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Biomedical subjects

Y Frank

Publications and source records attributed to Y Frank.

At least 19 recordsLinked to original sources
PubMed2001

Brain imaging in neurobehavioral disorders.

Neuroimaging studies of neurobehavioral disorders are using new imaging modalities. In dyslexia, anatomic imaging studies demonstrate an abnormal symmetry of the planum temporale. Functional imaging supports the hypothesis that developmental dyslexia is frequently the result of deficits in phonologic processing and that normal reading requires a patent network organization of a number of anterior and posterior brain areas. In autism, anatomic imaging studies are conflicting. Functional imaging demonstrates temporal lobe abnormalities and abnormal interaction between frontal and parietal brain areas. In attention-deficit-hyperactivity disorder, imaging studies suggest an abnormality in the prefrontal and striatal regions. Neuroimaging studies are often contradictory, but trends, especially with functional imaging analysis, are evolving. Because neurobehavioral disorders seem to be a result of a dysfunction in brain circuits, no one region will be abnormal in all patients studied. Further studies with well-defined patient populations and appropriate activation paradigms will better elucidate the pathophysiology of these conditions.

Attention Deficit Disorder with Hyperactivity↗
PubMed1999

Correlation of basal ganglia magnetic resonance spectroscopy with Apgar score in perinatal asphyxia.

BACKGROUND: Brain metabolite levels are measured by proton magnetic resonance spectroscopy (1H MRS) and include N-acetylaspartate (NAA), creatine (Cr), choline (Cho), and lactate and the ratios NAA to Cho and Cr (NAA-ChoCr), NAA-Cr, NAA-Cho, and Cho-Cr. Brain metabolite levels may correlate with the degree of neonatal asphyxia. OBJECTIVE: To determine which brain metabolite ratios have the strongest correlation with the Apgar scores in infants with possible asphyxia; whether the correlation is stronger with basal ganglia (BG) or anterior border-zone metabolites; and whether a combined approach using routine MR imaging (MRI), diffusion-weighted MRI, and MRS can be used to evaluate the severity of neonatal asphyxia. METHODS: Twenty infants with 1-minute Apgar scores of 6 or less were studied at 2 to 28 days of age. The MRS variables were compared with routine and diffusion-weighted brain MRI. Clinical variables and MRS findings were subjected to factor analysis and stepwise multiple regressions to determine interrelationships. RESULTS: The BG region NAA-Cho and NAA-ChoCr ratios correlated with the 1-minute (P<.001) and 5-minute (P = .01 for NAA-Cho; P = .006 for NAA-ChoCr). There was no correlation between metabolite levels and the 10-minute Apgar scores. The stongest predictions exist between the 1-minute Apgar scores and the NAA-Cho and NAA-ChoCr ratios. In the anterior border zone, the only correlation was between the 1-minute Apgar score and the NAA-Cho ratio, but there was a strong age effect in these data. Lactate was found in the BG of 3 infants, all of whom had 5-minute Apgar scores of 6 or less. Three patients had focal lesions on MRI; 2 of these had elevated lactate levels in the abnormal region; and the third, who had an intrauterine stroke, had no lactate in the region. CONCLUSIONS: Correlations between NAA-Cho and NAA-ChoCr ratios and the 1- and 5-minute Apgar scores are stronger in the BG region than in the frontal border zone. The presence or absence of lactate may indicate the severity of the brain insult, and the combination of MRS, MRI, and diffusion-weighted MRI may assist in localizing and predicting a long-term brain injury.

Apgar Score↗
PubMed1999

Hypertensive encephalopathy, reversible occipitoparietal encephalopathy, or reversible posterior leukoencephalopathy: three names for an old syndrome.

