Next-generation sequencing technology as a powerful detection and semi-quantitative method for herpes simplex virus type 1 in pediatric encephalitis

This case report presents a 1-year-old boy from China, with sudden onset of fever, convulsion, and sleepiness, screened for viral DNA in blood and cerebrospinal fluid (CSF) sample using next-generation sequencing (NGS) to diagnose herpes simplex virus type 1 (HSV-1) encephalitis, further validated by PCR. After acyclovir treatment, the patient’s symptom disappeared and HSV-1 DNA unique reads decreased from 4290 to zero in CSF, and from 23 to zero in blood detected by NGS. The clinical presentation and outcome were consistent with the pathogenic diagnostic results of NGS. NGS of CSF samples can be used as a diagnostic assay for HSV-1 encephalitis and also might be a semi-quantitative method for evaluation of treatment effect.     

Detection of virus in CSF from the cases with meningoencephalitis by next-generation sequencing

We screened for viral DNA in cerebrospinal fluid samples using next-generation sequencing (NGS) technology to diagnose CNS viral infections. We collected CSF samples from four cases with clinically suspected viral meningoencephalitis. DNA extracted from the samples was analyzed with NGS, and the results were further validated using PCR. Herpes simplex virus 1 (HSV-1) was detected in the CSF of two patients, HSV-2 and human herpes virus type 3 (HHV-3, VZV) in the CSF of two other patients separately. The number of unique reads of the identified viral genes ranged from 144 to 44205 (93.51 to 99.57 %). The coverage of identified viral genes ranged from 12 to 98 % with a depth value of 1.1 to 35, respectively. The results were further confirmed using PCR in three cases. The clinical presentation and outcomes of these four cases were consistent with the diagnostic results of NGS. NGS of CSF samples can be used as a diagnostic assay for CNS viral infection. Its further application for “pan-viral” or even “pan-microbial” screening of CSF might influence the diagnosis of CNS infectious diseases.     

Genome-based analysis of SFTSV causing severe encephalitis with brain lesions

Encephalitis is an infrequent manifestation in the various spectrums caused by severe fever with thrombocytopenia syndrome virus (SFTSV) infection. There are few data about the possible pathogenic mechanisms of SFTSV-associated encephalitis. Here, two SFTSV-infected patients with onset of encephalitis were enrolled. The whole genome of two SFTSV strains isolated from cerebrospinal fluid (CSF) was deeply sequenced by next-generation sequencing (NGS) and phylogenetic analysis was conducted. The specific mutations of M fragment were P98L and T665S respectively. The three-dimensional structure of glycoprotein Gn which was encoded by M fragment, an important virulence factor of SFTSV, was constructed by SWISS-MODEL. There was no significant variation in glycoprotein Gn of the two isolates comparing to other strains without encephalitis. Phylogenetic trees based on the complete sequences of M segment showed the two strains were highly identical to other local strains without encephalitis. Our study demonstrates that the virulence factors of SFTSV with encephalitis are not different from those without encephalitis. SFTSV itself is a neurotropic virus.     

Next-generation sequencing and genetic diagnosis of Charcot-Marie-Tooth disease

Over 70 different Charcot-Marie-Tooth disease (CMT)–associated genes have now been discovered and their number is growing. Conventional genetic testing for all CMT genes is cumbersome, expensive, and impractical in an individual patient. Next-generation sequencing (NGS) technology allows cost-effective sequencing of large scale DNA, even entire exome (coding sequences) or whole genome and thus, NGS platform can be employed to effectively target a large number or all CMT-related genes for accurate diagnosis. This overview discusses how NGS can be strategically used for genetic diagnosis in patients with CMT or unexplained neuropathy. A comment is made to combine simple clinical and electrophysiological algorithm to assign patients to major CMT subtypes and then employ NGS to screen for all known mutations in the subtype-specific CMT gene panel.     

