Miguel Guzman

Idiopathic Inflammatory Myopathies: Clinical Approach and Management

Idiopathic inflammatory myopathies (IIM) are a group of chronic, autoimmune conditions affecting primarily the proximal muscles. The most common types are dermatomyositis (DM), polymyositis (PM), necrotizing autoimmune myopathy (NAM), and sporadic inclusion body myositis (sIBM). Patients typically present with sub-acute to chronic onset of proximal weakness manifested by difficulty with rising from a chair, climbing stairs, lifting objects, and combing hair. They are uniquely identified by their clinical presentation consisting of muscular and extramuscular manifestations. Laboratory investigations, including increased serum creatine kinase (CK) and myositis specific antibodies (MSA) may help in differentiating clinical phenotype and to confirm the diagnosis. However, muscle biopsy remains the gold standard for diagnosis. These disorders are potentially treatable with proper diagnosis and initiation of therapy. Goals of treatment are to eliminate inflammation, restore muscle performance, reduce morbidity, and improve quality of life. This review aims to provide a basic diagnostic approach to patients with suspected IIM, summarize current therapeutic strategies, and provide an insight into future prospective therapies.

Anaphylaxis in the Pediatric Emergency Department: Analysis of 133 Cases After an Allergy Workup

BACKGROUND Data on the incidence and characteristics of pediatric anaphylaxis are scarce. Reported causes of anaphylaxis are mostly those suspected by the physician in the emergency department (ED), which may not coincide with the real triggers. OBJECTIVES To investigate the incidence, management, and etiology of pediatric anaphylaxis in the ED of a Spanish tertiary hospital and to determine the concordance between the suspected etiology in the ED and diagnosis after the allergy workup. METHODS We performed an observational, descriptive study of all patients with anaphylaxis attended in the pediatric ED from 2012 to 2014. Cases were considered anaphylaxis based on National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network criteria. We recorded data on clinical characteristics, management, etiology suspected by the ED physician and patient (or relatives), and the workup performed in the allergy department. RESULTS We recorded 133 cases of anaphylaxis (incidence, 0.12%), with 20 cases (15%) recorded in children younger than 12 months. Anaphylaxis was correctly diagnosed in the ED in 70 cases (53%). Food allergy was the cause of anaphylaxis in 106 out of 118 studied in the allergy department (AD) (90%). The final etiology differed from the etiology initially suspected in the ED in 42 cases (39%). After the study, the frequency of patients with unidentified triggers decreased by 75%. CONCLUSIONS The incidence of anaphylaxis is higher in children than previously reported in adults from the same center, and food is the trigger in most cases. To prevent erroneous diagnoses, the etiology of anaphylaxis should be established after an appropriate workup.

Grade II pilocytic astrocytoma in a 3‐month‐old patient with encephalocraniocutaneous lipomatosis (ECCL): Case report and literature review of low grade gliomas in ECCL

Encephalocraniocutaneous lipomatosis (ECCL) is a rare congenital syndrome with an unknown etiology. Since 1970, around 60 cases have been reported in English literature. ECCL is usually classified by cutaneous lesions and non‐progressive intracranial or spinal lipomas; however three cases of ECCL associated with low grade glioma (LGG) have been described. We report on the fourth case of LGG in a patient with ECCL; a grade II pilocytic astrocytoma with pilomyxoid features in a 3‐month‐old male, the youngest in literature.

Malignant transformation of a desmoplastic infantile ganglioglioma in an infant carrier of a nonsynonymous TP53 mutation.

INTRODUCTION Desmoplastic infantile ganglioglioma is a rare intracranial neoplasm classified as World Health Organization grade I tumor under neuronal and mixed neuronal-glial tumors (2007 World Health Organization brain tumor classification). It is usually a good prognosis, but 40% of patients require further medical, radiation, and/or surgical intervention, and 15% develop leptomeningeal spread or die from desmoplastic infantile ganglioglioma. Transformation to malignant glioblastoma occurs, but the genetic alterations associated with the transformation are generally unknown. METHODS We describe a desmoplastic infantile ganglioglioma in a 2-month-old boy, which showed aggressive behavior, requiring debulking at 2.5 months of age and chemotherapy at 10 months of age after tumor progression. At 8.5 years of age he developed malignant transformation to glioblastoma. Chromosome microarray analysis using oligo array and genomic sequencing was performed on the biopsy specimen from 2 months of age and on the subsequent transformed malignant glioblastoma. RESULTS After being clinically stable for 7.5-years, transformation to glioblastoma transformation occurred. He did well for 1 year but subsequently died from tumor progression. Chromosome microarray analysis using oligo array performed on the biopsy specimen obtained at 2 months of age did not reveal significant abnormalities; but there were significant genomic deletions and duplications associated with the glioblastoma. These included multiple genomic losses involving 4q and Y, gains of 5q, and amplification of 12q14. Genomic sequencing revealed a single nucleotide variant, p.R248Q in exon 7 of TP53, in the primary desmoplastic infantile ganglioglioma and the glioblastoma multiforme. CONCLUSIONS The nonsynonymous variant (p.R248Q in exon 7) of the TP53 gene is predicted to alter the structure of the L2/L3 motif of the DNA binding domain of p53 protein. It was detected in the primary desmoplastic infantile ganglioglioma and glioblastoma multiforme. This child illustrates the rare recurrence of desmoplastic infantile ganglioglioma with malignant transformation to glioblastoma caused by a nonsynonymous TP53 mutation, providing explanation for other rare benign tumor transformations. The TP53 gene is a known primary site of genetic alteration that predisposes to malignant tumors, and this case indicates that it might also be involved in the behavior and outcome of desmoplastic infantile ganglioglioma. Therefore more genetic testing is recommended on desmoplastic infantile ganglioglioma tumors, which may provide biologic prognostic markers.

