Magnetic resonance imaging of cerebral fat embolism

Massive cerebral involvement in fat embolism syndrome and intracranial pressure management

Fat embolism syndrome (FES) is a common clinical entity that can occasionally have significant neurological sequelae. The authors report a case of cerebral fat embolism and FES that required surgical management of intracranial pressure (ICP). They also discuss the literature as well as the potential need for neurosurgical management of this disease entity in select patients. A 58-year-old woman presented with a seizure episode and altered mental status after suffering a right femur fracture. Head CT studies demonstrated hypointense areas consistent with fat globules at the gray-white matter junction predominantly in the right hemisphere. This CT finding is unique in the literature, as other reports have not included imaging performed early enough to capture this finding. Brain MR images obtained 3 days later revealed T2-hyperintense areas with restricted diffusion within the same hemisphere, along with midline shift and subfalcine herniation. These findings steered the patient to the operating room for decompressive hemicraniectomy. A review of the literature from 1980 to 2012 disclosed 54 cases in 38 reports concerning cerebral fat embolism and FES. Analysis of all the cases revealed that 98% of the patients presented with mental status changes, whereas only 22% had focal signs and/or seizures. A good outcome was seen in 57.6% of patients with coma and/or abnormal posturing on presentation and in 90.5% of patients presenting with mild mental status changes, focal deficits, or seizure. In the majority of cases ICP was managed conservatively with no surgical intervention. One case featured the use of an ICP monitor, while none featured the use of hemicraniectomy.

À propos d'un cas d'embolie graisseuse pulmonaire différée post-ostéosynthèse vertébrale

A 37-year-old woman presented an acute respiratory distress syndrome six days after a post-traumatic vertebral osteosynthesis. First, a pulmonary embolism was suspected, and a thrombolysis realised. This diagnosis was secondary excluded, and the diagnosis of probable fatty embolism was established by the bronchoalveolar lavage. So, this case shows a delayed presentation of fatty embolism and permits a discussion about clinical presentation, and diagnosis methods of such pathology.

Cerebral lipiodol embolism after transcatheter arterial chemoembolization of hepatocellular carcinoma

A case of cerebral lipiodol embolism after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma is presented. A 76-year-old man underwent TACE for advanced hepatocellular carcinoma. Immediately after chemoembolization, his level of consciousness deteriorated. Computed tomography revealed deposition of iodized oil in the cerebral cortex, basal ganglia, and thalami. Magnetic resonance imaging showed restricted diffusion within the thalami and basal ganglia. The patient's level of consciousness gradually improved, and all neurologic symptoms disappeared over 6 weeks.

Bone marrow embolism in sickle cell disease: a review

The fat embolism syndrome is an important complication of patients with sickle cell hemoglobinopathies because of severe morbidity and mortality. Our recent experience with three cases that survived with intensive supportive care and prompt use of transfusion stimulates this review. A high index of suspicion, prompt use of diagnostic tools, and aggressive clinical management are the keys to a successful outcome.

Cerebral fat embolism: usefulness of magnetic resonance spectroscopy

We report a case of cerebral fat embolism which occurred in a 33-year-old man after a diaphyseal femoral fracture without cranial traumatism. The initial examination showed an incomplete picture of coma with tetrapyramidal syndrome and cutaneomucous purpura. There was no respiratory damage. We present a magnetic resonance spectroscopy analysis of the cerebral lesions observed in the initial phase of the embolism, as well as follow-up, which has strengthened the clinical and imaging features for the diagnosis.

Fat embolism after uncemented total hip arthroplasty

The authors present a 59-year-old woman who had a severe fat embolism syndrome develop after an uncemented total hip arthroplasty. The fat embolism syndrome was confirmed by clinical, laboratory, and imaging findings. The patient had a favorable outcome most likely related to early supportive therapy, her healthy background, and young age.

