Occurrence and predictive factors of heterotopic ossification in severe acquired brain injured patients during rehabilitation stay: cross-sectional survey

Heterotopic ossification following COVID-19 infections: systematic literature review of case reports and case series

BACKGROUND

This review aims to study the clinical characteristics, diagnostic results, treatments, and outcomes in patients with heterotopic ossification following COVID-19 infection.

METHODS

A literature search for eligible articles was conducted using MEDLINE/Pubmed, Global Health, and Scopus databases (January 12th, 2023), including all case reports and case series from any country and language. The criteria for inclusion in this review were cases of COVID-19 infection subsequently developing heterotopic ossification.

RESULTS

This systematic review analysed 15 reports (n = 20 patients) documenting cases of heterotopic ossification following COVID-19 infection. 80% of the patients were male, with a median age of 59 years. All patients required intensive care unit stay with an average duration of 48.5 days. Mechanical ventilation was necessary for all patients and 30% of them underwent tracheostomy. Common symptoms included stiffness and pain, most frequently affecting multiple locations (70%), with the hips and shoulders being predominantly involved. X-rays were the most commonly used imaging modality, followed by computed tomography. Although treatment was given, some of the patients continued to experience symptoms, particularly stiffness.

CONCLUSION

20 patients who developed heterotopic ossification after COVID-19 have been reported, the majority of which had at least two independent risk factors for this condition. The link between those two clinical entities is therefore uncertain, requiring further investigation. It is nonetheless important to suspect heterotopic ossification in patients with severe COVID-19 infection, prolonged immobilisation, mechanical ventilation, who develop joint pain and stiffness, as this condition can significantly impact patients' quality of life.

PROTOCOL REGISTRATION

CRD42023393516.

Sex as a Critical Variable in Basic and Pre-Clinical Studies of Fibrodysplasia Ossificans Progressiva

Heterotopic ossification (HO) is most dramatically manifested in the rare and severely debilitating disease, fibrodysplasia ossificans progressiva (FOP), in which heterotopic bone progressively accumulates in skeletal muscles and associated soft tissues. The great majority of FOP cases are caused by a single amino acid substitution in the type 1 bone morphogenetic protein (BMP) receptor ACVR1, a mutation that imparts responsiveness to activin A. Although it is well-established that biological sex is a critical variable in a range of physiological and disease processes, the impact of sex on HO in animal models of FOP has not been explored. We show that female FOP mice exhibit both significantly greater and more variable HO responses after muscle injury. Additionally, the incidence of spontaneous HO was significantly greater in female mice. This sex dimorphism is not dependent on gonadally derived sex hormones, and reciprocal cell transplantations indicate that apparent differences in osteogenic activity are intrinsic to the sex of the transplanted cells. By circumventing the absolute requirement for activin A using an agonist of mutant ACVR1, we show that the female-specific response to muscle injury or BMP2 implantation is dependent on activin A. These data identify sex as a critical variable in basic and pre-clinical studies of FOP.

Medical comorbidities in patients with prolonged disorder of consciousness: A narrative review

BACKGROUND

A few studies specifically addressed medical comorbidities (MCs) in patients with severe acquired traumatic or non-traumatic brain injury and prolonged disorders of consciousness (pDoC; i.e., patients in vegetative state/unresponsive wakefulness syndrome, VS/UWS, or in minimally conscious state, MCS).

OBJECTIVE

To provide an overview on incidence of MCs in patients with pDoC.

METHODS

Narrative review on most impacting MCs in patients with pDoC, both those directly related to brain damage (epilepsy, neurosurgical complications, spasticity, paroxysmal sympathetic hyperactivity, PSH), and those related to severe disability and prolonged immobility (respiratory comorbidities, endocrine disorders, metabolic abnormalities, heterotopic ossifications).

