Diagnosis, treatment, and prognosis of Mycoplasma pneumoniae childhood encephalitis: systematic review of 58 cases

Metagenomic next-generation sequencing of bronchoalveolar lavage fluid in non-severe and severe pneumonia patients

Metagenomic next-generation sequencing (mNGS) is widely used as a more promising technology than conventional tests. However, its clinical utility in the context of bronchoalveolar lavage fluid (BALF) samples for discriminating between non-severe and severe pneumonia is not well established. Thus, this study aimed to investigate the diagnostic performance of mNGS on BALF samples from 100 individuals suspected of pneumonia, and compared it with conventional microbiological tests (CMT) of BALF samples and the final clinical diagnosis. Twenty-seven cases of non-severe pneumonia and 73 cases of severe pneumonia patients were finally clinically diagnosed. Among 100 cases, diagnostic performance of mNGS and culture showed a significant difference; 65 cases had the same sample types, of which 25 cases were diagnosed as positive by mNGS only (38.46%) and 1 was diagnosed as positive by culture only (1.54%). Moreover, 24 cases were diagnosed positive in both mNGS and culture (36.92%) and 15 cases tested negative in both mNGS and culture (23.08%). Among 35 cases, 28 out of 35 cases were diagnosed as positive by mNGS, while only 4 out of 35 cases were diagnosed as positive by the indirect immunofluorescence method (IIFT). In addition, the positive rate of mNGS was higher than that of culture in cases regardless of prior antibiotic exposure. Mixed pathogens were found to be significantly more prevalent in severe pneumonia patients than in non-severe pneumonia patients. Importantly, among 38 cases who were diagnosed solely by mNGS, 25 patients experienced an improved outcome after physicians changed the therapy according to the mNGS results. In conclusion, the results showed that mNGS of BALF represents a potentially effective tool for detection of mixed pathogens in severe pneumonia.

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.

A CRISPR-Cas12a-Based platform for ultrasensitive, rapid, and highly specific detection of Mycoplasma pneumonia in clinical application

Mycoplasma pneumoniae (MP), which is responsible for a majority of community-acquired pneumonia (CAP) in children, has been largely underestimated. Here, we coupled multiple cross displacement amplification (MCDA) technique with CRISPR-Cas12a-based biosensing system to design a novel detection platform termed MP-MCDA-CRISPR assay for MP infection diagnosis and clinical application. The MP-MCDA-CRISPR assay amplified the CARDS gene of MP by MCDA method, followed by trans-cleavage of the reporter molecular upon the formation of CRISPR-Cas12a-gRNA-target DNA complex, which was confirmed by the release of fluorescent signals. A set of standard MCDA primers, an engineered CP1 primer, a quenched fluorescent ssDNA reporter, and a gRNA were designed targeting the CARDS gene of MP. The optimal temperature for MCDA pre-amplification is 64°C, and the time for CRISPR-Cas12a-gRNA biosensing process is 5 min. The limit of detection (LoD) of the MP-MCDA-CRISPR assay is 50 fg per reaction without any cross-reaction with other non-MP pathogens. The MP-MCDA-CRISPR assay accurately identified the 50 real time-PCR positive clinical samples and 78 negative ones. Taken together, the MP-MCDA-CRISPR assay designed here is a promising diagnostic tool for point-of care (POC) testing of MP infection.

[Clinical implications of the genus Mycoplasma]

Dentro del género Mycoplasma, las especies que tradicionalmente se han relacionado con cuadros infecciosos han sido principalmente M. pneumoniae, M. genitalium, M. hominis o U. urealyticum. Sin embargo, existen otras muchas que están implicadas y, que muchas veces, son desconocidas para los profesionales sanitarios. El objetivo de esta revisión es identificar todas las especies del género Mycoplasma que se han aislado en el hombre y determinar su participación en la patología infecciosa humana.

