The "starfield" pattern of cerebral fat embolism from bone marrow necrosis in sickle cell crisis

Fat Embolization Syndrome Secondary to Steroid Treatment in a Case of Sickle Cell Vaso-Occlusive Crisis

Fat embolization syndrome (FES) is often seen as a complication of fractures and has been known to cause respiratory failure, rashes of the skin, thrombocytopenia, and neurological damage. Nontraumatic FES is uncommon and occurs due to bone marrow necrosis. Vaso-occlusive crisis in sickle cell patients secondary to steroid therapy is a rare entity and not widely acknowledged. We report a case of FES secondary to steroid therapy administered for a patient with intractable migraine. FES is an uncommon yet serious complication that occurs due to bone marrow necrosis and is usually associated with increased mortality or damaging neurologic sequelae for the surviving patient. Our patient was initially admitted for intractable migraine and worked up to rule out any acute emergency conditions. She was then given steroids for her migraine which did not subside with the initial treatment. Her condition worsened, and she developed respiratory failure along with altered mental status requiring care in the intensive care unit (ICU). Imaging studies showed microhemorrhages throughout the cerebral hemispheres, brainstem, and cerebellum. The imaging of her lungs confirmed severe acute chest syndrome. The patient also had hepatocellular and renal injuries indicative of multiorgan failure. The patient was treated with a red cell exchange transfusion (RBCx) leading to an almost complete recovery in a few days. The patient, however, had residual neurological sequelae with the presence of numb chin syndrome (NCS). This report thus highlights the need to recognize potential multiorgan failure secondary to steroid treatment and the importance of initiating treatment with red cell exchange transfusions to decrease the risk of such complications secondary to steroids.

The sick(le) brain and spine: neuroimaging findings in paediatric patients with sickle cell disease

Sickle cell disease (SCD) is an autosomal recessive haemoglobinopathy, which manifests as multisystem ischaemia and infarction, as well as haemolytic anaemia. The morphological changes of red blood cells (RBCs) that promote ischaemia/infarction as the main multi-systemic manifestation, with associated vasculopathy, may also lead to haemorrhage and fat embolisation. Bone infarctions, whether of the skull or spine, are relatively common with subsequent increased infectious susceptibility. We present a broad spectrum of brain and spine imaging findings of SCD from a level III paediatric hospital in Lisbon, between 2010 and 2022. Our aim is to highlight brain and spine imaging findings from a serial review of multiple patients with SCD and respective neuroimaging characterisation.

Fat embolism in sickle-cell disease: A case report with literature review

Background

Sickle cell disease (SCD) is associated with an under-recognized and well-known complication of bone marrow necrosis known as cerebral fat embolism (CFE).

Case Presentation

We report a case of successfully treated SCD patient suffering from non-traumatic cerebral fat embolism (NCFE) who came with initial manifestation of localized pain followed by loss of consciousness and absence of cardiac shunt. This was an unusual case of fat embolism in SCD patient with the absence of right-to-left cardiac shunt indicating the biochemical etiology. Patient initially showed localized pain followed by loss of consciousness, suggesting that any such initial manifestation in patient of SCD should be suspected for CFE. MRI served as an accurate diagnostic tool showing the characteristic neuroradiologic sign. Treatment with exchange-transfusion recovered the patient successfully.

Conclusion

Overall, this case suggested that prompt diagnosis using MRI and treatment with RBC exchange could lead to better outcomes in SCD patients suffering from CFE.

Complete Neurologic Recovery of Cerebral Fat Embolism Syndrome in Sickle Cell Disease

Sickle cell disease is one of the most common inherited hemoglobinopathies diagnosed in the United States. Patients often present with severe anemia, pain crises, infections, and vaso-occlusive phenomena. Complications of these disorders can lead to significant debilitating morbidity and mortality. Fat embolism syndrome (FES) is a rare and devastating complication of sickle cell disease. It usually presents with a rapidly deteriorating clinical course, and the prognosis is dismal. We report a case of FES in a 19-year-old African American male with a history of sickle cell disease who presented with tonic-clonic seizures and was found to have multi-organ failure. FES was diagnosed 20 days from a presentation based on blood cytopenias and magnetic resonance imaging findings that were obscured at the initial presentation. We describe in this report, the patient’s course from presentation until diagnosis and resolution. Our case is peculiar as the patient had a very good outcome without the need for red blood cell (RBC) exchange; instead, supportive treatment and simple RBC transfusions were enough to change the clinical course of this almost fatal syndrome.

Fat embolism syndrome with neurological involvement: A case report

Background

Fat Embolism Syndrome (FES) occurs when the contents (or some component of) the bone marrow is released into the circulation, generally as the result of long bone fracture. It poses significant challenges in both diagnosis and treatment and, as such, is primarily a diagnosis of exclusion with no definitive treatment. We present a case where heightened awareness of the clinical team allowed for early identification and immediate initiation of supportive care, nitric oxide (NO) for potential mitigation of right heart failure, and pharmacological treatment with atorvastatin.

Patient

A 16-year-old male with multi-system trauma, including bilateral long-bone fractures, developed Fat Embolism Syndrome with neurological and respiratory symptoms within 24 h of admission.