RESULTS

Patients with pDoC are at high risk to develop at least one MC. Moderate or severe respiratory and musculoskeletal comorbidities are the most common MCs. Epilepsy and PSH seem to be more frequent in patients in VS/UWS compared to patients in MCS, likely because of higher severity in the brain damage in VS. Endocrine metabolic, PSH and respiratory complications are less frequent in traumatic etiology, whereas neurogenic heterotopic ossifications are more frequent in traumatic etiology. Spasticity did not significantly differ between VS/UWS and MCS and in the three etiologies. MCs are associated with higher mortality rates, worse clinical improvement and can impact accuracy in the clinical diagnosis.

CONCLUSIONS

The frequent occurrence of several MCs requires a specialized rehabilitative setting with high level of multidisciplinary medical expertise to prevent, appropriately recognize and treat them. Comprehensive rehabilitation could avoid possible progression to more serious complications that can negatively impact clinical outcomes.

Neuro-orthopaedic assessment and management in patients with prolonged disorders of consciousness: A review

BACKGROUND

Following a severe acquired brain injury, neuro-orthopaedic disorders are commonplace. While these disorders can impact patients' functional recovery and quality of life, little is known regarding the assessment, management and treatment of neuro-orthopaedic disorders in patients with disorders of consciousness (DoC).

OBJECTIVE

To describe neuro-orthopaedic disorders in the context of DoC and provide insights on their management and treatment.

METHODS

A review of the literature was conducted focusing on neuro-orthopaedic disorders in patients with prolonged DoC.

RESULTS

Few studies have investigated the prevalence of spastic paresis in patients with prolonged DoC, which is extremely high, as well as its correlation with pain. Pilot studies exploring the effects of pharmacological treatments and physical therapy show encouraging results yet have limited efficacy. Other neuro-orthopaedic disorders, such as heterotopic ossification, are still poorly investigated.

CONCLUSION

The literature of neuro-orthopaedic disorders in patients with prolonged DoC remains scarce, mainly focusing on spastic paresis. We recommend treating neuro-orthopaedic disorders in their early phases to prevent complications such as pain and improve patients' recovery. Additionally, this approach could enhance patients' ability to behaviourally demonstrate signs of consciousness, especially in the context of covert awareness.

Rehabilitation Care of the Child with an Acute Severe Traumatic Brain Injury

Children with traumatic brain injury (TBI) represent a unique and evolving population. Recovery and long-term prognosis are variable given the heterogeneity of ages, developmental stages, and types of injuries. This article summarizes important information regarding severe TBI epidemiology, pathophysiology, classification, and acute management. Early and longitudinal involvement of rehabilitation experts, such as pediatric physiatrists, is critical in managing complications and optimizing outcomes.

Role of Kinesiotherapy in the Prevention of Heterotopic Ossification: A Systematic Review

OBJECTIVE

The role of kinesiotherapy in heterotopic ossification remains unclear. The goal of this study was to revisit the literature on the preventive role of kinesiotherapy against heterotopic ossification formation and maturation.

DESIGN

A systematic review was performed in MEDLINE, OVID, Scopus, and Cochrane databases.

RESULTS

A high-quality clinical trial is missing from the literature. Of 9617 studies primarily identified, nine studies offered the proper data and were included. They infer that satisfactory results on neurogenic heterotopic ossification prevention were achieved with passive exercises, including continuous passive motion, that were initiated early and at a painless range of motion. On the contrary, for elbow posttraumatic heterotopic ossification and major joints burn-associated heterotopic ossification, active range of motion is indicated as early as possible.

CONCLUSIONS

Because of the very low quality of the studies included in this review, firm conclusions cannot be drawn about the effectiveness of kinesiotherapy. Nevertheless, it is recommended that controlled passive range of motion exercises (especially continuous passive motion) be applied early and pain-free especially in the neurogenic heterotopic ossification patients while active range of motion in painless limits is beneficial in the heterotopic ossification prevention of traumatic elbows or burn joints.

Paroxysmal Sympathetic Hyperactivity After Acquired Brain Injury: An Integrative Literature Review

BACKGROUND

Paroxysmal sympathetic hyperactivity may occur in patients with acute brain injury and is associated with physical disability, poor clinical outcomes, prolonged hospitalization, and higher health care costs.

