Original Article Neurological Soft Signs and Their Relationship with Measures of Executive Function in Chinese Adolescents Lin Cai, MD, Xiongzhao Zhu, MD, PhD, Jinyao Yi, MD, PhD, Mei Bai, MD, Mengcheng Wang, MS, Yuping Wang, MS, Muli Hu, MS, Shuqiao Yao, MD, PhD ABSTRACT: Objective: To examine the prevalence of neurological soft signs (NSS) in Chinese adolescents and their associations with sex, age, and executive function. Methods: A total of 3892 14- to 19-year-old adolescents were recruited from 7 big cities in China. NSS were assessed using the soft sign subscales of the Cambridge Neurological Inventory. Executive functions were tested using the arrows task (AT) and the Stroop color-word test (SCWT). Results: The prevalence of individual signs of NSS in Chinese adolescents varied from 1.3% to 24.6%. Boys obtained higher NSS scores than girls. Both boys and girls showed age- related reduction in prevalence of NSS. Adolescents with high NSS scores exhibited significantly higher scores in AT and SCWT reaction time and AT and SCWT interference and lower scores in AT and SCWT accuracy than adolescents with low NSS score. Conclusions: The current study indicated that boys have significantly higher rate of NSS than girls, and this difference in NSS rate between genders decreased with increasing age. Adolescents with high NSS scores exhibited more severe impairment in executive functions. (J Dev Behav Pediatr 34:197–204, 2013) Index terms: neurological soft signs, prevalence, executive function, adolescents. Neurological soft signs (NSS) are traditionally de- fined as minor or “soft” neurological abnormalities. 1 These abnormalities are then further subdivided into motor coordination (MC), sensory integration (SI) and disinhibition (DI) abnormalities, such as poor perfor- mance in sequencing complex motor tasks, sensory perceptual difficulties, and corresponding disinhibited motor movements that can be elicited objectively and reliably. 2 The NSS are associated risk factors for neuropsychiatric and cognitive disorders, including schizophrenia, 3 obses- sive-compulsive disorder, 4 attention-deficit hyperac- tivity disorder (ADHD), 5 and autism. 6 However, Hertzig et al 7 demonstrated the presence of 2 or more NSS in approximately 5% of typically developing school-age children. Recently, a study demonstrated that motor signs diminished with increasing age in adolescents 11 to 18 years. 8 Previously, Denckla 9 also found different base- rates of MC soft signs in children aged between 5 and 11 years. 9 Therefore, it has been proposed that NSS are part of a typical developmental trajectory 10 ; however, most of the conclusions were based on a relatively small sample size and are limited to MC, whereas the other 2 domains of NSS (SI signs and DI signs) have received relatively less attention. Recent studies have suggested that ethnicity and socioeconomic status may also affect presentation of NSS. 11,12 For example, NSS have been reported at higher rates in African-Americans compared with other ethnicities. 12 Chen and Chan 13 compared the levels of NSS between Chinese people and Caucasians and found that healthy Chinese people tended to have lower SI signs than healthy whites. However, the study by Chen and Chan only examined Chinese adults, and the prev- alence of NSS in Chinese adolescents has not been reported. The NSS have been observed to disappear in late childhood, suggesting that NSS are a signature of neural development. 14 In addition, recent functional imaging studies showed that NSS may be associated with a spe- cific neural network linking the right inferior prefrontal cortex to the middle prefrontal cortex. 15,16 Interestingly, studies have demonstrated that frontal brain regions are associated with executive functions. 17 A study by Chan et al 14 showed that MC scores correlated significantly with the Stroop interference score (an index of executive function) in healthy children. Therefore, we hypothesize that the maturation of some brain areas during adoles- cence, especially frontal brain regions, may be associated with variations in executive function. However, no study so far has systemically investigated the correlation be- tween all 3 NSS domains and executive functions in adolescents. From the Medical Psychological Institute, Second Xiangya Hospital, Central South University, Hunan, People’s Republic of China. Received August 2012; accepted December 2012. All authors declared no conflict of interest. Address for reprints: Xiongzhao Zhu, MD, PhD, Medical Psychological Institute, Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China; e-mail: xiongzhaozhu@163.com. Copyright Ó 2013 Lippincott Williams & Wilkins Vol. 34, No. 3, April 2013 www.jdbp.org | 197