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Biomedical subjects

R S Shalev

Publications and source records attributed to R S Shalev.

At least 37 records · Page 2Linked to original sources
PubMed1993

Developmental dyscalculia and medical assessment.

Developmental dyscalculia (DC) is a primary cognitive disorder of childhood manifested by disturbance of arithmetic ability. As an isolated learning disability (LD), it is usually treated by remedial education and not referred for further medical evaluation. We examined a group of 7 third-grade children with DC attending a mainstream school who had not progressed academically in spite of specific special education intervention. We were able to identify in all 7 children neurological conditions that had direct bearing on the children's cognitive disabilities and remedial programs. One child had petit mal seizures, another developmental Gerstmann syndrome, a third had dyslexia for numbers, and 4 children had attention deficit disorders without hyperactivity. Based on this experience, we suggest that the indications for medical or neurological assessment be broadened to include children who are not improving academically in spite of appropriate professional intervention.

Attention Deficit Disorder with Hyperactivity↗
PubMed1992

Striatal degeneration and spongy myelinopathy in glutaric acidemia.

The neuropathological findings in a 6 1/2-year-old boy with glutaric acidemia (GA) are described, and the pathology of 7 additional literature cases is briefly reviewed. Bilateral striatal degeneration and spongy change of the white matter were the salient features in this case and seem to represent the cardinal pathological features of the disease. Spongy myelinopathy was the result of intramyelinic vacuolation due to splitting of the myelin sheath along the intraperiod line, as illustrated here for the first time in GA. Based on morphological, biochemical and pharmacological data from humans and experimental animals, it is hypothesized that excitotoxin-mediated neuronal damage may account for the striatal degeneration, while toxic effect on myelin metabolism by the metabolic derangement of GA may explain the widespread white matter changes.

Amino Acid Metabolism, Inborn Errors↗
PubMed1992

Familial hypotonia of childhood caused by isolated 3-methylcrotonyl-coenzyme A carboxylase deficiency.

Hypotonia was the initial symptom in four siblings from a nonconsanguineous Tunisian-Jewish family. Plasma carnitine was severely deficient, and urinary organic acid analysis revealed increased excretion of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. 3-Methylcrotonyl-coenzyme A carboxylase activity was reduced in skin fibroblasts; pyruvate carboxylase and serum biotinidase activities were normal. We conclude that 3-methylcrotonyl-coenzyme A carboxylase deficiency should be added to the list of metabolic causes of familial hypotonia of childhood.

Carbon-Carbon Ligases↗
PubMed1989

Glutaric aciduria type I: enzymatic and neuroradiologic investigations of two kindreds.

Two kindreds with glutaric aciduria type I were investigated. Of 20 family members who underwent neurologic examination and organic acid analysis of urine, 18 had glutaryl-coenzyme A dehydrogenase (GDH) activity determined in cultured skin fibroblasts and 12 had computed tomographic brain scans. Six homozygotes were identified who had undetectable GDH activity and identical biochemical profiles (consisting of glutaric and 3-hydroxyglutaric aciduria, reduced serum carnitine concentrations, and frontotemporal atrophy). Serial computed tomographic brain scans of one homozygous infant demonstrated the sequential postnatal development of this atrophy during 3 years before the development of clinical manifestations. In three of the six homozygotes, including the father in one kindred, there were no clinical manifestations of glutaric aciduria type I. These findings raise questions about the value of prenatal diagnosis in predicting clinical manifestations in homozygous newborn infants.

Adult↗
PubMed1988

Developmental dyscalculia.

We conducted a neurobehavioral evaluation on eleven children with developmental dyscalculia in order to determine which aspects of arithmetic processes are affected in this disorder. Our results indicate that memorization of numerical facts in these children was poor or virtually non-existent and the ability to solve simple arithmetic exercises impaired. By contrast, comprehension and production of number functions were intact. Although all children had been referred for evaluation of selective deficits in arithmetic skills, they also displayed a mild degree of dyslexia, dysgraphia, anomia, and grapho-motor dysfunction. We conclude that cognitive mechanisms underlying arithmetic ability can be dissociated developmentally and suggest that remediation programs be designed only after detailed analyses of arithmetic and associated cognitive skills.

