Cerebral Fat Embolism: Recognition, Complications, and Prognosis

Delivery of miRNAs Using Nanoparticles for the Treatment of Osteosarcoma

Osteosarcoma is the predominant primary malignant bone tumor that poses a significant global health challenge. MicroRNAs (miRNAs) that regulate gene expression are associated with osteosarcoma pathogenesis. Thus, miRNAs are potential therapeutic targets for osteosarcoma. Nanoparticles, widely used for targeted drug delivery, facilitate miRNA-based osteosarcoma treatment. Numerous studies have focused on miRNA delivery using nanoparticles to inhibit the progress of osteosarcoma. Polymer-based, lipid-based, inorganic-based nanoparticles and extracellular vesicles were used to deliver miRNAs for the treatment of osteosarcoma. They can be modified to enhance drug loading and delivery capabilities. Also, miRNA delivery was combined with traditional therapies, for example chemotherapy, to treat osteosarcoma. Consequently, miRNA delivery offers promising therapeutic avenues for osteosarcoma, providing renewed hope for patients. This review emphasizes the studies utilizing nanoparticles for miRNA delivery in osteosarcoma treatment, then introduced and summarized the nanoparticles in detail. And it also discusses the prospects for clinical applications.

Trends and associated outcomes of fat embolism after trauma surgery

BACKGROUND

Fat embolism is a life-threatening complication often occurring in patients with traumatic injuries. However, temporal trends and perioperative outcomes of fat embolism remain understudied. Using a nationally representative cohort, we aimed to characterize temporal trends of fat embolism and its associated resource utilization in operatively managed trauma patients.

METHODS

All patients (≥18 years) undergoing any major operations after traumatic injuries were tabulated using the 2005 to 2020 National Inpatient Sample. Patients were stratified into those with fat embolism and those without. Multivariable logistic and linear regressions were developed to assess the association between fat embolism and outcomes of interest.

RESULTS

Of an estimated 10,600,000 hospitalizations, 7,479 (0.07%) patients had fat embolism. Compared to the non-fat embolism cohort, the fat embolism cohort was younger (55 [26-79] vs 69 [49-82] years, standard mean difference = 0.46) and more likely to receive treatment at a high-volume trauma center (42.9 vs 33.7%, standard mean difference = 0.19). Over the study period, there was an increase in annual mortality and hospitalization costs among the fat embolism group (nptrend <0.001). After risk adjustment, fat embolism was associated with greater odds of mortality (adjusted odds ratio: 2.65, 95% confidence interval: 2.24-3.14) compared to others. Additionally, fat embolism was associated with increased odds of cerebrovascular, infectious, and renal complications.

CONCLUSION

Among all operatively managed trauma patients, those who developed fat embolism had increased mortality, rates of complications, length of stay, and costs. Optimization of early and accurate identification of fat embolism is warranted to mitigate complications and improve resource allocation among trauma patients.

Unusual Presentation of Cerebral Fat Embolism Syndrome Post-femur Fracture: A Case Study and Diagnostic Insights

Cerebral fat embolism syndrome (CFES) is a rare but certainly devastating impediment following long bone fractures. The diagnosis of CFES primarily depends on identifying clinical manifestations like respiratory distress, petechial rash, and neurological symptoms. However, in rare instances, CFES can manifest with atypical or absent clinical features, posing diagnostic challenges. Here, we present a rare case report of a woman in her 20s who developed CFES after suffering a femur shaft fracture devoid of conventional clinical features. The diagnosis of CFES was built upon clinical suspicion and a typical MRI brain finding of a starfield pattern. Our case highlights the importance of including CFES in the differential diagnosis of neurological deterioration, especially after long bone fractures. We suggest early plate osteosynthesis to stop more emboli from forming in people with FES, as well as continuous neuromonitoring and a reminder that CFES can show up without any other signs or symptoms in the body.

Fat embolism: the hidden murder for trauma patients!

