Thirteen-year surveillance results of acute flaccid paralysis cases in Southeast Turkey and the effect of refugee movements on surveillance results

OBJECTIVE

Acute flaccid paralysis (AFP) is a major neurological problem. Turkey has accepted over 4 million refugees since 2011 due to the wars in neighbouring countries. In the long term, refugees can have adverse effects on the limited resources of health, sanitation, water supply, foodstuff, and shelter services of host countries, precipitating the transmission and spread of enteroviruses causing AFP. This study examines the 13-year surveillance and incidence of AFP cases in southeast Turkey, and questions possible impact of refugee movements on these parameters, comparing the periods before (2007-2010) and after (2011-2019) 2011, when the refugee movements emerged.

METHODS

The records of cases reported from southeast part of Turkey with suspected AFP between January 2007 and December 2019 were reviewed retrospectively.

RESULTS

Of the patients, 121 (58.5%) were male. Mean age was 80.36 ± 46.67 months. Eighty-five (41.1%) were aged 60 months or younger. The number of patients under 60 months increased significantly after 2011. Mean incidence was calculated as 0.88 cases/100,000 person years versus 1.58 cases/100,000 person years in the period before and after 2011, respectively. Guillain-Barré syndrome (GBS) was the most common cause of AFP in both periods. As of 2011, however, the incidence of acute transverse myelitis increased approximately 4 times and GBS decreased proportionally. Non-polio enteroviruses were the most frequent isolates, detected from 9.1% of stool samples.

CONCLUSION

Although refugee movements appear to may have adverse effects on AFP incidence and surveillance outcomes, larger studies involving the whole country, particularly at places where no refugees settled, are needed to achieve more conclusive evidence.

Acute flaccid myelitis: not uncommon in rural Uganda?

Acute Flaccid Myelitis is a paralytic illness with significant similarities to poliomyelitis, and which affects predominantly children. It was first fully delineated only in 2014 in the USA, occurring in epidemic clusters with a likely overall increasing incidence. It has subsequently rapidly been identified in Europe, the UK, and Australasia and the Far East, confirming it to be an emerging, global, infectious neurological disease. It has, however, been very little studied in low- and middle-income countries-reflecting partly of the global imbalance in science and medical research, and partly the extremely low provision of neurological care in most low- and middle-income countries: Uganda currently has no specialized neurology services outside the capital Kampala. During extended visits over a 2-year period with involvement in acute adult and paediatric internal medicine, one of us (NS) encountered at least six new patients with acute flaccid myelitis, suggesting that both the geographical reach and the frequency of the disorder may be significantly greater than previously thought. Here, these cases are described together with their clinical features and, where available, course and (limited) investigation results. These observations have significant implications concerning the current, and potentially the future geographical spread of the disease, and its clinical phenomenology. In addition, they highlight serious problems concerning the global applicability of the current Acute Flaccid Myelitis diagnostic criteria.

Acute Flaccid Myelitis: Review of Clinical Features, Diagnosis, and Management with Nerve Transfers

BACKGROUND

Acute flaccid myelitis (AFM) is a devastating neurologic condition in children, manifesting as acute limb weakness and/or paralysis. Despite increased awareness of AFM following initiation of U.S. surveillance in 2014, no treatment consensus exists. The purpose of this systematic review was to summarize the most current knowledge regarding AFM epidemiology, cause, clinical features, diagnosis, and supportive and operative management, including nerve transfer.

METHODS

The authors systematically reviewed the literature based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using multiple databases to search the keywords ("acute flaccid myelitis"), ('acute flaccid myelitis'/exp OR 'acute flaccid myelitis'), and (Acute AND flaccid AND myelitis). Included articles reported on (1) AFM diagnosis and (2) patient-specific data regarding epidemiology, cause, clinical features, diagnostic features, or management of AFM.

RESULTS

Ninety-nine articles were included in this review. The precise cause and pathophysiologic mechanism of AFM remain undetermined, but AFM is strongly associated with nonpolio enterovirus infections. Clinical presentation typically comprises preceding viral prodrome, pleocytosis, spinal cord lesions on T2-weighted magnetic resonance imaging, and acute onset of flaccid weakness/paralysis with hyporeflexia in at least one extremity. Supportive care includes medical therapy and rehabilitation. Early studies of nerve transfer for AFM have shown favorable outcomes for patients with persistent weakness.