Adolescent↗
PubMed1987

Glutaric aciduria type I: clinical heterogeneity and neuroradiologic features.

We present four patients, two pairs of siblings, with glutaric aciduria type I (GA I). All four had undetectable glutaryl-CoA dehydrogenase activity on fibroblast culture and massive urinary excretion of glutaric acid. All had serum carnitine deficiency at time of diagnosis except one patient who was diagnosed neonatally. All had a unique pattern of frontotemporal atrophy on CT. Remarkably, in both sibling pairs, one child was asymptomatic. This suggests that the biochemical markers hitherto identified with GA I do not encompass the entire scope of the metabolic or enzymatic abnormalities. Alternatively, as yet unidentified mechanisms might spare or delay the destructive process.

Atrophy↗
PubMed1986

Valproic acid in neonatal status convulsivus.

Valproic acid infused rectally was successful in controlling seizures in two neonates who failed to respond to conventional anti-convulsive therapy. We suggest that this drug may be a useful adjuvant in difficult cases of status convulsivus in neonates.

Humans↗
PubMed1986

Gowers' sign in discitis in childhood.

Three cases of discitis in early childhood presented with acute refusal to walk or change in gait pattern without neurologic deficits. In all three, a Gowers' sign was observed, although none had muscular weakness. The diagnosis of discitis was confirmed by the characteristic radiographic findings on survey lumbosacral films and/or by a hot spot at the L3 level on technetium bone scan.

Child, Preschool↗
PubMed1986

Sleep patterns in the Lennox-Gastaut syndrome.

Serial polysomnograms were performed on 11 children with primary Lennox-Gastaut syndrome (LGS), 6 control children with other seizure disorders, and 12 who were developmentally normal. Five LGS children had abnormal polysomnograms with either complete absence or marked reduction of REM sleep; the other six LGS children had only a mild reduction of REM sleep. The percentage of REM in LGS children was less than in the controls with other seizure disorders (p less than 0.05) or the normal children (p less than 0.005). The scatter of REM percentages in LGS may imply heterogeneity of the syndrome, perhaps related to the severity of brainstem dysfunction or neurochemical derangement.

Adolescent↗
PubMed1984

Erythrocyte (Ca2+ + Mg2+)-ATPase activity and calcium homeostasis in Duchenne muscular dystrophy.

Because the erythrocyte (RBC) in Duchenne's muscular dystrophy (DMD) is thought to be a suitable experimental paradigm for the sarcolemma, the RBC membrane-bound enzyme (Ca2+ + Mg2+)-ATPase has been investigated as to its relevance to abnormalities of calcium metabolism in DMD muscle. In this study, RBC (Ca2+ + Mg2+)-ATPase activity, intracellular calcium and potassium contents and complete hemogram were examined in 10 DMD patients and 16 age-matched controls. (Ca2+ + Mg2+)-ATPase activity was found elevated in the DMD RBC, consistent with reports from previous studies, but no abnormalities in intracellular calcium, potassium or hemograms were detected. It seems that although the (Ca2+ + Mg2+)-ATPase activity is changed, it bears no relevance to calcium homeostasis in DMD RBC. It is inferred that the increase in intramuscular calcium in DMD muscle, which is also found in other neuromuscular diseases, may be a non-specific finding in the diseased muscle and part of the final common pathway leading toward cellular degeneration and death.

Adolescent↗
PubMed1983

Complex partial status epilepticus.

Two children had complex partial status epilepticus, a rare convulsive disorder. The presumptive clinical diagnosis was based on the complex symptomatology occurring within a fluctuating state of consciousness, and on unsustained responses. The diagnosis was confirmed by the ictal EEG, which demonstrated continuous focal discharge in the left temporal region in one patient, and by constant focal spike-and-wave activity over the right temporal areas, which occasionally became hypersynchronous, in the other. We also discuss the possible anatomical substrate and neurophysiological mechanisms of this entity.

Child, Preschool↗