The neural correlates of motor intentional disorders in patients with subcortical vascular cognitive impairment.

Subcortical vascular cognitive impairment (SVCI) refers to cognitive impairment associated with small vessel disease. Motor intentional disorders (MID) have been reported in patients with SVCI. However, there are no studies exploring the neuroanatomical regions related to MID in SVCI patients. The aim of this study, therefore, was to investigate the neural correlates of MID in SVCI patients. Thirty-one patients with SVCI as well as 10 healthy match control participants were included. A "Pinch-Grip" apparatus was used to quantify the force control capabilities of the index finger in four different movement phases including initiation, development, maintenance, and termination. All participants underwent magnetic resonance imaging (MRI). Topographical cortical areas and white matter tracts correlated with the performances of the four different movement phases were assessed by the surface-based morphometry and tract-based spatial statistics analyses. Poorer performance in the maintenance task was related to cortical thinning in bilateral dorsolateral prefrontal, orbitofrontal and parietal cortices, while poorer performance in the termination task was associated with the disruption of fronto-parietal cortical areas as well as the white matter tracts including splenium and association fibers such as superior longitudinal fasciculus. Our study demonstrates that cortical areas and underlying white matter tracts associated with fronto-parietal attentional system play an important role in motor impersistence and perseveration in SVCI patients.

Measurements of lenticulostriate arteries using 7T MRI: new imaging markers for subcortical vascular dementia.

Recent studies have demonstrated that ultra-high resolution MRA imaging using 7 Tessla (T) MRI can be employed to noninvasively visualize the lenticulostriate arteries (LSA) that supply the basal ganglia and internal capsule. Subcortical vascular dementia (SVaD) is believed to involve these regions from an early stage. We investigated whether LSA abnormalities measured by 7T MRA correlate with MRI ischemia markers and neuropsychological/motor deficits. A total of 24 subjects (12 with SVaD, 12 normal controls (NC)) were imaged with 3T and 7T MRIs. We assessed the severity of white matter hyperintensities (WMH) and the number of lacunes and microbleeds (MB) by visually inspecting images obtained from conventional 3T MRI. We also analyzed three-dimensional models of the measured LSAs obtained from 7T MRI. Compared to the NC, the SVaD subjects had fewer branches of LSAs and greater radii of LSAs. The number of branches was correlated with the number of lacunes. The number of branches was correlated with the delayed recall scores on Rey's Complex Figure Test (RCFT). While not quite reaching statistical significance, the immediate recall, recognition scores on the RCFT, recognition scores on the Seoul Verbal Learning Test, and the word and color readings of Stroop trended in the direction of correlation with the number of branches, as well as with the extrapyramidal scores. Our findings suggest that LSA imaging using 7T MRI might be a potent candidate for the detection of SVaD.

Comparison of neuropsychological and FDG-PET findings between early- versus late-onset mild cognitive impairment: A five-year longitudinal study.

AIMS: Our purpose was to investigate differences in neuropsychological characteristics and glucose metabolism between early-onset mild cognitive impairment (EOMCI) and late onset MCI (LOMCI) patients and to determine if the baseline differences are predictive of conversion to dementia. METHODS: We enrolled 28 patients with MCI (12 EOMCI, 16 LOMCI) and 2 age-matched control groups. At the end of a 5-year follow-up, we compared the baseline neuropsychological and PET data between converters and nonconverters. RESULTS: The EOMCI patients obtained significantly higher scores in verbal recall and word fluency tests than the LOMCI patients. The EOMCI group, compared to the young controls, demonstrated hypometabolism in brain regions vulnerable in mild Alzheimer's disease. Converters were significantly more impaired in the delayed verbal recall test than nonconverters (p = 0.028) and tended to be more impaired in the semantic word fluency test (p = 0.084). The baseline PET scan of the converters demonstrated severer hypometabolism in frontal areas than that of the nonconverters both in the EOMCI and LOMCI groups. CONCLUSION: Our study suggests that EOMCI patients may differ from LOMCI in the patterns of cognitive deficits and glucose hypometabolism. In addition, baseline neuropsychological and FDG-PET findings suggest that MCI patients with poor memory or frontal dysfunction are at greater risk of conversion to dementia.

In-hospital medical complications and long-term mortality after ischemic stroke.

BACKGROUND AND PURPOSE: Inhospital medical complications account for a considerable portion of deaths during the early stage of stroke. However, relatively few studies have examined their long-term effects on mortality in stroke patients. METHODS: We prospectively and consecutively collected data on 579 patients with acute ischemic stroke from November 1998 to February 2001. Mortality was confirmed using national death certificate data from 1999 to 2003. RESULTS: During admission, one or more medical complications requiring intervention developed in 160 of these 579 patients (27.6%). For these 160 subjects, the 30-day, 90-day, 1-year, 2-year, 3-year, and 4-year mortalities were 16.3, 29.4, 46.9, 55.6, 61.3, and 70.7%, whereas the mortality figures for those without such complications (n=419) were 1.4, 3.8, 8.8, 15.0, 19.1, and 22.4 (P<0.001 with log-rank test). To eliminate the short-term effects of these complications and thus reveal their long-term effects, we investigated differences in mortality versus the presence of inhospital complications at more than 30 days, 90 days, 1 year, 2 years, and 3 years after stroke, respectively. Cox's proportional hazard regression analysis was applied at these times after stroke and showed that all hazard ratios of medical complications in terms of mortality were statistically larger than one, regardless of adjusting for effects of potential predictors on mortality. CONCLUSIONS: Our study shows that stroke patient mortality is influenced by inhospital medical complications significantly up to the chronic stage. This finding suggests that the appropriate prevention and management of inhospital complications could improve short-term and long-term prognoses after stroke.