Stroke; a journal of cerebral circulation
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Restricted acral sensory syndrome (RASS) after minor stroke most often manifests as a cheiro-oral syndrome. However, recent studies have described more varied patterns of RASS and also have reported that the degree of sensory symptoms may vary among individual digits. Until recently, however, there have been no reports in which sufficient numbers of patients were studied with detailed information on the symptomatic severity among individual digits. ⋯ These patterns of RASS generally agree with the previously observed sensory topography of monkeys, and they support anatomic proximity of sensory fibers from acral parts of the body. However, other mechanisms such as differential vulnerability of generation of paresthesia in different body parts or a low-threshold concept based on disproportionately large representing areas for the acral parts of the body in the human sensory system may also be required to explain some of the clinical observations.
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Although stroke mortality has been declining in the United States for decades, recent trends in stroke incidence based on national data have not been described. We used Medicare hospitalization data to estimate national trends in the incidence of stroke among Americans aged 70 years or older, and we provide evidence of the validity of the estimate. ⋯ Stroke incidence declined steadily from 1985 to 1989 and then increased slightly to 1991. Several postulated potential sources of bias were investigated and found to be unlikely to account for the incidence decline, although some may have contributed to the subsequent incidence increase.
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Pial arterioles transiently dilate during cortical spreading depression (CSD), although the mechanisms are unclear. We tested the hypothesis that increased production of nitric oxide (NO) promotes arteriolar dilation. ⋯ The reversible inhibition of CSD-induced pial arteriolar dilation by either L-NAME or L-NA suggests that NO contributes to arteriolar dilation observed with CSD.
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Comparative Study
Transcranial Doppler detection of vertebrobasilar vasospasm following subarachnoid hemorrhage.
Transcranial Doppler sonography is of established value in the detection and monitoring of middle cerebral artery vasospasm. Little information exists on the utility of transcranial Doppler for detection of posterior circulation vasospasm. ⋯ Our data suggest that transcranial Doppler has good specificity for the detection of vertebral artery vasospasm and good sensitivity and specificity for the detection of basilar artery vasospasm. Transcranial Doppler is highly specific (100%) for vertebral and basilar artery vasospasm when flow velocities are > or = 80 and > or = 95 cm/s, respectively.
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Quantitative data on sensory impairment in stroke patients are limited. We measured the perception thresholds for temperature and thermal pain in patients with different lacunar syndromes, correlated the results with clinical and magnetic resonance imaging (MRI) findings, and studied the long-term prognosis of sensory dysfunction. ⋯ Quantitative thermal testing confirmed an involvement of spinothalamic pathways in lacunar infarcts causing pure sensory and sensorimotor stroke and revealed a subclinical sensory impairment in patients with pure motor stroke. Infarction sites were similar in patients with pure motor and sensorimotor stroke.