES) is a primary haematological condition characterised by persistent, otherwise unexplained hypereosinophilia sufficient to cause organ damage. Various neurological complications are reported, but very few have mentioned CNS pathology and none has included CNS vasculitis. Our objective here is to report IHES as a new cause of histopathologically confirmed CNS vasculitis. A 39-year-old man presented with a relapsing sub-acute encephalopathy, with severe headaches, confusion and drowsiness, myoclonus, ataxia and papilloedema. He had a history of nephrotic syndrome 18 years earlier, stable for the past 5 years on low-dose corticosteroids and low-dose tacrolimus (2 mg bd); lichen planus, and (15 years previously) aloplecia totalis. On admission, he had a marked peripheral eosinophilia (up to 9.1 × 10 9 /dL), which—it subsequently became clear—had been intermittently present for 16 years. After extensive investigation, biopsies of brain and bone marrow confirmed diagnoses of cerebral vasculitis, with lymphocytic and macrophage (but not eosinophilic) cellular infiltration of blood vessel walls, and IHES. CNS vasculitis can therefore now be added to the list of neurological complications of IHES. A dramatic and sustained neurological improvement, and likewise of the eosinophilia, following treatment with corticosteroids and cyclophosphamide, emphasises the tractability of this newly described form of CNS vasculitis.