Factors associated with outcome of acute encephalitis in children: a retrospective study of three referral hospitals

BACKGROUND Encephalitis is more frequent in children and has a poor outcome. There was no data on encephalitis in children in Indonesia, so this study was aimed to evaluate clinical presentation and diagnostic examination of children with acute encephalitis, and factors related to outcome. METHODS This was a retrospective study of medical records between 2014 and 2018 in three referral hospitals in Jakarta and Tangerang. Clinical presentation at admission, cerebrospinal fluid analysis, neuroimaging, and electroencephalography (EEG) were documented. Outcome was determined at hospital discharge and classified as poor for severe neurological abnormalities at discharge or died. Logistic regression was used to evaluate associated factors with the outcome. RESULTS A total of 190 children were included and most were age >1 year (71%). Most subjects presented with fever (90%) and seizures (87%). Of those who had seizures, 80% experienced generalized seizures. Focal neurological deficit was seen in 90 patients (47%). EEG was positive in 90% subjects (n = 27/30). Probable cases were found in 51% of all subjects. The mortality was 23%. Focal seizures (odds ratio [OR] = 3.305, 95% confidence interval [CI] = 1.122–9.742) and age >1 year (OR = 3.076, 95% CI = 1.388–6.803) were risk factors for a poor outcome. CONCLUSIONS Acute encephalitis occurred most often in children aged >1 year. Fever and seizures were the most common symptoms. EEG was better than other examinations for confirming diagnosis of encephalitis. Focal seizures and age >1 year were associated with a three-fold increased risk for a poor outcome.

Mycoplasma pneumoniae Among Children Hospitalized With Community-acquired Pneumonia

Background

The epidemiology of Mycoplasma pneumoniae (Mp) among US children (<18 years) hospitalized with community-acquired pneumonia (CAP) is poorly understood.

Methods

In the Etiology of Pneumonia in the Community study, we prospectively enrolled 2254 children hospitalized with radiographically confirmed pneumonia from January 2010-June 2012 and tested nasopharyngeal/oropharyngeal swabs for Mp using real-time polymerase chain reaction (PCR). Clinical and epidemiological features of Mp PCR-positive and -negative children were compared using logistic regression. Macrolide susceptibility was assessed by genotyping isolates.

Results

One hundred and eighty two (8%) children were Mp PCR-positive (median age, 7 years); 12% required intensive care and 26% had pleural effusion. No in-hospital deaths occurred. Macrolide resistance was found in 4% (6/169) isolates. Of 178 (98%) Mp PCR-positive children tested for copathogens, 50 (28%) had ≥1 copathogen detected. Variables significantly associated with higher odds of Mp detection included age (10-17 years: adjusted odds ratio [aOR], 10.7 [95% confidence interval {CI}, 5.4-21.1] and 5-9 years: aOR, 6.4 [95% CI, 3.4-12.1] vs 2-4 years), outpatient antibiotics ≤5 days preadmission (aOR, 2.3 [95% CI, 1.5-3.5]), and copathogen detection (aOR, 2.1 [95% CI, 1.3-3.3]). Clinical characteristics were non-specific.

Conclusions

Usually considered as a mild respiratory infection, Mp was the most commonly detected bacteria among children aged ≥5 years hospitalized with CAP, one-quarter of whom had codetections. Although associated with clinically nonspecific symptoms, there was a need for intensive care in some cases. Mycoplasma pneumoniae should be included in the differential diagnosis for school-aged children hospitalized with CAP.

Pediatric West Nile Virus-Associated Neuroinvasive Disease: A Review of the Literature

Over the past two decades, West Nile virus has become the most common arbovirus in North America, leading to several outbreaks and infecting thousands of people. Mosquitos help transmit the virus in the majority of cases, but transmission occurs via blood transfusions, organ transplantation, and possibly pregnancy and breastfeeding. While most infected patients experience mild to no symptoms, thousands of West Nile virus-associated neuroinvasive cases have been reported in the United States, with over 700 cases occurring in children from 2003 to 2016. Neuroinvasive disease presents as meningitis, encephalitis, or acute flaccid paralysis, and carries a high likelihood of poor outcome, including severe neurological disability or death. To date, no pharmacologic treatment has proven effective. Therapeutic clinical trials have not been successfully completed due to the sporadic nature of viral outbreaks and resultant poor study enrollment. Although older age and chronic disease are risk factors for neuroinvasive West Nile virus disease in adults, the specific factors that influence the risk in pediatric populations have not been fully elucidated. This review summarizes the most recent literature regarding West Nile virus-associated neuroinvasive disease, especially as it pertains to the pediatric population. Moreover, the review describes the epidemiology, clinical, laboratory, and radiographic findings, and outlines the various therapies that have been trialed and potential future research directions.

