Biomedical subjects

Edith V Sullivan

Publications and source records attributed to Edith V Sullivan.

61 records · Page 4Linked to original sources

PubMed2002

A profile of neuropsychological deficits in alcoholic women.

Neuropsychological deficits, most notable in executive, visuospatial, and functions of gait and balance, are detectable in alcoholic men even after a month of sobriety. Less well established are the severity and profile of persisting deficits in alcoholic women. The authors used an extensive test battery to examine cognitive and motor functions in 43 alcoholic women who were sober, on average, for 3.6 months. Functions most severely affected in alcoholic women involved visuospatial and verbal and nonverbal working memory processes as well as gait and balance. Areas of relative sparing were executive functions, declarative memory, and upper-limb strength and speed. The authors found that lifetime alcohol consumption was related to impairment severity on Block Design (Wechsler Adult Intelligence Scale-Revised, D. Wechsler, 1981) and verbal and nonverbal working memory, suggesting a dose effect of alcohol abuse. The alcohol-related deficits in working memory, visuospatial, and balance implicate disruption of prefrontal, superior parietal, and cerebellar brain systems.

Adult↗

PubMed2002

The effects of alcoholism on auditory evoked potentials during sleep.

Normal aging is associated with a reduction in the probability that an auditory stimulus will evoke a K-complex during sleep. Additional concomitants of aging are a reduction in the amplitude of the K-complex-related N550, an augmentation of the P2 component and the appearance of a long-lasting positivity (LLP) in the auditory evoked potential. Normal aging is also associated with a dramatic reduction in slow wave sleep (SWS) and a reduction in the volume of cortical gray matter, particularly in the frontal and prefrontal regions of the brain. As in aging, alcoholism is associated with reductions in both cortical gray matter and SWS. It can, therefore, be hypothesized that alcoholics would show similar evoked potential changes to those seen in aging. To test this hypothesis, we studied seven middle-aged abstinent long-term alcoholics and eight age-matched normal controls. Each subject spent one night in the laboratory. Electroencephalogram (EEG) was recorded from six midline scalp sites and auditory stimuli were presented during stage 2 non-rapid eye movement sleep. N550 amplitude in the K-complex average was lower in the alcoholics as compared with controls as was the likelihood of K-complex production. No differences were noted in either amplitude or latency of the P2 or N350 components, and both groups displayed a prominent LLP potential. The pattern of reduced K-complex production and N550 amplitude in alcoholics as compared with age-matched controls is consistent with an hypothesized association between atrophy of the frontal lobes and reductions in SWS and K-complexes. The finding also suggests that the evoked K-complex may be a relatively simple measure of the effect of alcoholism on EEG during sleep.

Alcoholism↗

PubMed2002

Alcoholism and AIDS: magnetic resonance imaging approaches for detecting interactive neuropathology.

Both alcohol abuse and human immunodeficiency virus (HIV) infection have deleterious effects on brain structure, metabolism and function. In individuals with both afflictions these effects are doubtless additive and may interact to produce synergistic adverse effects. Further, the normal processes of aging produce brain degeneration that leaves older people especially vulnerable to the untoward effects of alcohol abuse and HIV infection. Advances in in vivo brain imaging now make practical the clinical study of the interaction of alcoholism and HIV infection and the potential of increased vulnerability produced by advancing age. In addition to structural magnetic resonance imaging (MRI), which provides quantitative assessments of brain macrostructure, are diffusion tensor imaging (DTI), which assesses microstructural integrity, magnetic resonance spectroscopy (MRS), which provides assessment of brain chemical moieties related to neuronal viability, and functional magnetic resonance imaging (fMRI), which provides assessment of localized blood oxygenation state association with performance of specific cognitive or motor tasks. Here, we first review postmortem observations on patients with HIV infection and with alcoholism to identify the cell types and brain regions most affected by the end stage of the disease. We then review in vivo neuroimaging studies of brain changes associated with HIV infection, chronic alcohol use, their interaction, and the potentiating effects of age. While there are many studies of people with either HIV infection or chronic alcohol use alone currently little has been published on the interactive effects of these variables, despite the high prevalence of overlap. We conclude with a consideration of the methodological issues such studies must address.

Acquired Immunodeficiency Syndrome↗

PubMed2002

Corpus callosum, pons, and cortical white matter in alcoholic women.

BACKGROUND: To measure the effect of alcohol abuse on white matter brain macrostructure in women with alcoholism and to determine whether observed abnormalities interact with age. METHODS: Quantitative measures of corpus callosum area, cortical white matter volume, and pons volume were derived from magnetic resonance imaging scans obtained from 34 women with DSM-III-R alcoholism (aged 28-64, mean 41 years) and 35 healthy women (aged 22-65, mean 42 years). Transverse relaxation time of the pons was also obtained. RESULTS: No significant group differences in any brain measures were observed. However, in alcoholics greater length of sobriety was associated with more cortical white matter, and higher lifetime levels of alcohol consumption were associated with smaller volumes and prolonged transverse relaxation time in the pons. CONCLUSIONS: Despite a lack of overall deficits in white matter macrostructural size in alcoholic women, certain white matter structures showed alcohol exposure vulnerability whereas others showed evidence of recovery with abstinence.

