A rare cervical complication of Kawasaki disease: a retrospective study of clinical and radiological features

Introduction

Kawasaki disease (KD) is a common acute vasculitis syndrome primarily affecting children, though its etiology remains largely unknown. It presents as a multisystemic disorder, with symptoms including conjunctival congestion, rash, and lymphadenopathy, and it can also involve the respiratory, gastrointestinal, nervous, and urinary systems (1). Research indicates that cervical lymphadenopathy (CL) occurs in approximately 50–75% of the KD patients (2). Approximately 12% of patients present with fever and CL as the initial symptom. These patients often exhibit a cervical mass, tenderness, and restricted neck movement (3).

Grisel’s syndrome (GS) primarily occurs in children and is a rare non-traumatic atlantoaxial subluxation, also known as atlantoaxial rotatory fixation (AARF) (4). It can result from any upper cervical inflammation, such as CL, or following otolaryngologic surgery (5). Given that CL is a common symptom of KD (6), it is reasonable to expect that GS might also occur in KD patients. However, current reports of GS predominantly come from the fields of otolaryngology, neurosurgery, and orthopedics, with limited documentation in the context of KD in children (7,8). Although there are sporadic case reports of GS in KD, systematic studies remain lacking. When diagnosed early, GS can typically be managed conservatively; however, delayed diagnosis may lead to severe atlantoaxial deformities necessitating complex surgical intervention (9,10).

Therefore, this study aims to: (I) compare the clinical and laboratory features of KD patients with and without GS; (II) identify risk factors for GS development in KD; and (III) assess factors associated with the severity of AARF in GS patients. The goal is to improve understanding of this rare KD complication, to facilitate early recognition and to improve prognostic assessment in practice. We present this article in accordance with the STROBE reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1762/rc).

Methods

Study population

This retrospective study was conducted at West China Second University Hospital, Sichuan University, where we reviewed the medical records of 2,451 patients diagnosed with KD and treated between January 2015 and December 2023. The diagnosis of KD was established according to the 2004 American Heart Association criteria (11). Patients aged ≤18 years with complete clinical and laboratory data prior to initial intravenous immunoglobulin (IVIG) treatment were included. Those with incomplete records, uncertain diagnosis, prior treatment at other institutions, or concomitant conditions such as trauma, surgery, or congenital cervical disorders were excluded.

The diagnosis of GS was based on both clinical and radiological criteria. For a patient without recent trauma who presents with neck pain, fever, restricted range of motion, and pain on attempted repositioning, the combination of these clinical features with radiological evidence of AARF establishes the diagnosis of GS (12-14). All patients received standardized treatment for KD according to established clinical guidelines (11). The treatment strategy for GS was based on the Fielding-Hawkins classification, with different subtypes corresponding to specific management approaches, including non-steroidal anti-inflammatory drugs (NSAIDs), physical therapy, analgesics, or surgical intervention (12). However, all patients in this study were treated with non-surgical approaches.

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of Sichuan University (No. 201712160121). Written informed consent was obtained from the guardians of all pediatric patients.

Data collection

To compare KD patients with and without concomitant GS, we retrospectively collected baseline characteristics, clinical manifestations at admission, complications, prognosis, and laboratory data from medical records. Baseline data included age, sex, body mass index (BMI), and the number of days of fever before IVIG treatment. Clinical features at admission included rash, edema and erythema of the extremities, bilateral bulbar conjunctival injection, erythema of the oral and pharyngeal mucosa, and CL. Complications and clinical outcomes were evaluated based on the presence of coronary artery lesions (CALs), resistance to IVIG, and length of hospital stay. CAL was diagnosed via echocardiography and determined using the Z-score, calculated based on body surface area, and a Z-score greater than 2 was defined as the presence of CAL (15,16).

Laboratory examinations data included white blood cell (WBC) count, neutrophil percentage, hemoglobin (HGB), platelet (PLT) count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB), creatinine, urea nitrogen and serum sodium and potassium. All laboratory tests were performed upon admission and prior to IVIG administration.