Preserved Gut Microbial Diversity Accompanies Upregulation of TGR5 and Hepatobiliary Transporters in Bile Acid–Treated Animals Receiving Parenteral Nutrition

Background: Parenteral nutrition (PN) is a lifesaving therapy but is associated with gut atrophy and cholestasis. While bile acids (BAs) can modulate intestinal growth via gut receptors, the gut microbiome likely influences gut proliferation and inflammation. BAs also regulate the bile salt export pump (BSEP) involved in cholestasis. We hypothesized that the BA receptor agonist oleanolic acid (OA) regulates gut TGR5 receptor and modulates gut microbiota to prevent PN-associated injury. Materials and Methods: Neonatal piglets were randomized to approximately 2 weeks of isocaloric enteral nutrition (EN), PN, or PN + enteral OA. Serum alanine aminotransferase, bilirubin, BAs, hepatic BSEP, gut TGR5, gut, liver morphology, and fecal microbiome utilizing 16S rRNA sequencing were evaluated. Kruskal-Wallis test, pairwise Mann-Whitney U test, and multilevel logistic regression analysis were performed. Results: PN support resulted in gut atrophy substantially prevented by OA. The median (interquartile range) for villous/crypt ratio was as follows: EN, 3.37 (2.82–3.80); PN, 1.73 (1.54–2.27); and OA, 2.89 (2.17–3.34; P = .006). Pairwise comparisons yielded P = .002 (EN vs PN), P = .180 (EN vs OA), P = .026 (PN vs OA). OA upregulated TGR5 and BSEP without significant improvement in serum bilirubin (P = .095). A decreased microbial diversity and shift toward proinflammatory phylum Bacteroidetes were seen with PN, which was prevented by OA. Conclusions: OA prevented PN-associated gut mucosal injury, Bacterioides expansion, and the decreased microbial diversity noted with PN. This study demonstrates a novel relationship among PN-associated gut dysfunction, BA treatment, and gut microbial changes.

H3 K27M mutations are extremely rare in posterior fossa group A ependymoma

BackgroundMutations in the tail of histone H3 (K27M) are frequently found in pediatric midline high-grade glioma’s but have rarely been reported in other malignancies. Recently, recurrent somatic nucleotide variants in histone H3 (H3 K27M) have been reported in group A posterior fossa ependymoma (EPN_PFA), an entity previously described to have no recurrent mutations. However, the true incidence of H3 K27M mutations in EPN_PFA is unknown.MethodsIn order to discern the frequency of K27M mutations in histone H3 in EPN_PFA, we analyzed 151 EPN_PFA previously profiled with genome-wide methylation arrays using a validated droplet digital PCR assay.ResultsWe identified only 1 case out of 151 EPN_PFA harboring the K27M mutation indicating that histone mutations are extremely rare in EPN_PFA. Morphologically, this single mutated case is clearly consistent with an ependymoma, and the presence of the K27M mutation was confirmed using immunohistochemistry.DiscussionK27M mutations are extremely rare in EPN_PFA. Routine evaluation of K27M mutations in EPN_PFA is of limited utility, and is unlikely to have any bearing on prognosis and/or future risk stratification.

Activation of extracellular regulated kinase and mechanistic target of rapamycin pathway in focal cortical dysplasia.