INTRODUCTION

fat embolism syndrome (FES) is an acute respiratory disorder that occurs when an inflammatory response causes the embolization of fat and marrow particles into the bloodstream. The exact incidence of FES is not well defined due to the difficulty of diagnosis. FES is mostly associated with isolated long bone trauma, and it is usually misdiagnosed in other trauma cases. The scope of this study was to identify and search the current literature for cases of FES in nonorthopedic trauma patients with the aim of defining the etiology, incidence, and main clinical manifestations.

METHODS

we perform a literature search via the PubMed journal to find, summarize, and incorporate reports of fat embolisms in patients presenting with non-orthopedic trauma.

RESULTS

the final literature search yielded 23 papers of patients presenting with fat embolism/FES due to non-orthopedic trauma. The presentation and etiology of these fat embolisms is varied and complex, differing from patient to patient. In this review, we highlight the importance of maintaining a clinical suspicion of FES within the trauma and critical care community.

CONCLUSION

to help trauma surgeons and clinicians identify FES cases in trauma patients who do not present with long bone fracture, we also present the main clinical signs of FES as well as the possible treatment and prevention options.

Fat embolism syndrome in Duchenne muscular dystrophy: Report on a novel case and systematic literature review

We report a non-ambulatory 13-year-old boy with Duchenne muscular dystrophy who experienced severe acute respiratory distress syndrome and cerebral fat embolism following elective soft tissue surgery. Post-surgery radiological examination revealed bilateral femoral fractures and marked osteopenia that were believed to have caused disseminated pulmonary and cerebral fat embolism. The patient had never been on glucocorticoid treatment. Five months post-surgery, he remained in a state of minimal consciousness. A literature review was performed and eleven publications included, providing case reports of a total number of 23 patients with Duchenne muscular dystrophy with fat embolism syndrome. The most common causes were falls from the wheelchair that predominantly resulted in femoral fractures. Median age at the event was around 14 years. Seven patients succumbed to complications of fat embolism. No event was described in the context of surgery. We want to raise awareness that spontaneous unnoticed fractures may occur especially in adolescents with DMD from traumatic injury of large bones and also during elective surgery with a high risk of causing fat embolism with severe sequelae.

Do you know the diagnostic importance of susceptibility-weighted imaging on MRI for patients with cerebral fat embolism?

Key Clinical Message

If you suspect cerebral fat embolism (CFE) of the diagnosis for the patients who present with impaired consciousness and hypoxia following a fracture, susceptibility-weighted imaging should be included of head MRI imaging.

Abstract

We report a case of cerebral fat embolism (CFE) that could be identified only by susceptibility-weighted imaging (SWI). Collection and analysis of previous case reports of CFE revealed utilization of SWI in less than one third of suspected cases, despite its known diagnostic ability for CFE.

Prospective study examining the probability of cerebral fat embolism based on magnetic resonance imaging

Purpose

Cerebral fat embolism (CFE) is a rare syndrome caused by the embolization of fat particles into the brain circulation. This prospective single-center observational study investigated the incidence of CFE in long-bone or pelvic fractures based on magnetic resonance imaging (MRI) findings. The purpose of this study was to investigate the incidence of CFE by MRI findings with or without symptoms suggestive of CFE.

Methods

Eligible patients were consecutive, aged 15 years or older, with high-energy traumas, including pelvic or femur fractures. Excluded patients were those who died, could not undergo MRI resulting from medical conditions, or had insufficient mental capacity and no consultee to provide consent. The MRI was scheduled within 4 weeks of the injury, and the images were reviewed by one of the three neuroradiologists who were unaware of the patient's clinical information. Patient data regarding demographics, preceding trauma, injury severity score (ISS), presentation and examination timing of MRI, management including surgery, and outcome were collected.

Results

Sixty-two patients were recruited, and three patients were excluded. All patients were injured by blunt trauma. The median patient age was 44 years. The median ISS was 13, and 53 patients needed surgical fixation. There were 22 patients with long-bone fractures, all of whom received external fixation or intramedullary nailing on admission day. MRI was performed after a median hospital day of 18 days. Using MRI imaging, three (5.0%) patients were diagnosed with CFE, and three patients were suspected of CFE.