Radiological data were obtained from cervical spine computed tomography (CT), including coronal, sagittal, and axial views (Figure 1). The lateral atlanto-dental interval (LADI) was measured on coronal images as the distance between the odontoid process and the lateral masses of the atlas on each side. Lateral atlanto-dental interval asymmetry (LADIA) was defined as the difference between the left and right LADI [LADIA = absolute value of (right LADI − left LADI)]. The anterior atlanto-dental interval (AADI), measured on sagittal images, was defined as the horizontal distance between the anterior arch of the atlas and the odontoid process. The thickness of the retropharyngeal space (RS) was measured on sagittal views as the distance from the odontoid process—at the level of the inferior margin of the atlas—to the posterior pharyngeal wall. The atlantoaxial rotational angle (ARA) was measured on axial views as the angle between the midline of the atlas and the midline of the odontoid process. The longest diameter of the largest lymph node reported in radiology was used to define the lymph node size.

Figure 1 Radiological measurements of cervical spine parameters. (A) The right and left LADIs (a, b) were measured on the coronal CT image of the cervical spine. (B) The AADI (c) and the RS (d) were measured on the sagittal CT image. (C) The ARA (e) was measured on the axial CT image of the cervical spine. AADI, anterior atlanto-dental interval; ARA, atlantoaxial rotation angle; CT, computed tomography; LADI, lateral atlanto-dental interval; RS, retropharyngeal space.

Statistical analyses

Statistical analyses were performed using SPSS (version 21.0). Continuous variables were compared using appropriate parametric or non-parametric tests, and categorical variables with the Chi-squared or Fisher’s exact test. Variables with significance in univariate analyses were entered into a multivariate logistic regression model. Correlations between radiological parameters and lymph node size were assessed using Pearson correlation. A two-tailed P<0.05 was considered statistically significant.

Results

A total of 2,137 KD patients were included, comprising 1,214 males and 923 females. Of the 2,137 patients, 46 (2.15%) developed GS, while the remaining were classified as the non-GS group.

Univariate analysis (Table 1) showed that the GS group was significantly older than the non-GS group (6.97±1.96 vs. 2.29±2.00 years, P<0.001). CL was present in 80.4% of GS patients versus 47.0% of non-GS patients (37/46 vs. 983/2,091, P<0.001).

As summarized in Table 2, patients with GS had higher neutrophil percentage (75.36%±5.31% vs. 66.23%±15.63%, P<0.001), ESR (88.40±17.95 vs. 63.03±26.96 mm/h, P=0.047), creatinine (32.61±6.43 vs. 27.21±9.29 µmol/L, P=0.003), and urea nitrogen (3.65±1.63 vs. 3.11±1.59 µmol/L, P=0.022).

Multivariate logistic regression (Table 3) identified age, ESR, and creatinine as significant predictors of GS, with age showing the highest odds ratio (OR; OR =4.806). To account for the potential confounding effect of age, an additional regression model excluding this variable was constructed (Table 4). In this model, female sex, CL, and neutrophil percentage remained significant predictors.

The methods for diagnose AADI was 2.57±0.85 mm. Based on this mean value, patients were stratified into high- and low-AADI subgroups (22 vs. 24 cases, Table 5). The high-AADI subgroup had significantly larger lymph nodes (3.04±1.01 vs. 2.24±0.75 cm, P=0.004) and more frequent cervical traction use (8/22 vs. 2/24, P=0.022).

Although laboratory parameters did not differ between subgroups (Table 6), radiological analysis showed greater LADIA (2.96±1.46 vs. 1.97±1.01 mm, P=0.010) and RS thickness (10.99±3.02 vs. 8.50±2.10 mm, P=0.002) in the high-AADI group.

Pearson correlation analysis (Table 7) demonstrated significant positive correlations between AADI and lymph node size (r=0.492, P<0.05), AADI and RS (r=0.375, P<0.05), as well as between lymph node size and RS (r=0.504, P<0.05). This quantifies the relationship between local anatomical changes and atlantoaxial instability in GS.

Discussion

GS was first described in 1830 by Charles Bell, who, during an autopsy of a patient who died from acute spinal cord compression due to syphilitic pharyngeal ulcers, discovered erosion and ulceration of the atlantoaxial transverse ligament (17). In 1930, French physician Pierre Grisel further characterized the clinical manifestations, pathophysiology, and radiographic features of the condition in two case reports, which subsequently led to its eponym (8,18). Current evidence suggests that inflammation secondary to head and neck infections or surgical procedures is the primary trigger for GS. In recent years, KD has also been recognized as a potential cause of AARF and should therefore be considered a risk factor for GS (13,19-21). However, KD does not fall into these categories, as it is a non-infectious systemic inflammatory condition. KD is a common systemic inflammatory condition in children that may involve the cervical region and is often associated with CL, making the development of GS in KD patients theoretically plausible (6). However, published reports remain limited, consisting primarily of isolated case studies, with few investigations based on larger clinical cohorts (22-25). To our knowledge, large-sample, systematic evaluations of the clinical and imaging features of KD with GS are still scarce, and our study adds further evidence.

