A nationwide survey of opsoclonus-myoclonus syndrome in Japanese children.

BACKGROUND: Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease characterized by opsoclonus, myoclonus, ataxia, and behavioral changes. The aim of our study was to investigate the epidemiological characteristics of OMS in Japan and to clarify the association between therapy and prognosis. METHODS: We retrospectively collected the data from 626 Japanese medical institutions from 2005 to 2010, and analyzed the clinical features of pediatric patients with OMS based on the data. RESULTS: In this survey, there were 23 patients (10 males and 13 females). The median ages at the disease onset and the time of study were 16.5 months (range: 11-152 months) and 54 months (range: 24-160 months), respectively. The principal symptoms were opsoclonus (23 patients, 100%), myoclonus (21 patients, 91.3%), and ataxia (23 patients, 100%). The related factors were neuroblastoma (10, 43.5%), infection (9, 39.1%), and immunization (2, 8.7%). The treatments for OMS were included intravenous immunoglobulin (17, 73.9%), methylprednisolone pulse (13, 56.5%), oral prednisolone (12 patients, 52.2%), and chemotherapy and/or operation for the underlying tumors (6, 26.1%), and rituximab (2, 8.7%). Complete remissions were obtained in 35.3%, 23.1%, 33.3%, 66.7%, and 100% of these treatments, respectively. At the latest follow-up period, 8 (34.8%) and 17 patients (73.9%) showed neurological sequelae of motor and intellectual functions, respectively. Patients whose treatment was started more than 30 weeks after the disease onset suffered from the severest neurological sequelae (OMS severity 4) more frequently than those less than 30 weeks (p=0.022). CONCLUSION: The annual incidence of OMS was estimated to be 0.27-0.40 cases per million in Japanese children. More than 70% of OMS patients had neurological sequelae, especially intellectual function. Early effective treatments within 30 weeks after the onset may be required to prevent the serious neurological outcome.

High mobility group box 1 in patients with 2009 pandemic H1N1 influenza-associated encephalopathy.

BACKGROUND: Patients with 2009 pandemic H1N1 influenza-associated encephalopathy (pIE) have been reported in Japan. The most common clinical symptoms of this condition are seizures and progressive coma with high-grade fever. We previously highlighted the cytokine profile of pIE; our results suggest that proinflammatory cytokines play an important role in the pathogenesis. High mobility group box 1 (HMGB1) protein is a late mediator of inflammation or sepsis. However, there are few reports regarding the serum and cerebrospinal fluid (CSF) levels of HMGB1 in pIE patients. METHODS: We measured serum and CSF levels of HMGB1 in the following: pIE patients with poor outcomes, pIE patients without neurological sequelae, influenza patients without pIE, and control subjects. RESULTS: Serum HMGB1 levels were significantly higher in pIE patients with poor outcomes compared to those without neurological sequelae. In contrast, there was no difference in CSF HMGB1 levels among all groups. Regarding pIE patients, we found a significant positive correlation between HMGB1 levels and IL-6 in the serum but not in the CSF. CONCLUSIONS: Our results suggest that HMGB1 protein may be involved in the pathogenesis of pIE and that a high serum, but not CSF, level of inflammatory cytokines plays an important role in the severity of pIE.

Serum and cerebrospinal fluid levels of visinin-like protein-1 in acute encephalopathy with biphasic seizures and late reduced diffusion.

BACKGROUND: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) has recently been recognized as an encephalopathy subtype. Typical clinical symptoms of AESD are biphasic seizures, and MRI findings show reduced subcortical diffusion during clustering seizures with unconsciousness after the acute phase. Visinin-like protein-1 (VILIP-1) is a recently discovered protein that is abundant in the central nervous system, and some reports have shown that VILIP-1 may be a prognostic biomarker of conditions such as Alzheimer's disease, stroke, and brain injury. METHODS: However, there have been no reports regarding serum and cerebrospinal fluid (CSF) levels of VILIP-1 in patients with AESD. We measured the serum and CSF levels of VILIP-1 in patients with AESD, and compared the levels to those in patients with prolonged febrile seizures (FS). RESULTS: Both serum and CSF levels of VILIP-1 were significantly higher in patients with AESD than in patients with prolonged FS. Serum and CSF VILIP-1 levels were normal on day 1 of AESD. CONCLUSIONS: Our results suggest that both serum and CSF levels of VILIP-1 may be one of predictive markers of AESD.

Serum soluble CD163 levels in patients with influenza-associated encephalopathy.

BACKGROUND: Influenza-associated encephalopathy (IE) is a serious complication during influenza viral infection. Common clinical symptoms of IE include seizures and progressive coma with high-grade fever. We previously reported that hypercytokinemia and monocyte/macrophage activation may play an important role in the pathogenesis of IE. CD163 is a scavenger receptor for hemoglobin-haptoglobin complexes and is expressed by monocytes/macrophages. Proteolytic cleavage of monocyte-bound CD163 by matrix metalloproteinases releases soluble CD163 (sCD163). However, there have been no reports regarding serum sCD163 levels in IE patients. METHODS: We measured serum levels of sCD163 as a marker of monocyte/macrophage activation in IE patients with poor outcomes, those without neurological sequelae, influenza patients without IE, and control subjects. RESULTS: Serum sCD163 levels were significantly higher in IE patients with poor outcomes than in those without neurological sequelae. In particular, sCD163 levels in cases of death were significantly higher than those in other cases. CONCLUSIONS: Our results suggest that monocyte/macrophage activation is related to the pathogenesis of severe IE.