Fibrosis, adipogenesis, and muscle atrophy in congenital muscular torticollis

Muscle texture features on preoperative MRI for diagnosis and assessment of severity of congenital muscular torticollis

OBJECTIVES

To develop an objective method based on texture analysis on MRI for diagnosis of congenital muscular torticollis (CMT).

MATERIAL AND METHODS

The T1- and T2-weighted imaging, Q-dixon, and T1-mapping MRI data of 38 children with CMT were retrospectively analyzed. The region of interest (ROI) was manually drawn at the level of the largest cross-sectional area of the SCM on the affected side. MaZda software was used to obtain the texture features of the T2WI sequences of the ROI in healthy and affected SCM. A radiomics diagnostic model based on muscle texture features was constructed using logistic regression analysis. Fatty infiltration grade was calculated by hematoxylin and eosin staining, and fibrosis ratio by Masson staining. Correlation between the MRI parameters and pathological indicators was analyzed.

RESULTS

There was positive correlation between fatty infiltration grade and mean value, standard deviation, and maximum value of the Q-dixon sequence of the affected SCM (correlation coefficients, 0.65, 0.59, and 0.58, respectively, P < 0.05).Three muscle texture features-S(2,2)SumAverg, S(3,3)SumVarnc, and T2WI extreme difference-were selected to construct the diagnostic model. The model showed significant diagnostic value for CMT (P < 0.05). The area under the curve of the multivariate conditional logistic regression model was 0.828 (95% confidence interval 0.735-0.922); the sensitivity was 0.684 and the specificity 0.868.

CONCLUSION

The radiomics diagnostic model constructed using T2WI muscle texture features and MRI signal values appears to have good diagnostic efficiency. Q-dixon sequence can reflect the fatty infiltration grade of CMT.

Clinical Results after Release of Sternocleidomastoid Muscle Surgery for Neglected Congenital Muscular Torticollis-Unipolar vs. Bipolar Release Surgery

BACKGROUND

Although the surgical release of the sternocleidomastoid muscle (SCM) is required for residual congenital muscular torticollis (CMT), the surgical outcomes between bipolar and unipolar SCM release remained unclear. The purpose of the present study was to assess surgical outcomes after bipolar and unipolar release of SCM in adolescent/adult patients with neglected CMT.

METHODS

Twenty-one consecutive adolescent/adult patients with neglected CMT who underwent surgical treatment were enrolled. Clinical and radiographic outcomes were evaluated at preoperative and final follow-up.

RESULTS

The bipolar release of SCM was performed in 3 patients (B group; males, n = 1, females, n = 2) and the unipolar release of SCM in 18 patients (U group; males, n = 6, females, n = 12). The mean age at surgery was 40.0 ± 17.0 years in Group B, and that was 32.3 ± 13.1 years in Group U (p = 0.47). The mean follow-up period was 16.0 ± 5.7 months in Group B and 10.4 ± 7.6 months in Group U (p = 0.22). Cervicomandibular angle correction rates were comparable at 75.4 ± 2.4% for the B group and 73.1 ± 11.7% for the U group (p = 0.62). There was no significant difference in clinical outcome according to the modified Cheng and Tang score between the two groups (p = 0.89). No major complications arose, although one patient exhibited a transient neurological deficit of the greater auricular nerve, and one patient developed a hematoma in the B group.

CONCLUSIONS

The unipolar SCM release appeared to be a non-inferiority and less invasive procedure, minimizing surgical scars and avoiding potential auricular nerve damage in adolescent/adult patients with neglected CMT.

Experience with the management of 2599 cases of congenital muscular torticollis and a multicenter epidemiological investigation in 17 hospitals in China

BACKGROUND

Congenital muscular torticollis (CMT) is a common musculoskeletal disease affecting infants and young children. If CMT is not treated correctly and timely, it can lead to limited head and neck movements, head and neck deviation, and abnormal posture. In order to improve patients' symptoms and alleviate the negative impact of the disease on their lives, we are committed to exploring the treatment of CMT.