In this study, 46 cases of GS were identified, corresponding to an incidence rate of 2.15%, which is higher than the 0.6% reported in our previous investigation (26) and also greater than the rates reported by Michihata et al. (24) (0.23%), Oshita et al. (27) (1.08%). We speculate the higher incidence is due to increased clinical awareness. After our initial report identifying GS as a KD complication, clinicians became more proactive in obtaining cervical imaging for KD patients with suspicious symptoms, thereby raising the detection rate. This also indicates that cervical imaging should be given greater consideration for KD patients with neck symptoms to avoid missed GS diagnoses.

Clinically, this complication appears to affect older children with KD, with a mean age of 6.96±1.81 years. In addition, female patients appear to be at higher risk. Oshita et al. (27) conducted a retrospective analysis of insurance claims data to examine the incidence of AARF in children and adolescents. They reported a peak incidence around the age of 6 years, which is consistent with our findings. We further speculate that the current diagnostic approach in KD may influence the detection rate of GS. Older children are more likely to report neck pain or restricted mobility, and their caregivers may be more attentive to limitations in neck movement caused by the disease. Considering the potential risks associated with radiological imaging in children (28,29) and the difficulties in acquiring satisfactory images due to their limited cooperation (30), pediatricians typically do not include cervical imaging in the routine evaluation of KD unless neck-related symptoms are explicitly reported. This may partly explain the higher detection rate of GS in older children.

In contrast to our findings, Oshita et al. (27) reported in 2024 that observed a higher incidence of AARF in males. However, this cohort included patients without KD, which may account for the discrepancy from the present study. In a subsequent 2025 study, Oshita et al. (31) focusing specifically on KD-associated AARF found that female KD patients had a higher probability of developing AARF. Moreover, Michihata et al. (24), using a national database, observed a higher incidence of AARF in female KD patients. Furthermore, a case series by Nozaki et al. (23) involving nine patients reported that seven were female. Collectively, these findings are consistent with our results, suggesting that female KD patients may indeed be at greater risk of developing GS. Nevertheless, the existing evidence is largely derived from regionally confined cohorts. Future large-scale, multi-center studies with long-term follow-up will be necessary to validate these observations. Moreover, investigating the underlying molecular and biological mechanisms contributing to the higher prevalence of GS among female patients may provide deeper insights into the pathogenesis of this condition.

The GS and non-GS groups also demonstrated differences in laboratory findings. In this study, the neutrophil percentage was significantly higher in the GS group. Although WBC count was also higher in the GS group, the difference did not reach statistical significance. Jun et al. (6) reported that patients with cervical masses tend to have elevated WBC and neutrophil counts and are at higher risk of coronary artery dilation, suggesting that the presence of a CL may be indicative of more severe clinical presentation. However, our findings showed no significant increase in the incidence of CAL or IVIG resistance among patients with GS, suggesting that GS may be less strongly associated with the overall level of systemic inflammation and may have a limited relationship with the severity of vasculitis. Serum creatinine is a widely used marker for evaluating renal function. As creatinine is a product of muscle metabolism, its levels vary by age and sex. Previous studies have shown that serum creatinine levels increase with age (32). Similarly, urea nitrogen levels also change with age, and the ratio of urea nitrogen to creatinine significantly decreases as age increases (32,33), which is consistent with the findings of our study.