Children with hypertension, seizures, lethargy, encephalopathy, headache, and occipital blindness are reviewed. After undergoing antihypertensive therapy, most children improve. Some patients have a similar syndrome associated with chemotherapy, transplantation, transfusion, or human immunodeficiency virus-1 (HIV-1) infection. These latter children can develop symptoms with only minimal or no discernible elevations in blood pressure and improve, in the case of cancer-associated encephalopathy, after discontinuing chemotherapy. The reported children with this distinctive clinical condition are compared to adults with reversible posterior leukoencephalopathy syndrome. Since both gray and white matter are involved, we had suggested previously that the name be changed to (reversible) occipitoparietal encephalopathy syndrome. However, reversible posterior leukoencephalopathy has been used in the adult population and probably should be employed in children for the sake of uniformity, since both children and adults have the same clinical presentation and presumably a similar pathophysiology for the encephalopathy syndrome. The diagnosis is confirmed by reversible posterior abnormalities seen on T2-weighted brain magnetic resonance imaging, and by the presence of either headache, altered mental status, seizures, or visual disturbances.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Frontal systems dysfunction in children with attention-deficit/hyperactivity disorder and learning disabilities.

Tests of attention, inhibition, working memory, motor learning, and problem solving--functions associated with the brain's frontal systems--were administered to 26 children with attention-deficit/hyperactivity disorder and learning disabilities (ADHD + LD), 22 children with LD only, and 10 with ADHD only. Percentages of abnormal test results and significantly impaired scores were higher for the two groups with LD than for the ADHD-only group. The groups differed significantly on some tests of attention-inhibition-cueing, working memory, and problem solving, with the ADHD + LD and LD groups performing worse than the ADHD-only group. Abnormalities of frontal systems tests are not exclusive ADHD characteristics and are also present in LD children, implying a strong connection between centers of "processing" and centers of "executive" functions.

Analysis of Variance↗
PubMed1998

Electrophysiological changes in children with learning and attentional abnormalities as a function of age: event-related potentials to an "oddball" paradigm.

This study investigated age-related electrophysiological differences between children diagnosed with Learning Disabilities (LD), Attention Deficit Hyperactivity Disorder (ADHD), LD-ADHD and Conduct Disorder, using Event-Related Potentials recorded during a two-tone discrimination test. Although age-related (N1 and N2 amplitude), as well as diagnostic group-related (P3 latency and amplitude) ERP changes were found, there was no significant interaction between the diagnostic groups and age grouping. We conclude that: 1) Electrophysiological abnormalities in LD and ADHD do not significantly change with age during childhood. This study does not, therefore, support a hypothesis of age-related brain abnormalities in LD and ADHD. 2) Significant group differences for P3 latency and amplitude were found between normal children and the LD groups (LD and LD-ADHD), but not between normal children and those with ADHD alone, suggesting that main correlates of P3 abnormalities in these children are "processing" and not attentional problems.

Adult↗
PubMed1998

Neuropsychological testing in adult attention deficit hyperactivity disorder: a pilot study.

Diagnosing adult ADHD is frequently problematic because behavioral information from the patient's childhood, and multiple informants who can delineate the patient's current behavior, are often unavailable. This preliminary study was designed to explore whether objective neuropsychological testing may be a useful adjunct in the diagnosis of adult ADHD. Nineteen adults diagnosed with ADHD according to DSM-IV criteria, along with 10 controls, were assessed using a neuropsychological battery which comprised tests assessing linguistic, visual-spatial perceptual, academic, attentional and inhibitory control, mnestic and executive functions. Following preliminary analyses, designed to determine which variables best discriminated the groups, receiver operating characteristic (ROC) curves were constructed to determine the sensitivity and specificity of the best measures both alone and in combination. Only three measures significantly (p < 0.01) distinguished the groups; Digits Backwards from the WAIS-R and two reaction time measures from a computerized task modeled after Luria's Competing Motor Programs. ROC curve analyses indicated that in combination these measures had greater than 90% accuracy for classifying ADHD and non-ADHD patients. While further research is necessary these preliminary findings suggest that neuropsychological testing may be a useful adjunct in the differential diagnosis of adult ADHD.

Adolescent↗
PubMed1998

Brain lactate and N-acetylaspartate in pediatric AIDS encephalopathy.