Conclusions

This is the first study to prospectively examine the probability of CFE based on MRI. Since fat embolism syndrome (FES) is confirmed in patients without clinical symptoms, CFE may be more common in patients with trauma than currently believed. Therefore, studies to determine the diagnostic criteria combined with symptoms, MRI, or other objective findings are required in the future.

Fat Embolism Syndrome Without Bone Fracture: Is It Possible?

BACKGROUND: Fat embolism syndrome is a life challenge syndrome. Early diagnosing and treatment can significantly improve the patient’s prognosis and likelihood of success. This syndrome occurs mainly after long bones fractures or orthopedic surgery up to 95% of diagnosed cases, but in unusual situation can be faced as well. These rare situations include diabetes mellitus, video-assisted thoracoscopies, fatty liver, and fat injection in plastic and cosmetic procedures. The likelihood of this syndrome can be increased if multiplex long bones fractures occur in the same patient simultaneously. This syndrome is usually manifested with respiratory changes (hypoxemia and ARDS), neurological focal symptoms (confusion, headache, aphasia, and hemiplegia), and skin abnormalities (petechias, and rush in conjunctiva and oral mucosa). The clinical scenario begins typically after 24−72 h of injury, and mainly, respiratory changes are the first, followed by neurological abnormalities and finally petechias as the most significant sign. CASE REPORT: In this case, we report a rare case of unexpected fat embolism syndrome after soft-tissue minimal trauma. This is the first case that we faced according to literature, and the aim of reporting this case is to emphasize that fat syndrome embolism can happen perhaps in every trauma patient even in minor soft-tissue trauma in absence of bone fractures. CONCLUSION: We strongly suggest that this case should make the physicians taking in consideration fat embolism syndrome even if bone fracture missed, to early diagnosing and adequately treating the patient, and optimizing his chances to survive.

Fat Embolism Syndrome and in-Hospital Mortality Rates According to Patient Age: A Large Nationwide Retrospective Study

Introduction

Fat embolism syndrome (FES) is a rare life-threatening condition that can develop after traumatic orthopedic injuries. Controversy remains concerning the epidemiology in the elderly population. Therefore, this study aims to report FES related to in-hospital mortality stratified by age.

Methods

A retrospective trauma cohort study was conducted using data from the National Trauma Data Bank (NTDB) from 2007 to 2014. All FES cases were included in the study with the diagnosis of FES (ICD9 958.1). Death on arrival cases were excluded. Patients were stratified by age cohort: less than 40 (G1), 40–64 (G2), and greater than 65 (G3) years of age. The primary outcome evaluated was in-hospital mortality. Multivariable regression models were performed to adjust for potential confounders.

Results

Between 2007 and 2014, 451 people from a total of 5,836,499 trauma patients in the NTDB met the inclusion criteria. The incidence rate was 8 out of 100,000. The inpatient mortality rate was 11.8% for all subjects with the highest mortality rate of 17.6% in patients over 65. Multivariable analyses demonstrated that age greater than 65 years was an independent predictor of mortality (aOR 24.16, 95% CI 3.73, 156.59, p=0.001), despite higher incidence and injury severity of FES among patients less than 40. No significant association with length of hospital stay, length of intensive unit care, or length of ventilation use was found between the groups. Subgroup analysis of the elderly population also showed a higher mortality rate for FES in femoral neck fracture patients (18%) than other femoral fractures (14%).

Conclusion

In this retrospective cohort analysis, old age (≥ 65 years) was found to be an independent risk factor for in-hospital mortality among fat embolism syndrome patients. Elderly patients specifically with femoral neck fractures should be monitored for the development of FES.

Aneurysmal bone cyst of the proximal femur concomitant with Graves' disease and Moyamoya disease: report of a rare case

Aneurysmal bone cyst is a type of benign bone pathology with expansile and osteolytic features whose etiology remains unclear. Graves' disease is an autoimmune disease characterized by diffuse goiter and hyperthyroidism. Moyamoya disease is a progressive cerebral vasculopathy. It has been reported that Graves' disease and Moyamoya disease share a similar etiology involving cytokines and autoimmune and genetic factors. There are no previous reports regarding the relationship between aneurysmal bone cyst and Graves' disease. Here, we present the rare case of a 25-year-old woman with suspected aneurysmal bone cyst of the left proximal femur and a definite preoperative diagnosis of Graves' disease, in whom lesion resection combined with left total hip replacement was indicated. Biopsy confirmed the diagnosis of aneurysmal bone cyst. Three days postoperatively, the patient developed acute ischemic cerebral infarction owing to Moyamoya disease, which was subsequently confirmed. This case elucidates the potential interaction among aneurysmal bone cysts, Graves' disease, and Moyamoya disease and provides lessons regarding appropriate perioperative preparation for patients with Graves' disease who require surgery to avoid potential severe complications.