METHODS

The general clinical and ultrasonographic data of 2599 children with CMT who received standardized treatment at Shenzhen Children's Hospital from 2004 to 2020 were retrospectively reviewed. According to given treatment, children with CMT were divided into the physiotherapy group, physiotherapy combined with glucocorticoid treatment group, and surgical treatment group. We divided children with CMT into local mass, uniform thickening, and atrophy according to ultrasound features. General clinical information, treatment, and ultrasound examination data in each group were compared. Additionally, electronic medical records of 2344 patients admitted due to CMT in 17 tertiary children's hospitals of China's Futang Research Center of Pediatric Development (FRCPD) from 2015 to 2019 were retrospectively analyzed. Data on sex, age, year of admission and discharge, and treatment costs during hospitalization were extracted from the first medical record pages according to the ICD codes. The data were assessed for normality using the Kolmogorov-Smirnov test. Depending on the data distribution, they were analyzed using parametric tests, such as the t-test, or non-parametric tests. Qualitative data are expressed as percentages (%) and analyzed using the chi-square or Fisher's exact probability test, with α = 0.05 as the test level. P < 0.05 was considered to be indicative of a statistically significant difference.

RESULTS

Three types of CMT were defined based on sternocleidomastoid muscle ultrasound examination characteristics: local mass, uniform thickening, and atrophy. Age at first diagnosis was 69.21 ± 108.41 days in local mass type group, 216.85 ± 324.09 days in uniform thickening group, and 417.88 ± 739.05 days in atrophy- type group; while age at first physiotherapy use was 94.06 ± 206.49 days, 255.00 ± 430.62 days, 540.92 ± 1059.29 respectively. The children included in local mass type group have shown a high success rate of conservative treatment, with a rate of 7.5% of children underwent surgery. Age at first diagnosis was 112.44 ± 224.12 days in the physiotherapy group, 115.87 ± 144.86 days in the physiotherapy combined with glucocorticoid treatment subgroup, whereas the age at first physiotherapy use was 137.38 ± 312.11 and 196.91 ± 344.26 days respectively. In the observation period (2015-2019) the mean age at surgery for CMT in 17 tertiary children's hospitals of the FRCPD was 50 months. Overall, 663 children with CMT were 1-2 years of age, accounting for the largest proportion (28.3%). Followed by 417 individuals (17.8%) were 7-14 years of age, indicating that there are still more children with CMT receiving surgical treatment later.

CONCLUSIONS

Early diagnosis and treatment are essential to improve the conservative treatment success rate and achieve good prognosis in children with CMT. Our team's concept for treating CMT is as follows: after diagnosing the children, we will adopt the standardized protocol of treatment, with physiotherapy combined with the injection of glucocorticoid drugs and SCM release surgery, when needed. This program has a high conservative treatment success rate and may facilitate the achievement of better prognosis and reduced teratogenicity rate.

Efficacy of Intensive Inpatient Therapy in Infants with Congenital Muscular Torticollis Involving the Entire Sternocleidomastoid Muscle

The efficacy and frequency of physiotherapy in the prognosis of congenital muscular torticollis (CMT) that involves the entire sternocleidomastoid (SCM) muscle continues to be unclear. This study investigated the therapeutic effect of intensive inpatient therapy given to infants with CMT that involves the whole SCM using clinical measurements and ultrasound (US). This study included 54 infants (27 boys and 27 girls; mean corrected age of 18.57 days) evaluated for CMT at our outpatient clinic from January 2014 to May 2021. The included patients were divided into three groups (groups 1, 2, and 3). Patients in group 1 underwent outpatient treatment 12 times. Patients in groups 2 and 3 underwent therapeutic exercise followed by US diathermy with microcurrent twice daily for 1 or 2 weeks, respectively. Passive range of motion of the cervical rotation (PCRROM) and SCM thickness were evaluated pre- and post-treatment. Among the three groups, the demographic data at baseline were not significantly different, SCM thickness and PCRROM were significantly decreased/increased at post-treatment compared to pre-treatment (p < 0.05), mean PCRROM change was significantly greater in group 3 (p < 0.05), and mean SCM thickness reduction between pre-treatment and 3 months post-treatment was significantly greater in groups 2 and 3 (p < 0.05). Therefore, intensive inpatient therapeutic exercise and US diathermy with microcurrent may enhance the prognosis of CMT involving the entire SCM muscle.

The tilts, twists, and turns of torticollis

PURPOSE OF REVIEW

The purpose of this review is to outline the most recent understanding of torticollis in the pediatric population.