CONCLUSIONS

Supportive care and physical therapy are the foundation of a multidisciplinary approach to managing AFM. For patients with persistent limb weakness, nerve transfer has shown promise for improving function in distal muscle groups. Surgeons must consider potential spontaneous recovery, patient selection, donor nerve availability, recipient nerve appropriateness, and procedure timing.

Global prevalence and case fatality rate of Enterovirus D68 infections, a systematic review and meta-analysis

A substantial amount of epidemiological data has been reported on Enterovirus D68 (EV-D68) infections after the 2014 outbreak. Our goal was to map the case fatality rate (CFR) and prevalence of current and past EV-D68 infections. We conducted a systematic review (PROSPERO, CRD42021229255) with published articles on EV-68 infections in PubMed, Embase, Web of Science and Global Index Medicus up to January 2021. We determined prevalences using a model random effect. Of the 4,329 articles retrieved from the databases, 89 studies that met the inclusion criteria were from 39 different countries with apparently healthy individuals and patients with acute respiratory infections, acute flaccid myelitis and asthma-related diseases. The CFR estimate revealed occasional deaths (7/1353) related to EV-D68 infections in patients with severe acute respiratory infections. Analyses showed that the combined prevalence of current and past EV-D68 infections was 4% (95% CI = 3.1–5.0) and 66.3% (95% CI = 40.0–88.2), respectively. The highest prevalences were in hospital outbreaks, developed countries, children under 5, after 2014, and in patients with acute flaccid myelitis and asthma-related diseases. The present study shows sporadic deaths linked to severe respiratory EV-D68 infections. The study also highlights a low prevalence of current EV-D68 infections as opposed to the existence of EV-D68 antibodies in almost all participants of the included studies. These findings therefore highlight the need to implement and/or strengthen continuous surveillance of EV-D68 infections in hospitals and in the community for the anticipation of the response to future epidemics.

Enterovirus D68 (EV-D68) infections represent a global public health concern. EV-D68 are detected in apparently healthy subjects and patients with acute respiratory illnesses, acute flaccid myelitis, and asthma-related illnesses. Enterovirus D68 was first described in 1962 and exhibited sporadic circulation until August 2014 when outbreaks of EV-D68 infections were reported in the USA and Canada mainly in children with acute flaccid myelitis and severe acute respiratory disease. We systematically reviewed the literature on EV-D68 infections globally in the present study to determine the case fatality rate and prevalence of current and past infections. Our results show sporadic deaths in patients with severe acute respiratory EV-D68 infections. Our data also show a low prevalence of EV-D68 in current infections unlike the presence of EV-D68 antibodies (past infections) in almost all individuals of all ages. EV-D68 infections were more prevalent in hospital outbreaks, industrialized countries, children < 5 years, and patients with acute flaccid myelitis and asthma-related diseases. These data highlight the need to strengthen the surveillance of EV-D68 infections.

Acute flaccid rhombencephalomyelitis with radiculitis in a child with an enterovirus A71 infection seen for the first time in Denmark: a case report

Background

Acute flaccid myelitis is a serious condition of the spinal cord. More than 80% of patients experience a mild respiratory illness or fever consistent with a viral infection prior to acute flaccid myelitis development. Enterovirus A71 is known to circulate in Denmark, and has previously been associated with severe neurological symptoms. In this case report we describe acute flaccid rhombencephalomyelitis with radiculitis in an infant with an enterovirus infection.

Case presentation

The 8-month-old male of Asian origin presented with fever and gastrointestinal symptoms, followed by severe neurological deficits such as flaccid paralysis of the neck and upper extremities. An initial magnetic resonance imaging scan of the brain was normal, and the boy was treated for encephalitis. A follow-up magnetic resonance imaging scan of the brain and spinal cord 1 week later showed the development of pathological symmetrical gray matter hyperintensity lesions on T2-weighted images in the brainstem and upper medulla spinalis, and nerve enhancement in the terminal thread of the spinal cord and the cervical roots; findings consistent with rhombencephalomyelitis with radiculitis causing flaccid paralysis. Enterovirus A71 was detected in both nasopharyngeal and fecal specimens. Other differential diagnostic etiologies of viral and bacterial encephalitis, including poliovirus, were excluded.

