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Biomedical subjects

G R DeLong

Publications and source records attributed to G R DeLong.

At least 37 records · Page 2Linked to original sources
PubMed1994

Focal cerebral metabolic abnormality in a patient with continuous spike waves during slow-wave sleep.

We report an 11-year-old boy with continuous spike-wave discharges during sleep accompanied by partial motor and atypical absence seizures, psychomotor regression, and severe behavior problems. During wakefulness, epileptiform discharges occurred over the right parietal region, suggesting that the continuous spike-wave discharges during sleep were a manifestation of secondary bilateral synchrony. Bilateral suppression of the spike-and-wave activity was observed after right-sided intracarotid amobarbital injection, further supporting the impression of secondary bilateral synchrony. The right superior temporoparietal increase in metabolic activity during continuous spike-wave discharges and noncontinuous spike-wave discharges was seen on [18F]fluorodeoxyglucose positron emission tomography and supports a right temporoparietal focus in our case. The presence of a focal abnormality suggests that surgical therapy may be effective.

Amobarbital↗
PubMed1994

Neuroimaging in infantile autism.

Metabolic findings using [18F]fluorodeoxyglucose (FDG) with positron emission tomography (PET) and correlative anatomic findings with computed tomography (CT) or magnetic resonance imaging (MRI) were characterized in 13 children with infantile autism. Four of 13 patients had both an abnormal FDG-PET and an abnormal MRI, whereas seven of 13 patients had both a normal FDG-PET and a normal CT or MRI. Sixteen of a total of 195 brain areas qualitatively examined with FDG-PET had a hypometabolic abnormality on PET. Three of the five abnormal structural imaging studies revealed neuronal migrational anomalies (focal pachygyria). In two of the five patients with anatomic abnormalities, these were noted only after knowledge of the FDG-PET findings. Our experience reveals that anatomic and metabolic abnormalities can be found in children who exhibit autistic behavior. An FDG-PET study may provide evidence of metabolic dysfunction after an initially unremarkable MRI scan because subtle anatomic abnormalities (as those seen with neuronal migrational anomalies) may be found only after knowledge of a regional metabolic abnormality.

Autistic Disorder↗
PubMed1993

Magnetic resonance imaging of brain and the neuromotor disorder in endemic cretinism.

Neurological endemic cretinism, resulting from severe iodine deficiency, is characterized by mental deficiency, deafmutism, and a spastic-rigid motor disorder. Its neuropathology and pathophysiology have been investigated very little. We report the clinical and magnetic resonance imaging brain scan findings of 3 adult Chinese cretins. All show an apparent magnetic resonance imaging abnormality in the globus pallidus and substantia nigra, with hyperintensity on T1-weighted images and hypointensity on T2-weighted images. The motor abnormality, characterized by truncal and proximal limb-girdle rigidity and spasticity, with relative sparing of the hands and feet, is analogous to other extrapyramidal disorders. Endemic cretinism is a unique form of cerebral palsy of potential interest for students of human neuromotor development.

Adult↗
PubMed1993

Effects of nutrition on brain development in humans.

Brain development in humans is remarkably resistant to permanent damage from protein-energy malnutrition. However, specific nutrients have crucial roles. Iodine deficiency is the most important and widespread nutrient deficiency; it causes endemic cretinism, associated with deaf-mutism and cerebral palsy. Iodine deficiency during pregnancy causes both maternal and fetal hypothyroxinemia, resulting in irreversible impairment of brain development at a critical stage. Neuropathological data place this after 14 wk, perhaps continuing through the third trimester. Gross brain structure, including the gyral pattern of the cerebral cortex, develops normally; the insult affects neuron and dendrite growth. Recent magnetic-resonance-imaging (MRI) images of neurological cretin brains show remarkably normal appearance except for gliotic lesions of the globus pallidus, correlating with the proximal motor rigidity seen clinically. Myxedematous cretinism is paradoxical in showing more severe hypothyroidism and growth failure, yet better intellectual, motor, and hearing function; these observations implicate a second independent factor in its pathogenesis.

Avitaminosis↗
PubMed1992

Autism, amnesia, hippocampus, and learning.

Autism is held to be the result of the failure of a central cognitive processor which is necessary for flexible multidimensional association of sensorial stimuli, memory, and motivational states. Failure of this processor produces rigid, invariant, rote behavior, thought and language and aberrant modulation of emotion. It is argued that this central processing function is critically dependent on the hippocampus. Thus autism is postulated to be the developmental syndrome of hippocampal dysfunction. The hippocampus is postulated to be necessary for normal development in the child of language syntax, semantics, and pragmatics; the capacity for creativity and generativity in language and behavior, and combinatorial possibilities in general; for the integration of motivational states with experience and learning; and for the construction of a complex, useful and flexible structure of meaning. These constructs may become independent of hippocampus for use, but hippocampus is still required to modify or add to them. Finally, this analysis suggests a specific hypothesis of hippocampal organization which I advance as an hypothesis: that the hippocampus can be modelled as a multidimensional system in which the unique intersection of all input dimensions is the resultant.

