Biomedical subjects

C Helgason

Publications and source records attributed to C Helgason.

6 recordsLinked to original sources

PubMed2006

Predictors of recurrent stroke in African Americans.

BACKGROUND: Stroke incidence and mortality are disproportionately higher among African Americans than among whites. OBJECTIVE: To describe the recurrent stroke characteristics and determine the predictability of known vascular risk factors for stroke recurrence in African Americans. METHODS: The authors followed 1,809 African Americans in the African-American Antiplatelet Stroke Prevention Study with recent noncardioembolic ischemic stroke for recurrent stroke, recurrent stroke subtype, and disability. RESULTS: Of the subjects, 10.6% experienced a recurrent stroke during follow-up. The mean interval between eligibility and recurrent stroke was 325 days (median 287 days, SD = 224 days). Stroke recurrence resulted in an average 1.5-point increase in the National Institute of Health Stroke Scale (p < 0.001) and a 3.5-point decrease in modified Barthel Index (p < 0.001). Of previously nondisabled subjects, 48% became disabled or died after stroke recurrence (p < 0.0001). Longitudinal analysis resulted in a hazard for recurrent stroke for each 10-mm Hg increase in systolic blood pressure of 1.103 (95% CI: 1.031 to 1.179, p = 0.004), pulse pressure 1.123 (95% CI: 1.041 to 1.213, p = 0.003), and mean arterial pressure 1.123 (95% CI: 1.001 to 1.260, p = 0.048). Multivariate analysis revealed increases in the recurrent stroke hazard for increases in baseline Glasgow Outcome Score (1.449, 95% CI: 1.071 to 1.961, p = 0.016) and increases in longitudinal pulse pressure (1.009, 95% CI: 1.001 to 1.017, p = 0.029). CONCLUSION: Recurrent stroke leads to disability and disability predicts recurrent stroke. Hypertension is the most predictive modifiable stroke risk factor.

Activities of Daily Living↗

PubMed1990

Caudate infarcts.

Eighteen patients had caudate nucleus infarcts (10 left-sided; 8 right-sided). Infarcts extended into the anterior limb of the internal capsule in 9 patients, and also the anterior putamen in 5 patients. Thirteen patients had motor signs, most often a slight transient hemiparesis. Dysarthria was common (11 patients). Cognitive and behavioral abnormalities were frequent, and included abulia (10 patients), agitation and hyperactivity (7 patients), contralateral neglect (3 patients, all right caudate), and language abnormalities (2 patients, both left caudate). The majority of patients had risk factors for penetrating artery disease. Branch occlusion of Heubner's artery, or perforators from the proximal anterior or middle cerebral arteries were the posited mechanism of infarction.

Adult↗

PubMed1988

Acute pseudobulbar mutism due to discrete bilateral capsular infarction in the territory of the anterior choroidal artery.

Pseudobulbar mutism is rarely attributed to bilateral discrete posterior limb internal capsule-medial globus pallidus infarction. Few cases of bilateral anterior choroidal (AchA) artery territory infarction have been reported. We present 8 patients with ischaemic stroke in this location and vascular distribution who have a characterizable syndrome. All had the abrupt onset of inability to speak, swallow or phonate, accompanied by varying degrees of facial diplegia, hemiparesis, hemisensory loss, lethargy, neglect and change in affect. The appearance of clinical signs depends upon the presence of a new infarct contralateral to an older lesion in mirror position. The pathogenesis and progression of neurological deficit appears to be intimately related to hypertension. The role of intrinsic intracranial vascular pathology related to diabetes mellitus, embolism of cardiac origin and atherosclerosis is currently undefined. The prognosis for recovery is poor. Half of our patients died within a year of onset of symptoms. Capsular pseudobulbar mutism is recognized by the abrupt appearance of neurological deficit consistent with internal capsular pathology and is confirmed by CT scan or MRI.

Acute Disease↗

PubMed1986

Anterior choroidal artery-territory infarction. Report of cases and review.

Occlusion of the anterior choroidal artery (AChA) can cause infarction in the posterior limb of the internal capsule. Infarction is less frequent in the thalamus, midbrain, temporal lobe, and lateral geniculate body territories of the AChA. The most common clinical sign is hemiparesis. Hemisensory loss is usually transient but may be severe at onset. Homonymous upper-quadrant anopia, hemianopia, or upper- and lower-quadrant sector anopsia can be present. A homonymous defect in the upper and lower visual fields sparing the horizontal meridian is probably diagnostic of a lesion in the lateral geniculate body in the territory of the AChA. The most common stroke mechanism is small-vessel occlusive disease, predominantly found in hypertensive and diabetic patients, but cardiac-origin embolism also can affect the AChA territory. Two of our patients had infarction after temporal lobe resection for epilepsy. Occasionally patients have associated disabilities of higher cortical function that are usually transient. The lesion should be recognizable by computed tomography.

Adult↗

PubMed1985

Aberrations in the diurnal rhythms of plasma glucose, plasma insulin, liver glycogen, and hepatic glycogen synthase and phosphorylase activities in genetically diabetic (db/db) mice.

The diurnal rhythms of plasma glucose, insulin, liver glycogen, and hepatic glycogen synthase and phosphorylase activities were determined in control and genetically diabetic (db/db) mice 8 weeks of age. The diabetic mice showed wide fluctuations in their plasma glucose levels, although being similar to controls near the end of the light period. Little variation was observed in their elevated plasma insulin levels. Liver glycogen levels in diabetic mice were not depleted to the low levels seen in controls during the last part of the light period but were maintained at significantly higher levels. However, maximum attained glycogen levels were similar in the two groups of mice. Alterations were also observed for the diurnal rhythms of glycogen synthase and phosphorylase activities, although again the daily maximums were similar in control and diabetic mice. These findings suggest that the reported changes of several of these metabolic parameters in the db/db mouse may be due to alterations in the diurnal pattern rather than to absolute changes.

Animals↗

PubMed1985

Occlusive disease of the middle cerebral artery.

We studied 20 patients with severe occlusive disease of the mainstem middle cerebral artery (MCA) or its major division branches, and 25 patients with internal carotid artery (ICA) disease. MCA disease patients were more often black, female, younger, and had fewer TIAs than the ICA disease patients. Neurologic signs in patients with MCA disease evolved progressively during days to weeks, whereas ICA disease patients more often had an acute onset of nonprogressive deficits. CT commonly showed restricted subcortical or wedge-shaped infarcts in MCA disease patients. All MCA disease patients had stroke, but 40% of ICA disease patients had no infarction. MCA lesions usually affected the mainstem MCA or its major superior division. Patients with MCA disease seldom had recurrent ischemia in the same vascular territory as the stroke and had a low incidence of subsequent cardiac death.

Adult↗