Mycoplasma pneumoniae ecephalitis

Determining the Clinical Characteristics, Treatment Strategies, and Prognostic Factors for Mycoplasma pneumoniae Encephalitis in Children: A Multicenter Study in China

BACKGROUND AND PURPOSE

Most of the knowledge of Mycoplasma pneumonia (M. pneumoniae) encephalitis (MPE) in children is based on case reports or small case series. This study aimed to describe the clinical features and prognostic factors of MPE, and the efficacy of azithromycin with or without immunomodulatory therapy.

METHODS

The medical data of 87 patients with MPE from 3 medical centers in southwestern China over a 7-year period were reviewed.

RESULTS

MPE was found in children of all ages except for neonates. The most common neurological manifestations included consciousness disturbance (90%) and headache (87.4%), the most common extraneurological manifestations included fever (96.5%) and respiratory system involvement (94.3%); multisystem involvement (98.2%) and elevated C-reactive protein (CRP) (90.8%) were also prominent. M. pneumoniae was detected in cerebrospinal fluid (CSF) less often than in blood and respiratory tract secretions. Azithromycin with intravenous immunoglobulin or/and corticosteroid treatment can shorten the hospitalization duration and the clinical improvement process. Most patients (82.8%) received a favorable prognosis; serum lactate dehydrogenase (LDH) and CSF protein levels were higher in the poor-outcome group than in the good-outcome group (p<0.05). Neurological sequelae are likely to continue when the onset of this condition occurs during teenage years.

CONCLUSIONS

MPE generally presented with nonspecific clinical manifestations. In children with acute encephalitis accompanied by multi-system involvement and prominently elevated CRP, M. pneumoniae should be considered as a possible pathogen. Immunomodulating therapies should be recommended regardless of the duration of the prodromal period. High CSF protein level, blood LDH elevation, and higher age may be associated with an unfavorable outcome.

Autoimmune Movement Disorders in Children

Over the last decade, there have been significant advances in the identification, characterization, and treatment of autoimmune neurologic disorders in children. Many of these diseases include a typical movement disorder that can be a powerful aid to diagnosis. Frequently, movement disorders in autoimmune conditions are the sole or among a few presenting symptoms, allowing for earlier diagnosis of an underlying malignancy or systemic autoimmune disease. Given that early detection and treatment with immunotherapy may confer improved outcomes, recognizing these patterns of abnormal movements is essential for child neurologists. The purpose of this review is to summarize the clinical characteristics, diagnosis, and treatment of movement disorders that occur in pediatric autoimmune disorders.

Seroprevalence of lymphocytic choriomeningitis virus and Ljungan virus in Finnish patients with suspected neurological infections

Directly-transmitted rodent-borne zoonotic viruses, such as lymphocytic choriomeningitis virus (LCMV) can cause nervous system infections. Rodent-borne Ljungan virus (LV) is considered potentially zoonotic possibly causing neurological symptoms. Our objective was to understand the role of these two viruses compared to other pathogens in causing neurological infections in Finnish patients. Routine screening data were available for 400 patients aged 5-50 years, collected from December 2013 to December 2014 with suspected neurological infection. Depending on symptoms, patients were variously tested for herpesviruses, enteroviruses, varicella zoster virus, and Mycoplasma pneumoniae, while those suspected of tick bite were further tested for Borrelia spp. and tick-borne encephalitis virus using antibody and/or nucleic acid tests. For 380 patients, we also screened the RNA and antibody prevalence of LCMV and LV in order to test if either of these viruses were the causative agent. Data collected indicated that the causative microbial agent was confirmed in only 15.5% of all Finnish patients with neurological symptoms, with M. pneumoniae (26 cases) being the most common causative agent found in sera, whereas Borrelia spp. (15), herpes simplex viruses (7), and enteroviruses (5) were the most common agents confirmed in the CSF. The seroprevalences for LV and LCMV were 33.8% and 5.0%, respectively, but no samples were PCR-positive. In this study, M. pneumoniae and Borrelia spp. were the most common causative agents of neurological infections in Finland. No LCMV or LV infections were detected. We conclude there was no association of LV with neurological diseases in this patient cohort.

Infectious encephalitis: Management without etiological diagnosis 48hours after onset

Introduction

The etiological diagnosis of infectious encephalitis is often not established 48 hours after onset. We aimed to review existing literature data before providing management guidelines.

Method

We performed a literature search on PubMed using filters such as “since 01/01/2000”, “human”, “adults”, “English or French”, and “clinical trial/review/guidelines”. We also used the Mesh search terms “encephalitis/therapy” and “encephalitis/diagnosis”.

Results

With Mesh search terms “encephalitis/therapy” and “encephalitis/diagnosis”, we retrieved 223 and 258 articles, respectively. With search terms “encephalitis and corticosteroid”, we identified 38 articles, and with “encephalitis and doxycycline” without the above-mentioned filters we identified 85 articles. A total of 210 articles were included in the analysis.

Discussion

Etiological investigations must focus on recent travels, animal exposures, age, immunodeficiency, neurological damage characteristics, and potential extra-neurological signs. The interest of a diagnosis of encephalitis for which there is no specific treatment is also to discontinue any empirical treatments initially prescribed. Physicians must consider and search for autoimmune encephalitis.