RECENT FINDINGS

It is important to diagnose the underlying condition of torticollis early in childhood, as some conditions that cause torticollis may result in major developmental delays in early motor milestones. Recent studies have highlighted that many of the rarer causes of torticollis are often misdiagnosed as congenital muscular torticollis, suggesting that physicians should pay close attention to the results of clinical and radiographic examinations when patients present with torticollis.

SUMMARY

Congenital muscular torticollis is the most common cause of torticollis. Other, less common causes of torticollis include vertebral abnormalities, ocular torticollis, gastrointestinal disorders, soft tissue infections of the neck, posterior fossa tumors, and benign paroxysmal torticollis. Although rare, these differential diagnoses should be considered during a clinical work-up for a patient who presents with torticollis.

Neurodevelopmental outcomes and comorbidities of children with congenital muscular torticollis: evaluation using the National Health Screening Program for Infants and Children database

BACKGROUND

Congenital muscular torticollis (CMT) is a common musculoskeletal disorder occurring at birth or in infancy.

PURPOSE

This study aimed to investigate the risk of comorbidities in CMT and explore the differences in neurodevelopmental outcomes between children who received physical therapy and those who did not.

METHODS

Children with CMT born in 2008 and 2009 in Korea were included. CMT was defined as a primary diagnosis of congenital deformity of sternocleidomastoid muscle according to the International Classification of Diseases 10th revision. Here we investigated the associated neurological/musculoskeletal comorbidities of children with CMT versus those of the general population. We divided those with torticollis into treatment and nontreatment groups and assessed their developmental outcomes within both groups of children using the Korean-Ages and Stages Questionnaire (K-ASQ).

RESULTS

Of the 917,707 children, 0.2% (n=1,719) were diagnosed with CMT. In children with torticollis, the prevalence of congenital hip deformities significantly increased to 4.5% (n=78). The prevalence of congenital head/spine deformities and other congenital malformations of the skull and facial bones increased to 2.6% (n=44), while the prevalence of congenital foot deformities was 2.4% (n=42). The risk ratio (RR) for delayed development based on the K-ASQ was higher for the total assessment (adjusted RR=0.97; 95% confidence interval, 0.93-0.99) in the CMT patients without physical therapy than in those with therapy. There was no significant intergroup difference in the assessment of each developmental area.

CONCLUSION

The prevalence of comorbid musculoskeletal deformities was higher in children with CMT than in the control group. The risk of developmental delay was higher in children who did not receive physical therapy than in those who did.

Myofiber stretch induces tensile and shear deformation of muscle stem cells in their native niche

Muscle stem cells (MuSCs) are requisite for skeletal muscle regeneration and homeostasis. Proper functioning of MuSCs, including activation, proliferation, and fate decision, is determined by an orchestrated series of events and communication between MuSCs and their niche. A multitude of biochemical stimuli are known to regulate MuSC fate and function. However, in addition to biochemical factors, it is conceivable that MuSCs are subjected to mechanical forces during muscle stretch-shortening cycles because of myofascial connections between MuSCs and myofibers. MuSCs respond to mechanical forces in vitro, but it remains to be proven whether physical forces are also exerted on MuSCs in their native niche and whether they contribute to the functioning and fate of MuSCs. MuSC deformation in their native niche resulting from mechanical loading of ex vivo myofiber bundles was visualized utilizing mT/mG double-fluorescent Cre-reporter mouse and multiphoton microscopy. MuSCs were subjected to 1 h pulsating fluid shear stress (PFSS) with a peak shear stress rate of 6.5 Pa/s. After PFSS treatment, nitric oxide, messenger RNA (mRNA) expression levels of genes involved in regulation of MuSC proliferation and differentiation, ERK 1/2, p38, and AKT activation were determined. Ex vivo stretching of extensor digitorum longus and soleus myofiber bundles caused compression as well as tensile and shear deformation of MuSCs in their niche. MuSCs responded to PFSS in vitro with increased nitric oxide production and an upward trend in iNOS mRNA levels. PFSS enhanced gene expression of c-Fos, Cdk4, and IL-6, whereas expression of Wnt1, MyoD, Myog, Wnt5a, COX2, Rspo1, Vangl2, Wnt10b, and MGF remained unchanged. ERK 1/2 and p38 MAPK signaling were also upregulated after PFSS treatment. We conclude that MuSCs in their native niche are subjected to force-induced deformations due to myofiber stretch-shortening. Moreover, MuSCs are mechanoresponsive, as evidenced by PFSS-mediated expression of factors by MuSCs known to promote proliferation.