Prognostic evaluation of child patients with infectious encephalitis through AEEG and REEG

This study investigated prognostic evaluation of child patients with viral encephalitis through ambulatory electroencephalogram (AEEG) and regular electroencephalogram (REEG). A total of 94 child patients who were clinically diagnosed with viral encephalitis in Yantaishan Hospital of Yantai from May 2010 to July 2014, was examined with AEEG and REEG, respectively and randomly divided into AEEG group (n=47) and REEG group (n=47). The probabilities of detecting abnormal electroencephalographic activities with two examination methods were compared. The detection rates of abnormal electroencephalographic activities with AEEG and REEG were 80.0 and 65.0%, respectively, with significant differences (P<0.05); the probabilities of detecting epileptiform discharge with AEEG and REEG were 42.5 and 6.3%, respectively, with significant differences (P<0.05). The hospitalization time and time of electroencephalogram (EEG) restoring to normal of child patients with encephalitis in the REEG group were significantly longer than those of child patients with encephalitis in the AEEG group, with statistically significant differences (P<0.05). Among child patients in the AEEG group, the incidence rate of severe illness was 2.1%, and both the incidence rates of clinical recurrence and of sequela were 0. Among child patients in the REEG group, the incidence rate, clinical recurrence rate and incidence rate of sequela were 8.5, 12.7 and 8.5%, respectively, with statistically significant differences (P<0.05). To some extent, the EEG abnormality reflects the disorder degree of brain environment of child patients with viral encephalitis. The treatment effect and prognosis of child patients with viral encephalitis can be clinically evaluated based on EEG monitoring results of child patients, which has a certain clinical guiding significance. AEEG has important significance to the auxiliary diagnosis of viral encephalitis, with higher sensitivity than REEG.

Reversible splenial lesion syndrome associated with acute Mycoplasma pneumoniae-associated encephalitis: A report of four cases and literature review

Reversible splenial lesion syndrome (RESLES) is a rare clinico-radiological syndrome that is defined as reversible lesions that involve the splenium of the corpus callosum (SCC). RESLES has been reported in patients with a broad spectrum of diseases and conditions, including infections, hypoglycemia and poisoning. The present report described four RESLES cases triggered by Mycoplasma pneumoniae (M. pneumoniae) and discussed the associated diagnostic challenges. Four cases of acute M. pneumoniae-associated encephalitis that displayed RESLES were reviewed. The clinical presentations were nonspecific in these patients. However, magnetic resonance imaging (MRI) revealed consistent lesions in the SCC with a hyperintensity in diffusion-weighted imaging (DWI) and hypointensities in T1WI, which disappeared after a variable lapse. Treatment with azithromycin or combined treatment with immunomodulatory agents if necessary led to a good prognosis. The present findings indicated that radiological diagnosis of RESLES should be considered in patients with M. pneumoniae-associated encephalitis. Furthermore, serum Mycoplasma antibody is important for the diagnosis of M. pneumoniae-associated encephalitis.

Management of adult infectious encephalitis in metropolitan France

Infectious encephalitis is a severe disease leading to a high mortality and morbidity. The most frequent causes include Herpes simplex virus, Varicella Zoster virus, Listeria monocytogenes, and Mycobacterium tuberculosis. Urgent treatment is required (anti-infective therapy and nonspecific supportive care). The aim of this study was to define treatment strategy, empirical and after microbiological documentation at 48hours, through a systematic literature review.

MR imaging of adult acute infectious encephalitis

BACKGROUND

Imaging is a key tool for the diagnosis of acute encephalitis. Brain CT scan must be urgently performed to rule out a brain lesion with mass effect that would contraindicate lumbar puncture. Brain MRI is less accessible than CT scan, but can provide crucial information with patients presenting with acute encephalitis.

METHOD

We performed a literature review on PubMed on April 1, 2015 with the search terms "MRI" and "encephalitis".

RESULTS

We first described the various brain MRI abnormalities associated with each pathogen of acute encephalitis (HSV, VZV, other viral agents targeting immunocompromised patients or travelers; tuberculosis, listeriosis, other less frequent bacterial agents). Then, we identified specific patterns of brain MRI abnomalies that may suggest a particular pathogen. Limbic encephalitis is highly suggestive of HSV; it also occurs less frequently in encephalitis due to HHV6, syphillis, Whipple's disease and HIV primary infection. Rhombencephalitis is suggestive of tuberculosis and listeriosis. Acute ischemic lesions can occur in patients presenting with severe bacterial encephalitis, tuberculosis, VZV encephalitis, syphilis, and fungal infections.