The methods for diagnosing AARF have been extensively described in previous studies. However, discussions regarding the gold standard for diagnosing AARF are still ongoing (34,35). Among the proposed measures, the AADI has received increasing attention in recent years and has been demonstrated to be effective in the diagnosis of AARF (36,37). In this study, AADI was used to stratify patients within the GS group. Bertozzi et al. (38) reported that the normal range of AADI in children should be less than 2.6 mm, which is very close to the cutoff value (2.57 mm) we used to distinguish between the high- and low-AADI groups in our study. Those in the high-AADI group had a higher incidence of CL, larger lymph nodes, and a greater need for cervical traction. These findings suggest a potential association between subluxation severity and the extent of cervical lymph node enlargement in KD patients with GS. Further analysis revealed no significant differences in laboratory parameters between the high- and low-AADI groups, suggesting that subluxation severity may not be closely related to systemic inflammatory activity. In contrast, radiological parameters such as LADIA and RS were significantly higher in the high-AADI group. Pearson correlation analysis demonstrated that AADI was positively correlated with both lymph node size and RS. These findings support the hypothesis that GS development in KD may be primarily driven by mechanical compression from enlarged cervical lymph nodes and thickened retropharyngeal tissues, rather than by systemic inflammation.

In summary, GS is an uncommon complication of KD, and its incidence may be underestimated. Although all patients in this study responded effectively to conservative treatment without experiencing severe complications, it is important to consider that children may develop irreversible severe atlantoaxial joint deformities, requiring complex surgical intervention. Therefore, in any febrile child with CL (after excluding common infections), clinicians should promptly consider KD and administer IVIG without delay. This may help prevent the development of GS. At the same time, the current diagnostic process may have limitations. As mentioned earlier, the diagnosis of GS relies on radiological examination, and whether imaging is conducted often depends on the patient’s or caregiver’s reported symptoms of the children, potentially leading to missed diagnoses. Our study indicates that, in addition to age, female sex, CL, high neutrophil percentage, and elevated ESR are risk factors for the development of GS. We also propose a new hypothesis regarding the pathogenesis of GS: soft tissue swelling plays a central role in mechanically displacing the atlantoaxial joint. Enlarged lymph nodes, together with adjacent edematous soft tissues, may exert combined mechanical pressure leading to AARF. Current guidelines and related studies have suggested that CL may be associated with deep cervical inflammation, leading to manifestations such as parapharyngeal and retropharyngeal edema (1,39). However, its potential link to the subsequent development of GS has not been clearly established, and standardized diagnostic and therapeutic protocols remain lacking (40). Therefore, we recommend that in cases presenting with CL, early imaging evaluation should be considered. Once the risk of GS is identified, conservative management can be initiated as a first-line approach, with close monitoring of symptom progression during the disease course and timely escalation to further treatment if necessary.

In addition, several emerging considerations warrant attention. Pediatricians may consider exploring new methods for assessing neck symptoms in children. The Modified Japanese Orthopaedic Association (mJOA) score and the Neck Disability Index (NDI) are commonly used in the field of spinal surgery to evaluate cervical spine disorders and neck function (41,42). A study by Sergeenko et al. (43) demonstrated that the mJOA is a reliable and effective tool for assessing cervical spine diseases in pediatric patients. Therefore, pediatricians could explore and validate the applicability and effectiveness of these adult-focused assessment and diagnostic tools in the pediatric population in future studies.

This study has several constraints. First, as a single-center study with participants limited to a specific region, there may be potential bias. Therefore, larger multi-center studies are needed to reduce such bias and improve generalizability. Second, most cases of GS in KD are acute and transient, and cervical spine imaging is not routinely performed during KD evaluation. As a result, the true incidence of GS may be underestimated due to missed or delayed diagnoses. More importantly, given the rarity of GS in KD, long-term follow-up data—particularly regarding post-discharge functional outcomes—were not systematically collected. Therefore, the mid- and long-term prognosis of affected patients remains unclear. Despite these shortcomings, this study represents the first large-scale investigation of GS in KD and offers valuable insights that may inform future clinical practice and research.

Conclusions

GS is a relatively rare complication in patients with KD, with an incidence of 2.15% in this cohort. Our findings suggest that GS predominantly affects older children and is associated with female sex, CL, elevated neutrophil percentage, and increased ESR. The development of GS does not appear to increase the risk of CAL or IVIG resistance, indicating only a limited association with systemic inflammatory response. Instead, it may be more closely related to mechanical compression of the atlantoaxial joint caused by CL and thickening of the RS. Given the risk of missed diagnoses due to the lack of routine imaging, pediatricians should maintain a high index of suspicion for GS in KD patients presenting with neck symptoms. Early recognition and timely radiological evaluation are essential to ensure accurate diagnosis and prevent potential complications.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1762/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1762/dss