Advanced Simultaneous Isolation, Culture, and Identification of Myoblasts and Fibroblasts From Sternocleidomastoid Muscle of Congenital Muscular Torticollis

BACKGROUND

Congenital muscular torticollis (CMT) is a common pediatric disease caused by contracture of sternocleidomastoid muscle (SCM) that leads to neck stiffness and deformity. Based on the adhesion characteristics of different cells in affected SCM of CMT, myoblasts and fibroblasts can be isolated simultaneously by advanced culture conditions. Our study aimed to explore and optimize the isolation, culture, and identification of myoblasts and fibroblasts in SCM of CMT.

METHODS

Myoblasts and fibroblasts were separated by combined digestion with trypsin and collagenase. With this improved method, the morphology of isolated myoblasts and fibroblasts was observed under the microscope, the cell growth curve was drawn, and the purity of myoblasts and fibroblasts was determined by immunofluorescence.

RESULTS

The method allowed to satisfactorily culture myoblasts and fibroblasts. The cells could stably grow and be passaged, provided they were at least 80% confluent. Immunofluorescence of myoblasts and fibroblasts showed high rate of positive staining, and cell count showed excellent growth state. Moreover, according to the growth curve, fibroblasts grew at a higher rate than myoblasts.

CONCLUSIONS

The isolated myoblasts and fibroblasts have high purity, intact structure, and relatively high vitality. This method can be used to establish a cell model with myoblasts and fibroblasts, which can be applied to investigate etiology of CMT or mechanisms of drug action.

Two-Dimensional Ultrasound and Shear Wave Elastography in Infants With Late-Referral Congenital Muscular Torticollis

OBJECTIVES

To investigate the feasibility of using 2-dimensional ultrasound (US) and shear wave elastography (SWE) to evaluate infants with late-referral congenital muscular torticollis (CMT).

METHODS

A total of 46 infants with late-referral CMT were enrolled and divided into 4 groups according to the degree of the passive range of motion (PROM) deficit in neck rotation. We introduced 6 metrics to represent the US features of the sternocleidomastoid muscle detected by 2-dimensional US and SWE studies.

RESULTS

There were no significant differences in the age at referral, sex, weight, or side of involvement between the 4 groups (P > .05). The thickness and shear modulus of the involved sternocleidomastoid muscle were positively correlated with the degree of the PROM deficit in neck rotation in late-referral infants with CMT (r = 0.71 and 0.82, respectively; P < .01). However, the difference in the shear modulus between adjacent PROM-limited groups of late-referral infants was not as significant as that of early-referral infants.

CONCLUSIONS

The shear modulus ratio may be one of the best diagnostic indicators of CMT available. However, more effective differential diagnostic SWE indicators late-referral infants with CMT need to be further explored.

Congenital Muscular Torticollis: Bridging the Gap Between Research and Clinical Practice

Congenital muscular torticollis (CMT) is a common postural deformity evident shortly after birth, typically characterized by ipsilateral cervical lateral flexion and contralateral cervical rotation due to unilateral shortening of the sternocleidomastoid muscle. New evidence is emerging on the pathogenesis of CMT, the negative long-term consequences of delaying intervention, and the importance of early identification and early intervention to maximize outcomes. Our purpose in this article is to inform pediatricians and health care providers about new research evidence and share selected recommendations and implementation strategies specifically relevant to pediatric practice to optimize outcomes and health services for infants with CMT.

Frequency-Specific Microcurrent for Treatment of Longstanding Congenital Muscular Torticollis

PURPOSE

This case describes the first episode of care, using conservative treatment, massage, and frequency-specific microcurrent (FSM), for a 19-month-old boy with grade 8 left congenital muscular torticollis with fibrotic nodules.

METHODS

Ten weeks of physical therapy provided stretching, strengthening, massage, and parent education, adding FSM in weeks 3 to 10 for this patient.

RESULTS

Full passive cervical rotation and lateral flexion, 4/5 lateral cervical flexion strength, improved head tilt, and inability to palpate fibrotic nodules were achieved by week 8, with partial home program adherence.