CONCLUSION

Brain MRI plays a crucial role in the diagnosis of acute encephalitis. It detects brain signal changes that reinforce the clinical suspicion of encephalitis, especially when the causative agent is not identified by lumbar puncture; it can suggest a particular pathogen based on the pattern of brain abnormalities and it rules out important differential diagnosis (vascular, tumoral or inflammatory causes).

Mycoplasma pneumoniae-associated mild encephalitis/encephalopathy with a reversible splenial lesion: report of two pediatric cases and a comprehensive literature review

BACKGROUND

No literature review exists on Mycoplasma pneumoniae-associated mild encephalitis/encepharopathy with a reversible splenial lesion (MERS).

METHODS

M.pneumoniae-associated MERS cases were searched till August 2016 using PubMed/Google for English/other-language publications and Ichushi ( http://www.jamas.or.jp/ ) for Japanese-language publications. Inclusion criteria were children fulfilling definition for encephalitis, M.pneumoniae infection, and neuroimaging showing hyperintensity in the splenium of the corpus callosum (SCC) alone (type I) or SCC/other brain areas (type II).

RESULTS

We described two children with type I and II M.pneumoniae-associated MERS. Thirteen cases found by the search and our 2 cases were reviewed. Mean age, male/female ratio, duration of prodromal illness was 8.3 years, 1.5 and 3.5 days. The most common neurological symptom was drowsiness, followed by abnormal speech/behavior, ataxia, seizure, delirium, confusion, tremor, hallucination, irritability, muscle weakness, and facial nerve paralysis. Fever was the most common non-neurological symptom, followed by cough, headache, gastrointestinal symptoms, headache, lethargy and dizziness. Seizure and respiratory symptoms were less common. All were diagnosed for M.pneumoniae by serology. Cerebrospinal fluid (CSF) M.pneumoniae was undetectable by PCR in the 3 patients. Three patients were clarithromycin-resistant. Leukocytosis, positive C-reactive protein, hyponatremia, CSF pleocytosis and slow wave on electroencephalography frequently occurred. All except 2 were type I MERS. Neuroimaging abnormalities disappeared within 18 days in the majority of patients. All type I patients completely recovered within 19 days. Two type II patients developed neurological sequelae, which recovered 2 and 6 months after onset.

CONCLUSIONS

Prognosis of M.pneumoniae-associated MERS is excellent. Type II MERS may increase a risk of neurological sequelae.

Encephalopathy and Axonal Neuropathy Associated With Mycoplasma Pneumoniae Infection: Response to Intravenous Immunoglobulin Therapy

Mycoplasma pneumoniae infection frequently presents as a self-limited process, however, severe cases and even fatalities have been reported. The authors present a case of Mycoplasma pneumoniae infection associated with both encephalopathy and peripheral neuropathy that responded to intravenous immunoglobulin therapy. To our knowledge, this is the first documented case of Mycoplasma pneumoniae related to encephalitis and peripheral axonal neuropathy. To date, there is insufficient data on the effect of intravenous immunoglobulin on the course of mycoplasma-associated central nervous system/peripheral nervous system disease. While intravenous immunoglobulin has aided in a variety of autoimmune-mediated disorders, its efficacy in mycoplasma-mediated encephalitis treatment remains unclear. In this patient case, reversal of both central and peripheral nervous system symptoms after treatment with intravenous immunoglobulin suggested a possible therapeutic benefit.

Infection with and Carriage of Mycoplasma pneumoniae in Children

“Atypical” pneumonia was described as a distinct and mild form of community-acquired pneumonia (CAP) already before Mycoplasma pneumoniae had been discovered and recognized as its cause. M. pneumoniae is detected in CAP patients most frequently among school-aged children from 5 to 15 years of age, with a decline after adolescence and tapering off in adulthood. Detection rates by polymerase chain reaction (PCR) or serology in children with CAP admitted to the hospital amount 4–39%. Although the infection is generally mild and self-limiting, patients of every age can develop severe or extrapulmonary disease. Recent studies indicate that high rates of healthy children carry M. pneumoniae in the upper respiratory tract and that current diagnostic PCR or serology cannot discriminate between M. pneumoniae infection and carriage. Further, symptoms and radiologic features are not specific for M. pneumoniae infection. Thus, patients may be unnecessarily treated with antimicrobials against M. pneumoniae. Macrolides are the first-line antibiotics for this entity in children younger than 8 years of age. Overall macrolides are extensively used worldwide, and this has led to the emergence of macrolide-resistant M. pneumoniae, which may be associated with severe clinical features and more extrapulmonary complications. This review focuses on the characteristics of M. pneumoniae infections in children, and exemplifies that simple clinical decision rules may help identifying children at high risk for CAP due to M. pneumoniae. This may aid physicians in prescribing appropriate first-line antibiotics, since current diagnostic tests for M. pneumoniae infection are not reliably predictive.

