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Mitsuyoshi Ayabe

Publications and source records attributed to Mitsuyoshi Ayabe.

12 recordsLinked to original sources
PubMed2006

Adult meningism and viral meningitis, 1997-2004: clinical data and cerebrospinal fluid cytokines.

OBJECTIVE: Although meningism manifesting acute headache has been observed to be associated with common viral and bacterial infections, its definition and pathogenesis have not been clarified. Clinical findings and cerebrospinal fluid (CSF) cytokines in adult patients with meningism were investigated and compared with those in viral meningitis. PATIENTS AND METHODS: Among the adult inpatients in our hospital from 1997 to 2004, 5 with meningism and 17 with viral meningitis were identified according to the criteria described in this study, and their clinical data were analyzed. In the CSF samples of the 5 patients with meningism and the 17 with viral meningitis, the concentrations of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, and IL-10 were determined using a cytometric bead array. RESULTS: The five patients with meningism all showed fever and meningeal signs such as severe headache and nuchal stiffness without CSF pleocytosis (<5 cells/mm3). Four patients were associated with herpetic Kaposi's eczema, herpes simplex, or herpes zoster, and all five patients had favorable outcomes. The levels of all CSF cytokines in patients with meningism were below normal values, whereas IFN-gamma and IL-6 in patients with viral meningitis were moderately elevated. CONCLUSION: The normal cytokine levels in meningism may possibly reflect the lack of direct viral infection and may be helpful in differentiating both meningism and viral meningitis at an early stage.

Adult↗
PubMed2005

Probable chronic viral encephalitis with microglial nodules in the entire brain: a case report with necropsy.

BACKGROUND: Chronic encephalitis has rarely been seen, probably due to its viral origins, which may produce the disease in healthy or immunocompromised hosts. The etiology and pathophysiology of these types of encephalitis have not yet been clarified. CASE REPORT: A 63-year-old Japanese woman with underlying multiple myeloma developed chronic encephalitis with fever and progressive dementia, bilateral mild thalamic lesions on magnetic resonance imaging, and a prolonged pleocytosis, normal glucose value, and elevated interleukin-6 and interferon-gamma in the cerebrospinal fluid (CSF). The patient died of pneumonia 6 months after the onset of illness, and diffuse microglial nodules were found in the entire brain. No causative viral agents were identified by polymerase chain reaction and serological tests. CONCLUSIONS: The patient was presumed to have suffered from chronic viral encephalitis, based on clinical findings, including CSF and cytokine changes. Microglial nodules are observed in flavivirus group encephalitides, Rickettsia infections, and cytomegalovirus encephalitis in immunocompromised hosts. The possible pathogenesis of this rare encephalitis is discussed.

Autopsy↗
PubMed2005

Herpes simplex virus type 2 recurrent meningitis (Mollaret's meningitis): a consideration for the recurrent pathogenesis.

We report a 44-year-old Japanese woman with herpes simplex virus (HSV) type 2 recurrent meningitis (Mollaret's meningitis). The diagnosis was confirmed by nested polymerase chain reaction in her cerebrospinal fluid, but the patient's conventional HSV antibodies by complement fixation, neutralizing test or enzyme immunoassay showed low titres with low lymphoproliferative response. Several similar cases are discussed. Although the reason for the recurrent pathogenesis is uncertain, our report suggests that the low immune response including immune evasion may be involved in the pathogenesis of HSV type 2 recurrent meningitis. For this patient, long-term suppressive and patient-initiated therapies were conducted to prevent the recurrence of meningitis.

Acyclovir↗
PubMed2005

Herpes simplex encephalitis presenting with bilateral hippocampal lesions on magnetic resonance imaging, simultaneously complicated by small cell lung carcinoma.

We report a 75-year-old man who developed herpes simplex encephalitis (HSE), presenting with bilateral hippocampal lesions on magnetic resonance imaging, and this case was simultaneously complicated by small cell lung carcinoma. We identified a new anti-neuronal antibody in the cerebrospinal fluid of this patient. Our findings suggest that HSE and paraneoplastic limbic encephalitis (PLE) can overlap, and we discuss the relationships of HSE, PLE, and related disorders.

Aged↗
PubMed2004

Non-herpetic acute limbic encephalitis: cerebrospinal fluid cytokines and magnetic resonance imaging findings.

