Background and Purpose: Strokes are a frequent complication in uremic patients on dialysis. We wanted to evaluate the effect of this treatment on cerebral hemodynamic parameters, particularly those of patients with carotid stenosis, who are at higher risk for atherothrombotic ischemic events.Methods: We used transcranial Doppler ultrasonography to evaluate blood velocity of the middle cerebral artery in 18 uremic patients before and after hemodialysis. Carotid stenosis was evaluated by echo-Doppler investigation. Six patients were also studied before and after recombinant human erythropoietin treatment.Results: Dialysis treatment decreased mean blood velocity in all patients (/><0.001). Eight of 18 patients (44%) with mild (16-50%), moderate (51-80%), or severe (>80%) carotid stenosis had lower velocity than patients with normal carotid arteries (/?<0.01), and they experienced a further decrease to even lower levels after hemodialysis (/><0.05). In patients treated with recombinant human erythropoietin, hematocrit increased from 28±8% to 37±5% (p<0.001), and blood velocity had a further decrease by 11%. All changes were associated with modifications toward normality of pH, Paco 2 , and hematocrit.Conclusions: Transcranial Doppler ultrasonography represents a useful method for monitoring cerebral circulation of uremic patients, especially of those at possible risk for ischemia. (Stroke 1991;22:1508-1511)
An 11-month-old male infant was referred to our clinic because of a painful ulcer of approximately 5 months' duration on the ventral surface of the tongue (Fig. 1). On physical examination, the lesion was circular (3 cm x 2 cm) with erythematous, raised, and indurated borders. No pathologic findings emerged from the laboratory data, neurologic examination, or clinical history. The family history was also negative for developmental disorders and congenital syndromes. No biopsy was performed in view of the age of the infant, the particular site of the lesion, and the clinical evidence of diagnosis. The treatment included odontologic cream (methylvinylether/maleic acid) as a protective shield, a collutorium (chlorhexidine 0.2%), and the use of a teething ring. Complete healing of the lesion (Fig. 2) occurred within 3 weeks.
Idiopathic facial aseptic granuloma is a chronic, benign, and painless facial nodule occurring exclusively in childhood. Its pathogenesis is unclear, although some interesting hypotheses have been advanced. On the basis of the relationship existing between this disease and recurrent chalazions and conjunctivitis, we hypothesize that it could be considered to be a possible marker of childhood rosacea.
Homocystinuria due to cystathionine beta-synthase deficiency and familial hypercholesterolemia are inherited disorders of metabolism that are associated with premature development of cardiovascular disease. This study addresses the possibility that different patterns of carotid wall damage and cerebral blood flow hemodynamics are present in these two metabolic diseases. Twelve patients with homocystinuria due to cystathionine beta-synthase deficiency (mean age, 24 years), 10 patients with homozygous familial hypercholesterolemia (mean age, 26 years), and 11 healthy control subjects (mean age, 26 years) underwent a vascular examination by noninvasive methods. B-mode ultrasound imaging was used to obtain measurements of intima-media thickness of common carotid, bifurcation, and internal carotid arteries as an index of atherosclerosis. Cerebral blood flow velocity was estimated from vascular examination of the middle cerebral artery by transcranial Doppler. Systolic, diastolic, and mean velocities were measured. Pulsatility index, a possible indicator of vascular resistance in the cerebral circulation, was also calculated. Mean maximum intima-media thickness was 1.4 mm in patients with familial hypercholesterolemia, 0.6 mm in patients with homocystinuria, and 0.6 mm in control subjects. The difference between hypercholesterolemic and homocystinuric patients or control subjects was statistically significant (P < .001). Diastolic blood flow velocities were significantly reduced in the middle cerebral arteries of hypercholesterolemic patients compared with homocystinuric patients or control subjects (P < .05), whereas systolic or mean velocities did not differ. The pulsatility index, a possible indicator of vascular resistance in the cerebral circulation, was significantly higher in hypercholesterolemic patients compared with homocystinuric patients or healthy control subjects (P < .01). A direct relation was demonstrated between pulsatility index of the middle cerebral artery and mean maximum intima-media thickness of carotid arteries on the same side (P < .001). Familial hypercholesterolemia is responsible for diffuse and focal thickening of carotid arteries and possibly also for hyperlipidemic endothelial dysfunction extending to small resistance arteries and leading to a disturbed cerebral blood flow. Patients with homocystinuria due to homozygosis for cystathionine beta-synthase deficiency seldom have plaques in their carotid arteries. They are similar to healthy control subjects with regard to both intima-media thickness and blood flow velocity in the middle cerebral artery. Therefore, it is unlikely that typical atherosclerotic lesions precede thrombotic events in homocystinuria. However, it is possible that arterial dilatations caused by medial damage lead to thrombosis in homocystinuric patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.