OBJECTIVE

To comprehensively review current literature and provide information about paroxysmal sympathetic hyperactivity for nurses.

METHODS

An integrative literature review was conducted according to Whittemore and Knafl's method. The search was conducted from October 2020 through January 2021. The main targets of the literature search were definition, incidence rate, causes, clinical characteristics, pathophysiology, diagnosis, and treatment of paroxysmal sympathetic hyperactivity in pediatric and adult patients. The results were reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

The most characteristic clinical features of paroxysmal sympathetic hyperactivity are hypertension, tachycardia, tachypnea, hyperthermia, diaphoresis, and abnormal motor posturing. Reported incidence rates of paroxysmal sympathetic hyperactivity in patients with brain injury range from 8% to 33%. Various diagnostic criteria have been proposed; most are based on clinical symptoms. Ruling out other causes of the signs and symptoms of paroxysmal sympathetic hyperactivity is important because the signs and symptoms are nonspecific. The major goals of paroxysmal sympathetic hyperactivity management are avoidance of stimuli that may trigger a paroxysmal episode, inhibition of sympathetic overactivity, and prevention of damage to other organs.

CONCLUSIONS

Critical care nurses should be aware of the signs and symptoms of paroxysmal sympathetic hyperactivity in patients with acute brain injury. Early identification is important to ensure timely treatment for patients with paroxysmal sympathetic hyperactivity.

Predicting outcome of patients with prolonged disorders of consciousness using machine learning models based on medical complexity

Patients with severe acquired brain injury and prolonged disorders of consciousness (pDoC) are characterized by high clinical complexity and high risk to develop medical complications. The present multi-center longitudinal study aimed at investigating the impact of medical complications on the prediction of clinical outcome by means of machine learning models. Patients with pDoC were consecutively enrolled at admission in 23 intensive neurorehabilitation units (IRU) and followed-up at 6 months from onset via the Glasgow Outcome Scale-Extended (GOSE). Demographic and clinical data at study entry and medical complications developed within 3 months from admission were collected. Machine learning models were developed, targeting neurological outcomes at 6 months from brain injury using data collected at admission. Then, after concatenating predictions of such models to the medical complications collected within 3 months, a cascade model was developed. One hundred seventy six patients with pDoC (M: 123, median age 60.2 years) were included in the analysis. At admission, the best performing solution (k-Nearest Neighbors regression, KNN) resulted in a median validation error of 0.59 points [IQR 0.14] and a classification accuracy of dichotomized GOS-E of 88.6%. Coherently, at 3 months, the best model resulted in a median validation error of 0.49 points [IQR 0.11] and a classification accuracy of 92.6%. Interpreting the admission KNN showed how the negative effect of older age is strengthened when patients' communication levels are high and ameliorated when no communication is present. The model trained at 3 months showed appropriate adaptation of the admission prediction according to the severity of the developed medical complexity in the first 3 months. In this work, we developed and cross-validated an interpretable decision support tool capable of distinguishing patients which will reach sufficient independence levels at 6 months (GOS-E > 4). Furthermore, we provide an updated prediction at 3 months, keeping in consideration the rehabilitative path and the risen medical complexity.

Redefining a minimal rehabilitation assessment protocol for severe acquired brain injuries

BACKGROUND

The assessment of patients with severe Acquired Brain Injury (sABI) is mandatory in every phase and setting of care, and requires a multidimensional and interdisciplinary approach, to develop the individual rehabilitation project, and monitor long-term functional outcomes. In 2001 the Italian Society of Physical and Rehabilitation Medicine (SIMFER) published the minimal assessment protocol for traumatic sABI, providing a comprehensive, standardized functional assessment based on the International Classification of Functioning, Disability and Health (ICF), 2001. In 2007, a new protocol was published, extended to all sABI patients (PMGCA). In 2019, the SIMFER appointed a working group to provide a revised, updated version: the PMGCA2020.

AIM

The purpose of this study was to describe the minimal assessment protocol to be applied at every stage and setting of the care process of patients with sABI.