OBJECTIVE: Non-herpetic acute limbic encephalitis (non-herpetic ALE) is regarded as a new subgroup of limbic encephalitis. In the present study, clinical findings and cerebrospinal fluid (CSF) cytokines in patients with non-herpetic ALE were investigated. PATIENTS AND METHODS: For adult inpatients in our hospital and related hospitals from 1996 to 2001, non-herpetic ALE was examined according to the criteria described in this study. Six patients were diagnosed as having non-herpetic ALE, and their clinical data and magnetic resonance imaging (MRI) were analyzed. In the CSF samples of the 6 patients with non-herpetic ALE and 6 patients with herpes simplex encephalitis (HSE), the concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and interferon (IFN)-gamma were determined using sandwich-type enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: The six patients with non-herpetic ALE showed all the acute encephalitis features, such as fever, altered consciousness, seizures, memory impairment, and mild CSF pleocytosis. MRI demonstrated selective abnormal signals in the limbic system, including the bilateral hippocampi and amygdalae. The levels of CSF IL-6 and IFN-gamma in patients with non-herpetic ALE were significantly lower than those in patients with HSE (p<0.05 and p<0.01, respectively). The levels of both TNF-alpha and IL-1beta were below the detection limits in both groups. CONCLUSION: Six patients were newly diagnosed as having non-herpetic ALE in this study. These patients revealed both acute limbic encephalitis and MRI abnormalities in the bilateral hippocampi and amygdalae. The levels of IL-6 and IFN-gamma in the CSF of patients with non-herpetic ALE were significantly lower than those of patients with HSE, possibly reflecting an immunological process in this type of ALE rather than direct viral infection.

Acute Disease↗
PubMed2004

An unexpected outbreak of Japanese encephalitis in the Chugoku district of Japan, 2002.

Six patients unexpectedly presented with Japanese encephalitis (JE) from early August to mid-September 2002 in the Chugoku district of Japan. The mean age was 67.5 years (range 42 - 89 years); the onset period in two patients shifted to the middle of September. The JE virus was isolated from the cerebrospinal fluid samples from two patients, and the strain isolated in the one was identified as genotype III. Neurologically, consciousness impairment, meningeal signs, rigidity, hemiparesis, tetraparesis, and convulsive seizures were commonly observed. Magnetic resonance imaging uniformly revealed high signal intensities in the bilateral thalami, brainstem (substantia nigra), hippocampi, and brain cortices. In all patients, acyclovir was used, due to the unexpected outbreak of JE. Five patients, except for one without sequelae, had a severe outcome, including one death. This report indicates that JE in Japan is still a threat to adults and the elderly with decreased or absent immunity to the JE virus.

Adult↗
PubMed2003

A case of adult-onset Alexander disease with Arg416Trp human glial fibrillary acidic protein gene mutation.

Heterozygous point mutations in the coding region of the human glial fibrillary acidic protein (GFAP) gene have been reported in patients with various forms of Alexander disease (AD). We report a case of genetically confirmed adult-onset AD with palatal myoclonus, pyramidal tract signs, cerebellar signs, and marked atrophy of the medulla oblongata and spinal cord, autonomic dysfunction and heterozygous R416W GFAP mutation. Interestingly, this R416W mutation has also been reported in both infantile and juvenile forms of Alexander disease. The fact that a R416W mutation causes various types of AD suggests that clinical severities of AD are due not only to the different sites and nature of mutations in GFAP, but also to other modifying factor(s).

Adult↗
PubMed2003

Epstein-Barr virus infections of the central nervous system.

OBJECTIVE: Epstein-Barr virus (EBV), a lymphotropic herpes virus causing infectious mononucleosis (IM), also causes various central nervous system (CNS) infections. In the present study, EBV CNS infections were investigated. PATIENTS AND METHODS: For adult inpatients in our hospital and related hospitals between 1984-2002, CNS syndromes with IM symptoms were examined, and serologic positives were assessed according to established criteria. Polymerase chain reaction (PCR) was performed for cerebrospinal fluid (CSF) from seven patients. RESULTS: Ten patients with EBV-related CNS infections were found; their mean age was 36 years (20-79 years). The neurologic forms were as follows: acute encephalitis (4 patients), acute cerebellar ataxia (1), acute disseminated encephalomyelitis (ADEM) (2), myelitis (1), and meningitis (2). The PCR from CSF was positive in two patients with meningitis, one patient with ADEM, and one patient with encephalitis-associated chronic EVB infection. One case of encephalitis and another of relapsing ADEM were attributed to chronic EBV infection. CONCLUSION: Our study identified a variety of EBV-related CNS infections. EBV CNS infections are divided into two groups: 1) CNS syndromes associated with primary EBV or reactivated infection, and 2) those associated with chronic EBV infection; it is notable that in the former, diverse CNS syndromes including ADEM can occur, whereas in the latter, chronic or recurrent CNS syndromes are produced.

Adult↗
PubMed2002

A case of adult influenza A virus-associated encephalitis: magnetic resonance imaging findings.

A 27-year-old man presented with fever, convulsive seizure, and sudden impairment of consciousness. Magnetic resonance imaging (MRI) abnormalities were found in the bilateral thalami, including the brain stem and white matter. The possibility of a previous influenza A virus infection was considered, and cerebrospinal fluid cells and interleukin-6 were elevated. The MRI findings closely resembled those found in cases of childhood acute necrotizing encephalopathy (ANE). The present case suggests that adult influenza A virus-associated encephalitis/encephalopathy or ANE can occur during winter influenza epidemics.

Adult↗