Cerebral Fat Embolism: A Rare East African Conundrum

Cerebral fat embolism (CFE) is a potentially fatal condition associated with displaced long bone fracture of the lower extremities. CFE, usually seen in young men, has an incidence ranging between 0.9% and 11% in patients with long bone fractures. CFE can present with various neurological symptoms, and a diffusion-weighted magnetic resonance imaging (MRI) (DWI) remains the definitive diagnostic study. Early treatment of the fracture is crucial in the management of CFE. To the best of our knowledge, we are the first to report a case of CFE in East Africa.

Catastrophic Cerebral Fat Embolism Syndrome Lacks Hyperacute MRI Findings

A 64-year-old female with sickle cell (hemoglobin SC) disease and prior embolic strokes was admitted for vaso-occlusive pain crisis and developed sudden onset coma. Hyperacute brain MRI showed only small areas of mismatch between diffusion weighted imaging (DWI) and T2 fluid attenuated inversion recovery (T2 FLAIR) sequences that were insufficient to explain her profoundly altered level of consciousness. Repeat MRI 24 hours later showed innumerable foci of restricted diffusion and petechial microhemorrhage, confirming a diagnosis of cerebral fat embolism due to sickle cell crisis.

Can the rate of mortality and neurological recovery be predicted from the time of onset of symptoms and MRI grade in patients with cerebral fat embolism? : a study of 34 patients

AIMS

The aim of this study was to assess whether it is possible to predict the mortality, and the extent and time of neurological recovery from the time of the onset of symptoms and MRI grade, in patients with the cerebral fat embolism syndrome (CFES). This has not previously been investigated.

METHODS

The study included 34 patients who were diagnosed with CFES following trauma between 2012 and 2018. The clinical diagnosis was confirmed and the severity graded by MRI. We investigated the rate of mortality, the time and extent of neurological recovery, the time between the injury and the onset of symptoms, the clinical severity of the condition, and the MRI grade. All patients were male with a mean age of 29.7 years (18 to 70). The mean follow-up was 4.15 years (2 to 8), with neurological recovery being assessed by the Glasgow Outcome Scale and the Mini-Mental State Examination.

RESULTS

In all, seven who had early-onset CFES (< 24 hours), and a severe Takahashi grade on MRI, died. There was a significant association between the time of onset of neurological signs and mortality (p = 0.035). Mortality was also significantly associated with a severe Takahashi grade (p < 0.001). Among the 27 surviving patients, 26 (96.3%) recovered completely. One (3.7%) had a cognitive deficit. The mean time to recovery was 4.7 weeks (2 to 13), with late recovery aftereight eight weeks being recorded in three patients.

CONCLUSION

There was a significantly increased rate of mortality in patients with CFES who had an early onset of symptoms and a severe grade on MRI. Complete neurological recovery can be expected in most patients with CFES who survive. Cite this article: Bone Joint J 2022;104-B(1):142-149.

Subacute fat embolism syndrome in a young female trauma patient during COVID-19

We report the symptom evolution of a young female trauma patient leading to a diagnosis of fat embolism syndrome (FES). Twenty-four hours post-trauma she developed respiratory distress, followed by transient neurological compromise and later petechia. The subtle and fluctuating nature of her presentation made the diagnosis via existing clinical criteria challenging, as did the lack of specificity of thoracic computerized tomography due to the concurrent coronavirus (COVID-19) pandemic. Making the diagnosis was important as it changed the patient's management, likely preventing a diagnosis in extremis. This case emphasizes the importance of maintaining a high clinical suspicion of FES in any (poly)trauma patient. This is especially true during COVID-19, as correctly identifying non-COVID-19 causes of respiratory failure will prevent additional pandemic victims. In addition, this case supports the need for a diagnostic approach that balances clinical, biochemical and imaging features and takes a cumulative approach in order to identify subacute FES.