Adult↗

PubMed2002

Speed and efficiency but not accuracy or timing deficits of limb movements in alcoholic men and women.

BACKGROUND: Lesions of the cerebellum, a concomitant of alcoholism, can disrupt quality and regularity of movement. Whether evidence for such dysfunction lingers in patients with uncomplicated alcoholism, which is known to affect cerebellar structural integrity, is controversial. METHODS: We used quantitative measures to examine component processes of five classes of movement associated with regional cerebellar function: limb ataxia (alternated finger tapping and variants of the finger-to-nose and heel-to-shin tests), paced tapping, eye-hand coordinated tracing, timed response reflecting preparation and execution time, and postural stability. The subjects examined were 39 abstinent alcoholics (13 men and 26 women) and 21 age-matched controls (9 men and 12 women). For limb ataxia, the dependent measures were the trajectory deviation from the subject's own average movement path and the speed of travel from beginning points to endpoints. RESULTS: Repeated-measures analysis of variance comparing movement speed of finger to nose and heel to shin yielded significant interactions in all conditions (p < 0.007); this indicated that the alcoholics were relatively slower in the upper- than lower-limb tasks. Movements by the alcoholic men were significantly slower but less deviant from an ideal trajectory in all upper-limb conditions than those of the control men (p < 0.002). Although measures of lower-limb movement trajectory did not distinguish the groups, tests of ataxia of stance and gait did. The groups did not differ, however, on tests of timed tapping or sinusoid tracing. CONCLUSIONS: Alcohol-related postural instability in abstinent alcoholics is functional evidence supporting the postulated damage to the anterior superior vermis. Altered speed or accuracy trade-offs, with alcoholics moving slower to attain equivalent or even smaller trajectory deviations, are symptomatic of cerebellar hemisphere dysfunction that is characterized by deliberation of otherwise automatic movements.

Adult↗

PubMedDate not supplied

Influences of chorion type on measurements of the corpus callosum in adult monozygotic male twins?

MRI imaging was used to estimate volumes of corpus callosum structure in 45 pairs of identical (monozygotic, MZ) twins from the National Heart, Lung, and Blood Institute (NHLBI) twin study. Age range of the study subjects was from 68-78 years. Finger, palm, and footprint data (dermatoglyphics) collected at previous examinations of the NHLBI twin study were available for 39 pairs. The dermatoglyphics were scored for an index to retrospectively assess chorion type in MZ twin-pairs. The results indicated an association between variability in various structures of the corpus callosum with some of these dermatoglyphic traits, suggesting greater structural variation within pairs with dichorionic placentas. In contrast, total intracranial volume, which has similar heritability estimates as a result of shared genetic effects with the corpus callosum, was unrelated to the dermatoglyphic traits. The results provide indirect evidence that the intrauterine environment may influence twin-pair similarity of corpus callosum measures in adults.

Adult↗

PubMedDate not supplied

Gray matter N-acetyl aspartate deficits in secondary progressive but not relapsing-remitting multiple sclerosis.

BACKGROUND AND PURPOSE: Spectroscopic examination of multiple sclerosis (MS) patients has revealed abnormally low N-acetyl-aspartate (NAA) signal intensity, even in brain tissue that appears normal on high-resolution structural MR images but has yielded inconclusive evidence to distinguish the well-documented clinical differences between MS subtypes. This study used proton MR spectroscopic imaging (MRSI) and high-resolution MR imaging to characterize metabolite profiles in normal-appearing brain tissue of relapsing-remitting multiple sclerosis (RRMS) and secondary progressive (SP) MS. METHODS: Volumetric spiral MRSI was used together with high-resolution MR imaging to derive absolute measures of metabolite concentrations separately in normal-appearing supratentorial cerebral gray matter and white matter in five RRMS patients, five SPMS patients, and nine age-matched controls. Structural MR images were segmented into compartments of gray matter, white matter, CSF, and lesions, and metabolite signals per unit of tissue volume were calculated for gray matter and white matter separately. RESULTS: Only the SPMS group had significantly lower NAA concentrations in normal-appearing gray matter compared with concentrations in controls. NAA in normal-appearing white matter was equally reduced in RRMS and SPMS patients. The functional relevance of this brain metabolite measure was suggested by the observed but statistically nonsignificant correlation between higher disability scores on the Expanded Disability Status Scale and lower gray matter NAA concentrations. CONCLUSION: The otherwise occult abnormality in supratentorial gray matter in SPMS but not RRMS may explain the more severe physical and cognitive impairments afflicting patients with SPMS that do not correlate well with visible lesion burden.

Adult↗