Objective To analyze etiology,clinical manifestation and diagnosis process of vertigo and dizziness in children.Method The clinical data of 82 children with vertigo and dizziness treated in our hospital from January 2006 to December 2016 were retrospectively analyzed.Results There were 46 girls and 36 boys with a female:male ration of 1.28:1.The median age of patients was 9.0 years (14 months-18.0 years) and 21 cases were less than 6 years old.The chief complaints were repeatedly falling,crying,walking unsteadily and scratching the ear for unknown reasons.For children aged ＞ 5 years may express " roof or tent rotation";for those aged ＞ 6-＜ 15 years (n =34),the main complaint was more ambiguous "dizziness";for those aged ≥ 15-≤ 18 years (n =27) with the main complaint of " dizziness" may clearly express the " sense of rotation" or " the feeling of feeling drowsy,the top-heavy sense," and the accompanying deafness,earfullness,tinnitus and so on.Among 82 cases,there were 15 cases of benign paroxysmal vertigo (BPV,18.3％),12 cases of secretory otitis media (SOM,14.6％),11 cases of vestibular migraine (VM,13.4％),9 cases of benign paroxysmal positional vertigo (BPPV,11.0％),8 cases of inner ear malformation (9.8％),8 cases of Meniere's disease (9.8％),7 cases of vestibular neuritis (8.5％),6 cases of sudden deafness with vertigo (7.3％),4 cases of central vertigo (4.9％),1 case of rare genetic disease (1.2％) and 1 case of vertigo due to mental psychological (1.2％).The incidence of BPV,VM and Meniere's disease in girls was higher than that in boys.There was a tendency to self heal in BPV with the age increasing,in 15 BPV cases,8 after 12 years of age,3 after 14 years old had no vertigo attacks,and 4 cases were still in follow-up.The attack frequency of VM was decreased,and the extent was reduced with the age.Children older than 6 years were able to cooperate to vestibular function tests,and the majority completed the tests.Conclusion The analysis shows that the etiology of vertigo and dizziness in children is different from that of adults.Central vertigo and rare genetic disorders with dizziness as the first symptom are of great harmfulness,so intensive observation and multidisciplinary consultations are recommended.

Objective:To synthesize a novel site-specifically labelled probe 68Ga-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-Cys-Asp-Val (CDV)-Nb109 and explore its potential for detection of the programmed cell death ligand 1 (PD-L1) expression level in different tumors. Methods:Firstly, CDV was inserted into the tail of the sequence of Nb109 by genetic engineering. Then the precursor DOTA-CDV-Nb109 was prepared by mixing the maleimide-DOTA and the single-domain antibody CDV-Nb109 (amount of substance ratio 1∶1) via the maleimide-cysteine site-specific coupling strategy. Subsequently, the DOTA-CDV-Nb109 was labeled with 68Ga and purified by PD-10 column. Human melanoma A375, human PD-L1 transfected melanoma A375-hPD-L1 and human glioma U87 tumor-bearing mice models were established, and the diagnostic value of 68Ga-DOTA-CDV-Nb109 was evaluated by stability assay, cellular uptake, and microPET imaging. One-way analysis of variance and the least significant difference t test were used to analyze the data. Results:The probe 68Ga-DOTA-CDV-Nb109 was obtained with the radiochemical yield of (69.79±4.69)%, radiochemical purity more than 97%, and molar activity of (12.85±1.51) GBq/μmol. 68Ga-DOTA-CDV-Nb109 had strong binding affinity for A375-hPD-L1 with the dissociation constant ( Kd) of (66.43±17.89) nmol/L. The uptake of 68Ga-DOTA-CDV-Nb109 in A375-hPD-L1 and U87 cells were (3.17±0.15) percentage of the added radioactivity dose (%AD) and (2.08±0.03) %AD respectively, which were significantly higher than that in A375 cells ((1.21±0.14) %AD; F=82.87, t values: 15.23, 9.98, P values: <0.001, 0.003). The tumor uptake of the probe in A375-hPD-L1 ((5.21±0.35) percentage of injected dose per ml (%ID/ml)) and U87 tumor-bearing mice ((3.44±0.69) %ID/ml) were significantly higher than that in A375 tumor-bearing mice ((2.17±0.36) %ID/ml; F=249.72, t values: 35.70, 3.43, both P<0.001). Conclusion:The site-specifically labelled probe 68Ga-DOTA-CDV-Nb109, which can non-invasively and dynamically monitor the change of PD-L1 expression level in different tumors and help screen patients who can benefit from PD-L1 immune checkpoint blocking therapy, is successfully synthesized with high radiochemical purity.