Conclusions

This is the first case in Denmark of a patient diagnosed with acute flaccid rhombencephalomyelitis strongly linked to an enterovirus A71 infection. This case emphasizes the diagnostic importance of combining a history of respiratory and/or gastrointestinal illness, fever, and delayed onset of varying degrees of paralysis with progressive characteristic spinal and brain lesions. Analysis of respiratory, fecal, and cerebrospinal samples for the presence of enterovirus, and eliminating other differential pathogens, is essential to confirm the diagnosis.

Nerve Transfers for Restoration of Elbow Flexion in Patients With Acute Flaccid Myelitis

PURPOSE

The purpose of this study was to evaluate short- to midterm outcomes of patients with acute flaccid myelitis who underwent nerve transfers for restoration of elbow flexion.

METHODS

Patients with a minimum of 10 months of follow up after undergoing nerve transfers to restore elbow flexion were clinically assessed using the Active Movement Scale (AMS). They were evaluated for any postoperative complications, particularly weakness in the distribution of the donor nerve(s). Fifteen of 25 consecutive patients who were treated using this surgical technique were included in the final analysis.

RESULTS

All patients exhibited poor elbow flexion preoperatively (AMS 0 to 3). At a mean follow up of 17.3 months, 80% (15/25) of patients achieved excellent elbow flexion (AMS 6 or 7); 9 of these 15 had full active range of motion. Two patients achieved good elbow flexion (AMS 5) with antigravity movement to less than 50% of the passive range of motion. No cases of superficial or deep infection were reported, and all patients maintained identical motor function, relative to preoperative status, of the muscles innervated by the donor nerves.

CONCLUSIONS

Nerve transfer surgery has shown promising short- to midterm results for recovery of nerve and muscle function, particularly for the restoration of elbow flexion. We recommend this treatment option for patients not demonstrating clinical improvement after 6 to 9 months of incomplete recovery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Acute Flaccid Myelitis

Acute flaccid myelitis (AFM) is an incompletely understood neurologic disorder occurring in epidemic fashion causing weakness ranging from mild paresis to devastating paralysis in children and some adults. This article reviews the case definition of AFM as well as its epidemiology and association with enteroviral infection. The clinical presentation, diagnostic investigation with particular attention to electrodiagnostics, acute management, and surgical options are described. Clinical outcomes and considerations for acute and long-term rehabilitation management are discussed extensively based on review of current literature, highlighting avenues for further study.

Acute flaccid myelitis: cause, diagnosis, and management

Acute flaccid myelitis (AFM) is a disabling, polio-like illness mainly affecting children. Outbreaks of AFM have occurred across multiple global regions since 2012, and the disease appears to be caused by non-polio enterovirus infection, posing a major public health challenge. The clinical presentation of flaccid and often profound muscle weakness (which can invoke respiratory failure and other critical complications) can mimic several other acute neurological illnesses. There is no single sensitive and specific test for AFM, and the diagnosis relies on identification of several important clinical, neuroimaging, and cerebrospinal fluid characteristics. Following the acute phase of AFM, patients typically have substantial residual disability and unique long-term rehabilitation needs. In this Review we describe the epidemiology, clinical features, course, and outcomes of AFM to help to guide diagnosis, management, and rehabilitation. Future research directions include further studies evaluating host and pathogen factors, including investigations into genetic, viral, and immunological features of affected patients, host-virus interactions, and investigations of targeted therapeutic approaches to improve the long-term outcomes in this population.

Acute flaccid myelitis outbreak through 2016-2018: A multicenter experience from Turkey

AIM

We aim to describe the demographic characteristics, etiology, neurophysiology, imaging findings, treatment, prognosis, and prognostic factors of acute flaccid myelitis.

METHODS

The clinical data, laboratory test and, magnetic resonance imaging (MRI) results of pediatric patients diagnosed with acute flaccid myelitis according to the Centers for Disease Control criteria between August 1, 2016, and December 31, 2018, from 13 centers in Turkey were reviewed.

