Association of plasma homocysteine concentration with atherosclerotic carotid plaques and lacunar infarction.

BACKGROUND AND PURPOSE: Higher plasma total homocysteine (tHcy) levels have been associated with carotid atherosclerosis and cerebral infarction in whites. However, data regarding such associations are limited for Asians. This study examined associations between tHcy levels and severity of carotid atherosclerosis in Japanese subjects. Additionally, because lacunar infarction is the most prevalent type of ischemic stroke in Japan, we also investigated its associations with tHcy levels. METHODS: The subjects were 152 Japanese patients (age, 66.2+/-11.0 years) at our hospital. Using ultrasound, we evaluated severity of carotid atherosclerosis by plaque score, which is defined by the sum of all plaque (intima-media thickness > or =1.1 mm) height in bilateral carotid arteries. In 112 of 152 patients, the existence of lacunar infarction was evaluated on brain MRI scans. RESULTS: A moderate linear association was found between tHcy levels and plaque score (r=0.48, P<0.0001). Moreover, tHcy level was associated with plaque score (beta=0.26, P<0.001) independently of traditional atherosclerotic risk factors. In logistic regression analyses, each 1-micromol/L-higher tHcy level was associated with a 1.37-fold-higher [95% confidence interval (CI), 1.19 to 1.58] likelihood for lacunar infarction, increasing the likelihood by 1.22-fold (95% CI, 1.04 to 1.43) independently of traditional atherosclerotic risk factors. CONCLUSIONS: Higher tHcy levels appear to have associations with increased severity of carotid atherosclerotic plaques and prevalent lacunar infarction in the Japanese. Larger prospective studies are necessary to establish whether higher tHcy levels serve as a harbinger for insidious carotid and cerebrovascular diseases.

Imaging of distal internal carotid artery by ultrasonography with a 3.5-MHz convex probe.

BACKGROUND AND PURPOSE: Conventionally, carotid ultrasonography has been performed with a 7.5-MHz linear probe to evaluate the extracranial internal carotid artery (ICA). However, usually only the carotid bulb or proximal portion of the ICA can be evaluated. We attempted to evaluate the distal extracranial ICA with a 3.5-MHz convex probe. METHODS: The subjects were 17 consecutive patients with ICAs free of occlusive disease and 3 other patients with distal extracranial ICA stenosis. Using a 7.5-MHz linear probe and a 3.5-MHz convex probe, we performed long-axis B-mode imaging of the ICAs to evaluate the distance between the distal limit of visualized ICA and the bifurcation of the common carotid artery. RESULTS: The distal limit of the ICA, visualized with a 7.5- or a 3.5-MHz probe, was 31+/-11 or 57+/-8 mm distal to the common carotid artery bifurcation, respectively. In the 3 patients with distal extracranial ICA stenosis, the lesion could be successfully diagnosed with only the 3.5-MHz probe. CONCLUSIONS: This form of carotid imaging is feasible and may be potentially useful in the evaluation of carotid disease.

Correlation of angiographic circulation time and cerebrovascular reserve by acetazolamide-challenged single photon emission CT.

BACKGROUND AND PURPOSE: Although cerebral circulation time (CCT) is one of the main parameters in cerebral blood flow measurements, its clinical significance is controversial. To assess the importance of CCT by using a nondiffusible indicator, we studied the relationship between angiographic CCT and cerebrovascular reserve. METHODS: Twenty-eight patients, each with a unilateral occlusive lesion in the internal carotid artery or middle cerebral artery, were examined. To assess the CCT, the regional arteriocapillary circulation time (rACCT) was measured by angiography and the ratio of the value on the occlusive side to the value on the contralateral side was calculated as the rACCT ratio. To estimate the cerebrovascular reserve, acetazolamide-challenged single photon emission CT was used. Patients with a decreased cerebrovascular reserve were defined as the "poor reserve" group, and those without a decrease were defined as the "normal reserve" group. The ratio of the radioactivity count on the occlusive side to the count on the contralateral side was calculated as the asymmetry index, and the proportion of the acetazolamide-challenged asymmetry index to the baseline asymmetry index was defined as the regional reactivity index. RESULTS: The rACCT ratio in the poor reserve group (n = 19) was significantly (P <.001) larger than that in the normal reserve group (n = 9), and a significant correlation (r = -0.83, P <.01) was found between the rACCT ratio and the regional reactivity index. CONCLUSION: The angiographic CCT and the cerebral vasoreactivity to acetazolamide on single photon emission CT were well correlated, suggesting that measurement of the CCT by using a nondiffusible indicator could be used as an index of cerebrovascular reserve.

Case reports of unexpected suicides in patients within six months after stroke.

Suicide after stroke is a grievous occurrence. Since the majority of cases under study had shown signs of recovery from stroke, persons surrounding these patients were severely shocked by these suicides. Six patients who attempted suicide within six months after stroke were investigated to determine factors following stroke that relate to suicide in order to prevent future post-stroke suicides. Clinical findings in these six cases were retrospectively analyzed in collaboration with stroke neurologists and coworkers caring for these patients. Four of six patients had sustained a recent infarction extending from the temporal cortex to the parietal cortex. Four of six patients showed depression, and five of six patients showed moderate disability after stroke. Physicians should carefully observe patients with infarction extending from the temporal cortex to the parietal cortex, depression and moderate disability, in order to prevent suicidal behavior.