Spina bifida, the normal, the pathological and the in-between: first evidence from a forensic osteological collection.

Spina bifida (SB), a rare congenital disorder, is often mentioned as an individualizing factor in Forensic Anthropology. A lack of empirical data regarding SB is noticed in the scientific literature. Moreover, within the scope of anthropological research on SB disparities in terminology, classification systems, and methodological approaches result in incomparable results. The wide range (1,2%-50%) of "spina bifida occulta" reported prevalences is a good example. This research aims to analyze and debate the standard diagnostic criteria of SB on human skeletal remains, and attempts to elaborate on an universal system, premised on the distinction between SB as a pathology, and cleft neural arch (CNA) as an anatomical variant, according to Barnes (1994, p. 360 [1). A study-base of 209 individuals (88 males; 121 females; 44-99 years old) from the 21st Century Identified Skeletal Collection from the University of Coimbra (CEI/XXI) was macroscopically analyzed, focusing on the sacrum and remaining vertebrae. Four individuals presented complete posterior opening of the sacral canal (2,6%[4/156]). The observed bone changes, combined with the analysis of the entire skeleton, indicate that CNA, rather than SB linked to a neural tube defect, is the most reliable explanation for these cases. Overall, CNA was observed on 11 skeletons (7.05% of 156). The viability and applicability of the developed methodology for the identification of SB/CNA in forensic and/or osteological contexts are discussed, as well as the possibility of a lower prevalence of SB occulta, in the general population, than speculated before. HIGHLIGHTS: • Spina bifida has been studied so far under different methodologies, classification systems and nomenclature, leading to unstandardized and incomparable data. • Spina bifida as a pathological manifestation of a neural tube defect, as opposed to cleft neural arch as a simple form of skeletal variation. • Both spina bifida and complete sacral cleft fit the criteria of an individualizing trait in Forensic Anthropology.

Epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis: a single-institution experience in Japan.

BACKGROUND: Lumbar spondylolysis, a common identifiable cause of low back pain in young athletes, reportedly has a higher incidence rate in males. However, the reason for its higher incidence in males is not clear. This study aimed to investigate the epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis. METHODS: A retrospective study was conducted in 197 males and 64 females diagnosed with lumbar spondylolysis. These patients visited our institution from April 2014 to March 2020 with their main complaint being low back pain, and they were followed-up until the end of their treatment. We investigated associations between lumbar spondylosis, their background factors, and characteristics of the lesions and analyzed their treatment results. RESULTS: Males had a higher prevalence of spina bifida occulta (SBO) (p = 0.0026), more lesions with bone marrow edema (p = 0.0097), and more lesions in the L5 vertebrae (p = 0.021) than females. The popular sports disciplines were baseball, soccer, and track and field in males, and volleyball, basketball, softball in females. The dropout rate, age at diagnosis, bone union rate, and treatment period did not differ between the sexes. CONCLUSION: Lumbar spondylolysis was more common in males than in females. SBO, bone marrow edema, and L5 lesions were more frequent in males, and sports discipline varied between the sexes.

Association of spinal anomalies with spondylolysis and spina bifida occulta.

PURPOSE: To investigate the association of spinal anomalies with lumbar spondylolysis and spina bifida occulta (SBO). METHODS: A total of 1190 patients with thoracic, abdominal, and pelvic computed tomography scans available were categorized according to the number of presacral (thoracic and lumbar) mobile vertebrae and the presence or absence of lumbosacral transitional vertebrae (LSTV). The prevalence of spondylolysis and SBO and the association of spinal anomalies with these disorders were evaluated. RESULTS: Normal morphology (17 mobile vertebra with no LSTV) was found in 607 men (86.5%) and 419 women (85.9%) and about 14% of patients had anomalies. Spondylolysis was found in 74 patients (6.2%), comprising 54 men (7.7%) and 20 women (4.1%). SBO involving the lumbar spine was found in 9 men (1.3%) and 2 women (0.4%). Spondylolysis was significantly more common in men with 18 vertebrae without LSTV (21.1%) than in those with 17 vertebrae without LSTV (7.2%) (p = 0.002). The prevalence of spinal anomalies was 55.6% in men and 50.0% in women with SBO that included a lumbar level was significantly higher than in both men (13.5%, p < 0.001) and women (4.8%, p = 0.003) without SBO. CONCLUSION: These findings indicate that there is a relationship between spinal anomalies and both spondylolysis and SBO, which may lead to elucidation of the mechanism of onset of spondylolysis and improve its treatment and prognosis. Awareness that patients with SBO involving the lumbar spine have an increased likelihood of a spinal anomaly may help to prevent level errors during spinal surgery.

