Noninvasive evaluation of arterial abnormalities in young patients with neurofibromatosis type 1

Neurofibromatosis regroups at least two different autosomal dominant geneti c disorders: neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (N F2). Vascular disease is an underestimated complication of NF1. Few studies are available on this, all based on case reports. Neurofibromin, NF1 prote in product, has also been detected in aortic smooth muscle. The purpose of this study was to evaluate the physical properties of the vessels, by measu ring the carotid-femoral pulse wave velocity (PWV). This parameter was asse ssed by the Complior(R), a new noninvasive, validated device, used to scree n a large population. The authors studied 64 neurofibromatosis patients (34 boys and 30 girls) with a mean age of 12 years (range 5-25 years). To inve stigate the presence of vascular lesions, aortic stiffness was evaluated by carotid-femoral PWV by using an automatic processor (Complior(R)). They co mpared data from the PWV with a control group (30 healthy children, 17 boys and 13 girls, mean age 11 years, range 5-23 years). The calculated mean PW V in the control group was 6.5 +/- 1.15 m/s. The mean PWV of the 64 young p atients with NF1 was 6.3 +/- 1.02 m/s. There was no difference between the two groups (p=0.39). Nevertheless, analysis of the linear regression has sh own a linear relationship between systolic blood pressure (SBP) and PWV in the control group, while in NF1 patients this relationship is not present. The authors suggest that the coexistence of different factors, such as inti mal proliferation, thinning media, fragmentation of the elastic tissue, irr egularity, stenosis and tortuosity of the vessels, dysplasia of the small v essels, that counterbalance PWV, normalize the mean value. They emphasize t he importance of a careful vascular evaluation, using noninvasive method, s uch as Complior(R). This device is well accepted by NF1 patients.