抗GABA(B)R脑炎临床、脑电图及随访研究

目的分析抗GABA(B)R脑炎临床,影像学及脑电图(EEG)特征。方法 5例血清和脑脊液(CSF)抗GABA(B)R抗体阳性的抗GABA(B)R脑炎,分析CSF白细胞数、头颅磁共振(MRI)、24h长程视频脑电图(VEEG)和预后特点。结果 5例抗GABA(B)R脑炎中,精神行为异常2例,意识障碍2例,CSF白细胞数增高4例,癫痫发作5例,其中癫痫持续状态4例(80%)。24h VEEG监测3例各导可见多量阵发性长程持续5~30s、4~6Hzθ节律,并前额、额、前颞可见尖波或复合性慢波。未见异常2例。头颅MRI异常1例,累及海马、额叶皮质。呼吸衰竭1例,行气管插管,未用呼吸机辅助呼吸。1例合并血和CSF抗Hu抗体阳性并发肺癌。随访半年死亡3例(60%),完全正常2例(40%)。结论抗GABA(B)R脑炎是以癫痫发作为特点的疾病,本组5例患者均早期出现严重的癫痫发作。预后与癫痫的严重程度和是否合并肿瘤有关。     

Encephalomyeloradiculopathy associated with Epstein-Barr virus: primary infection or reactivation?

Introduction - Encephalomyeloradiculopathy (EMR) is a new syndrome, characterized by extensive involvement of the nervous system at different levels, including brain, medulla and spinal roots. We describe a patient presenting with prodromal febrile illness, followed by a wide infection of the nervous system with transverse myelitis and less severe meningitis, encephalitis and polyradiculopathy. The patient was treated with high-dose corticosteroids, antibiotics and acyclovir; in spite of therapy his condition improved very slowly, with severe neurological sequelae. Material and methods - Antiviral antibodies were searched for in serum and cerebrospinal fluid (CSF) by commercially available ELISA kits. Viral investigations were performed by cell culture isolation and search for viral antigens, and genomic nucleic acids were investigated by polymerase chain reaction (PCR). Results - Virological and serological studies evidenced a primary infection by cytomegalovirus (CMV), possibly responsible for the prodromal illness, persisting in the course of the disease. PCR performed in the peripheral blood mononuclear cells (PBMCs), DNA collected early and in the CSF drawn 30 days after the onset of the disease showed Epstein-Barr virus (EBV) DNA. The serum panel of EBV antibodies was typical of an intercurrent virus reactivation, more than of a primary infection. Conclusion - EBV is known to be highly infectious for the nervous system, in this case of EMR the presence of DNA sequences in the PBMCs and CSF suggests that EBV plays a role in the development of this newly described syndrome.     

Frequent convulsions in the post-eruptive stage of exanthem subitum]

We report here three infants with frequent convulsions in the post-eruptive stage of exanthem subitum (ES) due to human herpesvirus 6 (HHV-6) infection. Postictal electroencephalogram (EEG) showed in all the patients abnormal epileptic discharges, which disappeared in the following by three to eighteen months. In one case, brain magnetic resonance imaging (MRI) revealed focal gliosis. SPECT demonstrated hypoperfusion of the lesion. In the cerebro spinal fluid (CSF) of all the patients, HHV-6 DNA was negative on polymerase chain reaction (PCR) and HHV-6 antibodies were not significantly increased. Although encephalitis has been reported to complicate primary HHV-6 infection, our patients were not diagnosed as having encephalitis because of the clinical, CSF, EEG and CT findings. However, they had frequent convulsions. Not only virus invasion but also a secondary reaction including vasculitis may cause the central nervous system complications of HHV-6 infection. Frequent convulsions may occur in the post-eruptic stage after HHV-6 infection.     

Limbic encephalitis associated with drug-induced hypersensitivity syndrome due to phenobarbital--a case report]

A 68-year-old man was diagnosed as drug-induced hypersensitivity syndrome (DIHS) with erythema and liver dysfunction three weeks after an administration of phenobarbital. Three weeks after the appearance of skin eruptions, the patient developed disturbed consciousness and status epilepticus. MRI findings revealed bilateral symmetrical abnormalities localized in the amygdala, hippocampi, parahippocampal gyri, and insula regions, which showed high intensities on diffusion weighted images and decreased apparent diffusion coefficient (ADC) values on an ADC map. We considered that the MRI abnormalities were indicative of cytotoxic edema. Increased serum anti-human herpesvirus 6 (HHV-6) IgG antibody titer and presence of HHV-6 DNA in peripheral blood, revealed by polymerase chain reaction (PCR) analysis, suggested reactivation of HHV-6. However, PCR analysis performed with DNA extracted from the CSF was negative for HHV-6. We concluded that limbic encephalitis in the present case might have been caused by an autoimmune inflammatory mechanism associated with drug-induced hypersensitivity syndrome, as well as a direct infection of HHV-6 to the central nervous system.     

