Acute Neuromuscular Disorders in the Pediatric Intensive Care Unit

Neuromuscular problems of the critically Ill neonate and child

Acute neuromuscular disorders occasionally occur in the Pediatric Neurologic Intensive Care Unit. Many of these are primary disorders of the motor unit that may present acutely or exacerbate during an intercurrent illness. Additionally, acute neuromuscular disorders may develop during an acute systemic illness requiring intensive care management that predispose the child to another set of acute motor unit disorders. This chapter discusses acute neuromuscular crises in the infant, toddler, and adolescent, as well as neuromuscular disorders resulting from critical illness.

Emerging trends and insights in acute flaccid myelitis: a comprehensive review of neurologic manifestations

Acute Flaccid Myelitis (AFM) is a neurological condition in the anterior portion of the spinal cord and can be characterised as paraplegia (paralysis of the lower limbs), and cranial nerve dysfunction. These lesions are caused by the infection due to Enterovirus 68 (EV-D68); a member of the Enterovirus (EV) family belongs to the Enterovirus species within the Picornavirus family and a Polio-like virus. In many cases, the facial, axial, bulbar, respiratory, and extraocular muscles were affected, hence reducing the overall quality of the patient's life. Moreover, severe pathological conditions demand hospitalisation and can cause mortality in a few cases. The data from previous case studies and literature suggest that the prevalence is high in paediatric patients, but careful clinical assessment and management can decrease the risk of mortality and paraplegia. Moreover, the clinical and laboratory diagnosis can be performed by Magnetic resonance imaging (MRI) of the spinal cord followed by Reverse transcription polymerase chain reaction (rRT-PCR) and VP1 seminested PCR assay of the cerebrospinal fluid (CSF), stool, and serum samples can reveal the disease condition to an extent. The primary measure to control the outbreak is social distancing as advised by public health administrations, but more effective ways are yet to discover. Nonetheless, vaccines in the form of the whole virus, live attenuated, sub-viral particles, and DNA vaccines can be an excellent choice to treat these conditions. The review discusses a variety of topics, such as epidemiology, pathophysiology, diagnosis/clinical features, hospitalisation/mortality, management/treatment, and potential future developments.

Vocal Cord Paralysis and Feeding Difficulties as Early Diagnostic Clues of Congenital Myasthenic Syndrome with Neonatal Onset: A Case Report and Review of Literature

Herein, we present a newborn female with congenital vocal cord paralysis who required a tracheostomy in the neonatal period. She also presented with feeding difficulties. She was later diagnosed with a clinical picture of congenital myasthenia, associated with three variants of the MUSK gene: the 27-month follow-up was described. In particular, the c.565C>T variant is novel and has never been described in the literature; it causes the insertion of a premature stop codon (p.Arg189Ter) likely leading to a consequent formation of a truncated nonfunctioning protein. We also systematically collected and summarized information on patients' characteristics of previous cases of congenital myasthenia with neonatal onset reported in the literature to date, and we compared them to our case. The literature reported 155 neonatal cases before our case, from 1980 to March 2022. Of 156 neonates with CMS, nine (5.8%) had vocal cord paralysis, whereas 111 (71.2%) had feeding difficulties. Ocular features were evident in 99 infants (63.5%), whereas facial-bulbar symptoms were found in 115 infants (73.7%). In one hundred sixteen infants (74.4%), limbs were involved. Respiratory problems were displayed by 97 infants (62.2%). The combination of congenital stridor, particularly in the presence of an apparently idiopathic bilateral vocal cord paralysis, and poor coordination between sucking and swallowing may indicate an underlying congenital myasthenic syndrome (CMS). Therefore, we suggest testing infants with vocal cord paralysis and feeding difficulties for MUSK and related genes to avoid a late diagnosis of CMS and improve outcomes.

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.

Does acute flaccid myelitis cause respiratory failure in children?

INTRODUCTION

Acute flaccid myelitis (AFM) is a rare disease that affects spinal cord gray matter, results in acute flaccid weakness of one or more limbs and predominantly involves the cervical spinal cord, which places patients at higher risk for respiratory failure. Our study aims to describe respiratory failure in pediatric AFM patients with emphasis on the need for assisted ventilation and respiratory nerve involvement from an acute and long-term perspective.

MATERIALS AND METHODS

We reviewed the medical records of patients diagnosed with AFM seen in a multidisciplinary clinic for persistent limb weakness between 2016 and 2020.

RESULTS

We studied 54 patients, 35% were female. The median age of patients at illness onset was 5 years (range 7 months-19 years). The median age of patients at the time of study was 8.5 years (range 2-20 years). Eleven patients (20%) required assisted ventilation for acute respiratory failure. Of those that experienced acute respiratory failure, 81% developed chronic respiratory failure. Fifty-six percent of patients with chronic respiratory failure were able to wean off assisted ventilation by 1 year. All patients that experienced unilateral diaphragm impairment with AFM onset experienced acute and chronic respiratory failure.

DISCUSSION

Many patients with AFM may experience respiratory compromise and develop chronic respiratory failure. However, most of these patients can be weaned off ventilatory support by 1 year from illness onset. Most children with unilateral diaphragm impairment can sustain adequate ventilation without the need for long-term ventilatory support.

Pediatric Simplified Acute Physiology Score II: Establishment of a New, Repeatable Pediatric Mortality Risk Assessment Score

Objectives: In critical care it is crucial to appropriately assess the risk of mortality for each patient. This is especially relevant in pediatrics, with its need for accurate and repeatable scoring. Aim of this study was to evaluate an age-adapted version of the expanded Simplified Acute Physiology Score II; (p-SAPS II), a repeatable, newly-designed scoring system compared to established scores (Pediatric Sequential Organ Failure Assessment Score/pSOFA, Pediatric Logistic Organ Dysfunction Score-2/PELOD-2 and Pediatric Index of Mortality 3/PIM3). Design: This retrospective cohort pilot study included data collected from patients admitted to the Pediatric Intensive Care Unit (PICU) at the Medical University of Vienna between July 2017 through December 2018. Patients: 231 admissions were included, comprising neonates (gestational age of ≥ 37 weeks) and patients up to 18 years of age with a PICU stay longer than 48 h. Main Outcomes: Mortality risk prediction and discrimination between survivors and non-survivors were the main outcomes of this study. The primary statistical methods for evaluating the performance of each score were the area under the receiver operating characteristic curve (AUROC) and goodness-of-fit test. Results: Highest AUROC curve was calculated for p-SAPS II (AUC = 0.86; 95% CI: 0.77-0.96; p < 0.001). This was significantly higher than the AUROCs of PELOD-2/pSOFA but not of PIM3. However, in a logistic regression model including p-SAPS II and PIM3 as covariates, p-SAPS II had a significant effect on the accuracy of prediction (p = 0.003). Nevertheless, according to the goodness-of-fit test for p-SAPS II and PIM3, p-SAPS II overestimated the number of deaths, whereas PIM3 showed acceptable estimations. Repeatability testing showed increasing AUROC values for p-SAPS II throughout the clinical stay (0.96 at day 28) but still no significant difference to PIM 3. The prediction accuracy, although improved over the days and even exceeded PIM 3. Conclusions: The newly-created p-SAPS II performed better than the established PIM3 in terms of discriminating between survivors and non-survivors. Furthermore, p-SAPS II can be assessed repeatably throughout a patient's PICU stay what improves mortality prediction. However, there is still a need to optimize calibration of the score to accurately predict mortality sooner throughout the clinical stay.