Neuropathology of resected brain tissue has revealed an association of focal cortical dysplasia (FCD) with drug‐resistant epilepsy (DRE). Recent studies have shown that the mechanistic target of rapamycin (mTOR) pathway is hyperactivated in FCD as evidenced by increased phosphorylation of the ribosomal protein S6 (S6) at serine 240/244 (S240/244), a downstream target of mTOR. Moreover, extracellular regulated kinase (ERK) has been shown to phosphorylate S6 at serine 235/236 (S235/236) and tuberous sclerosis complex 2 (TSC2) at serine 664 (S664) leading to hyperactive mTOR signaling. We evaluated ERK phosphorylation of S6 and TSC2 in two types of FCD (FCD I and FCD II) as a candidate mechanism contributing to mTOR pathway dysregulation. Tissue samples from patients with tuberous sclerosis (TS) served as a positive control. Immunostaining for phospho‐S6 (pS6240/244 and pS6235/236), phospho‐ERK (pERK), and phospho‐TSC2 (pTSC2) was performed on resected brain tissue with FCD and TS. We found increased pS6240/244 and pS6235/236 staining in FCD I, FCD II and TS compared to normal‐appearing tissue, while pERK and pTSC2 staining was increased only in FCD IIb and TS tissue. Our results suggest that both the ERK and mTOR pathways are dysregulated in FCD and TS; however, the signaling alterations are different for FCD I as compared to FCD II and TS.

Diffusion tensor imaging and myelin composition analysis reveal abnormal myelination in corpus callosum of canine mucopolysaccharidosis I

Children with mucopolysaccharidosis I (MPS I) develop hyperintense white matter foci on T2-weighted brain magnetic resonance (MR) imaging that are associated clinically with cognitive impairment. We report here a diffusion tensor imaging (DTI) and tissue evaluation of white matter in a canine model of MPS I. We found that two DTI parameters, fractional anisotropy (a measure of white matter integrity) and radial diffusivity (which reflects degree of myelination) were abnormal in the corpus callosum of MPS I dogs compared to carrier controls. Tissue studies of the corpus callosum showed reduced expression of myelin-related genes and an abnormal composition of myelin in MPS I dogs. We treated MPS I dogs with recombinant alpha-L-iduronidase, which is the enzyme that is deficient in MPS I disease. The recombinant alpha-L-iduronidase was administered by intrathecal injection into the cisterna magna. Treated dogs showed partial correction of corpus callosum myelination. Our findings suggest that abnormal myelination occurs in the canine MPS I brain, that it may underlie clinically-relevant brain imaging findings in human MPS I patients, and that it may respond to treatment.

Impact of DTI tractography on surgical planning for resection of a pediatric pre-pontine neurenteric cyst: a case discussion and literature review

We report a case of a four-year-old male who presented with symptoms of brainstem compression and lower cranial nerve neuropathies. MRI revealed a large, pre-pontine mass causing brainstem compression with an uncertain intra-axial component. Using diffusion tensor imaging (DTI) tractography and other imaging modalities, we were able to confirm that the lesion was extra-axial and did not involve the corticospinal tracts. In addition, DTI tractography illustrated that corticospinal tracts were displaced to the right obligating a left-sided approach. Upon resection, the mass was identified as a pre-pontine, extra-axial neurenteric cyst (NEC), which represents a rare finding in the pediatric population. The patient ultimately did well following the drainage and resection of the cyst wall and had excellent recovery. In this paper, we discuss the pathophysiology of and treatment options for NECs and explain how DTI tractography in our case assisted in planning the surgical approach.

Holocord syringomyelia secondary to tethered spinal cord associated with anterior sacral meningocele and tailgut cyst: case report and review of literature.

Background and importanceAnterior sacral meningoceles are lesions that are uncommonly reported and can be associated with other pathology including presacral masses, tethered spinal cord, and syringomyelia. Tethered spinal cord and syringomyelia can result in neurologic deficits, while large meningoceles and presacral masses can have gastroenterologic, urologic, reproductive, and oncologic consequences.Clinical presentationThe authors report a case of a 14-year-old girl with an anterior sacral meningocele, tailgut cyst, and tethered cord with holocord syringomyelia who presented with a tethered cord syndrome, manifested by constipation, urinary retention, bilateral lower extremity weakness, and sensory deficits. After extensive radiographic and urodynamic workups were performed, the patient was treated by the neurosurgery and pediatric surgery teams with a posterior sagittal approach for cord detethering, resection of an intradural cystic mass, resection of the anterior sacral meningocele, and resection of the adjacent presacral mass. After surgical treatment, motor weakness and sensory deficits were resolved, though urinary symptoms persisted. The syrinx resolved after detethering alone. Pathology of the intradural cystic mass and the presacral mass inferior to the anterior sacral meningocele were consistent with tailgut cyst.ConclusionThe patient’s clinical and surgical management are discussed, and a literature review related to anterior sacral meningoceles and their related pathologies is presented. An interdisciplinary approach is required for the best treatment of this constellation of findings.