CONCLUSIONS AND RECOMMENDATIONS FOR PRACTICE

Excellent outcomes were achieved with conservative care in a patient with poor prognosis and likelihood of surgical referral. Combining stretching, strengthening, massage, postural reeducation, and FSM resulted in full range and good strength in an exceptionally short time. The combination of massage and FSM, not previously reported, are tools that may be effective in congenital muscular torticollis treatment.

Unique finding in congenital muscular torticollis: Clinic screening on the neck of one day old neonate and ultrasonographic imaging from birth through 3 years of follow-up

Congenital muscular torticollis (CMT) is a common musculoskeletal abnormality in children, which has been characterized by unclarified pathological changes in the sternocleidomastoid muscle (SCM) and various hypothetical etiologies. There are 2 main hypothetical etiologies for CMT in the literature: 1 infers that CMT may represent the sequela of an intrauterine or perinatal compartment syndrome, and the other regard CMT as a maldevelopment of the fetal SCM.To better understand the etiopathogenesis of CMT, we screened the necks of 1-day-old newborns that may potentially have CMT for evidence of SCM trauma or tumor.A convenience sample of 2564 full-term (>37 weeks) Chinese neonates were included in this study. All neonates were screened for CMT by physical examination at birth. If CMT was suspected, further ultrasonic and physical examinations were performed. When CMT was confirmed, we provided appropriate interventions and follow-up. The progress and changes in patients with CMT were recorded.Following physical examination, 44 of 2564 neonates were diagnosed with suspected CMT based on obvious facial asymmetry or palpable swelling or mass in the SCM. Among these, ultrasound examination showed 81.8% (36/44) had asymmetry in the thickness of the bilateral SCM. The 36 neonates were followed-up for 6 months; among them, 1 infant developed CMT and 35 showed normal development in bilateral SCM. The 1 patient with CMT underwent regular physiotherapy and recovered with no evidence of recurrence after the final 3 years of follow-up. No neonates suffered from signs of neck trauma, such as hematoma or subcutaneous ecchymosis.There was no evidence of neck trauma in this 1 day old newborn. The pseudotumor of SCM that developed after birth underwent differentiation, maturation, and disappeared as the baby grew. The SCM asymmetry did exist in some of the newborn babies, and became symmetric with the baby's growth. Data from this clinical study and our previous ultra-structural pathological studies suggested that both prenatal and postnatal factors play important roles in CMT. We hypothesized that CMT might be a developmental disease.

Expression of Bax/Bcl-2, TGF-β1, and Type III Collagen Fiber in Congenital Muscular Torticollis

BACKGROUND This study investigated the expression of Bax/Bcl-2, TGF-β1 and type III collagen fiber in sternocleidomastoid of congenital muscular torticollis (CMT), and explored the possible mechanisms of fibrosis in sternocleidomastoid of CMT. MATERIAL AND METHODS The localization and expression of Bax, Bcl-2, TGF-β1, and type III collagen were detected in the control group and experimental group by using immunohistochemical staining method. The RT-PCR assay was used to measure the expression of TGF-β1 in the control group and experimental group. RESULTS HE staining results showed that the collagen fiber in the experimental group had more abundant hyperplasia compared to the control group (p<0.05). Immunohistochemical staining results showed that the expression of Bax, Bax/Bcl-2, TGF-β1, and type III collagen in the experimental group was significantly increased compared to the control group (p<0.01). There were positive correlations between expression of Bax/Bcl-2 and TGF-b1, and between expression of TGF-β1 and type III collagen fiber (p<0.05, r=0.32 and 0.83, respectively). The RT-PCR results showed that the expression of TGF-β1 mRNA was also significantly elevated in the experimental group compared to the control group (p<0.05). CONCLUSIONS Increased muscular apoptosis may aggravate the formation of muscular fibrosis, which may be involved in the pathogenesis of sternocleidomastoid of CMT.