Pathogenesis of Mycoplasma pneumoniae: An update

Genus Mycoplasma, belonging to the class Mollicutes, encompasses unique lifeforms comprising of a small genome of 8,00,000 base pairs and the inability to produce a cell wall under any circumstances. Mycoplasma pneumoniae is the most common pathogenic species infecting humans. It is an atypical respiratory bacteria causing community acquired pneumonia (CAP) in children and adults of all ages. Although atypical pneumonia caused by M. pneumoniae can be managed in outpatient settings, complications affecting multiple organ systems can lead to hospitalization in vulnerable population. M. pneumoniae infection has also been associated with chronic lung disease and bronchial asthma. With the advent of molecular methods of diagnosis and genetic, immunological and ultrastructural assays that study infectious disease pathogenesis at subcellular level, newer virulence factors of M. pneumoniae have been recognized by researchers. Structure of the attachment organelle of the organism, that mediates the crucial initial step of cytadherence to respiratory tract epithelium through complex interaction between different adhesins and accessory adhesion proteins, has been decoded. Several subsequent virulence mechanisms like intracellular localization, direct cytotoxicity and activation of the inflammatory cascade through toll-like receptors (TLRs) leading to inflammatory cytokine mediated tissue injury, have also been demonstrated to play an essential role in pathogenesis. The most significant update in the knowledge of pathogenesis has been the discovery of Community-Acquired Respiratory Distress Syndrome toxin (CARDS toxin) of M. pneumoniae and its ability of adenosine diphosphate (ADP) ribosylation and inflammosome activation, thus initiating airway inflammation. Advances have also been made in terms of the different pathways behind the genesis of extrapulmonary complications. This article aims to comprehensively review the recent advances in the knowledge of pathogenesis of this organism, that had remained elusive during the era of serological diagnosis. Elucidation of virulence mechanisms of M. pneumoniae will help researchers to design effective vaccine candidates and newer therapeutic targets against this agent.

Community-Acquired Pneumonia Caused by Mycoplasma pneumoniae: How Physical and Radiological Examination Contribute to Successful Diagnosis

Mycoplasma pneumoniae is one of the most common causes of community-acquired pneumonia (CAP), particularly in young adults. Vital signs are usually normal except for temperature. On physical examination, general appearance is normal compared with that of typical pneumonia such as pneumococcal pneumonia patients. Mycoplasma sometimes causes ear infections such as otitis media. It is important to distinguish between typical pneumonia and atypical pneumonia such as mycoplasma pneumonia because having the right diagnosis allows for the use of the correct antibiotic to treat CAP while preventing development of drug-resistant bacteria and also decreasing medical cost. The symptoms and diagnosis of mycoplasma pneumonia is multi-fold. Auscultation of patients can demonstrate trace late inspiratory crackles or normal alveolar sounds; however, bilateral polyphonic wheezes can sometimes be heard because of bronchiolitis. With regard to radiological findings, a chest radiogragh often shows bilateral reticulonodular or patchy consolidation in both lower lobes. Pleural effusion is rarely observed in adult cases. Immunocompetent patients tend to reveal more extensive shadowing compared with immunocompromised patients. As serological diagnostic methods are not able to offer 100% reliable diagnosis, integration of physical and radiological examination is crucial to accurately diagnose mycoplasma pneumonia. Herein, I review the typical findings from physical examination and imaging patterns of patients with mycoplasma pneumonia.

Detection of macrolide resistant Mycoplasma pneumoniae in England, September 2014 to September 2015

Mycoplasma pneumoniae infection can cause pneumonia, particularly in children. Global increase in macrolide-resistant M. pneumoniae is of concern due to limited therapeutic options. We describe the detection of macrolide resistance-conferring mutations in 9.3% of 43 clinical specimens where M. pneumoniae was detected in England and Wales from September 2014‒September 2015. This study aims to impact by highlighting the presence of macrolide resistance in M. pneumoniae positive patients, promoting increased clinical vigilance.

Consensus guidelines for the investigation and management of encephalitis in adults and children in Australia and New Zealand

Encephalitis is a complex neurological syndrome caused by inflammation of the brain parenchyma. The management of encephalitis is challenging because: the differential diagnosis of encephalopathy is broad; there is often rapid disease progression; it often requires intensive supportive management; and there are many aetiologic agents for which there is no definitive treatment. Patients with possible meningoencephalitis are often encountered in the emergency care environment where clinicians must consider differential diagnoses, perform appropriate investigations and initiate empiric antimicrobials. For patients who require admission to hospital and in whom encephalitis is likely, a staged approach to investigation and management is preferred with the potential involvement of multiple medical specialties. Key considerations in the investigation and management of patients with encephalitis addressed in this guideline include: Which first-line investigations should be performed?; Which aetiologies should be considered possible based on clinical features, risk factors and radiological features?; What tests should be arranged in order to diagnose the common causes of encephalitis?; When to consider empiric antimicrobials and immune modulatory therapies?; and What is the role of brain biopsy?