Two children with acquired immunodeficiency syndrome (AIDS) and progressive encephalopathy underwent MR spectroscopy before and after antiretroviral therapy. Initial MR spectroscopy of the basal ganglia region showed decreased N-acetylaspartate (NAA)/creatine (Cr) and a lactate peak. After therapy, there was improvement in NAA/Cr and an absence of the abnormal lactate peak. We suggest that decreased NAA/Cr in AIDS is reversible, that brain lactate might correlate with inflammation, and that MR spectroscopy can be useful in treatment trials.

AIDS Dementia Complex↗
PubMed1997

Occipital-parietal encephalopathy: a new name for an old syndrome.

A boy presented with hypertension, seizures, lethargy, headache, and occipital blindness. He improved with antihypertensive therapy. Other reported children with a similar distinctive clinical condition are compared with adults with a syndrome termed reversible posterior leukoencephalopathy. Because both gray and white matter are involved, we suggest that the name be changed to occipital-parietal encephalopathy syndrome.

Adolescent↗
PubMed1997

Evaluation of pharmacokinetics, safety, tolerance, and activity of combination of zalcitabine and zidovudine in stable, zidovudine-treated pediatric patients with human immunodeficiency virus infection. AIDS Clinical Trials Group Protocol 190 Team.

A double-blind phase II trial compared zalcitabine (0.03 mg/kg/day) in combination with zidovudine (720 mg/m2/day) and zidovudine monotherapy in 250 clinically stable, previously zidovudine-treated, human immunodeficiency virus-infected children. The combination was well-tolerated except for an increased incidence of neutropenia (14%) compared with that in children receiving monotherapy (5%). No differences were noted for time to first AIDS-defining illness or death, neuropsychologic status, or weight Z scores. In patients in the combination arm, the CD4 cell count decline was slower (13% per year) than in patients receiving monotherapy (25% per year) (P = .03), and quantitative peripheral blood mononuclear cell virus load remained lower at all time points (P = .08). Deaths were fewer in patients receiving combination therapy (4) compared with those in patients receiving monotherapy (10) (P = .083). Thus, administration of zidovudine with zalcitabine to children with prior zidovudine treatment did not result in a significant increase in toxicity compared with that resulting from zidovudine monotherapy and demonstrated improvement in immunologic and virologic surrogate markers.

AIDS-Related Opportunistic Infections↗
PubMed1996

Central brain atrophy in childhood AIDS encephalopathy.

OBJECTIVE: To determine differential patterns of brain atrophy in pediatric AIDS encephalopathy. DESIGN: We measured the bicaudate, bifrontal, and ventricle-brain ratio in brain magnetic resonance imaging scans of 42 control children, nine children with progressive AIDS encephalopathy, 25 AIDS children without progressive encephalopathy, and 23 children with cerebral atrophy of other causes. RESULTS: When compared with controls, encephalopathy patients showed significantly increased bicaudate and ventricle-brain ratios, but no significant increase in bifrontal ratio, whereas children with brain atrophy from causes other than AIDS showed increases in all three ratios. CONCLUSION: Children with AIDS encephalopathy demonstrate a specific pattern of brain atrophy distinct from other etiologies: a central atrophy, primarily affecting the subcortical white matter or the basal ganglia regions.

AIDS Dementia Complex↗
PubMed1996

Proton MR spectroscopy of the basal ganglia in healthy children and children with AIDS.

PURPOSE: To evaluate proton magnetic resonance (MR) spectroscopy in children with the acquired immunodeficiency syndrome (AIDS) and to establish an age-dependent spectroscopic database of the normal basal ganglia in children. MATERIALS AND METHODS: Eighteen healthy children and 45 children with AIDS underwent both brain MR imaging and single-voxel MR spectroscopy with a long-echo-time point-resolved technique. A large part of the region of interest studied at MR spectroscopy included the basal ganglia. RESULTS: Seven patients with progressive encephalopathy and eight with static encephalopathy had significantly lower mean N-acetyl aspartate (NAA)/creatine (Cr) ratios than age-matched control subjects (P<.02). In determining the presence of progressive encephalopathy in children with AIDS, MR spectroscopy appears to be more sensitive and specific than MR imaging and immunologic testing. Thirty patients without encephalopathy had normal NAA/Cr ratios but significantly lower choline/Cr ratios than age-matched control subjects (P<.02). CONCLUSION: Proton MR spectroscopy may be a more sensitive diagnostic technique than MR imaging in childhood AIDS encephalopathy.