Sacral spina bifida occulta rare occurrence in Byzantine Belentepe population in Mugla, Turkey: A possible case for adequate folic acid intake.

Spina bifida may occur during the first weeks after conception; folic acid deficiency is strongly related to this anomaly. We argue that the low prevalence rate of spina bifida may indicate a relatively good nutrition state of a population, given that folic acid is found in many food products commonly eaten. The aim of this study is to examine the relationship between folic acid intake and spina bifida occulta prevalence in the Belentepe Byzantine population in Anatolian peninsula, and to compare the prevalence rates with various other ancient Anatolian populations by focusing on sacral spina bifida occulta in the Byzantine population. A total of 62 available human sacra were included in the study and compared with other sacra from relevant research using chi-squared test. Four male individuals had sacral spina bifida occulta with a prevalence rate of 6.45%, which is found to be lower in comparison to other ancient populations from western to eastern Anatolia. The present-day ecology of Belentepe indicates that foods rich with folic acid are common in and around the region. While some studies indicate the contrary, a comparison regarding the sacral spina bifida occulta prevalence with other populations in Anatolia shows a correlation between folic acid intake and proximity to a Mediterranean climate.

Awareness of spina bifida among family of affected child. A cross sectional questionnaire.

OBJECTIVES: To evaluate the awareness of spina bifida (SB), risk factors and possible preventive measures among mothers who had been following in our clinic with a spina bifida affected child. Methods: A cross-sectional questionnaire-based study with 38 mothers of SB patients who are following at SB and hydrocephalus clinic at King Fahad University Hospital, Khobar, Eastern Province, Saudi Arabia. RESULTS: Thirty-eight mother were included in this questionnaire. Most of the participants were Saudi (94.7%). Ten out of 38 women (26.3%) had used medications during pregnancy (pain medications and herbal drugs), 4 out of 38 (10.5%) had been exposed to imaging radiation, while 9 (23.7%) had experienced moderate to high grade fever (39-41°C) during pregnancy. Moreover, the majority (86.8%) of these women did not receive folic acid (FA) before pregnancy, and 42.1% of them did not have FA during their first trimester. Only one (2.6%) gave positive family history of SB while, 6 (15.8%) reported having other SB children.  Conclusion: There is a considerably low level of awareness in mothers of SB patients despite prevalence of this anomaly in the Eastern province. This necessitates an effort from health care providers to educate the community about this birth defect entity. Furthermore, genetic counseling should be encouraged especially in those who have a positive familial history for better understanding. Also, larger sample size with randomized controlled trials and larger epidemiological studies should be implemented.

The paleoepidemiology of Sacral Spina Bifida Occulta in population samples from the Dakhleh Oasis, Egypt.

OBJECTIVE: To document sacral spina bifida occulta (SSB0) prevalence in a population sample from the Dakhleh Oasis, Egypt, and address methodological issues in recording and quantifying SSBO variations. MATERIALS: 442 adult sacra from two temporally disjunct samples from the same deme traversing the 3rd intermediate (TIP) and the Roman Periods. METHODS: Sacra were scored for SSBO, excluding the sacral hiatus. Risk of SSBO was calculated with the common odds ratio and statistical significance by X2. Data were compared to other archaeological SSBO data. RESULTS: SSBO was present in 15.6% of the sample with a slight, but not significant, temporal increase (TIP to Roman Period) in males, and a significant age-correlated increase in both sexes. Most open sacra occurred in young adults. CONCLUSIONS: Data support that SSBO can be considered as a morphogenetic variant. Dakhleh data fall within the prevalence range for most populations, however inter-population comparisons are complicated by methodological inconsistencies. SIGNIFICANCE: SSBO can be used in paleogenetic research. LIMITATIONS: Methodological differences in scoring SSBO prevent effective comparative study. SUGGESTED FUTURE RESEARCH: Future studies require more rigorous and standardized scoring methods. aDNA may be used to corroborate the morphogenetic value of SSBO and determine its clinical significance.