Cerebral Large Vessel Occlusion Caused by Fat Embolism-A Case Series and Review of the Literature

The diagnosis of fat embolism syndrome typically involves neurological, respiratory and dermatological manifestations of microvascular occlusion 24–72 h after a precipitating event. However, fat embolism causing cerebral large vessel occlusion strokes and their sequelae have rarely been reported in the literature. This case series reports three patients with fat emboli post operatively causing cerebral large vessel occlusions, as well as a review of the literature to identify differences in clinical presentations and outcomes in stroke secondary to fat emboli causing large vessel occlusions compared to those with fat embolism syndrome.

Intraparenchymal Neuromonitoring of Cerebral Fat Embolism Syndrome

Objectives:

We aimed to characterize the cerebrovascular physiology of cerebral fat embolism using invasive multimodal neuromonitoring.

Data Sources:

ICU, Vancouver General Hospital, Vancouver, BC, Canada.

Study Selection:

Case report.

Data Extraction:

Patient monitoring software (ICM+, Cambridge, United Kingdom), clinical records, and surgical records.

Data Synthesis:

None.

Conclusions:

Our integrated assessment of the cerebrovascular physiology of fat embolism syndrome provides a physiologic basis to investigate the importance of augmenting mean arterial pressure to optimize cerebral oxygen delivery for the mitigation of long-term neurologic ischemic sequelae of cerebral fat embolism.

Microbleeds show a characteristic distribution in cerebral fat embolism

This systematic review aims to test the hypothesis that microbleeds detected by MRI are common and show a characteristic pattern in cerebral fat embolism (CFE). Eighty-four papers involving 140 CFE patients were eligible for this review based on a systematic literature search up to 31 January 2020. An additional case was added from hospital records. Patient data were individually scrutinised to extract epidemiological, clinical and imaging variables. Characteristic CFE microbleed pattern resembling a "walnut kernel" was defined as punctuate hypointensities of monotonous size, diffusely located in the subcortical white matter, the internal capsule and the corpus callosum, with mostly spared corona radiata and non-subcortical centrum semiovale, detected by susceptibility- or T2* weighted imaging. The presence rate of this pattern and other, previously described MRI markers of CFE such as the starfield pattern and further diffusion abnormalities were recorded and statistically compared. The presence rate of microbleeds of any pattern, the "walnut kernel microbleed pattern", diffusion abnormality of any pattern, the starfield pattern, and cytotoxic edema in the corpus callosum was found to be 98.11%, 89.74%, 97.64%, 68.5%, and 77.27% respectively. The presence rate between the walnut kernel and the starfield pattern was significantly (p < 0.05) different. Microbleeds are common and mostly occur in a characteristic pattern resembling a "walnut kernel" in the CFE MRI literature. Microbleeds of this pattern in SWI or T2* MRI, along with the starfield pattern in diffusion imaging appear to be the most important imaging markers of CFE and may aid the diagnosis in clinically equivocal cases.

Cerebral fat embolism after traumatic bone fractures: a structured literature review and analysis of published case reports

Background

The incidence of cerebral fat embolism (CFE) ranges from 0.9–11%, with a mean mortality rate of around 10%. Although no univocal explanation has been identified for the resulting fat embolism syndrome (FES), two hypotheses are widely thought: the ‘mechanical theory’, and the ‘chemical theory’. The present article provides a systematic review of published case reports of FES following a bone fracture.

Methods

We searched MEDLINE, Web of Science and Scopus to find any article related to FES. Inclusion criteria were: trauma patients; age ≥ 18 years; and the clinical diagnosis of CFE or FES. Studies were excluded if the bone fracture site was not specified.