METHODS

The working group, including one neurologist and 11 physiatrists experts in sABI rehabilitation, performed a review of the international recommendations for sABI assessment focusing on the following key words: "sABI assessment," "sABI rehabilitation," "sABI prognostic factors," "sABI rehabilitation assessment," "sABI outcome," in MEDLINE. Revision and integration proposals by each member were written and motivated, discussed and voted.

RESULTS

The PMGCA2020 is addressed to sABI adult patients. It investigates the main clinical problems of sABI at any time of the rehabilitation pathway. It includes a demographic/anamnestic section, a clinical/functional assessment section and an outcome measures section following the ICF model of functioning and the model of the construction of the rehabilitation project.

CONCLUSIONS

The PMGCA2020 provides an updated tool for the multidimensional rehabilitation assessment of sABI patients, at any stage of the rehabilitation pathway. Further studies will allow the validation of this minimum set of variables paving the way to an assessment standardization of patients with sABI in the rehabilitation settings.

CLINICAL REHABILITATION IMPACT

This minimum set of variables, defining patient's functioning and clinical status and outcomes, at every stage and setting of the care process to provide a framework for the standardization of the clinical evaluation of patients with sABI in rehabilitation settings.

The Impact of Continuous Passive Motion on Heterotopic Ossification Maturation

ABSTRACT

Heterotopic ossification is the formation of pathological bone in soft tissues. It is postulated that continuous passive motion is a helpful adjuvant in the halt of the heterotopic ossification progression and the maintenance or increase of the joint mobility. The purpose of this clinical case study is to present the effectiveness of continuous passive motion. A 46-yr-old male patient experiencing right hemiparesis arrived in our rehabilitation department with limitation on passive flexion of the right hip. On x-ray of the pelvis, immature heterotopic bone formation was found. To halt this ongoing process of heterotopic bone formation, a program of continuous passive motion was implemented. In addition, risedronate was administrated. We started the continuous passive motion at 50 degrees of flexion for 30 mins that was increased to 100 degrees for 3 hrs daily. The final range of motion at the hip was: flexion 85 degrees, extension 0 degrees, internal rotation 10 degrees, external rotation 10 degrees, abduction 10 degrees, and adduction 10 degrees. Based on our results, continuous passive motion plays a role in heterotopic ossification maturation. The effectiveness of continuous passive motion implementation against HO should be further investigated for selected cases.

Neurogenic heterotopic ossification in the upper limb

Neurogenic heterotopic ossifications (NHOs) are periarticular ectopic ossifications that frequently develop after a central nervous system injury, most often a traumatic one. They limit range of motion and cause pain, interfering with limb positioning and function, whether active or passive. Highly described in the lower limbs, NHOs can also develop in the upper limb, with specific characteristics depending on their location. This article provides a summary of the diagnostic and therapeutic management of NHOs in the upper limb, based on the current literature.

Quercetin Attenuates Trauma-Induced Heterotopic Ossification by Tuning Immune Cell Infiltration and Related Inflammatory Insult

Heterotopic ossification (HO) is one of the most intractable disorders following musculoskeletal injury and is characterized by the ectopic presence of bone tissue in the soft tissue leading to severe loss of function in the extremities. Recent studies have indicated that immune cell infiltration and inflammation are involved in aberrant bone formation. In this study, we found increased monocyte/macrophage and mast cell accumulation during early HO progression. Macrophage depletion by clodronate liposomes and mast cell stabilization by cromolyn sodium significantly impeded HO formation. Therefore, we proposed that the dietary phytochemical quercetin could also suppress immune cell recruitment and related inflammatory responses to prevent HO. As expected, quercetin inhibited the monocyte-to-macrophage transition, macrophage polarization, and mast cell activation in vitro in a dose-dependent manner. Using a murine burn/tenotomy model, we also demonstrated that quercetin attenuated inflammatory responses and HO in vivo. Furthermore, elevated SIRT1 and decreased acetylated NFκB p65 expression were responsible for the mechanism of quercetin, and the beneficial effects of quercetin were reversed by the SIRT1 antagonist EX527 and mimicked by the SIRT agonist SRT1720. The findings in this study suggest that targeting monocyte/macrophage and mast cell activities may represent an attractive approach for therapeutic intervention of HO and that quercetin may serve as a promising therapeutic candidate for the treatment of trauma-induced HO by modulating SIRT1/NFκB signaling.

