Signal Hyperintensities (signal + hyperintensity)

Distribution by Scientific Domains


Selected Abstracts


Neuropathological evidence for ischemia in the white matter of the dorsolateral prefrontal cortex in late-life depression

INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 1 2003
Alan J. Thomas
Abstract Background Signal hyperintensities on magnetic resonance imaging in late-life depression are associated with treatment resistance and poor outcome. These lesions are probably vascular in origin and proposed sites for vascular damage include the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC). Methods We therefore examined white matter in these areas for microvascular disease and evidence of ischemia using intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1). We obtained postmortem tissue from elderly depressed (n,=,20) and control (n,=,20) subjects and blindly rated microvascular disease and ICAM-1 and VCAM-1 amount using quantitative image analysis in sections of the DLPFC, ACC and occipital cortex (OC; control area). Results We found a significant increase in ICAM-1 in the deep white matter of the DLPFC in the depressed group (p,=,0.01) and a trend towards an increase for VCAM-1 (p,=,0.10). In the gyral white matter there was a trend towards significance for both molecules (p,=,0.07 and 0.10). No differences were found in the ACC or OC or for microvascular disease in any area. Conclusions These findings are consistent with white matter ischemia in the DLPFC and lend support to the ,vascular depression' hypothesis. They implicate the DLPFC as an important site in the pathogenesis of late-life depression and have major implications for the understanding and management of late-life depression and raise the possibility of novel treatments being introduced in the future. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Cognitive correlates of brain MRI subcortical signal hyperintensities in non-demented elderly

INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 1 2006
Gad A. Marshall
Abstract Objective To investigate the relationship between magnetic resonance imaging (MRI) subcortical gray and capsular (SGCH) and white matter hyperintensities (WMH) and cognitive functions in non-demented community dwelling elderly. Methods The severity of SGCH and WMH on proton density and T2 MR images in 16 subjects was scored using the semi-quantitative rating scale of Scheltens et al. (1993). A limited series of cognitive tests selected a priori were then correlated with severity of SGCH and WMH. Results Analysis demonstrated that severity of SGCH was inversely related to performance on the Digit Span (R,=,,0.64, p,<,0.01) and the Stroop Color Word Tests (R,=,,0.64, p,<,0.01). Severity of WMH was related to worsening performance on the Trail Making Test (R,=,0.67, p,<,0.005). Conclusions These findings indicate that severity of WMH is negatively related to more pure executive cognitive functions, specifically set shifting, while severity of SGCH is inversely related to more basic functions of attention and working memory. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Increased White Matter Signal Hyperintensities in Long-Term Abstinent Alcoholics Compared with Nonalcoholic Controls

ALCOHOLISM, Issue 1 2009
George Fein
Background:, The harmful effects of alcohol dependence on brain structure and function have been well documented, with many resolving with sufficient abstinence. White matter signal hyperintensities (WMSH) are thought to most likely be consequences secondary to the vascular (i.e., hypertension and atherosclerosis) effects of AD. We hypothesized that such effects would persist into long-term abstinence, and evaluated them in middle-aged long-term abstinent alcoholics (LTAA) compared with age and gender comparable nonalcoholic controls (NAC). Methods:, Ninety-seven participants (51 LTAA and 46 NAC) underwent cognitive, psychiatric, and structural brain magnetic resonance image evaluations. WMSH were identified and labeled as deep or periventricular by an automated algorithm developed in-house. WMSH volumes were compared between groups, and the associations of WMSH measures with demographic, alcohol use, psychiatric, and cognitive measures were examined within group. Results:, Long-term abstinent alcoholics had more WMSH than NAC. There was a significant group by age interaction, with WMSH increasing with age in LTAA, but not in NAC. Within LTAA, WMSH load was independently positively associated with alcohol burden and with age. No associations were evident between WMSH volumes and abstinence duration, family drinking history, years of education, or psychiatric or cognitive variables. Conclusion:, The magnitude of alcohol abuse was related to increased WMSH volume. The presence of an age effect in the LTAA but not the controls indicates a synergistic effect wherein alcohol advances the onset of aging-related WMSH formation. The increased WMSH load did not appear to have any significant clinical correlates, indicating that the white matter lesions in our sample may not have been severe enough to manifest as cognitive deficits. A limitation of the study is that we did not have data on the presence or severity of lifetime or current indices of vascular risk factors such as hypertension, smoking, or diabetes. [source]


The neuropsychology and neuroanatomy of bipolar affective disorder: a critical review

BIPOLAR DISORDERS, Issue 3 2001
Carrie E Bearden
Objectives: To present a comprehensive review of the existing neuropsychological and neuroimaging literature on bipolar affective disorder. This review critically evaluates two common conceptions regarding the neuropsychology of bipolar disorder: 1) that, in contrast to schizophrenia, bipolar affective disorder is not associated with general cognitive impairment independent of illness episodes, and 2) relative right hemisphere (RH) dysfunction is implicated in bipolar illness patients, supported by reports of relatively greater impairment in visuospatial functioning, lateralization abnormalities, and mania secondary to RH lesions. Methods: The major computerized databases (Medline and PSYCInfo) were consulted in order to conduct a comprehensive, integrated review of the literature on the neuropsychology and neuroanatomy of bipolar disorder. Articles meeting specified criteria were included in this review. Results: In a critical evaluation of the above notions, this paper determines that: 1) while there is little evidence for selective RH dysfunction, significant cognitive impairment may be present in bipolar illness, particularly in a subgroup of chronic, elderly or multiple-episode patients, suggesting a possible toxic disease process, and 2) the underlying functional correlate of these cognitive deficits may be white matter lesions (,signal hyperintensities') in the frontal lobes and basal ganglia, regions critical for executive function, attention, speeded information processing, learning and memory, and affect regulation. While this hypothesized neural correlate of cognitive impairment in bipolar disorder is speculative, preliminary functional neuroimaging evidence supports the notion of frontal and subcortical hypometabolism in bipolar illness. Conclusions: The etiology of the structural brain abnormalities commonly seen in bipolar illness, and their corresponding functional deficits, remains unknown. It is possible that neurodevelopmental anomalies may play a role, and it remains to be determined whether there is also some pathophysiological progression that occurs with repeated illness episodes. More research is needed on first-episode patients, relatives of bipolar probands, and within prospective longitudinal paradigms in order to isolate disease-specific impairments and genetic markers of neurocognitive function in bipolar disorder. [source]