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Biomedical subjects

E L Dick

Publications and source records attributed to E L Dick.

10 recordsLinked to original sources
PubMed1999

Corpus callosal signal intensity in treatment-naive pediatric obsessive compulsive disorders.

1. Obsessive compulsive disorder (OCD) is increasingly recognized as a severe, highly prevalent and chronically disabling disorder, emerging during childhood in as many as 80% of cases. The authors previously found significant abnormalities in the region of the corpus callosum (CC) connecting ventral prefrontal cortex and striatum in pediatric OCD patients compared to controls that correlated significantly with OCD symptom severity. We speculated that this abnormality might reflect aberrant myelinization in OCD patients. 2. In order to better characterize the abnormality, the authors examined CC signal intensity (SI), believed to be a reliable index of myelinization of the CC. Lower numbers would indicate a greater concentration of white matter, while higher numbers indicate higher concentrations of gray matter. We compared the SI from midsagittal magnetic resonance images of 21 treatment-naive OCD patients, 7.2-17.7 years, and 21 case-matched healthy controls to examine regional CC signal intensity of the anterior, middle and posterior genu, body, isthmus, and the anterior, middle and the posterior splenii. 3. Mean total genu SI for the patient group (.993 + .006) was significantly less than the total genu SI of controls (.994 + .006) at F(1,37) = 4.73; p = .036. This abnormality in SI was localized to the CC region connecting ventral PFC and striatum, the anterior genu for the OCD group (.991 + .007) which was also less than control (.995 + .007) at F(1,37) = 5.47; p = .025., with no abnormality observed in middle or posterior genu regions. Genu SI was also inversely correlated with OCD symptom severity (r = -.55, p = .013) but not illness duration. Genu SI also correlated positively with genu area (r = .52, p = .020) in OCD patients but not controls. 4. Developmental abnormalities in genu size may arise from abnormalities in myelination in early onset OCD patients. The increased genu myelination observed in OCD patients may alter signal transduction and function of VPFC-striatal association circuits.

Adolescent↗
PubMed1999

Neuropsychological study of frontal lobe function in psychotropic-naive children with obsessive-compulsive disorder.

OBJECTIVE: The authors' goal was to evaluate cognition in children with obsessive-compulsive disorder (OCD) early in their illness. METHOD: They administered neuropsychological tests to 21 pediatric patients with OCD and 21 healthy children matched for age, sex, socioeconomic status, and intelligence. The children with OCD were not depressed, and none had ever received psychotropic medication. The neuropsychological tests were used to assess the relationship between psychiatric symptoms and cognitive function. RESULTS: The children with OCD performed as well as the healthy children on the neuropsychological tests. Psychiatric symptoms and cognitive performance were not related. CONCLUSIONS: Nondepressed children with recently diagnosed OCD who had never received psychotropic medication demonstrated no cognitive impairment according to their performance on neuropsychological tests. The authors conclude that OCD symptoms may not interfere with cognitive abilities early in the illness.

Age of Onset↗
PubMed1999

Molar pregnancy presenting with hyperemesis gravidarum.

Nausea and vomiting are common complaints in pregnancy, occurring in more than 50% of pregnant women. Occasionally, the vomiting becomes severe and persistent enough to develop into the syndrome called hyperemesis gravidarum and sometimes requires hospitalization. A 20-year-old woman presented with hyperemesis gravidarum, which was later found to be associated with a molar pregnancy. Hyperemesis gravidarum is reported to occur in as many as 26% of molar pregnancies. Increases in the level of serum beta-human chorionic gonadotropin may be the mechanism of hyperemesis gravidarum in molar pregnancy. Hyperthyroid states linked to molar pregnancy may further exacerbate hyperemesis gravidarum. Physicians should be aware of this possibility of molar pregnancy in all patients with hyperemesis gravidarum and be familiar with the appropriate management to monitor and prevent an often-fatal trophoblastic neoplasm.

Adult↗
PubMed1997

Frontostriatal measurement in treatment-naive children with obsessive-compulsive disorder.

BACKGROUND: Abnormalities in frontostriatal circuits have been implicated in obsessive-compulsive disorder (OCD). Although OCD commonly emerges during childhood or adolescence, few studies have examined frontostriatal anatomy in psychotropic-naive children with OCD near the onset of illness to determine the possible role of atypical developmental processes in this disorder. METHODS: Magnetic resonance imaging scans from 19 children with OCD who had not been exposed to psychotropic drugs, aged 7 to 18 years, and 19 case-matched healthy control subjects were analyzed to determine the volumes of the following structures: prefrontal cortex, striatum (caudate and putamen), lateral and third ventricles, and intracranial volume. RESULTS: Patients with OCD had significantly smaller striatal volumes and significantly larger third ventricle volumes than controls, but did not differ in prefrontal cortical, lateral ventricular, or intracranial volumes. Striatal volumes were inversely correlated with OCD symptom severity but not illness duration. CONCLUSIONS: Our findings provide new evidence of abnormalities of the striatum in pediatric OCD. These results are preliminary, given the small sample size.