Funding: This study was supported financially by grants from Natural Science Foundation of Sichuan Province (No. 2024YFFK0272) and Key Research and Development Project of Chengdu Science and Technology Bureau (No. 2024-YF05-00237-SN).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1762/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of Sichuan University (No. 201712160121). Written informed consent was obtained from the guardians of all pediatric patients.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. McCrindle BW, Rowley AH, Newburger JW, Burns JC, Bolger AF, Gewitz M, Baker AL, Jackson MA, Takahashi M, Shah PB, Kobayashi T, Wu MH, Saji TT, Pahl EAmerican Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young. Council on Cardiovascular and Stroke Nursing; Council on Cardiovascular Surgery and Anesthesia; Council on Epidemiology and Prevention. Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association. Circulation 2017;135:e927-99. [Crossref] [PubMed]
2. Burgner D, Festa M, Isaacs D. Delayed diagnosis of Kawasaki disease presenting with massive lymphadenopathy and airway obstruction. BMJ 1996;312:1471-2. [Crossref] [PubMed]
3. Yoskovitch A, Tewfik TL, Duffy CM, Moroz B. Head and neck manifestations of Kawasaki disease. Int J Pediatr Otorhinolaryngol 2000;52:123-9. [Crossref] [PubMed]
4. Spinnato P, Zarantonello P, Guerri S, Barakat M, Carpenzano M, Vara G, Bartoloni A, Gasbarrini A, Molinari M, Tedesco G. Atlantoaxial rotatory subluxation/fixation and Grisel's syndrome in children: clinical and radiological prognostic factors. Eur J Pediatr 2021;180:441-7. [Crossref] [PubMed]
5. White MD, Hansberry DR, Prabhu AV, Agarwal N, Kandula V. Grisel’s syndrome: A rare cause of torticollis with subluxation of the atlantoaxial joint secondary to a retropharyngeal abscess. Interdisciplinary Neurosurgery 2020;22:100872.
6. Jun WY, Ann YK, Kim JY, Son JS, Kim SJ, Yang HS, Bae SH, Chung S, Kim KS. Kawasaki Disease with Fever and Cervical Lymphadenopathy as the Sole Initial Presentation. Korean Circ J 2017;47:107-14. [Crossref] [PubMed]
7. Karkos PD, Benton J, Leong SC, Mushi E, Sivaji N, Assimakopoulos DA. Grisel's syndrome in otolaryngology: a systematic review. Int J Pediatr Otorhinolaryngol 2007;71:1823-7. [Crossref] [PubMed]
8. Osiro S, Tiwari KJ, Matusz P, Gielecki J, Tubbs RS, Loukas M. Grisel’s syndrome: a comprehensive review with focus on pathogenesis, natural history, and current treatment options. Childs Nerv Syst 2012;28:821-5. [Crossref] [PubMed]
9. Anania P, Pavone P, Pacetti M, Truffelli M, Pavanello M, Ravegnani M, Consales A, Cama A, Piatelli G. Grisel Syndrome in Pediatric Age: A Single-Center Italian Experience and Review of the Literature. World Neurosurg 2019;125:374-82. [Crossref] [PubMed]
10. Pini N, Ceccoli M, Bergonzini P, Iughetti L. Grisel's Syndrome in Children: Two Case Reports and Systematic Review of the Literature. Case Rep Pediatr 2020;2020:8819758. [Crossref] [PubMed]
11. Newburger JW, Takahashi M, Gerber MA, Gewitz MH, Tani LY, Burns JC, Shulman ST, Bolger AF, Ferrieri P, Baltimore RS, Wilson WR, Baddour LM, Levison ME, Pallasch TJ, Falace DA, Taubert KACommittee on Rheumatic Fever, Endocarditis and Kawasaki Disease. Council on Cardiovascular Disease in the Young; American Heart Association; American Academy of Pediatrics. Diagnosis, treatment, and long-term management of Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association. Circulation 2004;110:2747-71. [Crossref] [PubMed]