HSV encephalitis in a child with brain stem glioma: a rare complication of therapy

BACKGROUND: Herpes simplex virus (HSV) encephalitis is a rare association with pediatric neurosurgical pathologies. CASE REPORT: A 13-year-old boy was diagnosed with an inoperable, biopsy-proven pontine grade II astrocytoma. During radiotherapy, he developed status epilepticus controlled by thiopentone with intubation and ventilation. Empiric cefotaxime and aciclovir were given. Lumbar cerebrospinal fluid (CSF) showed a normal white cell count, normal glucose, and a slightly elevated protein level. However, the CSF showed a positive polymerase chain reaction (PCR) for HSV type 1 DNA. Intravenous aciclovir was given for 21 days and foscarnet for 7 days. He was extubated after 4 weeks at which time he was aphasic with spastic diplegia. After 8 weeks, MRI brain scan showed the typical bitemporal pattern of HSV encephalitis. He made slow improvement but died 8 months after diagnosis from tumor progression. CONCLUSION: HSV encephalitis is a rare but life threatening complication in neurosurgical patients. A low threshold for both investigation with CSF PCR and empirical treatment with intravenous aciclovir is warranted. As in this case, initial microscopic examination of the CSF may be normal. The literature on HSV encephalitis in neurosurgical patients is discussed.     

Early diagnosis and successful treatment of acute cytomegalovirus encephalitis in a renal transplant recipient

Summary We report the case of a 40-year-old male HIV-negative renal transplant patient with allograft rejection and immunosuppressive therapy who presented with acute cytomegalovirus (CMV) encephalitis. CT and MRI of the brain were normal but EEG showed diffuse slowing and dysrhythmia. In cerebrospinal fluid (CSF) initially 81 cells/l were found and immunocytochemistry showed a decreased CD4/CD8 ratio and increased values of activated lymphocytes, natural killer cells and immunoglobulin-containing cells. CMV-specific IgM antibodies in CSF and serum, immunostaining of CMV antigen in CSF cells and virus culture from CSF and urine were negative. During the first 3 weeks of illness no intrathecal production of immunoglobulins could be detected. Early diagnosis of CMV encephalitis was made by in situ hybridization (ISH) on CSF cell preparations and the polymerase chain reaction (PCR) which was positive in CSF and blood. On day 26 diagnosis was confirmed by detection of CMV-specific intrathecal IgG production. The patient was treated with ganciclovir, anti-CMV immunoglobulins and intrathecal beta interferon. He recovered completely after 2 months. Our data demonstrate the usefulness of ISH and PCR in the early diagnosis of CMV encephalitis and perhaps may encourage the use of intrathecal beta interferon in other patients with this disease.     

A case of limbic encephalitis associated with breast cancer developed in an HTLV-1 carrier]

We here present a case of 44-year-old woman, a carrier of human T-lymphotrophic virus type-1 (HTLV-1), who suffered from limbic encephalitis and breast cancer. In December 1997, the patient's behavior became abnormal. Three weeks later, she became markedly forgetful. At that time neurological examinations revealed that she had anterograde and retrograde amnesia, disorientation, and confabulation, although her consciousness was clear. Anti-Hu and anti-Yo antibodies and antinuclear antibodies in the serum were negative. Flow cytometric study of the peripheral blood lymphocytes showed an increased percentage of CD3+CD25+ cells, although the percentages of CD4+CD45RA+ and CD4+CD45RO+ cells were normal. Lymphocytic responses to phytohemagglutinin or concanavalin A were normal. Anti-HTLV-1 antibody was positive both in the serum and in the cerebrospinal fluid (CSF). The level of immunoglobulin G was high and two oligoclonal immunoglobulin G bands were positive in the CSF. Cytological study of the CSF showed no atypical cells. Findings for herpes simplex virus type I and II DNAs were negative with polymerase chain reaction in the CSF. There was no elevation of antibody titers against viruses including herpes simplex virus, cytomegalovirus, and measles virus, either in the serum or the CSF. Magnetic resonance imaging showed signal abnormalities in the medial portions of both temporal lobes, in particular, in the bilateral hippocampus. Six weeks after the onset, a cancerous tumor in her right breast was detected and removed by open surgery. The pathological diagnosis was invasive ductal carcinoma with neuroendocrine features. After mastectomy, anterograde and retrograde amnesia and disorientation mildly improved. The follow-up magnetic resonance imaging showed that signal abnormalities in the medial portions of both temporal lobes decreased and that the bilateral hippocampus became atrophic. We diagnosed the present case as paraneoplastic limbic encephalitis. There has been only one case report of limbic encephalitis associated with breast cancer.     