RESULTS

Of the 34 cases identified, 31 were confirmed (91.2%). Eighteen patients (55.9%) were boys. The median patient age was 4 years (interquartile range 2.5-6.9 years). Most of the patients were admitted in 2018 (n = 27). A preceding history of a febrile illness was reported in all patients, with a median of 4 days (interquartile range 3-7 days) before symptom onset. Thirty-one patients had T2 hyperintensity on spinal MRI, and 18 patients had cerebrospinal fluid pleocytosis. The most common infectious agents were entero/rhinoviruses (n = 5) in respiratory specimens. All patients except one received immunotherapy either alone or in combination. Among 27 patients with follow-up data 24 had persistent weakness. Involvement of four limbs together with an abnormal brain MRI at onset were associated with a poor prognosis.

CONCLUSION

The number of patients with acute flaccid myelitis increased since 2012, spiking with every 2-year interval, largely in the pediatric population. The median age decreases with every outbreak. Clinicians should be aware of the clinical picture for early collection of specimens and early start of rehabilitation programs. Further studies are needed to better characterize the etiology, pathogenesis, risk factors, and treatment of this rare condition.

Enterovirus D68 molecular and cellular biology and pathogenesis

In recent years, enterovirus D68 (EV-D68) has advanced from a rarely detected respiratory virus to a widespread pathogen responsible for increasing rates of severe respiratory illness and acute flaccid myelitis (AFM) in children worldwide. In this review, we discuss the accumulating data on the molecular features of EV-D68 and place these into the context of enterovirus biology in general. We highlight similarities and differences with other enteroviruses and genetic divergence from own historical prototype strains of EV-D68. These include changes in capsid antigens, host cell receptor usage, and viral RNA metabolism collectively leading to increased virulence. Furthermore, we discuss the impact of EV-D68 infection on the biology of its host cells, and how these changes are hypothesized to contribute to motor neuron toxicity in AFM. We highlight areas in need of further research, including the identification of its primary receptor and an understanding of the pathogenic cascade leading to motor neuron injury in AFM. Finally, we discuss the epidemiology of the EV-D68 and potential therapeutic approaches.

Acute Flaccid Myelitis: A Single Pediatric Center Experience From 2014 to 2019

BACKGROUND

Acute flaccid myelitis has emerged as the leading cause of acute flaccid paralysis in children. Acute flaccid myelitis leads to significant physical disability; hence, objective outcome measures to study disease severity and progression are desirable. In addition, nerve transfer to improve motor function in affected children needs further study.

METHODS

Retrospective study of acute flaccid myelitis subjects managed at Children's Healthcare of Atlanta from August 2014 to December 2019. Clinical, electromyography and nerve conduction study, neuropsychological functional independence (WeeFIM), and nerve transfer data were reviewed.

RESULTS

Fifteen children (11 boys and 4 girls) mean age 5.1±3.2 years (range 14 months to 12 years) were included. All subjects (n = 15) presented with severe asymmetric motor weakness and absent tendon reflexes. Motor nerve conduction study of the affected limbs in 93% (n = 14) showed absent or markedly reduced amplitude. Ten patients received comprehensive inpatient rehabilitation and neuropsychological evaluation. Admission and discharge WeeFIM scores showed deficits most consistent and pronounced in the domains of self-care and mobility. Multiple nerve transfer surgery was performed on 13 limbs (9 upper and 4 lower extremities) in 6 children. Postsurgery (mean duration of 10.4 ± 5.7 months) follow-up demonstrated improvement on active movement scale (AMS) in 4 subjects.

CONCLUSION

Acute flaccid myelitis affects school-age children with asymmetric motor weakness, absent tendon reflexes, and reduced or absent motor amplitude on nerve conduction study. Comprehensive rehabilitation and nerve transfer led to improvement in motor function on neuropsychology WeeFIM and AMS scores.

