The Domestic Incidence Of Spina Bifida Occulta In China And Related Factors

Objective To probe the domestic incidence of spina bifida occulta and its related factors ,and to approach its regularity.Methods 1082cases of spiral CT images were reviewed,with 508 cases below 18 years old,574 cases above 18 years old. The former were divided into 18 groups with a 12-month interval, and the incidence of spina bifida occulta in each group were compared. The relationship between incidence and age was proposed. Cases above 18 years old was divided into 6 groups with a 10-year interval, and the incidence of spina bifida occulta in each group and in different sex group was calculated and compared. Data of CT examination of 141 patients with paruria(81 cases below 18 years,60 cases above 18 years) was retrospectively analyzed and its incidence of spina bifida occulta was compared with that of the corresponding age group without the symptoms. Cases above 18 years old were divided into two groupsaccording to whether he had low back pain, and their incidence of spina bifida occulta was compared.The occurrence of spina bifida occulta or not for each case was evaluated on the back view image of Volume Rendering(VR) post processing. Spina bifida occulta was counted if any one or more vertebrae open in L5,S1,S2. SPSS 11.5 software was adopted for statistic process with U test,P<0.05 as statistic significant.Results The incidence of spina bifida occulta was 94%-97% in 8 groups of within 0-8y cases, with no statistic difference; The incidence was 48-52% in 6 groups of cases within 8y-14y, no statistic difference; 19%-22% in 4 groups of 14y-18y cases, no statistic difference; The incidence was 16% in group above 18 years old.The overall incidence of 3 age segments as 0-8y,8y-14y,14y-18y with statistic difference respectively. No statistic difference for incidence of spina bifida occulta between 14y-18y and above 18y groups. Incidence range of simple and mixed type of spina bifida occulta in the 18 groups below 18 years old was 11%～20% and 80%～89% respectively, and no significant difference was found in incidences among these groups. Incidence of simple and mixed type in the group above 18 years old was 71% and 29% respectively, and the incidence difference was significant. repectively. Besides the age factor, spina bifida occulta has nothing to do with paruria. In cases above 18 years old, spina bifida occulta has no relationship with the age ,sex or low back pain.Conclusion The bony vertebral arches continue to develop for fused form after birth,this process can be divided into 3 period: unclosed period for 0-8y, transition period for 8y-14y, closed period for above 14y and adults. The spina bifida occulta can be considered a kind of anatomic variation rather than a disease. Besides the age factor, spina bifida occulta has nothing to do with paruria. In cases above 18 years old, spina bifida occulta has no relationship with the age ,sex or low back pain.