Multi-center observational study on occurrence and related clinical factors of neurogenic heterotopic ossification in patients with disorders of consciousness

Aims: to assess occurrence and clinical correlates of neurogenic heterotopic ossifications (NHO) in patients with prolonged disorder of consciousness (DoC).Design: multi-center cross-sectional observational study.Setting: 23 intensive neurorehabilitation units.Subjects: 287 patients with prolonged disorder of consciousness (DoC; 150 in vegetative state, VS, and 128 in minimally conscious state, MCS) of different etiology (vascular = 125, traumatic = 83, anoxic = 56, others = 14).Main Measures: clinical evidence of NHO confirmed by standard radiological and/or sonographic evaluation; Coma Recovery Scale-Revised; Disability Rating Scale (DRS); Early Rehabilitation Barthel Index; presence of ventilator support, spasticity, bone fractures and paroxysmal sympathetic hyperactivity.Results: 31 patients (11.2%) presented NHO. Univariate analyses showed that NHO was associated with VS diagnosis, traumatic etiology, high DRS category and total score, and high occurrence of limb spasticity and bone fractures. A cluster-corrected binary logistic regression model (excluding spasticity available in a subset of patients) showed that only lower DRS total score and presence of bone fractures were independently associated with NHO.Conclusions: NHO are relatively frequent in patients with DoC, and are independently associated with functional disability, bone fractures and spasticity. These findings contribute to identifying patients with DoC prone to develop NHO and requiring special interventions to improve functional recovery.

The tracheotomy tube weaning in patients with severe acquired brain injury: comparison of two operative procedures in a postacute rehabilitation hospital

BACKGROUND

Despite the high frequency of tracheotomy in severe acquired brain injury (sABI) patients, available literature about the weaning procedure is mainly represented by expert opinions with no standardized and evidence-based criteria.

AIM

The Institute of Physical and Rehabilitation Medicine "Gervasutta" adopted a new decannulation procedure, recommended by the Italian Society of Physical Medicine and Rehabilitation (SIMFER). This study evaluates whether the new procedure helps to improve the decannulation process of sABI patients.

DESIGN

A prospective observational with historical control was performed by dividing sABI patients into two groups depending on whether they were treated with or without the new procedure.

SETTING

The Department of Neurorehabilitation of the Institute of Physical and Rehabilitation Medicine "Gervasutta" in Udine, Italy.

POPULATION

sABI patients with tracheal cannula admitted to the Institute of Physical and Rehabilitation Medicine "Gervasutta" from January 2015 to March 2019.

METHODS

Clinical data were collected as both process and outcome indicators before and after the adoption of the new procedure. Data have been processed with Simple Interactive Statistical Analysis (SISA; Irving, TX, USA) software.

RESULTS

A sample of 141 patients was analysed. Among the 141 patients, 57 (40.4%) were treated with the new procedure. No differences were found between the two groups in terms of complications, functional independence measure (FIM), or level of cognitive functioning (LCF) at the admission. When the new procedure was applied, the decannulation rate was significantly higher (OR=1.8; 95% CI=1.2-9.8; P=0.01) and the time (days) between admission and oral feeding resumption was significantly lower (P<0.001; 95% CI=-10, -34 days).

CONCLUSIONS

The introduction of the new protocol allowed the safe achievement of both oral feeding resumption and decannulation, which are two of the main early rehabilitation goals.

CLINICAL REHABILITATION IMPACT

The standardization of the decannulation process has determined the achievement of a significantly faster oral feeding resumption and an increase in the decannulation rate during the rehabilitation of sABI patients.