The Utilization of Nerve Transfer for Reestablishing Shoulder Function in the Setting of Acute Flaccid Myelitis: A Single-Institution Review

BACKGROUND

Acute flaccid myelitis (AFM) is a rare disease of young children. The typical presentation involves acute-onset flaccid paralysis in one or more extremities with a nonspecific viral prodrome. Long-term outcomes demonstrate that functional recovery plateaus around six to nine months. The purpose of this study was to evaluate the efficacy of nerve transfers for restoring shoulder function in these patients.

METHODS

A retrospective review of all patients diagnosed with AFM at a single institution. Shoulder function was evaluated using the active movement scale (AMS). Children at a minimum of six months after diagnosis with plateaued shoulder AMS scores of 4 or less were indicated for surgery.

RESULTS

Eleven patients were identified with a mean time from symptom onset to surgery of 12 months. Average follow-up was 19 months. The mean AMS score at follow-up for shoulder external rotation and abduction was 4.6 and 2.8, respectively. A total of six different nerve transfers with five different donor nerves were used individually or in conjunction with each other. The most common transfers were from the spinal accessory nerve to the suprascapular nerve (n = 8) and from the intercostal nerves ×3 to the axillary nerve (n = 5). Patients who received a transfer from the radial nerve to the axillary nerve (n = 2) had the best functional returns, with the mean AMS score of 6.5 in both external rotation and abduction at follow-up.

CONCLUSION

Nerve transfer procedures may help restore shoulder function in the setting of AFM. Combination procedures that involve a transfer from the radial nerve to the axillary nerve may provide the best functional results.

Polio - The old foe and new challenges: An update for clinicians

The Global Polio Eradication Initiative since 1988 has seen the impact of poliovirus decline from frequent global epidemics in the early 1900s to being now only endemic in two countries today. Global vaccination programmes and surveillance for the disease have resulted in the landmark eradication of two of the three poliovirus strains in the last 5 years. Australia continues to contribute to global surveillance efforts for the disease via the Australian Paediatric Surveillance Unit and the Paediatric Active Enhanced Disease Surveillance Network, which aim to detect cases of acute flaccid paralysis in children, the key clinical feature of poliomyelitis. Today, in the era of the polio 'endgame', there is growing recognition of non-polio enteroviruses causing paralytic diseases that are polio-like, particularly in children, with an increased need for awareness and vigilance by paediatric clinicians.

Update on acute flaccid myelitis: recognition, reporting, aetiology and outcomes

Acute flaccid myelitis, defined by acute flaccid limb weakness in the setting of grey matter lesions of the spinal cord, became increasingly recognised in 2014 following outbreaks in Colorado and California, temporally associated with an outbreak of enterovirus D68 respiratory disease. Since then, there have been biennial increases in late summer/early fall. A viral infectious aetiology, most likely enteroviral, is strongly suspected, but a definitive connection has yet to be established. Patients typically present with asymmetric weakness, maximal proximally, in the setting of a febrile illness. MRI demonstrates T2/FLAIR abnormalities in the central grey matter of the spinal cord, and cerebrospinal fluid typically shows a lymphocytic pleocytosis with variable elevation in protein. The weakness may be progressive over several days and involve respiratory muscles, making early recognition and close monitoring essential. Other complications in the acute period may include autonomic instability and bowel/bladder involvement. There is no clear recommended treatment at this time, although intravenous immunoglobulin, steroids and plasma exchange have been used. Intensive therapies and rehab services have shown benefit in maximising function, and surgical interventions may be considered in cases without optimal response to therapies. Close attention should also be paid to psychosocial factors. Prognosis is generally guarded, and additional factors that predict final outcome, including host factors and treatment effects, have yet to be elucidated. Multicentre collaborative efforts will be required to provide answers about this rare but serious disorder.

Acute Flaccid Myelitis Among Hospitalized Children in Texas, 2016

BACKGROUND

Acute flaccid myelitis is characterized by acute-onset flaccid limb weakness with predominantly gray matter lesions in the spinal cord spanning one or more segments. Rates of full recovery are poor, and there is no standard treatment or definitive cause.

METHODS

This is a retrospective review of children diagnosed with acute flaccid myelitis in Texas during 2016. Patients were identified through a Texas collaborative of six hospitals in four major metropolitan areas. Data abstraction included health history, illness presentation, medical treatments, laboratory studies, imaging data, recovery, and ability to perform activities of daily living up to approximately two years from illness onset.