Mycoplasma pneumoniae Epidemiology in England and Wales: A National Perspective

Investigations of patients with suspected Mycoplasma pneumoniae infection have been undertaken in England since the early 1970s. M. pneumoniae is a respiratory pathogen that is a common cause of pneumonia and may cause serious sequelae such as encephalitis and has been documented in children with persistent cough. The pathogen is found in all age groups, with higher prevalence in children aged 5–14 years. In England, recurrent epidemic periods have occurred at ~4-yearly intervals. In addition, low-level sporadic infection occurs with seasonal peaks from December to February. Voluntarily reports from regional laboratories and hospitals in England from 1975 to 2015 were collated by Public Health England for epidemiological analysis. Further data pertaining cases of note and specimens submitted to Public Health England from 2005 to 2015 for confirmation, molecular typing is included.

[Neurological symptoms due to Mycoplasma pneumoniae infection in nine children]

Mycoplasma pneumoniae infection is common in children. Extrapulmonary symptoms usually reveal as neurological symptoms, mainly as encephalitis with significant morbidity and mortality. Various other neurological presentations have also been reported. We describe a cohort of nine children with neurological manifestations due to M. pneumoniae infection, including five cases of encephalitis, one of polyradiculoneuritis, one of ophthalmoplegia, one of optic neuritis, and one of myositis. Progression was variable from ad integrum recovery to severe brain damage. Diagnosis is usually confirmed by PCR and/or serological follow-up, but the latter is still insufficiently used in practice to systematically affirm the diagnosis. Therapeutic management is not clearly defined and long-term progression can be uncertain despite early antibiotic and/or anti-inflammatory treatments.

Cerebellitis and acute obstructive hydrocephalus associated with Mycoplasma pneumoniae infection

Mycoplasma pneumoniae is associated with a variety of extrapulmonary manifestations, including central nervous system inflammation. A 9-year-old boy presented with acute cerebellitis and M. pneumoniae infection, resulting in obstructive hydrocephalus requiring neurosurgical intervention. This case, along with 4 similar ones reported in the literature, suggests a distinct clinicopathologic sequence caused by mycoplasma infection.

Diverse seizure presentation of acute Mycoplasma pneumoniae encephalitis resolving with immunotherapy

We report 3 previously normal children that presented for evaluation of new onset seizures. Case 1, a 7-year-old female, presented with refractory left frontal lobe seizures associated with right arm simple motor seizures refractory to 6 antiepileptic medications at sufficient doses and levels. Case 2, a 15-year-old female, presented with left frontotemporal lobe seizures and nonconvulsive seizures, associated with neuropsychiatric symptoms refractory to 5 antiepileptic medications. Both patients received intravenous steroids and intravenous immunoglobulin. Case 3, an 11-year-old male, presented with a generalized tonic clonic seizure and worsening hallucinations responding to intravenous corticosteroids and 1 antiepileptic medication. All 3 patients had extensive infectious and metabolic evaluation and were found to be serum immunoglobulin M positive for mycoplasma pneumoniae. Despite their prolonged severe symptoms, all patients had virtually complete recovery with excellent seizure control after aggressive seizure management with immunotherapy and antiepileptic medication.

A case of Mycoplasma pneumoniae-associated encephalomyelitis in a 16-year-old female presenting to an adult teaching hospital

We report a rare cause of encephalitis that is not often described in the adult clinical setting. Our case was a 16-year-old female who presented with a clinical picture of viral encephalitis; however, magnetic resonance imaging showed a demyelinating lesion of the left frontal lobe. In this age group, differential diagnoses of acute demyelination encephalomyelitis and multiple sclerosis were entertained. Further investigations demonstrated positive Mycoplasma pneumoniae serology. As a result, a diagnosis of Mycoplasma pneumoniae-associated encephalitis was made based on a process of exclusion.

Prognostic values of a combination of intervals between respiratory illness and onset of neurological symptoms and elevated serum IgM titers in Mycoplasma pneumoniae encephalopathy

BACKGROUND/PURPOSE

To retrospectively analyze the clinical manifestations of Mycoplasma pneumoniae (M. pneumoniae)-associated encephalopathy in pediatric patients.

METHODS

Pediatric patients with positive serum anti-M. pneumoniae immunoglobulin M (IgM) were enrolled in this study. Clinical signs and symptoms, laboratory data, neuroimaging findings, and electrophysiological data were reviewed.

RESULTS

Of 1000 patients identified, 11 (1.1%; male:female ratio = 7:4) had encephalopathy and were admitted to the pediatric intensive care unit. Clinical presentation included fever, symptoms of respiratory illness, and gastrointestinal upset. Neurological symptoms included altered consciousness, seizures, coma, focal neurological signs, and personality change. Neuroimaging and electroencephalographic findings were non-specific. Specimens of cerebrospinal fluid (CSF) for M. pneumoniae polymerase chain reaction (PCR) were negative. Higher M. pneumoniae IgM titers and longer intervals between respiratory and CNS manifestations were associated with worse outcomes.

CONCLUSION

Clinical manifestations of M. pneumoniae-associated encephalopathy were variable. Diagnosis of M. pneumoniae encephalopathy should not rely on CSF detection of M. pneumoniae by PCR. M. pneumoniae IgM titers and intervals between respiratory and CNS manifestations might be possibly related to the prognosis of patients with M. pneumoniae-associated encephalopathy.