Does the Prevalence of Spondylolysis and Spina Bifida Occulta Observed in Pediatric Patients Remain Stable in Adults?

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To compare the prevalence of lumbar spondylolysis and spina bifida occulta (SBO) in pediatric and adult populations. SUMMARY OF BACKGROUND DATA: The prevalence of spondylolysis reported from radiograph-based studies in children had been questioned in computed tomography (CT)-based studies in adults; however, a recent CT-based study in pediatric patients has confirmed the previously reported data in pediatric populations. SBO, which has been associated with spondylolysis, has demonstrated a decreasing prevalence with increasing age during childhood and adolescence. No studies have compared the prevalence of spondylolysis and SBO in pediatric and adult patients using CT as a screening method. METHODS: We studied 228 pediatric patients (4-15 y old) and 235 adults (30-45 y old) who underwent abdominal and pelvic CT scans for reasons not related to the spine. The entire lumbosacral spine was evaluated to detect the presence of spondylolysis and SBO. We compared the prevalence of spondylolysis and SBO in pediatric patients and adults. RESULTS: The prevalence of spondylolysis in pediatric patients was 3.5% (1.1%-5.9%), and in adults, it was 3.8% (1.7%-6.8%), P=1. The prevalence of SBO in pediatric subjects was 41.2% (34.8%-59.2%) and dropped to 7.7% (4.3%-11.5%) in adults, P<0.01. The male prevalence of SBO in pediatric patients was 51.4%, whereas it was 32.2% in females (P<0.01); this sex difference was not significant in the adult population (P=0.8). CONCLUSIONS: The prevalence of lumbar spondylolysis remained constant from pediatric age through adulthood. The prevalence of SBO decreased from 41.2% in children to 7.7% in adults; this finding suggests that closure of the vertebral arch may not be completed in early childhood in a large percentage of subjects.

Spondylolysis and spina bifida occulta in pediatric patients: prevalence study using computed tomography as a screening method.

PURPOSE: The prevalence of spondylolysis reported from radiograph-based studies has been questioned in recent computed tomography (CT)-based studies in adults; however, no new data are available in pediatric patients. Spina bifida occulta (SBO), which has been associated to spondylolysis, may be increasing its prevalence, according to recent studies in adults in the last decades, but without new data in pediatric patients. We aimed to determine the prevalence of spondylolysis and SBO in pediatric patients using abdomen and pelvis CT as a screening tool. METHODS: We studied 228 patients 4-15 years old (107 males), who were evaluated with abdomen and pelvis CT scans for reasons not related to the spine. The entire lumbo-sacral spine was evaluated to detect the presence of spondylolysis and SBO. We compared the prevalence of spondylolysis in patients with and without SBO. A logistic regression analysis was performed to determine the effect of age and sex as independent predictors of spondylolysis and SBO. RESULTS: The prevalence of spondylolysis was 3.5 % (1.1-5.9 %); 2/8 patients presented with olisthesis, both with grade I slip. The prevalence of SBO was 41.2 % (34.8-59.2 %) (94 patients). Spondylolysis was not more frequent in patients with SBO than in patients without SBO. Male sex and decreasing age independently predicted the presence of SBO, but not of spondylolysis. CONCLUSION: We observed a 3.5 % prevalence of spondylolysis and a 41.2 % prevalence of SBO. SBO was significantly more frequent in males and younger patients.

How innocent is corpus callosum dysgenesis?

BACKGROUND/AIMS: We aimed to investigate the relationship between corpus callosum dysgenesis (CCD) and associated asymptomatic closed spinal dysraphisms (CSDs). METHODS: 2,840 pediatric patients who were referred to our outpatient clinic between the years 2005 and 2013 with the diagnosis of microcephaly, macrocephaly, congenital hydrocephaly, epilepsy, mental-motor retardation and suspicion of intracranial mass were evaluated. Eighty-five patients were identified with a CCD by cranial magnetic resonance imaging (MRI). The 85 patients with CCD were evaluated by whole spinal vertebral MRI for possible CSD and the results were evaluated. RESULTS: 31/85 (36.4%) patients (20 males, 11 females) were detected to have radiological findings of CSD. The most common radiological finding was a low-lying conus medullaris, either alone, or as part of a multiple pathology in 26 of the 31 patients, followed by diastematomyelia in 16 of 31 cases and spinal lipoma in 4 of the 31 cases. CONCLUSION: When the neuroaxis emerges as a whole, the structures of embryological ectodermal origin and cranial and spinal structures are not independent regions from each other and thus, asymptomatic CSDs have been demonstrated to accompany CCD. In diseases of neural origin in which early diagnosis is of the utmost importance, each case with dysgenesis, diagnosed incidentally or during differential diagnosis, should be evaluated for possible CSD and should be treated with a multidisciplinary approach before any neurological deficit appears.