Adolescent↗
PubMed1997

Corpus callosal morphology in treatment-naive pediatric obsessive compulsive disorder.

1. Abnormalities in association circuits have been described in Obsessive Compulsive Disorder (OCD) and may reflect neurodevelopmental abnormalities. Primary and association cortices are topographically mapped in the corpus callosum (CC). The authors hypothesized alterations in CC subdivisions that connect association, but not primary cortices in pediatric OCD. The authors predicted that normal age-related increases in CC area would be absent in OCD. 2. The authors compared the midsagittal magnetic resonance images of 21 psychotropic-naive, nondepressed OCD patients, 7.2-17.7 years, and 21 case-matched healthy controls. Total CC area as well as that of the anterior, middle and posterior genu, anterior and posterior bodies, isthmus, and the anterior, middle and the posterior splenii were measured. 3. All of the CC regions except the isthmus were significantly larger in OCD patients than in controls. CC area correlated significantly with OCD symptom severity but not illness duration. The age-related increase in CC size seen in normal subjects was absent in OCD patients. 4. These findings support theories of abnormal association cortex development in OCD but also suggest possible abnormalities of other primary cortical regions as well.

Adolescent↗
PubMed1997

Magnetic resonance imaging and spectroscopy in offspring at risk for schizophrenia: preliminary studies.

1. Studies of first-degree relatives of persons with schizophrenia provide an opportunity to characterize risk factors for the development of this illness. In this report the authors will provide preliminary data from an ongoing study of neurobiological alterations in the offspring of schizophrenia patients. 2. A series of offspring of schizophrenic patients (OS) were compared with age and sex matched healthy controls (HC) without psychiatric history in first degree relatives on psychiatric, volumetric Magnetic Resonance Imaging (MRI) of whole brain and proton Magnetic Resonance Spectroscopy (1H MRS) evaluations of the ventral prefrontal cortex. 3. Compared with HC group, high risk subjects had reduced left amygdala volume, enlarged third ventricular volume, and smaller overall brain volume. 4. 1H MRS studies showed a trend for decreased NAA/choline ratios in the anterior cingulate region in the OS group as compared to HC subjects. 5. Follow-up studies of these subjects are needed to confirm the predictive value of these measures for future emergence of schizophrenia in subjects at risk for this illness.

Adolescent↗
PubMed1997

Response-inhibition deficits in obsessive-compulsive disorder: an indicator of dysfunction in frontostriatal circuits.

Abnormalities in the orbital prefrontal cortex and its ventral striatal target fields are believed to be involved in causing obsessive and compulsive symptoms. Lesions to this brain circuitry result in a selective disturbance in suppressing responses to irrelevant stimuli. This disturbance might underlie the apparent inhibitory deficit suggested by the symptomatology of obsessive-compulsive disorder (OCD). Oculomotor tests were administered to 12 medication-free, nondepressed patients with OCD aged 18 to 44 y and 12 matched healthy controls to assess the ability to suppress responses and to execute delayed responses volitionally. Patients with OCD had more response-suppression failures than controls when peripheral visual targets were presented close to central fixation. No significant case-control differences were observed on the delayed-response task. A basic disturbance of neurobehavioral inhibition in OCD may underlie the repetitive behavior that characterizes the illness and be related to abnormalities in orbital prefrontal ventral striatal circuits.

Adolescent↗
PubMedDate not supplied

Superior temporal gyrus and the course of early schizophrenia: progressive, static, or reversible?

Accumulating evidence suggests alterations in brain structure, especially in the prefrontal and temporal cortex, in schizophrenia. Previous studies examining the progression of brain structural alterations in schizophrenia have led to conflicting results. Morphometric studies of the superior temporal gyrus (STG) volumes were conducted in a series of neuroleptic-naive first-episode schizophrenic patients, non-schizophrenic first-episode psychotic patients, and matched healthy controls. Three-dimensional MRI scans were carried out in these subjects before and after one year of treatment. Volume reductions were seen at baseline in the left superior temporal gyrus (adjusted for intracranial volume) in both of the patient groups. Pretreatment illness duration was inversely related to the volume of the left superior temporal gyrus; this relation was confined to males. One-year follow-up MRI investigations in a smaller subset of patients suggested that the STG volume reductions may be reversible. No significant changes were noted in the STG volumes in matched healthy controls who were also scanned at baseline as well as at one-year follow-up. These findings have implications for understanding the nature of the neuropathological processes in early schizophrenia, as well as the potential impact of early treatment.

Adult↗