Results

One hundred and seventy studies were included (268 cases). The male gender was most prominent (81.6% vs. 18.4%). The average age was 33 years (±18). The mean age for males (29 ± 14) was significantly lower than for females (51 ± 26) (p < 0.001). The femur was the most common fracture site (71% of cases). PFO was found in 12% of all cases. Univariate and multivariate regression analyses showed the male gender to be a risk factor for FES: RR 1.87 and 1.41, respectively (95%CI 1.27–2.48, p < 0.001; 95%CI 0.48–2.34, p < 0.001).

Conclusions

FES is most frequent in young men in the third decades of life following multiple leg fractures. FES may be more frequent after a burst fracture. The presence of PFO may be responsible for the acute presentation of cerebral embolisms, whereas FES is mostly delayed by 48–72 h.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00861-x.

Autonomic Hyperactivity

PURPOSE OF REVIEW

Autonomic hyperactivity is a relatively common consequence of severe acute brain injury and can also be seen with spinal cord and peripheral nerve disorders. This article reviews basic pathophysiologic concepts regarding autonomic hyperactivity, its various forms of clinical presentation, and practical management considerations.

RECENT FINDINGS

Paroxysmal sympathetic hyperactivity is most common after traumatic brain injury but can also occur after other forms of severe acute diffuse or multifocal brain injury. Formal criteria for the diagnosis and severity grading of paroxysmal sympathetic hyperactivity have now been proposed. A growing body of literature is beginning to elucidate the mechanisms underlying this disorder, but treatment remains based on observational data. Our mechanistic understanding of other distinct forms of autonomic hyperactivity, such as autonomic dysreflexia after traumatic spinal cord injury and dysautonomia after Guillain-Barré syndrome, remains rudimentary, yet clinical experience shows that their appropriate management can minimize the risk of serious complications.

SUMMARY

Syndromes of autonomic hyperactivity can result from injury at all levels of the neuraxis. Much more research is needed to refine our understanding of these disorders and guide optimal management decisions.

Paroxysmal Sympathetic Hyperactivity

Paroxysmal sympathetic hyperactivity (PSH) is a relatively common, but often unrecognized, complication of acute diffuse or multifocal brain diseases, most frequently encountered in young comatose patients with severe traumatic brain injury. It is presumed to be caused by loss of cortical inhibitory modulation of diencephalic and brain stem centers and possible additional maladaptive changes in the spinal cord that combine to produce exaggerated sympathetic responses to stimulation. The syndrome consists of repeated sudden episodes of tachycardia, tachypnea, hypertension, sweating, and sometimes fever and dystonic posturing. The diagnosis is clinical. Treatment includes reducing any external stimulation that can trigger the episodes, and starting abortive (e.g., intravenous morphine) and preventive medications (e.g., gabapentin, propranolol, clonidine). Prompt and adequate treatment of PSH may reduce the likelihood of secondary complications, such as dehydration, weight loss and malnutrition, and muscle contractures.

Fat embolism syndrome in blunt trauma patients with extremity fractures

OBJECTIVE

This study sought to provide a national, descriptive analysis to determine fat embolism syndrome (FES) risk factors, hypothesizing that femur fractures and multiple fractures are associated with an increased risk.

METHODS

The Trauma Quality Improvement Program was queried (2010-2016) for patients with extremity fractures. A multivariable logistic regression analysis model was used.

RESULTS

From 324,165 patients, 116 patients (0.04%) were diagnosed with FES. An age ≤30, closed femur fracture, and multiple long bone fractures were associated with an increased risk of FES.

CONCLUSION

Future research to validate these findings and develop a clinical risk stratification tool appears warranted.

