Clinical, electrophysiological, and imaging findings in childhood brachial plexus injury.

AIM: To assess the prognostic capabilities of various diagnostic modalities for childhood brachial plexus injuries (BPIs) and brachial plexus birth injury (BPBI) and postneonatal BPI. METHOD: In this single-center retrospective cross-sectional study, we examined children with BPIs diagnosed or confirmed by electrodiagnostic studies between 2013 and 2020, and compared the prognostic value of various components of the electrophysiologic findings, magnetic resonance imaging (MRI) data, and the Active Movement Scale (AMS). We developed scoring systems for electrodiagnostic studies and MRI findings, including various components of nerve conduction studies and electromyography (EMG) for electrodiagnostic studies. RESULTS: We identified 21 children (10 females and 11 males) aged 8 days to 21 years (mean 8y 6.95mo) who had a total of 30 electrodiagnostic studies, 14 brachial plexus MRI studies, and 10 surgical procedures. Among the diagnostic modalities assessed, brachial plexus MRI scores, EMG denervation scores, and mean total EMG scores were the most valuable in predicting surgical versus non-surgical outcomes. Correspondingly, a combined MRI/mean total EMG score provided prognostic value. INTERPRETATION: Brachial plexus MRI scores and specific electrodiagnostic scores provide the most accurate prognostic information for children with BPI. Our grading scales can assist a multidisciplinary team in quantifying results of these studies and determining prognosis in this setting. WHAT THIS PAPER ADDS: A new scoring system to quantify results of electrodiagnostic and magnetic resonance imaging (MRI) studies is presented. Severity of denervation has good prognostic value for childhood brachial plexus injuries (BPIs). Composite electromyography scores have good prognostic value for childhood BPIs. Brachial plexus MRI has good prognostic value for childhood BPIs.

Lumbosacral ventral spinal nerve root atrophy identified on MRI in a case of spinal muscular atrophy type II.

Spinal muscular atrophies are rare genetic disorders most often caused by homozygous deletion mutations in SMN1 that lead to progressive neurodegeneration of anterior horn cells. Ventral spinal root atrophy is a consistent pathological finding in post-mortem examinations of patients who suffered from various subtypes of spinal muscular atrophy; however, corresponding radiographic findings have not been previously reported. We present a patient with hypotonia and weakness who was found to have ventral spinal root atrophy in the lumbosacral region on MRI and was subsequently diagnosed with spinal muscular atrophy. More systematic analyses of imaging studies in spinal muscular atrophy will help determine whether such findings have the potential to serve as reliable diagnostic markers for clinical evaluations or as outcome measure for clinical trials.

Neuroradiologic findings in Sengers syndrome.

Sengers syndrome is characterized by a constellation of congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, and lactic acidosis. Two forms of the disease have been described: a fatal neonatal form, and a more benign form in which patients live into their second or third decades. With the exception of time to death, no findings have distinguished these two forms. We present 3 cases of neonatal Sengers syndrome with significant central nervous system involvement, a finding not previously described. We suggest that the fatal neonatal form of Sengers syndrome would be more accurately described as a mitochondrial encephalomyopathy. Cranial imaging may help distinguish the two types of this syndrome.

Topiramate loading for refractory status epilepticus in children.

PURPOSE: To describe three cases of refractory status epilepticus (RSE) in children responsive to topiramate (TPM). METHODS: Patients with SE refractory to therapeutic doses of at least two antiepileptic medications were given TPM, 10 mg/kg/d, for 2 consecutive days, followed by maintenance doses of 5 mg/kg/d. RESULTS: This protocol has been used in three cases of RSE at our institution. In each case, SE was aborted within 21 h of the initial dose of TPM. Two patients avoided pharmacologic coma, and one was rapidly weaned from continuous benzodiazepine infusion. CONCLUSIONS: Our experience indicates that TPM loading can be effective in the treatment of RSE in children.

A Bayesian approach to randomized controlled trials in children utilizing information from adults: the case of Guillain-Barré syndrome.

BACKGROUND: Guillain-Barré syndrome (GBS) is a rare neurologic disease that occurs at all ages, causing a progressive, ascending paralysis that usually resolves over weeks or months. The disease appears to be identical in children and adults, except that children recover more quickly, with fewer residua. For patients who lose the ability to walk independently, the main treatment options are plasmapheresis or intravenous immune globulin (IVIg), treatments that have shown to have identical effectiveness in adults in two large RCTs involving 388 patients. The effectiveness of the treatments in children has only been studied in small, poorly controlled studies. If one could capture all eligible patients in the United States, only about 100-300 children would be available for a trial annually. METHODS: The goal of this case was to demonstrate how Bayesian methods could be used to incorporate prior information on treatment efficacy from adults to design a randomized noninferiority trial of IVIg versus plasmapheresis in children. A Bayesian normal-normal model on the hazard ratio of time to independent walking was implemented. RESULTS: An evidence-based prior was constructed that was equivalent to 72 children showing exact equivalence between the therapies. A design was constructed based on a Bayesian normal-normal model on the hazard ratio, yielding a sample size of 160 children, with a preposterior analysis demonstrating a "Type I" error rate of 5% and a power of 77%. CONCLUSIONS: This case study illustrates a rational approach to constructing an evidence-based prior that would allow information from adults to formally augment data from children to minimize unnecessary pediatric experimentation. The frequentist properties of a Bayesian design can be evaluated and reported as they would be for a standard design. Discussion of the appropriate prior for such designs is both a necessary and desirable feature of Bayesian trials.