Meningoencephalitis in the acute phase of measles. Report of 6 cases

We present the clinical and laboratory manifestations of encephalitis following measles in six patients which were diagnosed during the epidemics that occurred in the city of S?o Paulo, Brazil, in 1997. We performed retrospective case analysis of the six patients diagnosed as having encephalitis due to measles. Encephalitis was diagnosed based on clinical grounds and on the cerebrospinal fluid (CSF) alterations. All the cases were serologically confirmed. Of 467 patients with measles who presented themselves for medical care at the Instituto de Infectologia Emílio Ribas six were diagnosed with encephalitis. Patient's age was 2 months to 28 years old. The most frequent symptoms were drowsiness and nuchal rigidity. CSF showed an increased of white cell count in all cases. Four patients were admitted to the intensive care unit. Two of them required mechanical ventilation. In only two patients did the computerized tomography show abnormalities. All showed good recovery without sequelae.     

Chemotherapy-induced autoimmune-mediated encephalitis during germinoma treatment

BackgroundAutoimmune mediated encephalitis (AME), which includes autoantibody-associated encephalitis and acute disseminated encephalomyelitis, is a common cause of encephalitis as well as infectious encephalitis in children. AME may be triggered by autoimmune responses to paraneoplastic syndromes and infections. Infectious encephalitis associated with an immunocompromised status caused by anti-cancer chemotherapy is well recognized; however, there have been few reports on the relationship between AME and chemotherapy.Case reportA ten-year-old previously healthy, developmentally normal girl was diagnosed with a pure germinoma in the suprasellar region. Following 30 days of induction chemotherapy, she developed a depressed level of consciousness with accompanying right hemiplegia, aphasia, and unexplained fever. Cerebrospinal fluid (CSF) analysis revealed positive oligoclonal bands and elevated neopterin levels. Neither atypical cells suggesting tumor exacerbation nor pathogens known to cause encephalitis were identified in the CSF. She was administrated immunosuppressive therapy and her symptoms rapidly improved. No known autoantibodies associated with autoantibody-associated encephalitis were identified in blood or CSF. However, the presence of oligoclonal bands and elevated neopterin levels in the CSF, and the favorable response to immunosuppressive therapy were consistent with an AME diagnosis. Thirteen days after the third course of chemotherapy, the patient developed a depressed level of consciousness again. Due to the recurrence of encephalitis, re-administration of immunosuppressive therapy was performed, which led to improvement in her symptoms. Recurrence of encephalitis has not occurred for 1 year after completion of chemotherapy.ConclusionThe chemotherapy-induced abnormal immune response might have triggered the AME.     

Measurement of gamma-interferon in sera and CSF in patients with multiple sclerosis and inflammatory neurological diseases