Botulinum toxin type A relieves sternocleidomastoid muscle fibrosis in congenital muscular torticollis

Congenital muscular torticollis (CMT) is a neck deformity that involves shortening of sternocleidomastoid muscle (SCM) characterized by muscle atrophy and interstitial fibrosis. To investigate wheatear Botulinum toxin type A (BTA) has anti-fibrotic effects in CMT, we established acquired muscular torticollis that mimetics CMT in rabbit by intra-SCM injection of anhydrous alcohol. The treatment groups received BTA (2.5units or 5units) injection into the fibrotic SCM. The shortening and thickening of SCM were recorded by B-mode ultrasound. Changes in Col1A1, Fn, α-SMA expression were determined by immunohistochemistry. In vitro studies, TGF-β induced NIH3T3 fibroblasts were used to evaluate anti-fibrosis effect of BTA. Expression of the myofibroblast marker α-SMA and fibrosis markers Col1A1 and Fn were detected by Western blotting and quantitative RT-PCR. Our results showed that BTA injection attenuated shortening and thickening of fibrotic SCM. Elevated expression of Col1A1, Fn, α-SMA were confirmed in this fibrotic muscle model but reversed after BTA injection. Similar results observed in TGF-β induced NIH3T3 fibroblasts in both mRNA and protein levels. In conclusion, our results suggested that BTA could be a promising agent against SCM fibrosis in CMT through regulating fibroblast and inhibiting myofibroblast differentiation.

Shear wave sonoelastography in infants with congenital muscular torticollis

Congenital muscular torticollis (CMT) is characterized by shortening or excessive contraction of the sternocleidomastoid muscle (SCM). The main purpose of this study was to evaluate the feasibility of quantifying SCM stiffness using acoustic radiation force impulse (ARFI) sonoelastography in infants with CMT. Twenty infants with an SCM thickness greater than 10 mm with or without involvement of the entire SCM length (limitation of neck rotation passive range of motion [PROM]: group 1S >30°, group 1M = 15°-30°) and 12 infants with an SCM thickness smaller than 10 mm with or without involvement of any part of SCM (group 2) were included. The SCM thickness was measured using real time B-mode ultrasound, and the local SCM shear wave velocity (SWV) and subcutaneous fat layer using ARFI sonoelastography. The neck rotation PROM was significantly greater in group 1S (36.5° ± 5.3°) than in group 1M (18.8° ± 4.9°; P < .01); the SWV of the SCM in the affected side (2.96 ± 0.99 m/s) was significantly higher than that in the unaffected side (1.50 ± 0.30 m/s; P < .01) in group 1. The SWV of the SCM was significantly higher in group 1S than in group 1M. There was significant correlation between the degree of PROM deficit of neck rotation and the SWV of the affected SCM (r = .75; P < .01) in all infants. This study revealed a difference in the SWV of the affected SCM in relationship to the limitation of neck rotation PROM in infants with CMT, if there was no difference in SCM thickness among infants.

Buyang Huanwu Tang improves denervation-dependent muscle atrophy by increasing ANGPTL4, and increases NF-κB and MURF1 levels

Denervated-dependent skeletal muscle atrophy (DSMA) is a disorder caused by the peripheral neuro‑disconnection of skeletal muscle. The current study aimed to investigate the molecular mechanism and potential therapeutic strategies for the DSMA. A DSMA rat model was established. A lentiviral vector expressing small interfering RNA (siRNA) targeting angiopoietin‑like protein 4 (ANGPTL4) was generated and injected into the rats that were also treated with Buyang Huanwu Tang (BYHWT). Reverse transcription‑quantitative polymerase chain reaction was performed to examine ANGPTL4 mRNA expression in anterior cervical muscle samples. Western blot assay was used to evaluate ANGPTL4, nuclear factor‑κB (NF‑κB) and muscle RING‑finger protein‑1 (MURF1) expression. The ultrastructure of muscle tissues was viewed using transmission electron microscopy. The cell apoptosis in muscle tissues was detected using the terminal deoxynucleotidyl transferase dUTP nick end labeling. The results indicated that BYHWT treatment increased ANGPTL4 mRNA and protein levels in muscle tissues. The suppression of ANGPTL4 using siRNA significantly increased inflammatory cells compared with the control siRNA group. BYHWT protected the ultrastructure muscle tissues and inhibited cell apoptosis in the DSMA model. The protective effect of BYHWT protected may be mediated by increased expression of NF‑κB p65 and MURF1. In conclusion, BYHWT may improve denervation‑dependent muscle atrophy by increasing ANGPTL4 expression, involving NF‑κB and MURF1 signaling.