Coexistence of myositis, transverse myelitis, and Guillain Barré syndrome following Mycoplasma pneumoniae infection in an adolescent

Guillain-Barré syndrome (GBS) and transverse myelitis may occur coexistently in the pediatric population. This may be explained by a shared epitope between peripheral and central nervous system myelin. Coexistent transverse myelitis, myositis, and acute motor neuropathy in childhood have not been previously described. We describe a 14-year-old female patient with transverse myelitis, myositis, and GBS following Mycoplasma pneumoniae infection. She presented with weakness and walking disability. Weakness progressed to involve all extremities and ultimately, she was unable to stand and sit. Based on the clinical findings, a presumptive diagnosis of myositis was made at an outside institution because of high serum creatine kinase level. The patient was referred to our institution for further investigation. Magnetic resonance imaging of spine revealed enhancing hyperintense lesions in the anterior cervicothoracic spinal cord. The electromyography revealed acute motor polyneuropathy. Serum M. pneumoniae IgM and IgG were positive indicating an acute infection. Repeated M. pneumoniae serology showed a significant increase in Mycoplasma IgG titer. The patient was given intravenous immunoglobulin for 2 days and clarithromycin for 2 weeks. She was able to walk without support after 2 weeks of hospitalization. This paper emphasizes the rarity of concomitant myositis, transverse myelitis, and GBS in children.

Chronic Lyme Disease and Co-infections: Differential Diagnosis

In Lyme disease concurrent infections frequently occur. The clinical and pathological impact of co-infections was first recognized in the 1990th, i.e. approximately ten years after the discovery of Lyme disease. Their pathological synergism can exacerbate Lyme disease or induce similar disease manifestations. Co-infecting agents can be transmitted together with Borrelia burgdorferi by tick bite resulting in multiple infections but a fraction of co-infections occur independently of tick bite. Clinically relevant co-infections are caused by Bartonella species, Yersinia enterocolitica, Chlamydophila pneumoniae, Chlamydia trachomatis, and Mycoplasma pneumoniae. In contrast to the USA, human granulocytic anaplasmosis (HGA) and babesiosis are not of major importance in Europe. Infections caused by these pathogens in patients not infected by Borrelia burgdorferi can result in clinical symptoms similar to those occurring in Lyme disease. This applies particularly to infections caused by Bartonella henselae, Yersinia enterocolitica, and Mycoplasma pneumoniae. Chlamydia trachomatis primarily causes polyarthritis. Chlamydophila pneumoniae not only causes arthritis but also affects the nervous system and the heart, which renders the differential diagnosis difficult. The diagnosis is even more complex when co-infections occur in association with Lyme disease. Treatment recommendations are based on individual expert opinions. In antibiotic therapy, the use of third generation cephalosporins should only be considered in cases of Lyme disease. The same applies to carbapenems, which however are used occasionally in infections caused by Yersinia enterocolitica. For the remaining infections predominantly tetracyclines and macrolides are used. Quinolones are for alternative treatment, particularly gemifloxacin. For Bartonella henselae, Chlamydia trachomatis, and Chlamydophila pneumoniae the combination with rifampicin is recommended. Erythromycin is the drug of choice for Campylobacter jejuni.

Neuroinvasive Mycoplasma pneumoniae infection without intrathecal antibody response

The pathogenesis of extrapulmonary Mycoplasma pneumoniae-associated neurologic disease is unclear. We present a case of acute meningoencephalitis in a 15-year-old girl with central nervous system invasion of the bacterium but without intrathecal antibody synthesis. Our observations suggest that in this setting M. pneumoniae infection can be self-limiting and mild despite invasion of the central nervous system.

A case of meningoencephalitis associated with macrolide-resistant Mycoplasma pneumoniae infection

Mycoplasma pneumoniae, a common pathogen causing community-acquired pneumonia, is also known to cause meningoencephalitis in pediatric patients. We report herein a pediatric patient with meningoencephalitis and macrolide-resistant M. pneumoniae infection. We emphasize that macrolide-resistant M. pneumoniae must be taken into consideration in patients with encephalitis, along with consideration for using minocycline even in pediatric patients.

[Mycoplasma pneumoniae encephalitis associated with basal ganglia necrosis]

INTRODUCTION

Severe central nervous system diseases, such as encephalitis, have been reported in association with Mycoplasma pneumoniae infections.

CASE REPORT

A previously healthy 5-year-old boy presented with an atypical pneumonia; he rapidly developed encephalitis revealed by lethargy, generalized status epilepticus. MRI showed abnormal signals in the basal ganglia, typical of bilateral striatal necrosis. Serologic tests for M. pneumoniae were positive, the child recovered almost completely.

CONCLUSION

M. pneumoniae infection should be considered in all cases of acute encephalopathy; yet the pathogenesis of the disorder is unknown and the treatment uncertain.

Mycoplasmal cerebral vasculopathy in a lymphoma patient: presumptive evidence of Mycoplasma pneumoniae microvascular endothelial cell invasion in a brain biopsy

A 73-year-old man had episodic encephalopathy, ataxia and neuropathy. Symptoms largely resolved but adenopathy later lead to the diagnosis of a low-grade follicular lymphoma. The neurological symptoms soon recurred with new pontine calcifications identified by computed tomography. Brain biopsy revealed microvascular endothelial cell nuclear changes. Electron microscopy identified small polymorphic bacteria without a cell wall and with terminal and attachment organelles within endothelial cells and clustered in some microvascular lumina. Immunostaining was positive for Mycoplasma pneumoniae and convalescent serum enzyme immunoassay was positive for M. pneumoniae IgG. The patient again recovered and he was neurologically stable 33 months after the initial episode. The ultrastructural findings of the bacterial cells are distinctive of some mycoplasmal species when compared to other small bacteria. Mycoplasma-like organisms are reported in four autopsied patients who had chronic encephalopathy, movement disorders, and some of the same light- and electron-microscopic findings in the brain as our patient. Direct neuroinvasion by Mycoplasma species has been suggested, while anatomic observations in our patient and in the four autopsy cases show microvascular invasion but not parenchymal invasion. Most mycoplasmal encephalitis may be immune-mediated. The frequency of neurovascular invasion is not known. It may be rare and it may persist.

