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Brenda L Banwell

Publications and source records attributed to Brenda L Banwell.

9 recordsLinked to original sources
PubMed2006

Grandpa and I have dystrophinopathy?: approach to asymptomatic hyperCKemia.

This report describes three males from a single kinship, ages 7, 8, and 67 years with clinically asymptomatic dystrophinopathy. The index case was an 8-year-old male evaluated for asymptomatic but persistently elevated serum creatine kinase levels. Muscle biopsy demonstrated a mild myopathy, without necrotic fibers. Immunostaining for dystrophin revealed a slight reduction in sarcolemmal reactivity for the amino terminus of dystrophin. Dystrophin gene analysis revealed a deletion of exon 45 to exon 51. Genetic analysis identified two other affected males (age 7 years and 67 years), as well as four female carriers in the same family. The 7-year-old male had mildly increased creatine kinase levels with normal muscle strength. The 67-year-old grandfather had normal neuromuscular examination and serum creatine kinase levels. Asymptomatic dystrophinopathy in late adulthood is exceptionally rare, and highlights the importance of consideration of dystrophin mutation analysis in patients with hyperCKemia, even in the absence of muscle weakness.

Aged↗
PubMed2005

The cognitive burden of multiple sclerosis in children.

Little is known about the cognitive sequelae of pediatric-onset multiple sclerosis (MS). Ten pediatric patients with MS were evaluated using a comprehensive neuropsychological battery. Neuropsychological deficits were identified on measures of general cognition, language, visuomotor integration, and verbal and visual memory. Cognitive impairment occurs in children with MS, and those with longer disease duration and younger age at MS onset appear to be at greatest risk.

Adolescent↗
PubMed2004

MRI criteria for multiple sclerosis: Evaluation in a pediatric cohort.

This study assessed the validity of established MRI criteria for multiple sclerosis (MS) in a cohort of 20 children with clinically definite MS. The authors found that many pediatric MS patients did not meet the MRI criteria established for adult-onset MS, particularly the McDonald MRI criteria for dissemination in space. The authors thus suggest that MRI criteria for adult MS be applied cautiously to pediatric MS patients.

Adolescent↗
PubMed2004

Pediatric multiple sclerosis.

The onset of multiple sclerosis (MS) in childhood is being increasingly recognized. Despite this, there currently exist several barriers to the prompt diagnosis of MS in children. Many clinicians view MS as an exclusively adult-onset disease, and thus they may not entertain the diagnosis in a child. Also, the clinical and radiographic criteria for the diagnosis of MS have not been validated in a pediatric MS population. The available literature, as well as experience gained in a dedicated pediatric MS clinic, is used here to describe features of pediatric MS and contrast these with adult MS. The rationale and importance of future studies in pediatric MS is highlighted.

Adolescent↗
PubMed2004

Novel truncating RAPSN mutations causing congenital myasthenic syndrome responsive to 3,4-diaminopyridine.

Rapsyn is essential for clustering the acetylcholine receptor at the postsynaptic membrane of the neuromuscular junction. Direct sequencing of RAPSN in two children with congenital myasthenic syndromes with no mutation in any of the AChR subunits identified two heterozygous recessive mutations in each: a previously characterized N88K mutation in both, and a second frameshifting mutation in Patient (Pt) 1 and a nonsense mutation in Pt 2. An intercostal muscle biopsy in Pt 1 revealed decreased AChRs per endplate and decreased amplitude of the miniature endplate potential, predicted consequences of rapsyn deficiency. Clinically, both children manifested with hypomotility in utero, fatigable ocular and limb weakness since birth, decreased strength during viral illness, decremental response on electromyography, and absence of AChR antibodies. Pt 1, however, had a more severe clinical course with recurrent episodes of respiratory failure, contractures, and craniofacial malformations. In both patients, treatment with pyridostigmine was of some benefit, but the addition of 3,4-diaminopyridine led to significant clinical improvement. Thus, rapsyn deficiency predicting similar consequences at the cellular level can result in phenotypes with marked differences in severity of symptoms, risk of respiratory failure, and presence of contractures and craniofacial malformations.

4-Aminopyridine↗
PubMed2003

Targeted disruption of the ATP2A1 gene encoding the sarco(endo)plasmic reticulum Ca2+ ATPase isoform 1 (SERCA1) impairs diaphragm function and is lethal in neonatal mice.

Mutations in the ATP2A1 gene, encoding isoform 1 of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA1), are one cause of Brody disease, characterized in humans by exercise-induced contraction of fast twitch (type II) skeletal muscle fibers. In an attempt to create a model for Brody disease, the mouse ATP2A1 gene was targeted to generate a SERCA1-null mutant mouse line. In contrast to humans, term SERCA1-null mice had progressive cyanosis and gasping respiration and succumbed from respiratory failure shortly after birth. The percentage of affected homozygote SERCA1(-/-) mice was consistent with predicted Mendelian inheritance. A survey of multiple organs from 10-, 15-, and 18-day embryos revealed no morphological abnormalities, but analysis of the lungs in term mice revealed diffuse congestion and epithelial hypercellularity and studies of the diaphragm muscle revealed prominent hypercontracted regions in scattered fibers and increased fiber size variability. The V(max) of Ca(2+) transport activity in mutant diaphragm and skeletal muscle was reduced by 80% compared with wild-type muscle, and the contractile response to electrical stimulation under physiological conditions was reduced dramatically in mutant diaphragm muscle. No compensatory responses were detected in analysis of mRNAs encoding other Ca(2+) handling proteins or of protein levels. Expression of ATP2A1 is largely restricted to type II fibers, which predominate in normal mouse diaphragm. The absence of SERCA1 in type II fibers, and the absence of compensatory increases in other Ca(2+) handling proteins, coupled with the marked increase in contractile function required of the diaphragm muscle to support postnatal respiration, can account for respiratory failure in term SERCA1-null mice.

Animals↗
PubMed2003

Neurocognitive outcome after acute disseminated encephalomyelitis.

Cognitive dysfunction has been demonstrated in multiple sclerosis but has not been extensively studied after acute disseminated encephalomyelitis (ADEM). Because ADEM often presents with widespread demyelination, which may not completely resolve, these patients may be at risk for persistent cognitive dysfunction. The study objective was to explore the profile and severity of neurocognitive sequelae in pediatric ADEM. Children aged 6-15 years diagnosed with ADEM were invited to participate in a structured neurologic assessment, neuropsychological evaluation, and a follow-up magnetic resonance imaging. Nine of 15 children diagnosed with ADEM met the age criteria and six participated in the study. The mean age at presentation was 7.7 years; the mean duration of follow-up was 3.5 years. As a group, these children with prior ADEM performed within the average range on cognitive testing. However, a variety of mild cognitive deficits were demonstrated in each of the children, even in those whose magnetic resonance imaging studies had completely normalized. Four children demonstrated a cognitive profile of relatively poorer visuospatial/visuomotor function. The cognitive deficits observed in these children are similar but less severe than those previously reported in adults and children with multiple sclerosis, which may reflect the monophasic nature of ADEM, compared with the chronic, recurrent demyelination characteristic of multiple sclerosis.

Adolescent↗
PubMed2002

Pediatric tumefactive demyelination: case series and review of the literature.

Tumefactive demyelinating lesions may be misdiagnosed as brain neoplasms or abscesses. In this paper, we present four cases of pediatric tumefactive demyelination. Twelve cases of pediatric tumefactive demyelination previously reported in the English literature are also summarized. We describe the neuroimaging characteristics and clinical presentation of tumefactive demyelination and how these features may be used in differentiating demyelination from other mass lesions.

Adolescent↗