Amnesia↗
PubMed1991

Reversible neurotoxicity following hyperfractionated radiation therapy of brain stem glioma.

Two patients with brain stem gliomas were treated with hyperfractionated radiation therapy (HFR) (7,020 and 7,560 cGy, respectively). Despite initial clinical improvement during irradiation, both patients demonstrated clinical deterioration approximately 3 weeks after completion of radiotherapy. Cranial magnetic resonance imaging (MRI) revealed a progressive increase in distribution of abnormal brain stem signal consistent with either tumor or edema. 18FDG positron emission tomography (PET) was obtained in one patient and demonstrated a hypermetabolic lesion at diagnosis and a hypometabolic lesion at the time of clinical deterioration postirradiation. Management with a tapering dose of dexamethasone alone resulted in marked clinical (both patients) and radiographic (one patient) improvement, allowing reduction or discontinuation of this medication. These results suggest that patients with brain stem tumors demonstrating clinical and radiographic evidence of progressive tumor shortly after completion of HFR should be initially managed conservatively with dexamethasone, since these findings may be manifestations of reversible radiation-related neurotoxicity.

Adolescent↗
PubMed1991

Chronic inflammatory demyelinating polyradiculoneuropathy of childhood: treatment with high-dose intravenous immunoglobulin.

We treated four children with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with high-dose intravenous immunoglobulin (IVIG). All patients received 400 mg/kg of IVIG a day for 5 days during relapses, and one patient received additional periodic infusions of 400 mg/kg. All patients showed excellent recovery of motor strength following each relapse that was treated with IVIG. Compared with plasmapheresis (which was used to treat relapses earlier), recovery of function with IVIG treatments was similar, and in two patients it was superior, to plasmapheresis. There were no side effects with IVIG treatments as compared with plasmapheresis with which two children had infection of central lines with Staphylococcus epidermidis, one had profuse bleeding from accidental extrusion of a central line, and one had multiple episodes of major venous thromboses. High-dose IVIG was a safe and effective adjunctive therapy for childhood CIDP in these four patients.

Child↗
PubMed1988

Correlation of family history with specific autistic subgroups: Asperger's syndrome and bipolar affective disease.

The etiology of infantile autism is not known. To assess the possible role of familial psychopathology, we investigated a group of autistic subjects subgrouped by level of language function. Family histories were obtained by the family history method. Neurological status was assessed by neurological diagnostic examination and prenatal and perinatal history. The results showed a high incidence of Asperger's syndrome in family members of high-functioning autistic subjects only. The rate of bipolar affective disorder in family members was 4.2%, higher than in the general population; it was significantly higher in families with Asperger's syndrome, suggesting an etiological link between Asperger's syndrome and manic depression. Positive neurological findings were concentrated in the low-functioning subgroup. These findings imply different etiologies for high- versus low-functioning autism, with high-functioning autism related to familial factors, especially Asperger's syndrome.

Adolescent↗
PubMed1987

The 14 & 6-associated clinical complex: a rejected hypothesis revisited.

The 14 & 6 Hz positive spike phenomenon is generally considered a normal variant finding. Our experience prompted this re-evaluation, which consisted of three parts: In children referred for sleep electroencephalograms (EEGs), 100 children with normal EEG and 100 with 14 & 6--the 14 & 6 correlated with behavior disorder and aggression; In 75 children referred for neurological evaluation and EEG because of behavior problems, 52% had 14 & 6 (excluding those with paroxysmal EEGs); and In 57 symptomatic children having prominent 14 & 6, tabulation of symptoms yielded a complex but coherent clinical picture, including disturbances of temper, mood, attention, learning, and sleep. We conclude that 14 & 6 has clinical associations and deserves study.

Adolescent↗
PubMed1986

Manic-depressive illness in children: treatment with lithium carbonate.

A behavior questionnaire was used retrospectively in 21 manic-depressive children to quantitate manic-depressive behaviors before and after treatment with lithium carbonate. The study children were matched with 21 control children for age, race, sex, and socioeconomic status. The study children had significantly more seizures, relatives with psychotic disorders, allergies, food sensitivities, headaches, and abnormal behaviors in all categories measured. During treatment, manic-depressive children had a statistically significant reduction in disturbed behavior. This behavior, however, was still significantly more disturbed than normal control children.

Bipolar Disorder↗
PubMed1985

Neurological signs in congenital iodine-deficiency disorder (endemic cretinism).