12. Al-Hussain OH, Al-Hussain G. Diagnostic Approach and Treatment Options for Pediatric Cases of Grisel's Syndrome Post Otolaryngology Procedure: A Systematic Review. Cureus 2024;16:e51739. [Crossref] [PubMed]
13. Deichmueller CM, Welkoborsky HJ. Grisel's syndrome--a rare complication following "small" operations and infections in the ENT region. Eur Arch Otorhinolaryngol 2010;267:1467-73. [Crossref] [PubMed]
14. Harth M, Mayer M, Marzi I, Vogl TJ. Lateral torticollis on plain radiographs and MRI: Grisel syndrome. Eur Radiol 2004;14:1713-5. [Crossref] [PubMed]
15. Kobayashi T, Fuse S, Sakamoto N, Mikami M, Ogawa S, Hamaoka K, Arakaki Y, Nakamura T, Nagasawa H, Kato T, Jibiki T, Iwashima S, Yamakawa M, Ohkubo T, Shimoyama S, Aso K, Sato S, Saji T. Z Score Project Investigators. A New Z Score Curve of the Coronary Arterial Internal Diameter Using the Lambda-Mu-Sigma Method in a Pediatric Population. J Am Soc Echocardiogr 2016;29:794-801.e29. [Crossref] [PubMed]
16. Olivieri L, Arling B, Friberg M, Sable C. Coronary artery Z score regression equations and calculators derived from a large heterogeneous population of children undergoing echocardiography. J Am Soc Echocardiogr 2009;22:159-64. [Crossref] [PubMed]
17. Golzari SE, Ghabili K, Sajadi MM, Aslanabadi S. Early descriptions of Grisel's syndrome. Childs Nerv Syst 2013;29:359-60. [Crossref] [PubMed]
18. Battiata AP, Pazos G. Grisel's syndrome: the two-hit hypothesis--a case report and literature review. Ear Nose Throat J 2004;83:553-5.
19. Shen Y, Yang L, Liu X, Xie Y, Dai X, Wang C. Grisel’s syndrome associated with mumps: A case report. Front Pediatr 2022;10:916538. [Crossref] [PubMed]
20. Falsaperla R, Piattelli G, Marino S, Marino SD, Fontana A, Pavone P. Grisel's syndrome caused by Mycoplasma pneumoniae infection: a case report and review of the literature. Childs Nerv Syst 2019;35:523-7. [Crossref] [PubMed]
21. Welinder NR, Hoffmann P, Håkansson S. Pathogenesis of non-traumatic atlanto-axial subluxation (Grisel's syndrome). Eur Arch Otorhinolaryngol 1997;254:251-4. [Crossref] [PubMed]
22. Luo HH, Fan GZ, Wu YF, Hu P. Grisel syndrome and peripheral arthritis simultaneously occurred in a 7-year-old Chinese boy with Kawasaki disease. Arch Med Sci 2022;18:816-9. [Crossref] [PubMed]
23. Nozaki F, Kusunoki T, Tomoda Y, Hiejima I, Hayashi A, Kumada T, Miyajima T, Futami T, Fujii T. Grisel syndrome as a complication of Kawasaki disease: a case report and review of the literature. Eur J Pediatr 2013;172:119-21. [Crossref] [PubMed]
24. Michihata N, Suzuki T, Honda A, Oka I, Yoshikawa T, Saito K, Matsui H, Fushimi K, Yasunaga H. Clinical Features of Kawasaki Disease With Atlantoaxial Rotatory Fixation. Pediatr Infect Dis J 2022;41:626-30. [Crossref] [PubMed]
25. Wood AJ, Singh-Grewal D, De S, Gunasekera H. Kawasaki disease complicated by subluxation of cervical vertebrae (Grisel syndrome). Med J Aust 2013;199:494-6. [Crossref] [PubMed]
26. Liu X, Zhou K, Hua Y, Wu M, Liu L, Shao S, Wang C. Grisel's syndrome in Kawasaki disease. Orphanet J Rare Dis 2020;15:246. [Crossref] [PubMed]
27. Oshita Y, Takata K, Someya R, Uchikura T, Momo K. Retrospective analysis of atlantoaxial rotatory fixation describing age distribution and gender ratio in children and adolescents: A preliminary report. J Orthop Sci 2024;29:486-8. [Crossref] [PubMed]
28. Hall EJ. Lessons we have learned from our children: cancer risks from diagnostic radiology. Pediatr Radiol 2002;32:700-6. [Crossref] [PubMed]