Spina bifida occulta: not to be overlooked in children with nocturnal enuresis.

OBJECTIVE: Previous reports have suggested that the incidence of spina bifida occulta in patients with nocturnal enuresis is higher than in the general population. However, the effect of spina bifida occulta on the response to nocturnal enuresis treatment is controversial. The purpose of this study was to investigate the relationship between spina bifida occulta and response to treatment of nocturnal enuresis. METHODS: Between 2006 and 2009, the records of 160 children with nocturnal enuresis were reviewed. Children with other organic urological disease or symptoms suggestive of spinal dysraphism were excluded. Plain radiography for the kidney-ureter-bladder was carried out before the start of the nocturnal enuresis treatment. Response to treatment of children with and without spina bifida occulta was compared. RESULTS: Of 160 children, 53 were girls; the mean age was 7.8 ± 2.06 years. The mean duration of treatment was 8.7 ± 9.29 months. Spina bifida occulta was detected in 43 children (26.9%). Spina bifida occulta affected L4 in four children, L5 in 12 children, S1 in 26 children and S2 in one child. There was a significant difference between the spina bifida occulta and non-spina bifida occulta groups in terms of outcome (P=0.002), with a complete response more likely in children without spina bifida occulta (P=0.005). None of the children with primary non-mono symptomatic nocturnal enuresis and spina bifida occulta showed a complete response. CONCLUSIONS: The presence of spina bifida occulta significantly affects the response to treatment in patients with nocturnal enuresis. Thus, verifying spina bifida occulta in this patient population can facilitate the prediction of the response to nocturnal enuresis treatment.

Confirmation of microevolutionary increase in spina bifida occulta among Swiss birth cohorts.

Previous studies on the prevalence of spina bifida occulta have indicated a microevolutionary increase in its frequency and possible population differences in the prevalence of the condition. We studied the frequencies of closed and open sacral canals at each sacral level among two birth cohorts in Switzerland. Transverse CT scans and multiplanar reconstruction images of sacra of 95 males and 96 females born in 1940-1950 and 99 males and 94 females born in 1970-1980 in Switzerland were reviewed. We found that individuals born later have significantly more open sacral arches at all sacral levels compared to those born 30-40 years earlier. When results were related to previously published data on Australian cohorts, the trend was the same, but Swiss in both cohorts were less likely to have an open section than Australians at all locations apart from S2. This study confirmed a microevolutionary trend in the opening of sacral canal among two different generations in Switzerland and demonstrated a population difference in the prevalence of spina bifida occulta.

Latex sensitization and allergy in children with spina bifida in Turkey.

PURPOSE: The latex allergy is known as a very frequent problem of children with spina bifida (SB). The aim of this prospective study is to determine the frequency of latex sensitization and allergy in Turkish children with SB and to evaluate the related risk factors. METHODS: We enrolled a total of 175 children and collected them in four groups of patients: children with SB, children who had neurosurgical disorders other than SB, atopic children with allergic diseases, and healthy children as control group. All cases were evaluated for latex sensitivity and allergy with skin prick tests and specific IgE. The diagnosis of latex allergy was confirmed with the latex provocation test. RESULTS: Ten children with SB, two children with other neurological disorders, and three atopic children with allergic disease were found "sensitized to latex". Among these sensitized children, only one child with SB had latex allergy. Multivariate logistic regression analysis of the children with SB and other neurologic disorders and the whole group of patients showed that skin test positivity, the presence of noncentral nervous system (CNS) surgery, and the number of the operations were significant risk factors for latex sensitization. CONCLUSIONS: Our study showed that rates of latex sensitivity and allergy in children with SB in Turkey are significantly lower than published rates in literature. We also found that atopy, the presence of non-CNS operations in children with SB and other neurologic disorder, and total number of operations in the whole group of patients are the most important risk factors for latex sensitization.