We examined whether gamma-interferon (gamma-IFN) can be detected in serum and CSF of patients with multiple sclerosis and other inflammatory neurological diseases. Gamma-IFN was assayed by solid phase radioimmunoassay on the forward sandwich principle. In 7 serum samples in acute stage of multiple sclerosis without corticosteroid, in 2 CSF samples in acute stage, gamma-IFN was not detected. In stable stage there was no case with positive gamma-IFN. The patient with tuberculous meningitis showed high titer in CSF but not in serum. One case with herpes zoster meningitis, one case out of 2 aseptic encephalitis showed positive gamma-IFN in CSF. In one case with Vogt-Koyanagi-Harada disease, gamma-IFN was detected both in serum and CSF. One case with Neuro-Beh?et syndrome showed positive gamma-IFN in CSF. No gamma-IFN was detected in 2 cases with Guillain-Barré syndrome, one case with Crow-Fukase syndrome, Fisher syndrome, 2 cases with polymyosits. gamma-IFN in CSF was detected in meningitis and encephalitis, but not in serum. This suggests that the locally infiltrating cells produce gamma-IFN. However, we could not detect gamma-IFN in either CSF or serum of patients with multiple sclerosis. Negative results of gamma-IFN in patients with multiple sclerosis can be interpreted in 2 ways. 1. The half life of gamma-IFN is very short in vivo, and the level of gamma-IFN may not be detected at the time of sampling. 2. Generalized augmentation of gamma-IFN production may not be observed but locally infiltrating cells or astrocytes might produce gamma-IFN.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arterial spin labeling perfusion imaging in an infant with anti-N-methyl-D-aspartate receptor encephalitis: A case report

BackgroundAnti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is an autoimmune encephalitis characterized by complex neuropsychiatric syndromes and the presence of cerebrospinal fluid (CSF) antibodies against NMDAR. The characteristics of anti-NMDAR encephalitis in children, particularly infants, are unclear due to difficulties in neurologic assessment such as psychiatric symptoms. Additionally, subtle or non-specific findings of conventional magnetic resonance imaging (MRI) make early diagnosis even more difficult. Herein, we present the first case of infant anti-NMDAR encephalitis in which perfusion imaging demonstrated marked abnormalities and the absence of conventional MRI findings.Case presentationThe patient was an 11-month-old boy who was admitted because of seizure and prolonged fever. He presented with involuntary movements of the mouth and tongue. Brain MRI showed no morphological abnormalities, but three-dimensional arterial spin labeling (ASL) perfusion imaging showed reduced blood flow in the left temporal and frontal regions and the right cerebellum. After that, a positive anti-NMDAR antibody test result was received. Despite treatment with IVIG and methylprednisolone, the involuntary movements and autonomic dysfunction gradually became more prominent. After rituximab administration, the clinical symptoms improved slightly, and follow-up MRI revealed diffuse brain atrophy and improvement in the balance of brain perfusion.ConclusionsTo the best of our knowledge, this is the first case report of infantile anti-NMDAR encephalitis in which cerebral blood flow was evaluated using three-dimensional ASL perfusion imaging. Indeed, our case, which showed abnormalities only in ASL perfusion imaging, suggests that CBF assessment could aid in the early diagnosis of anti-NMDAR encephalitis in infants.     

Hyperammonemia in a case of herpes simplex and anti-N-methyl-d-aspartate receptor encephalitis

Herpes simplex encephalitis (HSE) is a widely accepted risk factor for anti N-methyl-d-aspartate receptor (NMDAR) encephalitis. Association of inherited metabolic disease has never been reported in a patient with HSE and anti-NMDAR encephalitis. Herein, we report a case of pediatric HSE complicated by development of anti-NMDAR encephalitis; this patient showed subsequent recurrent, unexplained episodes of encephalopathy associated with hyperammonemia. The patient was diagnosed with lysinuric protein intolerance (LPI), a rare inborn metabolic disorder. Although it would be difficult to make conclusions regarding the casual link of HSE and anti-NMDAR encephalitis with LPI from a single case, there have been many reports that autoimmune diseases and immunologic abnormalities are frequently associated with LPI. Thus, we speculate that LPI may contribute to the development of anti-NMDAR encephalitis following HSE.     

20例抗N-甲基-D-天冬氨酸受体脑炎患者临床特点分析

目的回顾性分析总结20例抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎患者的临床特点,增强对抗NMDAR脑炎的认识。方法对90例临床疑似脑炎患者的血清和脑脊液进行抗NMDAR-IgG检测,分析确诊为抗NMDAR脑炎的20例患者的临床表现、实验室检查、治疗及预后。结果抗NMDAR脑炎患者男女比例为6:14,中位年龄24岁,首发症状及主要精神症状多有不同。20例抗NMDAR脑炎患者中有12例患者血清和脑脊液中抗NMDAR-IgG抗体均阳性,其他8例仅在血清或脑脊液中检测到抗NMDAR-IgG抗体。5例盆腔检查异常,其中1例病理确诊为成熟囊性畸胎瘤。6例患者脑电图异常,7例头颅MRI异常。除1例患者未接受免疫治疗死亡外,其余患者接受免疫治疗后症状均有不同程度的缓解,其中3例未伴畸胎瘤的患者用二线免疫治疗后复检血清和脑脊液中抗NMDAR-IgG抗体水平下降。结论抗NMDAR脑炎患者中年轻女性发病率较高。二线免疫治疗可能对不伴有畸胎瘤患者的疗效更好。CSF中的抗NMDAR-IgG抗体的阳性率高于血清,同时检测血清和脑脊液中抗NMDAR抗体可以提高疾病的诊断效率。     