RESULTS

Among all sites, 21 patients met inclusion criteria. Treatments varied with the most common being intravenous immunoglobulin, high-dose methylprednisolone, and plasmapheresis. No differences were seen in response to medical treatments. A potential etiology was found in 12 (57%) cases, including four with enterovirus D68. Five cases recovered fully. Of the 16 patients without full recovery, abilities ranged from (1) able to perform all activities of daily living for age independently (n = 5), (2) mild deficits (n = 5), and (3) substantial reliance on caregivers for activities of daily living (n = 6).

CONCLUSION

Many reports describe symptoms and outcomes of acute flaccid myelitis, but limited data are available on long-term functional outcomes. We were unable to make a strong case for any single cause or treatment modality. Fortunately, the majority of patients (15, 71%) were able to perform activities of daily living with complete independence or only mild deficits.

Acute flaccid myelitis – has it gone unrecognised in Australian children?

We have identified a previously unrecognised cluster of a newly recognised condition – acute flaccid myelitis (AFM) – among acute flaccid paralysis (AFP) cases identified by the Australian Paediatric Active Enhanced Disease Surveillance Network (PAEDS) 2007–2017. In the 12 months before and after detection of enterovirus D68 (EV-D68) from a single AFP case in April 2016, 24 of 97 notified cases of AFP were found to be clinically compatible with AFM; of these 24 cases, ten, clustered in early 2016, met magnetic resonance imaging (MRI) criteria for AFM. Detection of emerging enteroviruses requires collection of respiratory, cerebrospinal fluid and stool specimens, and should be routine practice for all AFP cases.

Unmet Needs in the Evaluation, Treatment, and Recovery for 167 Children Affected by Acute Flaccid Myelitis Reported by Parents Through Social Media

BACKGROUND

We aimed to characterize the outcomes of 167 children affected by acute flaccid myelitis by leveraging the power of social media.

METHODS

Members of a closed social media (Facebook) group were invited to participate in an anonymous online survey. Descriptive statistics were applied to quantitative responses, and free-text responses were grouped into themes using a grounded theory approach.

RESULTS

Caregivers provided information about 167 affected children; 77% were at least 6 months since onset. Clinical features matched those of larger published case series (e.g., walking impairment in 76.7%, intravenous immunoglobulin treatment in 80.8%; 28.2% tested positive for Enterovirus D68; 17% children had asthma before acute flaccid myelitis onset). Mean duration of initial hospitalization was 49.1 (S.D., 74.0) days, and of initial inpatient rehabilitation was 42.3 (S.D., 67.6) days. Among challenges, parents frequently reported delays in diagnosis, including lack of neurological examination at initial medical evaluation for weakness. Other challenges included familial and professional impact of protracted hospitalizations, uncertainty about cause or prognosis of acute flaccid myelitis, and the dynamic nature of care needs in growing children. The social media group played a critical role not only for social support but also for dissemination of rehabilitation approaches and of networks of expert clinicians.

CONCLUSIONS

Children with acute flaccid myelitis have persistent and dynamic deficits, but many continue to show ongoing functional improvements beyond the initial expected window of recovery. In an emerging disease paralyzing young children, social media can strengthen knowledge networks and focus on rehabilitation.

Acute Flaccid Myelitis: Characteristics and Outcomes of 2014 and 2016 Cases at a Single Center

Acute flaccid myelitis (AFM) is a rare condition associated with spinal cord gray matter abnormalities and frequent persistent motor deficits in the limbs. We present our experience with the diagnosis, management, and outcomes of affected children in 2014 and 2016, emphasizing features that should trigger early consideration of AFM. Early viral testing may increase the rate of detecting associated viruses.

Acute flaccid myelitis temporally associated with rhinovirus infection: just a coincidence?