Outcome of children with acute encephalitis and refractory status epilepticus

Acute encephalitis in children is a life-threatening neurological emergency. However, little is reported about the outcome of this devastating illness in the United States. The authors retrospectively reviewed the charts of patients admitted to a regional pediatric intensive care unit with the diagnosis of acute encephalitis between 2006 and 2011. In 41 cases that met the inclusion criteria, the most common presenting symptoms were fever (65.9%), altered mental status (61%), and seizures (58.5%). Eight patients (19.5%) who presented with refractory status epilepticus had a longer median length of stay in the pediatric intensive care unit (46 vs. 4 days; P < .0001) and a significant worsening of Pediatric Cerebral Performance Category score on discharge by 2 or more points (odds ratio 20.38; 95% confidence interval, 2.89-143.52). All children survived to hospital discharge. In conclusion, children with acute encephalitis who present with refractory status epilepticus have a worse neurological outcome and a longer stay in the pediatric intensive care unit.

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.

Meningoencephalitis associated with Mycoplasma pneumoniae

We report a case of a child with meningoencephalitis of atypical etiology. The patient developed the disease after an infection in the upper airways with unfavorable evolution. The clinical recovery was only possible after the administration of adequate antibiotic therapy for the etiological agent. This case report describes a child with meningoencephalitis of atypical etiology. The patient developed the disease after an infection in the superior airways with negative evolution. The clinical recovery was possible only after the introduction of adequate antibiotic therapy for the etiological agent.

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.

Retrospective survey for sialidase activity in Mycoplasma pneumoniae isolates from cases of community-acquired pneumonia

Background

Sialidase is a well-known virulence factor of other respiratory pathogens, but was only recently documented to occur in some species of Mycoplasma. The sialidase activity expressed can vary quantitatively among strains within a species of mycoplasma, from undetectable to amounts that correlate positively with strain virulence. Very few isolates of Mycoplasma pneumoniae had ever been examined for sialidase activity, so it was unknown whether sialidase may contribute to diseases involving this species.

Findings

No sialidase activity was detected by spectrofluorometric assay of 15 laboratory strains and 91 clinical isolates of M. pneumoniae banked over many years from patients having radiologically-confirmed, uncomplicated community-acquired pneumonia.

Conclusions

The annotated genome of strain M129 (GenBank NC_000912, ATCC 29342), also isolated from a patient with pneumonia, accurately represents the absence of sialidase genes from strains of M. pneumoniae typically associated with uncomplicated community-acquired pneumonia. A possible involvement of sialidase in neurologic or other extra-respiratory manifestations of M. pneumoniae mycoplasmosis remains to be investigated.

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.

Mycoplasma felis-associated meningoencephalomyelitis in a cat

Mycoplasmas are frequently isolated from many animal species. In domestic cats, mycoplasmas may be isolated from respiratory and ocular mucosae, but other sites are also occasionally colonized by these organisms. No cases of Mycoplasma species-associated neurologic disease have been reported in cats. We describe a case of Mycoplasma felis-associated meningoencephalitis in a 10-month-old domestic shorthair cat.

Long-term outcomes of acute encephalitis in childhood

OBJECTIVES

The aims of this study were to investigate the long-term outcomes of childhood encephalitis and to examine possible prognostic factors.

METHODS

Of 93 children who were treated for acute encephalitis in 2000-2004, 71 were eligible for follow-up evaluations. A structured interview, using 2 questionnaires, was conducted with the parents. Fifteen of the children with the most-severe symptoms at the time of discharge also underwent electroencephalographic recording and tests of reaction times and working memory.