Autoimmune neurological disorders associated with group-A beta-hemolytic streptococcal infection

Although central nervous system (CNS) disorders associated with group-A beta-hemolytic streptococcal (GABHS) infection occur only rarely, Sydenham’s chorea is a well-recognized disease that can arise following infection. Children may develop a tic, obsessive compulsive disorder (OCD), and extrapyramidal movement subsequent to GABHS infection. These disorders have been termed pediatric autoimmune neuropsychiatric disorders associated with streptococci (PANDAS). Herein we report one case each of acute disseminated encephalomyelitis (ADEM), PANDAS and subacute encephalitis associated with GABHS infection. To evaluate the pathogenesis of the CNS disorders associated with GABHS infection, we measured levels of neurotransmitters, cytokines, anti-neuronal autoantibodies, and performed immunohistochemistry using patient sera to stain human brain sections. All three cases showed psychiatric behavioral disorders. Immunotherapy was effective, and homovanillic acid levels in the cerebrospinal fluid (CSF) were elevated at the acute stage in all three cases. In each case of ADEM and PANDAS, immunohistochemistry demonstrated neuronal impairment in the basal ganglia during the acute stage. Neuronal immunoreactivity was visualized in the cerebral cortex at the acute stage in the case of subacute encephalitis. There was no direct correlation between immunoreactivity of patient sera on the brain sections and positivity of anti-neuronal autoantibodies or CSF biomarkers. The results suggest that autoimmune responses may modulate neurotransmission, and the use of patient serum for immunohistochemistry is a sensitive screening method for the detection of anti-neuronal autoantibodies in CNS disorders associated with GABHS infection.     

A polymerase chain reaction assay of cerebrospinal fluid in patients with suspected herpes simplex encephalitis.

A polymerase chain reaction (PCR) was used to detect herpes simplex virus (HSV) deoxyribonucleic acid (DNA) in CSF of 109 patients with possible herpes simplex encephalitis. HSV DNA was found in 20/109 patients. In 14 of these patients the diagnosis was confirmed by a rise in CSF antibodies, isolation of HSV from the brain, or both. In 3 patients CSF antibodies did not rise and 3 patients did not have a follow up lumbar puncture or a brain biopsy. In 19/20 patients HSV DNA was present in the first CSF specimen. The virus was identified as HSV I in 15 patients and HSV II in 4; the virus was not typed in the other patient. A possible diagnosis of herpes simplex encephalitis was not confirmed in the 89 PCR-negative patients. HSV DNA was present in CSF of 3 patients who had meningitis with herpetic genital infections but it was not found in 24 patients with other neurological diseases. The results suggest that the detection of HSV DNA in CSF using a PCR assay will be an accurate method of early diagnosis of herpes simplex encephalitis.     

Murray valley encephalitis mimicking herpes simplex encephalitis.

We describe a patient with serologically proven Murray Valley encephalitis (MVE), whose presentation was clinically and radiologically characteristic of Herpes simplex encephalitis (HSE). The reports of MRI abnormalities in MVE, and the closely related Japanese Encephalitis and West Nile virusii are mostly of bilateral thalamic or grey matter involvement. The MRI scan findings in this case instead showed the typical temporal lobe changes of HSE. Our case report highlights that MVE can mimic HSE, both clinically and radiologically. Therefore it is important to collect an accurate and detailed travel history from patients where there is a risk of exposure to MVE virus. If suspected, antibody testing of serum and CSF, and CSF for MVE-RNA if available, should be undertaken. This case also highlights the potential under-diagnosis of Murray Valley encephalitis.