AIDS Dementia Complex↗
PubMed1996

Visual event related potentials and reaction time in normal adults, normal children, and children with attention deficit hyperactivity disorder: differences in short-term memory processing.

Visual Event Related Potentials were recorded during a memory search paradigm in 30 normal adults, 17 normal children, and 14 children with Attention Deficit Hyperactivity Disorder (ADHD). Group differences were found in P3 latency and amplitude, Reaction Time and number of errors. The findings indicate a different information processing pattern for ADHD children who possibly use a "self-terminating" as opposed to "exhaustive" search strategy.

Adolescent↗
PubMed1995

Magnetic resonance spectroscopy in childhood AIDS encephalopathy.

Twenty-five children with acquired immunodeficiency syndrome (AIDS) underwent cranial magnetic resonance imaging and proton magnetic resonance spectroscopy. Patients were divided into 2 groups based on clinical parameters: encephalopathy and nonencephalopathy. N-acetyl aspartate/creatine ratios were compared between the 2 groups and to control data. Spectra were obtained for 2 volumes of interest: the basal ganglia region and the white matter. The mean basal ganglia region ratio for the AIDS encephalopathy patients (n = 8) was 1.12 and the ratio for the AIDS nonencephalopathy patients (n = 17) was 1.48. The ratio for the 9 controls was 1.57. The encephalopathy group had a significantly lower ratio than both the control (P < .001) and the AIDS nonencephalopathy group (P < .002). The mean white matter ratio for the encephalopathy group (n = 8) was 1.47 and for the AIDS nonencephalopathy group (n = 13) was 1.82 with a control (n = 6) ratio of 1.82. The encephalopathy patients had a lower white matter ratio than the nonencephalopathy (P < .05) patients but the ratio was not different than controls (P < .11). It is concluded that N-acetyl aspartate/creatine ratios are reduced in childhood AIDS encephalopathy and proton magnetic resonance spectroscopy may be helpful in defining brain human immunodeficiency virus-1 infection. However, further longitudinal studies are necessary to determine the sensitivity and specificity of this technique.

AIDS Dementia Complex↗
PubMed1995

Malignant rhabdoid tumor of the brain and kidney in a child: clinical and pathologic features.

Malignant rhabdoid tumor (MRT) is most frequently found in the kidney, but can occur in other tissues including the brain. The simultaneous appearance of MRT in the brain and kidney has rarely been described. We report the first fully described case of simultaneous appearance of MRT in the kidney and cerebellum of an 8-month-old boy. Cytoplasmic inclusion-like masses, representing aggregates of intermediate filaments, positively stained by Vimentin and by epithelial membrane antigen, were abundant in the kidney tumor but rare in the cerebellar tumor, suggesting that this often-described characteristic of kidney MRT can be an infrequently observed feature of brain MRT, which consequently may be thought to represent another type of tumor.

Biomarkers, Tumor↗
PubMed1994

Event-related potentials to an "oddball" auditory paradigm in children with learning disabilities with or without attention deficit hyperactivity disorder.

Event Related Potentials (ERP) were recorded during a two-tone discrimination task in 18 children with Learning Disabilities (LD) and 36 children with Learning Disabilities and Attention Deficit Hyperactivity Disorder (LD-ADHD). Twenty-seven normal children served as a control group. P3 wave amplitude was significantly smaller in the LD and LD-ADHD groups compared with normal children. There was no difference between the LD and LD-ADHD groups. It is suggested that the smaller P3 amplitude in children with LD-ADHD syndromes reflects cognitive and processing difficulties, which frequently coexist with ADHD in these children and is not specifically related to an attention deficit.

Attention Deficit Disorder with Hyperactivity↗