RESULTS

Persisting symptoms were reported by 54% of children. The predominant symptoms were personality changes and cognitive problems. Children who made a complete recovery did so within 6 to 12 months. The only significant risk factor for sequelae was disease severity leading to admission to the ICU. The risk of subsequent epilepsy was increased for children with seizures at presentation. Most follow-up electroencephalograms showed improvement, but results had not normalized for 9 of 15 children. Children with encephalitis had slower reaction times, compared with control subjects, but no difference in working memory could be seen.

CONCLUSION

Persisting symptoms after childhood encephalitis were present for a substantial number of children. Seizures increased the risk of subsequent epilepsy; the only other prognostic marker was admission to the ICU. Even children who were considered fully recovered at discharge reported persisting symptoms at follow-up evaluations. Children who made a full recovery did so within 6 to 12 months, which suggests that all children with encephalitis should be monitored for 1 year after the acute illness.

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.

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.

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.

Mycoplasma pneumoniae-an emerging extra-pulmonary pathogen

Mycoplasma is a well-recognised pathogen that colonises mucosal surfaces of humans and animals. Mycoplasma pneumoniae infects the upper and lower respiratory tracts of children and adults, leading to a wide range of respiratory and non-respiratory clinical conditions. M. pneumoniae infection is frequently considered in the differential diagnosis of patients with respiratory illnesses, and is commonly managed empirically with macrolides and fluoroquinolones. This contrasts with patients who present with non-respiratory symptoms in the context of a recent or current unrecognised M. pneumoniae infection, for whom this pathogen is rarely considered in the initial differential diagnosis. This review considers the microbiological, epidemiological, pathogenic and clinical features of this frequent pathogen that need to be considered in the differential diagnosis of respiratory and non-respiratory infections.

Co-infection with Mycoplasma pneumoniae and human herpesvirus 6 (HHV-6) in an immunocompetent child with meningoencephalitis: a random association?

Encephalitis can represent a complication of both Mycoplasma and Human Herpesvirus type 6 infections and, although uncommon, is associated with significant morbidity and mortality. We describe a 13-year-old girl with fever, headache and mental changes with a pattern of concomitant Mycoplasma and Human Herpesvirus-6 infection. The hypothetical relationship between this dual infection and the central nervous system disease is discussed.

Pre- and post-encephalitic neuropsychological profile of a 7-year-old girl

Our understanding of the neuropsychological effects of encephalitis has largely come from studies in which the level of premorbid functioning is estimated. Moreover, data on the neuropsychological effects of encephalitogenic pathogens other than the herpes simplex virus (HSV) are scant. We present the case of a 7-year-old girl who had intellectual and language assessment seven months prior to the onset of non-HSV encephalitis (possible aetiology: Mycoplasma pneumoniae), and again post-encephalitis. MRI post-illness demonstrated basal frontal, temporal and (limited) parietal damage. Details of speech, psychological and neuropsychological assessments were also documented. Pervasive changes were apparent in the domains of personality, behaviour, emotionality, attention, executive function, speech, language and memory. The patient's profile appears to differ most from that seen following typical HSV encephalitis with respect to marked executive and attentional difficulties. Her deficits appear to reflect both her acute basal brain injury and more diffuse insult, probably caused by postinfectious encephalitis.

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.

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.

Role of prednisolone treatment in severe Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae pneumonia (MP) is responsible for 10-40% of cases of pediatric community-acquired pneumonia. Occasionally, progression to severe pneumonia occurs despite appropriate antibiotic therapy. We retrospectively evaluated the effect of prednisolone in 15 children with MP whose clinical and radiographic course worsened despite broad-spectrum antibiotics, including appropriate macrolides. The mean ( +/- SD) age was 6.1 +/- 1.9 years, and 10 were boys. All children had received macrolides at presentation, but they had persistent fever and progressively worsening radiographic findings. In addition to broad-spectrum antimicrobial therapy, we added prednisolone (1 mg/kg for 3-7 days, then tapered over 7 days) on day 6 (+/-1.5 days) of admission. Fourteen children became afebrile within 24 hr, and their clinical status and radiographic findings improved over several days. The white blood cell count at presentation was 7,500 +/- 2,000/mm3, with a proportion demonstrating lymphopenia (lymphocyte differential, 19.7 +/- 5.7%). In conclusion, corticosteroid treatment appeared to be temporally associated with clinical and radiographic improvement, and may be helpful for reducing morbidity in children with macrolide-nonresponsive severe MP. Further studies may be warranted.