Early diagnosis of heterotopic ossification among patients admitted to a neurological Post-Intensive Care Rehabilitation Unit

BACKGROUND

Heterotopic ossification (HO) is defined as the formation of endochondral bone within soft tissue. Non-genetic forms, mainly corresponding to a consequence of bone, brain or spinal cord injury, are the most common. HO leads to important functional limitations and alteration of quality of life. To our knowledge, the time between brain, bone, or spinal cord injury and clinical suspicion of HO has never been studied. By admitting patients with severe neurological disorders, we hypothesized that the prevalence of HO in neurological post-intensive care rehabilitation units (PICRU) might be significant as these patients have recognized risk factors for HO.

AIM

This study aimed to investigate HO among patients admitted to a neurological PICRU with two objectives: 1) to describe the prevalence of HO in PICRU; 2) to assess the time between neurological disorder, clinical suspicion of HO and radiological diagnosis.

DESIGN

A monocentric retrospective cohort study.

SETTING

PICRU in our public university teaching hospital. This inpatient referral department is specifically dedicated to the early discharge from Intensive Care Units (ICU) of patients with severe neurological impairment who need rehabilitation.

POPULATION

We study all patients admitted between April 2016 and January 2019. One hundred twenty-five subjects were admitted for a rehabilitation program after neuro-trauma or stroke. We included all first-time stays in PICRU lasting 7 days or longer.

METHODS

Retrospective data extraction using administrative data from an electronic patient management program was done to select eligible subjects. Included subjects were then identified by a retrospective review of electronic inpatient medical records after patient discharge. Data of interest were collected from these same medical records.

RESULTS

Forty-four HO were diagnosed in 24 subjects (24/125; 19%), with a median number of 2 [1; 2] HO per subject. Neurological trauma was the main reason for admission to ICU (89/125; 71%) and half of patients had a traumatic brain injury (TBI) (67/125; 54%). The diagnosis of HO was made in PICRU in 75% of cases. Clinical suspicion of HO (autonomic dysfunction, local inflammatory signs, pain, or reduced joint range of motion) was made 6 [5; 7] weeks after admission to ICU. Radiological confirmation of clinical suspicion or fortuitous diagnosis by imaging (50% of the cases) occurred 8 [7; 12] weeks after admission to ICU. The median time of clinical suspicion or radiological diagnosis was 1 week after admission to PICRU.

CONCLUSIONS

HO is a sub-acute complication which develops in patients admitted to ICU for severe central nervous system disorders as clinical suspicion or radiological confirmation of diagnosis was made within the first week after admission in neurological PICRU (i.e. 6 to 8 weeks after ICU admission).

CLINICAL REHABILITATION IMPACT

As treatment for HO may at least partially improves rehabilitation and quality of life, we recommend a systematic screening in PICRU patients for HO by clinical examination supplemented by imaging in case of suspicion.

Multi-center study on overall clinical complexity of patients with prolonged disorders of consciousness of different etiologies

Aim: to assess overall clinical complexity of patients with acquired disorders of consciousness (DoC) in vegetative state/unresponsive wakefulness syndrome (VS/UWS) vs. minimally conscious state- MCS) and in different etiologies..Design: Multi-center cross-sectional observational study.Setting: 23 intensive neurorehabilitation units.Subjects: 264 patients with DoC in the post-acute phase: VS/UWS = 141, and MCS = 123 due to vascular (n = 125), traumatic (n = 83) or anoxic (n = 56) brain injury.Main Measures: Coma Recovery Scale-Revised, and Disability Rating Scale (DRS); presence of medical devices (e.g., for eating or breathing); occurrence and severity of medical complications.Results: patients in DoC, and particularly those in VS/UWS, showed severe overall clinical complexity. Anoxic patients had higher overall clinical complexity, lower level of responsiveness/consciousness, higher functional disability, and higher needs of medical devices. Vascular patients had worse premorbid clinical comorbidities. The two etiologies showed a comparable rate of MC, higher than that observed in traumatic etiology.Conclusion: overall clinical complexity is significantly higher in VS/UWS than in MCS, and in non-traumatic vs. traumatic etiology. These findings could explain the worse clinical evolution reported in anoxic and vascular etiologies and in VS/UWS patients and contribute to plan patient-tailored care and rehabilitation programmes.