Mycoplasma pneumoniae-related postencephalitic epilepsy in children

PURPOSE

Mycoplasma pneumoniae, a common respiratory pathogen, has been implicated as an etiology of encephalitis, but there are few reports about it and postencephalitic epilepsy. This study aimed to investigate clinical factors, electroencephalography, and neuroradiologic features of M. pneumoniae-related encephalitis in a series of children with postencephalitic epilepsy and to examine possible prognostic factors.

METHODS

Cases of M. pneumoniae-related encephalitis between January 2001 and June 2010 were retrospectively reviewed. Systematic clinical data were evaluated.

KEY FINDINGS

The 99 enrolled patients with M. pneumoniae-related encephalitis were all positive by serology and 47 (47.5%) of them developed postencephalitic epilepsy. During the acute phase, 53 patients (53.5%) had seizures, the most common type of which was primary focal with secondary generalized tonic-clonic seizure (39.6%). The most common initial electroencephalography was focal/diffuse cortical dysfunction (37.4%) and focal epileptiform discharge (26.4%). The time of follow-up ranged from 6-131 months. At the end of the study, 19 (40.4%) of the 47 children with postencephalitic epilepsy had intractable seizures.

SIGNIFICANCE

Postencephalitic epilepsy is not a rare complication of M. pneumoniae-related encephalitis. Seizures in the acute phase and focal epileptiform discharges in initial electroencephalography are significant prognostic factors.

Pediatric multiple sclerosis

In the past 5 years, there has been an exponential growth in the knowledge about multiple sclerosis (MS) in children and adolescents. Recent publications have shed light on its diagnosis, pathogenesis, clinical course, and treatment. However, there remain several key areas that require further exploration. This article summarizes the current state of knowledge on pediatric MS and discusses future avenues of investigation.

Mycoplasma pneumoniae: Innocent Bystander or a True Cause of Central Nervous System Disease?

The consistency with which Mycoplasma pneumoniae has been implicated as a cause of encephalitis, and the increased incidence of central nervous system (CNS) disease observed during M. pneumoniae respiratory outbreaks, support the role of M. pneumoniae as a CNS pathogen. Three pathophysiologic mechanisms have been proposed: direct infection, autoimmunity, and vascular occlusion. Recent evidence demonstrating the organism's ability to survive intracellularly, presence of its DNA in the serum of individuals with acute encephalitis, case reports in which the organism is detected in brain parenchyma or cerebrospinal fluid (CSF), and animal data demonstrating CNS invasion by several Mycoplasma species support the contention that M. pneumoniae is capable of direct infection of the CNS. Because of limitations of current serologic assays and difficulty in interpreting the significance of positive polymerase chain reaction results in regard to acuity of infection and viability of the organism, the diagnosis of M. pneumoniae-associated CNS disease should be based on a combination of positive tests and exclusion of alternative diagnoses.

Complete resolution of advanced Mycoplasma pneumoniae encephalitis mimicking brain mass lesions: report of two pediatric cases and review of literature

Mycoplasma pneumoniae is a well-known cause of atypical pneumonia. CNS involvement is a relatively frequent extrapulmonary manifestation, most commonly manifesting as encephalitis in the pediatric population. We present two unusual cases of M. pneumoniae encephalitis that presented with symptoms and imaging findings suggesting mass occupying lesions, and worsening altered mental status. Biopsy of the lesions was necessary in both cases to aid with diagnosis. Histopathologic features excluded neoplasm, and established the diagnosis of encephalitis, but did not point toward its etiology. The only finding that indicated M. pneumoniae as the most likely pathogen was serum IgM positivity in the absence of any other identifiable infectious source, and complete neurologic recovery following specific anti-mycoplasmal treatment. The patients were successfully treated with antibiotics and steroids, with the second case also requiring intravenous immunoglobulin and anti-epileptics. The clinical presentation and histopathologic findings suggested an immune-mediated pathogenesis, but acute disseminated encephalomyelitis was excluded due to extensive gray matter involvement. Disease resolution despite status epilepticus and herniation in case 2 is a novel finding of the study. Current principles of diagnosis and management of encephalitis as the presenting manifestation of mycoplasmal infection are discussed.