Neurological examinations were made of 67 children and adults with congenital iodine-deficiency disorder (endemic cretinism) in four rural villages in highland Ecuador. There was a distinct and readily identifiable pattern of neurological deficits. These included, to varying degrees: deaf-mutism or lesser degrees of bilateral hearing-loss or dysarthria; spasticity, particularly involving the proximal lower extremities; mental deficiency of a characteristic type; and rigidity and bradykinesia. Not all of these elements were found in all cases. Less common features were strabismus, kyphoscoliosis and frontal-lobe signs. There were exceptional cases with hypotonia. In contrast, cerebellar function was largely spared, as were functions of emotion and attention, vegetative and autonomic functions, social interaction, and probably memory, except in the most severely involved.

Adolescent↗
PubMed1984

Neurodevelopmental outcome of survivors with posthemorrhagic hydrocephalus following Grade II neonatal intraventricular hemorrhage.

This report describes the neurodevelopmental outcome in 12 children who developed posthemorrhagic hydrocephalus following Grade II intraventricular hemorrhage. Grade II intraventricular hemorrhage is defined as the partial filling of both lateral ventricles by intraventricular blood, documented by computed tomographic brain scan. Characteristics of the study group included a mean birth weight of 1.8 kg and a mean gestation of 32.3 weeks. Subjects were followed for three to seven years (mean, four and one-half years). Neurological evaluations were conducted prospectively. Bayley's Scales of Infant Development and McCarthy's Scales of Children's Abilities were used for the psychometric evaluations. All children were ambulatory. Only 1 had moderate spastic diplegia. Nine children (75%) had IQ scores within the normal range. The results of this prospective analysis suggest a favorable outcome for infants surviving with Grade II intraventricular hemorrhage, even with the complication of posthemorrhagic hydrocephalus.

Cerebral Hemorrhage↗
PubMed1983

Mitochondrial cytochrome deficiency presenting as a myopathy with hypotonia, external ophthalmoplegia, and lactic acidosis in an infant and as fatal hepatopathy in a second cousin.

Fatal infantile mitochondrial myopathy with lactic acidosis, morphologically abnormal mitochondria, deficient cytochromes aa3 and b, and a Fanconi-like aminoaciduria has been described. We report two infants, second cousins, with a similar fatal mitochondrial disorder, the cytochrome deficiency limited to skeletal muscle in one child and to liver in the other. The first child at 3 months of age had weight loss, hypotonia, external ophthalmoplegia, and a severe lactic acidosis with a high lactate/pyruvate ratio. Electron microscopy of muscle showed marked proliferation of enlarged mitochondria, many containing concentric rings of cristae. In skeletal muscle mitochondria, cytochromes aa3 and b were not detectable but cytochrome cc was found to be normal by spectroscopy. Cytochrome c oxidase activity was less than 1% of normal. Mitochondria from kidney, liver, heart, lung, and brain examined postmortem had normal cytochromes and preserved cytochrome c oxidase activity. The second cousin at 5 months of age had weight loss and hepatomegaly but no systemic lactic acidosis. Liver biopsy showed hepatocytes packed with enlarged mitochondria. The liver mitochondria showed deficient cytochromes aa3 and b postmortem, and cytochrome c oxidase activity was less than 10% of normal. Kidney mitochondria had normal cytochromes. Muscles was not studied. The mitochondrial abnormality in the two cousins presumably is related. Unexplained are the mode of genetic transmission or environmental exposure and the apparent involvement of a single different organ in each child.

Acidosis↗
PubMed1982

Ammonia metabolism in Reye syndrome and the effect of citrulline.

Ammonia metabolism in Reye syndrome was studied by quantitative analysis of the time course of hyperammonemia and the urinary excretion of ammonia, urea, and total nitrogen. These measures were then utilized to assess the effect of citrulline administration in 8 patients compared to results in 22 patients managed without citrulline. Two indices of the severity and duration of hyperammonemia correlated strongly with mortality: the half-time for decline of hyperammonemia and the area under the hyperammonemia curve (an index of the total burden of ammonia presented to the brain). These results suggest that the total amount of ammonia delivered to brain may be important to the pathogenesis of encephalopathy. Citrulline-treated patients had more severe disease at admission and greater abnormalities in indices of nitrogen and ammonia metabolism, though the latter did not reach significance. The urine ammonia/urea nitrogen excretion ratio, an index of the efficiency of ammonia conversion to urea, normalized more rapidly in the citrulline-treated group, evidence that citrulline may have improved urea cycle function. Overall mortality did not differ in the two groups. The deaths of 2 citrulline-treated patients in this small group were attributable to factors unrelated to treatment, however, so the possible effect of citrulline on mortality was not definitively tested. No indication was found that citrulline was harmful, nor that it increased ammonia levels.

Ammonia↗