Genetic and Acquired Heterotopic Ossification: A Translational Tale of Mice and Men

Heterotopic ossification is defined as an aberrant formation of bone in extraskeletal soft tissue, for which both genetic and acquired conditions are known. This pathologic process may occur in many different sites such as the skin, subcutaneous tissue, skeletal muscle and fibrous tissue adjacent to joints, ligaments, walls of blood vessels, mesentery and other. The clinical spectrum of this disorder is wide: lesions may range from small foci of ossification to massive deposits of bone throughout the body, typical of the progressive genetically determined conditions such as fibrodysplasia ossificans progressiva, to mention one of the most severe and disabling forms. The ectopic bone formation may be regarded as a failed tissue repair process in response to a variety of triggers and evolving towards bone formation through a multistage differentiation program, with several steps common to different clinical presentations and distinctive features. In this review, we aim at providing a comprehensive view of the genetic and acquired heterotopic ossification disorders by detailing the clinical and molecular features underlying the different human conditions in comparison with the corresponding, currently available mouse models.

When the Nervous System Turns Skeletal Muscles into Bones: How to Solve the Conundrum of Neurogenic Heterotopic Ossification

PURPOSE OF REVIEW

Neurogenic heterotopic ossification (NHO) is the abnormal formation of extra-skeletal bones in periarticular muscles after damage to the central nervous system (CNS) such as spinal cord injury (SCI), traumatic brain injury (TBI), stroke, or cerebral anoxia. The purpose of this review is to summarize recent developments in the understanding of NHO pathophysiology and pathogenesis. Recent animal models of NHO and recent findings investigating the communication between CNS injury, tissue inflammation, and upcoming NHO therapeutics are discussed.

RECENT FINDINGS

Animal models of NHO following TBI or SCI have shown that NHO requires the combined effects of a severe CNS injury and soft tissue damage, in particular muscular inflammation and the infiltration of macrophages into damaged muscles plays a key role. In the context of a CNS injury, the inflammatory response to soft tissue damage is exaggerated and persistent with excessive signaling via substance P-, oncostatin M-, and TGF-β1-mediated pathways. This review provides an overview of the known animal models and mechanisms of NHO and current therapeutic interventions for NHO patients. While some of the inflammatory mechanisms leading to NHO are common with other forms of traumatic and genetic heterotopic ossifications (HO), NHOs uniquely involve systemic changes in response to CNS injury. Future research into these CNS-mediated mechanisms is likely to reveal new targetable pathways to prevent NHO development in patients.

Heterotopic ossification in a patient with paroxysmal sympathetic hyperactivity following multiple trauma complicated with vitamin D deficiency: a case report

Background

Paroxysmal sympathetic hyperactivity (PSH) may occur in patients with traumatic brain injury. Heterotopic ossification (HO) has frequently been observed in patients with PSH and has been found to impair patients’ recoveries. However, the pathophysiology of HO in patients with PSH remains unelucidated. Vitamin D deficiency is a common abnormality among critically ill patients and may be associated not only with musculoskeletal complications, but also with high morbidity and mortality. The association between vitamin D deficiency and HO in patients with PSH has not yet been evaluated.

Case presentation

A 21-year-old man was in a motorcycle accident. The initial diagnosis was diffused axonal injury, thoracic aortic injury, bilateral lung contusion with hemopneumothorax, liver injury, vertebral injury of T5, along with fractures of the right humerus, left patella, bilateral scapula, and a stable pelvic fracture, with an Injury Severity Score of 50. Two weeks after admission, he was diagnosed with PSH. One month after the injury, decreased joint mobility and progressive pain were evident. Computed tomography (CT) showed HO in his humerus, ulna, radius, scapula, ilium, pubis, ischium, knee joint, patella, and tibia, as well as renal calculus. To evaluate metabolic bone abnormalities, we measured levels of 25-OH vitamin D, parathyroid hormone, calcitonin, procollagen type I N-terminal propeptide (a marker of bone formation), and tartrate-resistant acid phosphatase 5b (a marker of bone resorption). This revealed a vitamin D deficiency. Bisphosphonate agents and vitamin D were administered for 1 month. Thereafter, his symptoms, radiographic findings, and laboratory abnormalities improved, and he was transferred to another facility.