We report the case of a 3.6-year-old male child who developed progressive hyposthenia of the left lower limb. Symptoms were preceded by rhinitis, malaise, and fever. Brain and spinal magnetic resonance imaging revealed diffuse signal abnormalities compatible with a subacute myeloencephalitis. A diagnostic lumbar puncture was performed and followed by an empirical therapy including Acyclovir, Ceftriaxone, and Clarithromycin. The cerebrospinal fluid analysis revealed clear fluid, glucose, proteins, albumin within the reference range, and 144 leukocytes/mm³. Oligoclonal bands were absent and a search for viruses was negative. Wide microbiological surveillance was performed on surface swabs, blood, urine, and stool. Both nasal and pharyngeal swabs were positive for PicoRNAvirus: sequencing identified Rhinovirus A44. This virus has been detected in association with acute flaccid paralysis in only a few patients worldwide, whereas in the great majority of patients with acute flaccid paralysis other Enterovirus species were identified. The most appropriate therapeutic approach towards acute flaccid paralysis is still a matter of debate in the scientific community, with no current definitivere commendations available. With a combined immunosuppressive and anti-inflammatory therapy including intravenous immunoglobulins, intravenous Methylprednisolone, oral Prednisone, and oral Ibuprofen, we experienced a positive outcome both from the clinical point of view and from three-month follow-up imaging studies. Given the rarity and the complexity of this condition, additional studies are needed to better define the potential role of Rhinovirus A44 in the pathogenesis of the disease and the efficacy of any therapeutic measure in the management of acute flaccid paralysis.

Enteroviruses Remodel Autophagic Trafficking through Regulation of Host SNARE Proteins to Promote Virus Replication and Cell Exit

Enterovirus D68 (EV-D68) is a medically important respiratory plus-strand RNA virus of children that has been linked to acute flaccid myelitis. We have determined that EV-D68 induces autophagic signaling and membrane formation. Autophagy, a homeostatic degradative process that breaks down protein aggregates and damaged organelles, promotes replication of multiple plus-strand viruses. Induction of autophagic signals promotes EV-D68 replication, but the virus inhibits the downstream degradative steps of autophagy in multiple ways. EV-D68 proteases cleave a major autophagic cargo adaptor and the autophagic SNARE SNAP29, which reportedly regulates fusion between autophagosome to amphisome/autolysosome. Although the virus inhibits autophagic degradation, SNAP29 promotes virus replication early in infection. An orphan SNARE, SNAP47, is shown to have a previously unknown role in autophagy, and SNAP47 promotes the replication of EV-D68. Our study illuminates a mechanism for subversion of autophagic flux and redirection of the autophagic membranes to benefit EV-D68 replication.

Comparative quantitative clinical, neuroimaging, and functional profiles in children with acute flaccid myelitis at acute and convalescent stages of disease

AIM

To quantify characteristics in acute flaccid myelitis (AFM) at acute and convalescent stages.

METHOD

This was a retrospective case series of children with AFM evaluated at a single institution in the USA (2014-2017). Acute inflammatory/ischemic myelopathies were excluded. Neurological assessments and segmental quantitative analysis of signal abnormalities on magnetic resonance imaging (MRI) of the brain and spinal cord were performed.

RESULTS

Sixteen patients (11 males, five females) were evaluated. Median age at onset was 4 years (interquartile range [IQR] 3-6y). All had parainfectious acute-onset limb weakness, lower motor neuron examination, and spinal fluid pleocytosis. On acute spinal cord MRI, longitudinally extensive T2 hyperintensities were identified throughout the spinal cord mostly within grey matter; five out of 12 patients had dorsal brainstem T2 hyperintensities. At a median of 2 months follow-up (IQR 2-3mo), spinal cord MRI improved in seven out of nine patients although focal T2 hyperintensities persisted in cervical and lumbar grey matter. At a median follow-up of 4 months (IQR 2-6mo), Medical Research Council sum score rose from a median of 29 to 32; distal muscle groups improved more than proximal ones; four out of 16 patients were ventilator-dependent; and two out of 16 patients were quadriplegic.

INTERPRETATION

While patients may show marked improvement on neuroimaging from acute to convalescent stages, the majority of children with AFM have limited motor recovery and continued disability. Clinicians should consider the timing of clinical and neuroimaging exams when assessing diagnosis and prognosis.