Results

Within 24 h of initiation of high dose atorvastatin and inhaled Nitric Oxide our patient showed signs of improvement, including decreasing oxygen requirement's and normalization of mental status.

Conclusion

We postulate that the combined therapy of high-dose atorvastatin with Nitric Oxide may have played a role in our patients' full recovery in a shortened timeframe. Ideally, further prospective research is needed to determine a universally accepted treatment regimen for pediatric patients with FES.

Coma secondary to cerebral fat embolism syndrome due to sickle cell disease fully recovering following red cell exchange transfusion

A 51-year-old woman known for sickle cell disease presented with 2 weeks of headache and bilateral lower limb pain. During admission, she suffered from multiple generalised tonic-clonic seizures but had an unremarkable CT of the brain. Incidentally, she had worsening baseline renal function. She was admitted to the intensive care unit with an acute confusional state. A bedside electroencephalogram showed triphasic waves and diffuse slow activity suggestive of encephalopathy with no epileptiform discharges. She remained obtunded despite appropriate medical therapy of hydration, antiepileptic and pain control. Lumbar puncture failed to identify an infectious cause. An urgent MRI of the brain was done and revealed features compatible with fat embolism syndrome (FES). Her haemoglobin S was 84.2%. Urgent red cell exchange transfusion was done, and within 3 days she fully regained her orientation and motor function. This represents the first case of such profound obtundation due to FES with a complete response to exchange transfusion.

A Case of Fat Embolism Syndrome with Cerebral Involvement in Sickle Cell Anemia

Fat embolism syndrome (FES) is a rare condition that can occur as a complication of sickle cell disease. We describe a case of a patient with sickle cell disease (homozygous Hb S or HBB: c.20A>T) presenting with initial signs and symptoms consistent with a vaso-occlusive crisis (VOC). Within 24 hours, the patient developed evidence of coagulopathy, multi organ failure and a reduced level of consciousness (LOC) prompting intubation. A diagnosis of FES was made on the basis of the patient's clinical presentation, in conjunction with magnetic resonance imaging (MRI) of the brain revealing innumerable tiny foci of restricted diffusion, intracytoplasmic microvesicular fat on Sudan Red staining of bronchoalveolar lavage samples and evidence of a pulmonary shunt on echocardiogram bubble study. Red blood cell (RBC) exchange transfusion was initiated 3 days following initial presentation and no further exchange transfusions were needed on the basis of subsequent Hb S (HBB: c.20A>T) levels. The LOC gradually improved and the patient was extubated 12 days following presentation. Neurological improvement was slow, with mild cognitive impairment initially evident at 3 months and no cognitive or neurological deficits remaining within 6 months of admission. This case highlights the importance of understanding the pathophysiology and clinical presentation of FES, as early exchange transfusion may improve survival in patients with sickle cell disease and FES.

Neurovascular disorders in children: an updated practical guide

Neurovascular disorders are an important cause of brain injury in the paediatric population, leading to substantial mortality and morbidity. These include ischaemic, haemorrhagic strokes, and cerebral venous sinus thromboses. Despite remarkable improvements in our understanding and management of strokes in general, and in the quality of immediate care and rehabilitation, the outcomes in childhood strokes lag far behind adult strokes. This is a multifaceted problem. There remain several challenges including delays in recognition due to vague clinical presentations, a failure to consider strokes in many cases, delays in obtaining imaging and inadequate imaging when performed, as well as limited evidence and availability for hyper acute intervention in children. Stroke in children is also a vastly different entity to adult strokes, with a unique set of risk factors and often with an underlying cause to be found. This review is by no means exhaustive, but instead aims to provide an overview of the epidemiology, sub-classification and aetiology of paediatric neurovascular disorders, mainly ischaemic, haemorrhagic strokes and cerebral venous sinus thrombosis. We also focus on the risk factors for each of these, the clinical presentation, recommended diagnostic protocol, pertinent imaging findings, as well as the current treatment and follow-up practices.

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 syndrome in sickle cell disease without evidence of shunt

Fat embolism syndrome (FES) is a known complication of sickle cell disease (SCD) that occurs secondary to vaso-occlusive crises, bone marrow infarction, and the subsequent release of fat globules into the venous circulation. Although neurologic involvement is common, the pathophysiology of cerebral fat emboli remains controversial. While fat microemboli can enter the arterial circulation through right-to-left shunts, the systemic release of free fatty acids may also cause indirect endothelial damage and disruption of the blood-brain-barrier. We present an unusual case of cerebral fat emboli in SCD that occurred in the absence of acute chest syndrome or right-to-left shunt, favoring a biochemical etiology. Treatment of FES includes supportive care and emergent red cell exchange transfusions.

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Cerebral fat embolism syndrome is a rare complication of sickle cell disease.

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Brain MRI shows multifocal punctate infarcts and hemorrhages in a “starfield” pattern.

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Fat microemboli can enter the brain through intrapulmonary or intracardiac shunts.

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In the absence of shunting, free fatty acids may cause indirect endothelial damage.

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Treatment involves supportive care and red cell exchange transfusions.