Conclusions

HO in patients with PSH, following severe head injury, may be associated with vitamin D deficiency. Medication for vitamin-D-related metabolism abnormalities may represent a novel intervention for HO with PSH.

Do Medical Complications Impact Long-Term Outcomes in Prolonged Disorders of Consciousness?

OBJECTIVE

To investigate medical complications (MCs) occurring within 6 months postinjury in brain-injured patients with prolonged disorders of consciousness (DoC) and to evaluate impact of MC on mortality and long-term clinical outcomes.

DESIGN

Prospective observational cohort study.

SETTING

Rehabilitation unit for acquired DoC.

PARTICIPANTS

Patients (N=194) with DoC (142 in vegetative state [VS], 52 in minimally conscious state; traumatic etiology 43, anoxic 69, vascular 82) consecutively admitted to a neurorehabilitation unit within 1-3 months postonset.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Mortality and improvements in clinical diagnosis and functional disability level (assessed by Coma Recovery Scale-Revised [CRS-R] and Disability Rating Scale) at 12, 24, and 36 months postonset.

RESULTS

Within 6 months postinjury, 188 of 194 patients (>95%) developed at least 1 MC and 142 of them (73%) showed at least 1 severe MC. Respiratory and musculoskeletal-cutaneous MCs were the most frequent, followed by endocrino-metabolic abnormalities. Follow-up, complete in 189 of 194 patients, showed that male sex and endocrine-metabolic MCs were associated with higher risk of mortality at all timepoints. Old age, anoxic etiology, lower CRS-R total scores, and diagnosis of VS at study entry predicted no clinical and functional improvements at most timepoints; however, epilepsy predicted no improvement in diagnosis at 24 months postonset only.

CONCLUSIONS

MCs are very frequent in patients with DoC within at least 6 months after brain injury, regardless of clinical diagnosis, etiology, and age. Endocrino-metabolic MCs are independent predictors of mortality at all timepoints; however,epilepsy predicted poor long-term outcome. Occurrence and severity of MCs in patients with DoC call for long-term appropriate levels of care after the postacute phase.

Identification of novel genes in aging osteoblasts using next-generation sequencing and bioinformatics

During the aging process, impaired osteoblastic function is one key factor of imbalanced bone formation and age-related bone loss. The aim of this study is to explore the differentially expressed genes in normal and aged osteoblasts and to identify genes potentially involved in age-related alteration in bone physiology. Based on next generation sequencing and bioinformatics analysis, 12 differentially expressed microRNAs and 22 differentially expressed genes were identified. Up-regulation of miR-204-5p was validated in an array of osteoporotic hip fracture in the Gene Expression Omnibus database (GSE74209). The putative targets for miR-204-5p were Kruppel-like factor 7 (KLF7) and SRY-box 11 (SOX11). Ingenuity Pathway Analysis identified SOX11, involved in osteoarthritis pathway and differentiation of osteoblasts, together with miR-204-5p, a potential upstream regulator, suggesting the critical role of miR-204-5p-SOX11 regulation in the aging process of human bones. In addition, as semaphorin 3A (SEMA3A) and ephrin type-A receptor 5 (EPHA5) were involved in nervous system related biological functions, we postulated a potential linkage between SEMA3A, EPHA5 and development of neurogenic heterotopic ossification. Our findings implicate new candidate genes in the diagnosis of geriatric musculoskeletal disorders, and provide novel insights that may contribute to the elaboration of new biomarkers for neurogenic heterotopic ossification.