WHAT THIS PAPER ADDS

During the 2014 to 2017 acute flaccid myelitis outbreak in the USA, clinical recovery was better in distal than proximal muscle groups. Lumbar spinal cord showed more residual abnormalities at convalescence.

Clinical Subpopulations in a Sample of North American Children Diagnosed With Acute Flaccid Myelitis, 2012-2016

IMPORTANCE

Acute flaccid myelitis (AFM) is an emerging poliolike illness of children whose clinical spectrum and associated pathogens are only partially described. The case definition is intentionally encompassing for epidemiologic surveillance to capture all potential AFM cases. Defining a restrictive, homogenous subpopulation may aid our understanding of this emerging disease.

OBJECTIVE

To evaluate the extent to which the US Centers for Disease Control and Prevention (CDC) case definition of AFM incorporates possible alternative diagnoses and to assess the plausibility of a case definition that enriches the biological homogeneity of AFM for inclusion in research studies.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective case analysis of children younger than 18 years diagnosed as having AFM between 2012 and 2016 using the CDC case definition. Group 1 included patients recruited from the United States and Canada based on the CDC case definition of AFM. Group 2 included patients referred to the Johns Hopkins Transverse Myelitis Center for evaluation of suspected AFM. Patients' records and imaging data were critically reviewed by 3 neurologists to identify those cases with definable alternative diagnoses, and the remaining patients were categorized as having restrictively defined AFM (rAFM). Clinical characteristics were compared between patients with rAFM (cases) and those with alternative diagnoses, and a case description distinguishing these AFM groups was identified. Interrater reliability of this description was confirmed for a subset of cases by a fourth neurologist. Data were analyzed between May 2017 and November 2018.

MAIN OUTCOMES AND MEASURES

Proportion of patients with possible alternative diagnosis.

RESULTS

Of the 45 patients who met the CDC AFM case definition and were included, the mean age was 6.1 years; 27 were boys (60%); and 37 were white (82%), 3 were Asian (7%), 1 was Hispanic (2%), and 4 were mixed race/ethnicity (9%). Of the included patients, 34 were classified as having rAFM, and 11 had alternate diagnoses (including transverse myelitis, other demyelinating syndromes, spinal cord stroke, Guillain-Barre syndrome, Chiari I myelopathy, and meningitis). Factors differing between groups were primarily asymmetry of weakness, lower motor neuron signs, preceding viral syndrome, symptoms evolving over hours to days, absence of sensory deficits, and magnetic resonance imaging findings. A case description was able to reliably define the rAFM group.

CONCLUSIONS AND RELEVANCE

We present an approach for defining a homogeneous research population that may more accurately reflect the pathogenesis of the prototypical poliomyelitis-like subgroup of AFM. The definition of rAFM forms a blueprint for inclusion criteria in future research efforts, but more work is required for refinement and external validation.

Acute flaccid myelitis and enterovirus D68: lessons from the past and present

Acute flaccid myelitis is characterized by the combination of acute flaccid paralysis and a spinal cord lesion largely restricted to the gray matter on magnetic resonance imaging. The term acute flaccid myelitis was introduced in 2014 after the upsurge of pediatric cases in the USA with enterovirus D68 infection. Since then, an increasing number of cases have been reported worldwide. Whereas the terminology is new, the clinical syndrome has been recognized in the past in association with several other neurotropic viruses such as poliovirus.Conclusion: This review presents the current knowledge on acute flaccid myelitis with respect to the clinical presentation and its differential diagnosis with Guillain-Barré syndrome and acute transverse myelitis. We also discuss the association with enterovirus D68 and the presumed pathophysiological mechanism of this infection causing anterior horn cell damage. Sharing clinical knowledge and insights from basic research is needed to make progress in diagnosis, treatment, and prevention of this new polio-like disease. What is Known: • Acute flaccid myelitis (AFM) is a polio-like condition characterized by rapid progressive asymmetric weakness, together with specific findings on MRI • AFM has been related to different viral agents, but recent outbreaks are predominantly associated with enterovirus D68. What is New: • Improving knowledge on AFM must increase early recognition and adequate diagnostic procedures by clinicians. • The increasing incidence of AFM urges cooperation between pediatricians, neurologists, and microbiologists for the development of treatment and preventive options.