Clinical significance of increased peripheral venous blood adipocyte-specific protein FABP4 after joint replacement

A new method of diagnosing fat embolism (FE) at the molecular level was proposed, and the diagnostic value of adipocyte-specific protein fatty acid-binding protein 4 (Homo sapiens [human]) gene ID = 2167 (FABP4) for FE was preliminarily explored. Eight joint replacement patients, 5 internal medicine patients, and 6 healthy persons were recruited. Serum of internal medicine patients, healthy people, and patients before and 24 hours after joint replacement were taken as study samples. Subcutaneous adipose, intra-articular adipose and intramedullary yellow bone marrow of patients undergoing joint replacement were taken as study samples. The level of FABP4 in the above samples was detected by enzyme-linked immunoassay. Normal distribution was tested. Paired sample T test was used for self-control. Univariate analysis of variance was used for multigroup comparison.There was no significant difference in serum FABP4 level between healthy persons, medical patients, and preoperative patients. The FABP4 level in yellow bone marrow and subcutaneous adipose was significantly higher than that in serum of healthy people, medical patients, and preoperative patients. FABP4 level in the serum after joint replacement was significantly higher than that before joint replacement. FABP4 may be a specific indicator of FE diagnosis, but further studies are needed to confirm its clinical value.

Unusual clinicopathological presentation of nontraumatic cerebral fat embolism: Two-case report

RATIONALE

Fat embolism syndrome (FES) is characterized by the classical triad of cerebral, respiratory, and cutaneous manifestations. In contrast, cerebral fat embolism (CFE), corresponding to incomplete pure type FES, is much rarer and usually follows trauma. CFE typically shows a "starfield" pattern on diffusion-weighted magnetic resonance imaging due to the involvement of multiple small arteries. We report 2 unusual cases of CFE that showed a nontraumatic etiology and the involvement of a single dominant cerebral artery.

PATIENT CONCERNS

Case 1 was a 33-year-old woman without a history of trauma who visited the emergency room due to hemiparesis and hemisensory deficits. She was a heavy smoker and had used oral contraceptives for several years. Most importantly, she had 2 experiences of autologous fat grafting 2 months previously. Magnetic resonance angiography (MRA) revealed acute occlusion of the right middle cerebral artery. Case 2 was an 80-year-old man suddenly presented with dizziness, ataxia, and left-sided sensorimotor dysfunction. He had a history of hypertension, untreated atrial fibrillation, and chronic alcoholism. MRA demonstrated the occlusion of the distal basilar artery.

DIAGNOSIS

Case 1: Microscopic findings demonstrated variable sized fat vacuoles intermixed with moderate amounts of thrombi. Case 2: Histologically, mature adipocytes were intermingled with fibrin, blood cells, and a fragment of entrapped soft tissue resembling the vessel wall.

INTERVENTION

Case 1 and 2 underwent aspirational thrombectomy guided by transfemoral cerebral angiography.

OUTCOME

Case 1 recovered well but Case 2 still suffers from gait ataxia.

LESSONS

CFE can rarely occur in various nontraumatic conditions, with or without evident etiology. Furthermore, it may not show characteristic clinicopathological manifestations. Therefore, careful follow up of those who have undergone procedures that are likely to trigger FES or who have hemodynamic or hypercoagulable risk factors is needed.

Incidence of Seizures in Fat Embolism Syndrome Over a 10-Year Period: Analysis of the National Inpatient Sample Database

BACKGROUND AND PURPOSE

Data regarding the incidence of seizures in patients diagnosed with fat embolism syndrome (FES) are lacking. We examined the incidence of seizures in patients with FES, and the impact of seizures on outcomes over a 10-year period.

METHODS

Using the National Inpatient Sample data set we identified adults (age 18 y old or above) with a diagnosis of FES (ICD-9 958.1) between 2005 and 2014, and categorized them according to the presence or absence of seizures. We excluded patients with a history of epilepsy or traumatic brain injury RESULTS:: Of the 66,227,531 discharges, we identified 1888 patients (0.003%) with FES of which 53% were male and mean age of 56 (±57.45). Seizure or epilepsy rate in patients with FES was 2.86% (1.69% with seizures and 1.16% with epilepsy), as compared with 3.6% in all hospitalized patients without FES. The Charlson Comorbidity Index for all FES patients was 2.38 (±5.28) and was similar for those with and without seizures. Hospital length of stay was higher in patients with FES and seizures versus those without seizures (14.59 vs. 10.82 d, P=0.09). No statistically significant difference in mortality was observed between the 2 groups.

CONCLUSIONS

The rate of seizure and epilepsy in patients with FES is low when compared with rates in all hospitalized patients or in patients with other causes of acute neurological injury such as intracerebral hemorrhage, subarachnoid hemorrhage, and traumatic brain injury. Further studies are needed to provide recommendations for antiepileptic medication use in FES.