Dermal sinus tract of the spine.

OBJECTIVE: Spinal dermal sinus tract (DST) is a rare entity which usually comes to clinical attention by cutaneous abnormalities, neurologic deficit, and/or infection. We performed this study to assess presentation patterns, associated anomalies, radiologic, urologic, and surgical findings in children afflicted with spinal DST. METHODS: Medical records of 35 children treated for spinal DST in Children's Medical Center from January 2001 to December 2008 were reviewed. RESULTS: Patients' age ranged from 3 days to 8.44 years. Dermal sinuses were located most frequently in the lumbar and lumbosacral regions. The most common causes for referral were abnormal skin findings (57.1%) and infection (31.4%). Notably eight patients presented with meningitis. The overall rate of neurologic abnormalities was 37.1%, four of whom presented acutely with rapidly progressive paraplegia and meningitis. The most common magnetic resonance imaging finding was tethered cord (63%). At least one urological evaluation was performed in 30 patients, which revealed abnormal results in 77% of them. All patients underwent complete resection of the tract and repair of associated abnormalities. Most tracts terminated within the intradural space. Fifteen patients (42.8%) had inclusion tumor with the dermoid tumor being the most common. None of the patients demonstrated neurological deterioration postoperatively. CONCLUSION: Dermal sinus tract is an innocuous-appearing spinal dysraphism that may contribute to devastating morbidities if not timely addressed. In order to prevent complications, timely surgical intervention including complete resection of sinus tract with intradural exploration and correction of associated abnormalities is of utmost importance.

Prevalence of sacral spina bifida occulta and its relationship to age, sex, race, and the sacral table angle: an anatomic, osteologic study of three thousand one hundred specimens.

STUDY DESIGN: An anatomic, osteologic study of spina bifida occulta (SBO). OBJECTIVE: To determine the prevalence and patterns of SBO in a large population and examine its relationship to age, sex, and race; then to evaluate SBOs relationship to the sacral table angle (STA) when compared with an age-matched control group. SUMMARY OF BACKGROUND DATA: SBO has a reported prevalence of 1.2% to 50% and has been implicated in various pathologic problems. SBO is often associated with spondylolysis or spondylolithesis. The STA has been implicated as an etiologic or predictive factor in the presence of pars defects. METHODS: Three thousand one hundred osteologic specimens were evaluated for the presence of SBO. SBO was graded on a scale from 0 to III. Information on the age, sex, race, and STA of each specimen was recorded and measured, respectively. Prevalence and patterns of SBO were enumerated. The STAs of an age-matched control group of 355 specimens were examined. The SBO group and control groups were compared in regards to STA, controlling for age, sex, and race. RESULTS: Overall, 355 specimens displayed SBO, for an overall prevalence of 12.4%. Of the SBO specimens, 68.7% were white, 88.2% were men, 53% were grade I, 37% II, and 10% III. All 3 grades of SBO were more common in men than women (88.2% vs. 11.8%) and more prevalent in whites than blacks (68.7% vs. 31.3%) (P = 0.01). SBO decreased in prevalence with increasing age. The average STA in SBO specimens was 95.9 degrees . This differed from an age-matched control group, 92.1 degrees (P < 0.0001). Every 1 degrees increase in STA resulted in a 6% increased likelihood of SBO. In SBO specimens, the STA decreased with increasing age, contrary to age-matched controls. CONCLUSION: SBO has an overall prevalence of 12.4% in a large, diverse population. SBO is more common in men and whites and decreases in prevalence with increasing age. The STA is greater in SBO when compared with controls and an increased STA predicts SBO. In SBO, the STA decreases with increasing age.

Variable morphology of the sacrum in a Chinese population.

