title: Central nervous system (CNS) involvement is a critical prognostic factor for hemophagocytic lymphohistiocytosis.
abstract: BACKGROUND
  Hemophagocytic lymphohistiocytosis (HLH) is a rare multisystem disorder that frequently involves the central nervous system (CNS). We compared the clinical characteristics, treatment, and prognosis of patients with HLH according to the degree of CNS involvement.
  
  
  METHODS
  The clinical manifestations, initial laboratory data, treatment, and outcomes for 50 patients diagnosed with HLH and treated at Asan Medical Center between January 1995 and August 2011 were retrospectively reviewed and analyzed. CNS involvement was defined as the presence of neurological symptoms or an elevated white blood cell (WBC) count in the cerebrospinal fluid (CSF).
  
  
  RESULTS
  Among these 50 patients, 23 (46%) developed CNS disease. Among patients with CNS disease, 19 had neurological symptoms, including seizures, altered consciousness, facial palsy, dysarthria, and dysphagia. Four patients had elevated CSF WBC counts without neurological symptoms. Twelve patients had abnormal brain imaging results, including high signal intensity lesions on T2-weighted magnetic resonance imaging (MRI) findings, ventriculomegaly, hemorrhage, atrophy, and leptomeningeal enhancement. Patients with CNS disease had lower ferritin, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels as well as reduced 5-year survival as compared to those without CNS disease.
  
  
  CONCLUSIONS
  CNS involvement is common among patients with HLH. Overall, patients with CNS disease achieve poorer outcomes than patients without CNS involvement. To improve outcomes, physicians must carefully monitor the neurological manifestations in patients with HLH and administer the appropriate course of intensified chemotherapy to patients with CNS disease.
authors: Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Myung-Mi
authors: MM
authors: Kim
authors: Mi-Sun
authors: MS
authors: Yum
authors: Hae-Won
authors: HW
authors: Choi
authors: Tae-Sung
authors: TS
authors: Ko
authors: Ho Joon
authors: HJ
authors: Im
authors: Jong-Jin
authors: JJ
authors: Seo
authors: Kyung-Nam
authors: KN
authors: Koh
keywords: Central nervous system involvement; Cerebrospinal fluid; Hemophagocytic lymphohistiocytosis; Neurological manifestations; Outcome