Levofloxacin for the treatment of Mycoplasma pneumoniae-associated meningoencephalitis in childhood

It has long been postulated that Mycoplasma pneumoniae plays a causative role in the development of neurological syndromes and this has recently been confirmed by highly sensitive and specific molecular diagnostic techniques for identifying infection due to this pathogen. Encephalitis and meningoencephalitis are the most frequent M. pneumoniae-associated neurological manifestations. Macrolides are considered the antibiotics of choice for treatment of paediatric M. pneumoniae infection, but the increase in macrolide minimal inhibitory concentrations of a substantial percentage of M. pneumoniae strains and the poor penetration of macrolides into cerebrospinal fluid suggest that drugs other than macrolides should be evaluated. Here we describe five paediatric cases of M. pneumoniae-associated meningoencephalitis in which 14 days of intravenous (i.v.) administration of levofloxacin (25 mg/kg/day in two divided doses) led to the disappearance of neurological signs and symptoms, with a good safety profile. Although further studies are needed to demonstrate whether or not M. pneumoniae-associated meningoencephalitis should always be treated with antimicrobials, what the drug of choice is, how long therapy should be administered and whether supportive therapy is useful, these findings suggest that i.v. levofloxacin should be considered for the treatment of paediatric M. pneumoniae-associated meningoencephalitis.

Analysis of status epilepticus with Mycoplasma pneumoniae encephalitis

Encephalitis is characterized clinically by fever, seizure, and an altered level of consciousness. Mycoplasma pneumoniae, a common respiratory pathogen, has been implicated as an etiology of encephalitis. The present study was designed to analyze status epilepticus associated with M. pneumoniae encephalitis in a series of children through retrospective review of cases between January 2002 and January 2008. Systematic clinical data were evaluated. Nine patients were identified: five girls and four boys, aged 4 years to 10 years. All were positive for M. pneumoniae by serology. Six of the nine children (67%) developed refractory status epilepticus. The major clinical symptoms included fever (100%) and upper respiratory symptoms (78%). The most common seizure type was primary focal with secondary generalized seizure (44%). The time of follow-up for this study ranged from 18 months to 86 months. At the end of the study period, two patients had died, seven had developed epilepsy or neurologic deficits, and none had returned to baseline. These data indicate that children with status epilepticus associated with M. pneumoniae encephalitis have high mortality and morbidity. Clinicians should be aware of the potential role of M. pneumoniae in status epilepticus.

The impact of left temporal lobe seizure disorder on learning disorders: a case study

This case study describes the relationship between left temporal lobe epilepsy (TLE) and learning disabilities in a 26-year-old male college student. The client developed seizures following an episode of mycoplasma encephalitis at the age of 7. The client underwent a left temporal lobectomy involving resection of the left mesial temporal lobe, amygdala, hippocampus, and part of the brain stem 6 years prior to the current evaluation, in an attempt to address the frequency of the seizures. The surgery was extensive, including neocortical resection extending posterior to the vein of Labbe along the inferior temporal gyrus. The lobectomy reportedly successfully eliminated the seizures and the need for anti-seizure medications, but no neurological or neuropsychological follow-up occurred until 2009 when he was referred by his academic program for an evaluation of learning disabilities. Results of the neuropsychological evaluation indicated significant expressive language functioning deficits, with generally better-preserved receptive language. However, compared to a pre-surgical neuropsychological evaluation there was evidence for subtle to mild improvement in several aspects of cognitive functioning, likely due to seizure elimination and discontinuation of the anti-seizure medication. Nonetheless, his deficits resulted in significant functional impact on his academic abilities, thus implications for academic intervention were discussed.

Pathogenesis of neurologic manifestations of Mycoplasma pneumoniae infection

Mycoplasma pneumoniae has been associated with various neurologic manifestations, but exactly how the organism can cause such a wide variety of diseases is a long-standing mystery. In this respect, although pneumonia has been considered the hallmark of Mycoplasma pneumoniae infection, emerging accumulations of data have revealed that the infection can cause a number of extrapulmonary manifestations even in the absence of pneumonia. The importance of host immune response in the pathomechanism of pneumonia has been established, but the pathomechanisms of extrapulmonary manifestations remain largely unknown. For this review, extrapulmonary manifestations due to M. pneumoniae infection were classified into three categories: a direct type, in which locally induced cytokines must play a role; an indirect type, in which immune modulation such as autoimmunity must play a role; and a vascular occlusion type, in which vasculitis or thrombosis (either or both, and with or without systemic hypercoagulable state) must play a role. This classification was then applied within a literature review for neurologic manifestations. Most neurologic manifestations due to M. pneumoniae infection could be reasonably classified into and explained by one of the three types of pathomechanisms.

Mycoplasma pneumoniae: nervous system complications in childhood and review of the literature

Mycoplasma pneumoniae is an important pathogen which causes nervous system disorders during or after the course of a respiratory tract infection. The exact pathogenic mechanism which causes neurological disorders still remains unknown. Although meningoencephalitis and acute disseminated encephalomyelitis are common complications, there are few cases of acute transverse myelitis and isolated abducens nerve palsy associated with M. pneumoniae infection in childhood. The association between ocular myasthenia gravis and M. pneumoniae infection has not been described before. Here, we describe five patients with different nervous system complications associated with M. pneumoniae infection and discuss the pathological features of central nervous system involvement.