29. Mulvihill DJ, Jhawar S, Kostis JB, Goyal S. Diagnostic Medical Imaging in Pediatric Patients and Subsequent Cancer Risk. Acad Radiol 2017;24:1456-62. [Crossref] [PubMed]
30. Cahoon GD, Davison TE. Prediction of compliance with MRI procedures among children of ages 3 years to 12 years. Pediatr Radiol 2014;44:1302-9. [Crossref] [PubMed]
31. Oshita Y, Okano I, Watanabe Y, Emori H, Ito R, Shirahata T, Hoshino Y, Kanzaki K, Toyone T, Ikeda H, Kudo Y. Clinical features of atlantoaxial rotatory fixation among children with Kawasaki disease. J Pediatr Orthop B 2026;35:23-7. [Crossref] [PubMed]
32. Rahbar M, Mardanpour K, Mardanpour N. Blood Urea Nitrogen, Serum Creatinine and Blood Urea Nitrogen to Creatinine Ratio Reference Values in Iranian Children. Journal of Clinical and Basic Research 2021;5:14-21.
33. Suwanrungroj S, Pattarapanitchai P, Chomean S, Kaset C. Establishing age and gender-specific serum creatinine reference ranges for Thai pediatric population. PLoS One 2024;19:e0300369. [Crossref] [PubMed]
34. Mahr D, Freigang V, Bhayana H, Kerschbaum M, Frankewycz B, Loibl M, Nerlich M, Baumann F. Comprehensive treatment algorithm for atlanto-axial rotatory fixation (AARF) in children. Eur J Trauma Emerg Surg 2021;47:713-8. [Crossref] [PubMed]
35. Landi A, Pietrantonio A, Marotta N, Mancarella C, Delfini R. Atlantoaxial rotatory dislocation (AARD) in pediatric age: MRI study on conservative treatment with Philadelphia collar--experience of nine consecutive cases. Eur Spine J 2012;21:S94-9. [Crossref] [PubMed]
36. Siempis T, Tsakiris C, Anastasia Z, Alexiou GA, Voulgaris S, Argyropoulou MI. Radiological assessment and surgical management of cervical spine involvement in patients with rheumatoid arthritis. Rheumatol Int 2023;43:195-208. [Crossref] [PubMed]
37. Lee EJ, Kim YJ, Song SO, Lee S, Ryu J, Choi N. Comparison of the diagnostic performance of the Swischuk line method and the anterior atlantodental interval method in atlantodental subluxation. BMC Med Imaging 2024;24:8. [Crossref] [PubMed]
38. Bertozzi JC, Rojas CA, Martinez CR. Evaluation of the pediatric craniocervical junction on MDCT. AJR Am J Roentgenol 2009;192:26-31. [Crossref] [PubMed]
39. Kasem Ali Sliman R, van Montfrans JM, Nassrallah N, Hamad Saied M. Retropharyngeal abscess-like as an atypical presentation of Kawasaki disease: a case report and literature review. Pediatr Rheumatol Online J 2023;21:34. [Crossref] [PubMed]
40. Hashimoto K, Nishimura S, Shinyashiki Y, Goto K. Grisel's Syndrome After COVID-19 in a Pediatric Patient: A Case Report. Cureus 2024;16:e62028. [Crossref] [PubMed]
41. Ghadami F, Amani Hamedani M, Rouhi G, Saber-Samandari S, Mehdi Dehghan M, Farzad-Mohajeri S, Mashhadi-Abbas F. The correlation between osseointegration and bonding strength at the bone-implant interface: In-vivo & ex-vivo investigations on hydroxyapatite and hydroxyapatite/titanium coatings. Journal of Biomechanics 2022;144:111310. [Crossref] [PubMed]
42. Kato S, Oshima Y, Oka H, Chikuda H, Takeshita Y, Miyoshi K, Kawamura N, Masuda K, Kunogi J, Okazaki R, Azuma S, Hara N, Tanaka S, Takeshita K. Comparison of the Japanese Orthopaedic Association (JOA) score and modified JOA (mJOA) score for the assessment of cervical myelopathy: a multicenter observational study. PLoS One 2015;10:e0123022. [Crossref] [PubMed]
43. Sergeenko OM, Savin DM, Evsyukov AV, Burtsev AV. Reliability and validity of the pediatric adaptation of the mJOA scale for evaluating cervical spine disorders. Spine Deform 2024;12:1595-606. [Crossref] [PubMed]