Supportive care for patients with Guillain-Barré syndrome.

A multidisciplinary consensus group searched MEDLINE from 1966 to May 2003, extracted relevant references, and prepared recommendations on supportive care for Guillain-Barré syndrome. In the absence of randomized controlled trials, we agreed on recommendations by consensus based on observational studies and expert opinion. In the acute phase in bed-bound adult patients, the group recommended the use of heparin and graduated pressure stockings to prevent deep vein thrombosis, monitoring for blood pressure, pulse, autonomic disturbances, and respiratory failure, and the timely institution of artificial ventilation and tracheostomy. Pain management is difficult, but carbamazepine or gabapentin may help. The cautious use of narcotic analgesics may be needed. Disabled patients should be treated by a multidisciplinary rehabilitation team and should receive an assistive exercise program. Persistent fatigue following Guillain-Barré syndrome is common and may be helped by an exercise program. Because of a very small and possibly only theoretical increase in the risk of recurrence following immunization, the need for immunization should be reviewed on an individual basis. More research is needed to identify optimal methods for all aspects of supportive care.

Mitochondrial abnormalities in dermatomyositis: characteristic pattern of neuropathology.

The objective of the work described in this paper was to evaluate mitochondrial abnormalities in perifascicular atrophic fibers in muscle biopsies from patients with dermatomyositis (DM). We localized cytochrome c oxidase (COX) and succinate dehydrogenase (SDH) histochemically in muscle biopsies of 12 patients with DM, and 12 control patients with neurogenic atrophy. These two histochemical techniques were also combined on single tissue sections in order to accentuate any COX-negative fibers. Eleven out of 12 patients (91.6%) with DM showed histochemical evidence of mitochondrial dysfunction in perifascicular distribution. Similar abnormalities in histochemical staining were not seen in comparably sized myofibers that were atrophic due to denervation. It is concluded that abnormal SDH and COX histochemical activities in atrophic perifascicular fibers are characteristic of dermatomyositis. These abnormal staining characteristics could not be accounted for solely by myofiber atrophy, or by generalized abnormalities in histochemical staining.

Guillain-Barré syndrome in children.

In industrialized nations with widespread immunization programs, Guillain-Barré syndrome is the most common cause of acute paralytic illness in children and adults. The incidence of the disease has been estimated to range from 0.5 to 1.5 in 100,000 in individuals less than 18 years of age. Approximately 15% of children with Guillain-Barré syndrome develop respiratory failure and require mechanical ventilatory support. Prospective randomized treatment trials in childhood Guillain-Barré syndrome are wanting; however, smaller case series studies using historical controls suggest that both plasmapheresis and administration of human immunoglobulin could be helpful in reducing morbidity in children with Guillain-Barré syndrome. The prognosis for recovery in children is generally excellent, with the majority of children achieving a complete functional recovery within 6 months from the onset of illness. Studies using an animal model of human Guillain-Barré syndrome, experimental allergic neuritis, have expanded our understanding of the pathogenesis of the disease and suggest new directions for exploration in the treatment of this disorder.

Epidemiology of childhood Guillain-Barré syndrome as a cause of acute flaccid paralysis in Honduras: 1989-1999.

The objective of this study was to investigate the incidence of acute flaccid paralysis in the pediatric population of Honduras over an 11-year period, determine what percentage of acute flaccid paralysis was Guillain-Barré syndrome, and identify the epidemiologic features of Guillain-Barré syndrome. There were 546 childhood cases of acute flaccid paralysis seen between January 1989 and December 1999 at the Hospital Escuela Materno-Infantil in Tegucigalpa, Honduras. Of these cases with acute flaccid paralysis, 394 (72.2%) were diagnosed with Guillain-Barré syndrome. Our incidence of Guillain-Barré syndrome in the Honduran pediatric population (1.37/100,000 per year) is higher than that shown in other studies. There was a significantly higher incidence of Guillain-Barré syndrome in younger children (ages 1-4 years), a significant preponderance of cases from rural areas, and a mild predominance in boys but a typical clinical presentation. The Honduran pediatric Guillain-Barré syndrome population had an increased mortality rate. Guillain-Barré syndrome has become the leading cause of childhood paralysis in Honduras. A better understanding of the population at highest risk and opportunities for earlier intervention with more effective therapeutic modalities may permit reducing the mortality among Honduran children who develop Guillain-Barré syndrome.