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Biomedical subjects

B Norrving

Publications and source records attributed to B Norrving.

62 records · Page 4Linked to original sources
PubMed1982

Progression of carotid disease after endarterectomy: a Doppler ultrasound study.

The clinical prognosis and evolution of carotid lesions after unilateral endarterectomy were determined in 64 patients examined 1 to 13 years after surgery (mean observation period, 6 years). Surgery mainly was confined to symptomatic patients with a stenosis only on the appropriate side. Average annual stroke rate was 1.6% on the operated and 0.8% on the nonoperated side. Direct Doppler examination at follow-up revealed a recurrent stenosis (greater than or equal to 50%) or occlusion in 36% of the operated carotid arteries, not significantly different from the proportion of progressive carotid lesions on the nonoperated side (27%). In total, 43.8% of the patients had developed new lesions in one or both carotid arteries, as compared to previous angiographic findings. About 30% of the progressive lesions were associated with symptoms of transient ischemic attacks or stroke, as opposed to 5.5% of vessels without progression of lesions (p less than 0.001). The incidence of recurrent stenosis on the operated side is considerably higher than that previously reported for symptomatic recurrent stenosis, but may represent the natural course of carotid disease in this population, in which carotid surgery thus should not be regarded as definitive treatment.

Adult↗
PubMed1981

Cerebral ischemia symptoms in carotid artery occlusion: role of hemodynamic factors.

The acute outcome in 59 patients with carotid artery occlusion was studied and related to the angiographic pattern of collateral flow. No patient with TIA only had retrograde ophthalmic artery flow, although such a pattern was found in 50 percent of patients with stroke. In a follow-up study (mean 48 months), the same distribution of the collateral pattern was found on ultrasonic Doppler examination. The absence of substantial retrograde ophthalmic flow was associated with an increased contralateral carotid flow. The findings show that the efficiency of the collateral pathways, mainly the contralateral carotid artery and the circle of Willis, largely determines the outcome of carotid artery occlusion.

Angiography↗
PubMed1981

Carotid artery occlusion: acute symptoms and long-term prognosis.

Fifty-nine patients with carotid artery occlusion diagnosed during 1968-1977 were studied. The presenting symptoms were ipsilateral TIA in 12 patients, stroke in 41, 9 of whom died in the acute phase, and TIA or stroke from other vascular territory in 6 patients. Thirty-nine percent of the patients had preceding TIA. At the time of follow up (mean 48 months), only 2 cases with TIA and 2 with stroke on the occluded side were found. Seven patients had recurrent symptoms from other vascular regions. Twelve patients died during follow up because of diseases unrelated to stroke. Thus the annual incidence of ipsilateral stroke (approximately 1%) and TIA (approximately 1%) was low. Anticoagulant treatment of 20 of the patients might have contributed to the low recurrence rate.

Acute Disease↗
PubMed1981

Doppler examination of the carotid arteries. A comparative study with angiography.

The ability of Doppler ultrasound to detect extracranial carotid arterial disease was evaluated in 148 carotid arteries, examined also angiographically. A continuous wave, directional Doppler with zero-crossing meter was used. Doppler diagnosis was based on direct examination of the carotid bifurcation. Of four quantitative variables evaluated, only the end-diastolic ICA/CCA frequency ratio was found to be useful. In stenoses exceeding 75% a deranged Doppler recording was obtained. For stenoses greater than 50% or occlusion sensitivity was 98.3%, specificity 96.6% and over-all accuracy 97.3% with the direct examination technique. Corresponding figures for an indirect Doppler test (frontal artery flow) were 45.8%, 100% and 78.4%. Stenoses less than 50% could not be separated from normal vessels. Direct Doppler examination with a zero-crossing detector is reliable, provided that the limitations of the frequency analysis are considered.

Adult↗
PubMed1979

The diagnostic value of spectrophotometric analysis of the cerebrospinal fluid in cerebral hematomas.

On a clinical basis it is sometimes impossible to distinguish between small intracerebral hematomas and reversible ischemic strokes (RIND). Analysis of the cerebrospinal fluid (CSF) has been used in ths context for several years and is still of importance even since the introduction of computerized tomography (CT) of the brain. CSF has been examined in 23 patients with intracerebral hematomas. Typical cell changes with an increase of poly- and mononuclear white cells are seen within the first days after the stroke, whereas clearly pathological spectrophotometric changes are not seen until about one week after the stroke. None of the investigated patients had a significant increase of the absorbance values at the wavelenths 406 and 415 nm (met- and oxyhemoglobin) until 5 days after the stroke.

Aged↗
PubMedDate not supplied

rCBF in patients with carotid occlusion. Resting and hypercapnic flow related to collateral pattern.

rCBF was measured by 133Xenon inhalation technique in 39 patients with unilateral carotid artery occlusion in a subacute-chronic stage. Resting flow values (ISI) varied between 23.7 and 52.4 ml/100 g/min. An almost constant finding was interhemispheric asymmetry, the degree of which was correlated with the severity of the initial symptoms. An ischemic focus was an insignificant finding. The CO2 response was normal in patients with angiographic signs of circle of Willis collateral flow and without significant contralateral carotid stenosis, whereas it was impaired in patients with a retrograde ophthalmic flow or collateral flow via the circle of Willis and contralateral carotid stenosis greater than or equal to 50%. It is concluded that the CO2 response in useful rCBF variable and may be applied for analysis of collateral flow capacity in patients with carotid artery occlusion considered for bypass surgery.

Adult↗
PubMedDate not supplied

The relationship of optokinetic nystagmus to pursuit eye movements, vestibular nystagmus and to saccades in humans. A clinical study.

The relationship of mean velocity of optokinetic nystagmus (OKN) to pursuit eye movements (PEM), to vestibular nystagmus and to voluntary saccades was analysed in 10 patients with peripheral vestibular lesions and in 30 patients with central vestibular lesions. PEM and vestibular nystagmus were significantly correlated to OKN, suggesting that a common neural pathway is used in the generation of these eye movements. Weak or no correlation was found between saccadic peak velocity and slow phase velocity of OKN. Using multiple linear regression analysis, it was found that 78.5% of the variation in the slow-phase velocity of OKN could be explained by a synthesis of PEM and vestibular test data. PEM test data were more powerful than those of vestibular nystagmus in deduction of OKN. The possible appearance of slow build-up of OKN could not be deduced from the reduction of PEM. Hence, the relationship between PEM and OKN in man is not a simple linear one, but is more complex.

Adolescent↗