Effectiveness of Decompressive Hemicraniectomy to Treat a Life-Threatening Cerebral Fat Embolism

Background and Importance

Cerebral fat embolism (CFE) occurs mainly after long-bone fractures. Often reducing to minor neurological disorders as confusion, it can sometimes cause more severe consequences such as coma or even death. While CFE has been described for several years, there is no consensual treatment.

Clinical Presentation

We report the case of a 15-year-old girl with a severe cerebral fat embolism secondary to a longboard fall with a femur fracture. She developed in less than 4 hours a coma. On day 4, she lost her brainstem reflexes with a clinical condition close to brain death, with a very high intracranial pressure (ICP) value above 75 mmgH at worst. She was treated as having a trauma brain injury based on ICP control with a decompressive hemicraniectomy. She recovered in some weeks, allowing discharge to a post ICU rehabilitation center, one month after admission.

Conclusion

We report a severe case of cerebral fat embolism with good outcome. It was managed as a trauma brain injury. We emphasize the neurological management based on ICP and discuss the position of hemicraniectomy.

Paroxysmal sympathetic hyperactivity syndrome caused by fat embolism syndrome

Paroxysmal sympathetic hyperactivity represents an uncommon and potentially life-threatening complication of severe brain injuries, which are most commonly traumatic. This syndrome is a clinical diagnosis based on the recurrent occurrence of tachycardia, hypertension, diaphoresis, tachypnea, and occasionally high fever and dystonic postures. The episodes may be induced by stimulation or may occur spontaneously. Underdiagnosis is common, and delayed recognition may increase morbidity and long-term disability. Trigger avoidance and pharmacological therapy can be very successful in controlling this complication. Fat embolism syndrome is a rare but serious complication of long bone fractures. Neurologic signs, petechial hemorrhages and acute respiratory failure constitute the characteristic presenting triad. The term cerebral fat embolism is used when the neurological involvement predominates. The diagnosis is clinical, but specific neuroimaging findings can be supportive. The neurologic manifestations include different degrees of alteration of consciousness, focal deficits or seizures. Management is supportive, but good outcomes are possible even in cases with very severe presentation. We report two cases of paroxysmal sympathetic hyperactivity after cerebral fat embolism, which is a very uncommon association.

Cerebral fat embolism syndrome (FES): similar cases with different outcomes

Fat embolism syndrome (FES) is a rare multisystem, clinical syndrome occurring in 0.9%-2.2% of long-bone fractures. The severity of FES can vary from subclinical with mild respiratory changes and haematological aberrations to a fulminant state characterised by sudden onset of severe respiratory and neurological impairment. Here we present two patients with cerebral FES secondary to femur fracture. Both patients exhibited profound neurological impairment with varied outcomes. Our cases highlight the importance of a high clinical suspicion of FES in patients with long-bone fractures and neurological deterioration. We recommend early plate osteosynthesis to prevent additional emboli in patients with FES and situational placement of intracranial pressure monitoring. Finally, cerebral FES has low mortality even in a patient with tentorial herniation and fixed, dilated pupils.

Fulminant Cerebral Fat Embolism: Case Description and Review of the Literature

The release of fat and bone marrow fragments is a common occurrence following traumatic and nontraumatic events. In most cases, they go symptomless or cause only minor disturbances, but occasionally they can determine a multiorgan dysfunction whose severity ranges from mild to fatal. The authors describe the case of a patient who became deeply comatose and ultimately died after a traffic accident in which he suffered the exposed right femoral and tibial fracture in the absence of other injuries. He underwent the external fixation of the fractured bones 2 hours after the admission under general anesthesia. Three hours later, he failed to awake at the suspension of the anesthetic agents and became anisocoric; a CT scan demonstrated a diffuse cerebral edema with the herniation of the cerebellar tonsils; these abnormalities were unresponsive to the treatment and the brain death was one day later. The causes, the mechanisms, the symptoms, the prevention, and the treatment of the syndrome are reviewed and discussed.