Epidemiology, clinical manifestations, pathogenesis and laboratory detection of Mycoplasma pneumoniae infections

Since its initial description in the 1940s and eventual elucidation as a highly evolved pathogenic bacterium, Mycoplasma pneumoniae has come to be recognized as a worldwide cause of primary atypical pneumonia. Beyond its ability to cause severe lower respiratory illness and milder upper respiratory symptoms it has become apparent that a wide array of extrapulmonary infectious and postinfectious events may accompany the infections in humans caused by this organism. Autoimmune disorders and chronic diseases such as asthma and arthritis are increasingly being associated with this mycoplasma, which frequently persists in individuals for prolonged periods. The reductive evolutionary process that has led to the minimal genome of M. pneumoniae suggests that it exists as a highly specialized parasitic bacterium capable of residing in an intracellular state within the respiratory tissues, occasionally emerging to produce symptoms. This review includes discussion of some of the newer aspects of our knowledge on this pathogen, characteristics of clinical infections, how it causes disease, the recent emergence of macrolide resistance, and the status of laboratory diagnostic methods.

The management of encephalitis: clinical practice guidelines by the Infectious Diseases Society of America

Guidelines for the diagnosis and treatment of patients with encephalitis were prepared by an Expert Panel of the Infectious Diseases Society of America. The guidelines are intended for use by health care providers who care for patients with encephalitis. The guideline includes data on the epidemiology, clinical features, diagnosis, and treatment of many viral, bacterial, fungal, protozoal, and helminthic etiologies of encephalitis and provides information on when specific etiologic agents should be considered in individual patients with encephalitis.

Clinical assessment of Mycoplasma pneumoniae-associated hemophagocytic lymphohistiocytosis

BACKGROUND

Mycoplasma pneumoniae has been reported to be an etiologic pathogen of infection-associated hemophagocytic lymphohistiocytosis (HLH), but few case reports have been available to date.

METHODS

The clinical features of four childhood cases of M. pneumoniae-associated hemophagocytic lymphohistiocytosis (Mp-HLH) were retrospectively assessed to obtain data that might be useful for early diagnosis and effective management. The previous English-language literature pertaining to Mp-HLH was also reviewed.

RESULTS

The patients were two boys and two girls, aged between 1 and 11 years of age. One patient was demonstrated to have concurrent infection with rubella. All the patients had typical radiographic features of M. pneumoniae pneumonia, and one patient also had encephalopathy as a complication. All the children underwent bone marrow examination because of antibiotic-refractory fever, mild hepatosplenomegaly, cytopenia, hyperferritinemia and elevated levels of urine beta2-microglobulin. Cytopenia and hepatosplenomegaly in the present patients were relatively mild as compared to those in cases of other infection-associated HLH such as Epstein-Barr virus infection-associated HLH. Treatment with corticosteroids resulted in prompt and complete resolution in two cases, and i.v. high-dose gammaglobulin therapy achieved a complete response in another child. Spontaneous resolution under treatment with antibiotics alone was observed in one case.

CONCLUSION

Although Mp-HLH is a rare complication of M. pneumoniae infection, it should always be considered in patients with antibiotic-refractory M. pneumoniae infections with cytopenia. Mp-HLH might be effectively treated by corticosteroids or high-dose gammaglobulin. To clarify the diverse clinical manifestations of M. pneumoniae infections, immunological interactions between M. pneumoniae and the host immune system should be further investigated.

Role of Mycoplasma pneumoniae in pediatric encephalitis

A retrospective study investigating all the infectious encephalitis cases hospitalized at the pediatric intensive care unit of Edouard Herriot University Hospital in Lyon, France, was carried out in order to estimate the prevalence of Mycoplasma pneumoniae in acute childhood encephalitis. From January 2001 to December 2005, the cases of 29 children were selected and reviewed. M. pneumoniae related encephalitis was considered as probable in five cases (17%) on the basis of positive serological tests or positive polymerase chain reaction (PCR) tests in throat or nasopharyngeal swab while the PCR tests performed from the cerebrospinal fluid were negative. This study suggests that M. pneumoniae may be a major cause of infectious encephalitis in children as well as enteroviruses or Epstein-Barr virus detected in five and three cases, respectively.

Pediatric encephalitis: what is the role of Mycoplasma pneumoniae?

BACKGROUND

Encephalitis is a complex, debilitating, and sometimes fatal neurologic condition to which children are especially prone. Mycoplasma pneumoniae, a common respiratory pathogen, has been implicated as an etiology of encephalitis. Evidence for recent or acute M. pneumoniae infection has been demonstrated in limited studies of both pediatric and adult patients with encephalitis.

PATIENTS AND METHODS

Unexplained encephalitis cases are referred to the California Encephalitis Project for diagnostic testing. Serum, cerebrospinal fluid, and respiratory specimens are tested by polymerase chain reaction and serology methods for the presence of multiple pathogens, including M. pneumoniae. M. pneumonia-associated cases of encephalitis were compared with other bacterial agents, herpes simplex virus 1, and enterovirus.

RESULTS

Of 1988 patients referred to the California Encephalitis Project, evidence of acute M. pneumoniae infection was found in 111 patients, of which 84 (76%) were pediatric patients. Eighty percent of the 84 patients were positive for M. pneumoniae by serology alone. Cerebrospinal fluid polymerase chain reaction for M. pneumoniae was rarely positive (2%). Patients with M. pneumoniae-associated pediatric encephalitis were a median of 11 years old, progressed rapidly (median: 2 days from onset to hospitalization), and were often in the ICU (55%). Symptoms included fever (70%), lethargy (68%), and altered consciousness (58%). Gastrointestinal (45%) and respiratory (44%) symptoms were less common. Compared with patients with other bacterial as well as viral agents, patients with M. pneumoniae-associated encephalitis had fewer seizures and less-severe hospital courses.