Although several morphological variations of sacrum have been reported in western populations, little attention has been paid to this anatomic issue in eastern people, and classification of sacral variability in particular. In this research of sacral morphology in Chinese people, we investigated and measured thoroughly and systematically 203 specimens of intact dry Chinese adult sacra. Morphological features of sacral variations were observed by visual inspection, and correlation parameters of variability were measured with a vernier caliper. The incidence of sacral variations was calculated. We found that the overall rate of sacral variations was 58.1% (male: 57.4%; female: 59.5%). The anatomical variants that we observed fell into the following five categories: accessory auricular surface (25 specimens, 12.3%); sacral skewness (48 specimens, 23.6%); transitional vertebra (34 specimens, 16.7%); sacral spina bifida occulta (57 specimens, 28.1%), Degrees I, II, and III of which were 36, 14, and 7 specimens, respectively; multiple variations (42 specimens, 20.7%), the types of which were diversified. This study reveals that sacral variations are common in Chinese population. The sacral variants in anatomic morphology should be taken into consideration when diagnosing and treating sacrum-related diseases.

Secular trend in the opening of the sacral canal: an Australian study.

STUDY DESIGN: Computer tomography scans were used to asses the opening of the sacral canal. OBJECTIVE: We investigated the prevalence of sacral spina bifida occulta in 2 population groups: born 1940 to 1950 and 1980 to 1990. SUMMARY OF BACKGROUND DATA: Comparison of the prevalence of spina bifida occulta in the first-century Pompeii with that in 20th century European and Mediterranean populations indicates that the degree of the closure of vertebral arches in the sacrum has undergone changes and the prevalence of spina bifida occulta is increasing. METHODS: Transverse computer tomograph scans and multiplanar reconstruction images of sacra of 100 males and 100 females born 1940 to 1950 and 100 males and 100 females born 1980 to 1990 were used after ethics committee approval. RESULTS: The individuals born later have significantly more open sacral arches when compared with those born 40 years earlier, especially in the midsacral region. Also, males have open sacral arches in the rostral segments of the sacrum more than females. CONCLUSION: This study demonstrates a secular trend in the opening of the sacral canal in both sexes that occurred within 2 generations. Also, the increased prevalence of open sacral canal in males suggests a different response between sexes to the forces of evolution.

Long-term urologic outcome in patients with caudal regression syndrome, compared with meningomyelocele and spinal cord lipoma.

BACKGROUND/PURPOSE: The long-term urologic outcome in a large series of patients with neural tube defects was evaluated. METHODS: The following clinical parameters in 398 patients ranging from 1 to 37 years of age--69 with caudal regression syndrome (CRS), 244 with meningomyelocele (MMC), and 85 with spinal lipoma (SL)--were studied: congenital renal anomalies, renal function, vesico-ureteric reflux, upper tract dilatation, urodynamic pattern, and urinary continence. RESULTS: Single kidney was much more frequent in CRS (20.3%), compared with MMC (1.2%) and SL (0%). Vesico-ureteric reflux was found in 37.7% of patients with CRS, 43.0% of MMC, and 21.2% of SL. Patients with CRS had a higher risk of impaired renal function (8.7%), compared with MMC (5.3%) and SL (1.2%). Neuropathic bladder was found in 61% of patients with CRS, 98% of MMC, and 42% of SL. Among them, clean intermittent catheterization and drugs allowed 30% of patients with CRS, 45% of MMC, and 71% of SL to be dry for more than 4 hours. CONCLUSIONS: Diagnosis influences the urologic outcome in neural tube defect. In CRS, the incidence of renal agenesis and vesico-ureteric reflux was unexpectedly high. The risk of renal damage and, in those with neuropathic bladder, of urinary incontinence, was similar to patients with MMC.

Attention and executive functions in adolescents with spina bifida.

OBJECTIVE: This study was designed to examine attention processes and executive functioning in adolescents with spina bifida, and to explore whether impairment in these domains contributes to problems with social adjustment. METHODS: A sample of adolescents with spina bifida (n = 68) and a matched comparison group (n = 68) and their families were followed longitudinally. All participants completed questionnaires, and the adolescent participants underwent neurocognitive testing. RESULTS: The spina bifida sample showed greater impairment on objective and subjective measures of attention and executive functioning, even when differences in intellectual functioning were controlled. Additionally, attention and executive deficits were found to be predictive of social adjustment difficulties. A mediational analysis suggested the neurocognitive deficits mediate associations between spina bifida status and social adjustment difficulties. CONCLUSIONS: Adolescents with spina bifida appear to exhibit clear impairment in attention and executive functioning and this impairment may contribute to their well-established social difficulties.