CONCLUSIONS

M. pneumoniae is the most common agent implicated in the California Encephalitis Project. Patients with M. pneumoniae-associated encephalitis are predominantly pediatric, and their presentations are clinically similar to enterovirus encephalitis, although they frequently require intensive care with prolonged hospitalizations. Given that M. pneumoniae infection is found more than any other pathogen, increased emphasis should be placed on elucidating the role and mechanism of M. pneumoniae in encephalitis.

Beyond viruses: clinical profiles and etiologies associated with encephalitis

BACKGROUND

Encephalitis is a complex syndrome, and its etiology is often not identified. The California Encephalitis Project was initiated in 1998 to identify the causes and further describe the clinical and epidemiologic characteristics of encephalitis.

METHODS

A standardized report form was used to collect demographic and clinical data. Serum, cerebrospinal fluid, and respiratory specimens were obtained prospectively and were tested for the presence of herpesviruses, arboviruses, enteroviruses, measles, respiratory viruses, Chlamydia species, and Mycoplasma pneumoniae. The association between an identified infection and encephalitis was defined using predetermined, organism-specific criteria for confirmed, probable, or possible causes.

RESULTS

From 1998 through 2005, a total of 1570 patients were enrolled. Given the large number of patients, subgroups of patients with similar clinical characteristics and laboratory findings were identified. Ten clinical profiles were described. A confirmed or probable etiologic agent was identified for 16% of cases of encephalitis: 69% of these agents were viral; 20%, bacterial; 7%, prion; 3%, parasitic; and 1%, fungal. An additional 13% of cases had a possible etiology identified. Many of the agents classified as possible causes are suspected but have not yet been definitively demonstrated to cause encephalitis; these agents include M. pneumoniae (n=96), influenza virus (n=22), adenovirus (n=14), Chlamydia species (n=10), and human metapneumovirus (n=4). A noninfectious etiology was identified for 8% of cases, and no etiology was found for 63% of cases.

CONCLUSIONS

Although the etiology of encephalitis remains unknown in most cases, the recognition of discrete clinical profiles among patients with encephalitis should help focus our efforts toward understanding the etiology, pathogenesis, course, and management of this complex syndrome.

Childhood encephalitis in Crete, Greece

This study included all 18 cases of children hospitalized for encephalitis in the referral university hospital of Heraklion, Crete, Greece, during the 5-year period from 2000 to 2004. Encephalitis was attributed to viral infection (echovirus, herpes simplex virus 1, varicella-zoster virus, cytomegalovirus, and influenza A) in eight children and to bacteria (Mycoplasma pneumoniae, group A beta-hemolytic streptococcus, and Rickettsia typhi) in a further five cases. Multiple hyperintense brain lesions on magnetic resonance imaging (MRI) were associated with a severe clinical presentation but not with a guarded long-term outcome. Five children still presented with mild to moderate sequelae after 1.5 to 5.3 (median 4.0) years. Our findings confirm the elimination of measles, mumps, and rubella-associated encephalitis in the postvaccine era. MRI appeared to be of great diagnostic value. Although no fatalities were observed, deficits did persist in several patients.

Mycoplasma pneumoniae central nervous system infections

PURPOSE OF REVIEW

Mycoplasma pneumoniae is associated with a wide range of central nervous system diseases, most importantly with childhood encephalitis. This review summarizes and discusses recent findings in the field of M. pneumoniae central nervous system infections in context with previously published findings, with reference to clinical spectrum, pathogenesis, diagnosis, and treatment.

RECENT FINDINGS

Further insight into the pathogenesis has been provided by studies on cytokine production and autoantibody formation. Some new manifestations have been described (e.g. Kluver-Bucy syndrome, intracranial hypertension). Anecdotal descriptions on the association of M. pneumoniae with uncommon neurologic diseases remain to be confirmed by additional reports, however, especially when aetiologic diagnosis relied exclusively on serology. New knowledge on treatment options targeting the immune system has been provided by isolated reports. Recent diagnostic advances refer to general methods (polymerase chain reaction, serology), without specific reference to neurologic disease.

SUMMARY

M. pneumoniae must be considered as causative agent of various neurologic diseases. The recent literature shows, however, that the clinical spectrum of M. pneumoniae central nervous system disease is still not well defined. In addition, the main future challenges are the investigation of the pathogenesis of M. pneumoniae central nervous system disease and the establishment of therapeutic approaches.

Mycoplasma pneumoniae-associated myelitis: a comprehensive review

Myelitis is one of the most severe central nervous system complications seen in association with Mycoplasma pneumoniae infections and both acute transverse myelitis (ATM) as well as acute disseminated encephalomyelitis (ADEM) have been observed. We reviewed all available literature on cases of Mycoplasma spp. associated ATM as well as ADEM with dominant spinal cord pathology and classified those cases according to the strength of evidence implicating M. pneumoniae as the cause. A wide range of data on diagnosis, epidemiology, immunopathogenesis, clinical picture, laboratory diagnosis, neuroimaging and treatment for this rare entity is presented. The use of highly sensitive and specific molecular diagnostic techniques may assist in clearly elucidating the role of M. pneumoniae in ATM/ADEM syndromes in the near future. Immunomodulating therapies may have a role in treating such cases.