Stroke in the postoperative period

Stroke in the postoperative period requires a certain level of sophistication in dealing not only with the patient, but also with the family and significant others. The consultant who is called in to assess the patient must deal with the delicate matter of addressing a presumably unforeseen complication; this often requires political deftness when the surgeon is reluctant to acknowledge that anything possibly could go awry. It is the ultimate hope of all involved that the patient will have a speedy and full recovery. It is important for the patient to be evaluated properly and thoroughly in an effort to prevent a minor, reversible deficit from becoming a major, irreversible neurologic disability. Family members should have all findings and the implications of such findings thoroughly explained to them. Efforts to minimize the potential ramifications of a postoperative stroke generally are not well received and can lead to questions about the integrity of the surgical team as well as the quality of care.

Cerebral fat embolism after a nondisplaced tibial fracture: case report

Fat embolism syndrome has been observed after traumatic or nontraumatic events. In traumatic cases, fat embolism syndrome is known to occur in patients with a fracture of a long bone. The case of a patient with a cerebral fat embolism associated with a nondisplaced fracture of the tibial shaft is reported.

Fatal fat embolism syndrome: a case report

Fat embolism syndrome is a dire complication of long bone trauma. It is usually associated with neurological, hematological and respiratory involvement, the latter being the major cause of death. We present a case of severe fat embolism syndrome occurring 3 hours after a long bone injury, leading to permanent vegetative state and death without any respiratory signs. The diagnosis was confirmed by cytology of the bronchoalveolar lavage fluid. Clinical presentation of the puzzling fat embolism syndrome and diagnostic tests in suspected fat embolism syndrome are reviewed.

Magnetic resonance imaging findings in cerebral fat embolism: correlation with clinical manifestations

OBJECTIVES

Cerebral fat embolism (CFE) is a serious complication after fracture of long bones. The mortality rate of CFE may be high. However, recent progress in treatment may decrease the mortality. We studied the validity of magnetic resonance imaging (MRI) to detect and grade severity of CFE in 11 patients with CFE.

METHODS

Glasgow Coma Scale score, PaO2, PaCO2 at the onset, and minimal hemoglobin and platelet levels were monitored, and phagocytes in bronchoalveolar lavage fluid were counted. Brain computed tomographic and MRI scans were performed serially. MRI findings were graded into four categories according to the severity of T2-weighted images.

RESULTS

High-intensity T2 signals were identified in the various brain regions as early as 4 hours after onset of CFE. The maximum MRI grade significantly correlated with Glasgow Coma Scale score at the onset of CFE (p < 0.01). High-intensity T2 signal lesions fused and enlarged with time. In most cases, they diminished within 2 weeks. Three patients had persistent morbidity.

CONCLUSION

MRI-T2-weighted imaging seems to be the most sensitive imaging technique for diagnosing CFE, and correlates well with the clinical severity of brain Injury. With the aid of proper treatment for pulmonary fat embolism, CFE is a potentially reversible disease that can have a good outcome.

[Cerebral fat embolism after closed leg injury]

A 21-year-old man sustained a closed fracture of the leg from an industrial accident, without associated head trauma. The orthopaedic treatment consisted of immediate immobilization by setting leg in plaster. Two hours after admission, the Glasgow coma scale score was 10. Four hours after admission he developed a coma (Glasgow coma scale score = 7) with repetitive seizures. No lesion was visible on cerebral CT scan. Chest X-ray was unremarkable. Petechiae on the anterior chest wall and abdomen with bilateral mydriasis occurred. Thrombocytopenia with prothrombine time increase were observed. Magnetic resonance imaging, 27 hours after admission, showed high-intensity areas on T2 weighted views due to fat embolism. Retinal haemorrhages were observed. The bronchoalveolar lavage showing fat staining of tracheal aspirates confirmed the diagnosis of fat embolism. This case report emphasizes the possibility of predominant neurologic manifestations of a fat embolism and the diagnostic help of cerebral magnetic resonance imaging.

-The value of MRI in cerebral fat embolism-

We report two clinical cases of cerebral fat embolism, thereby demonstrating the value of MRI.

[From fat emboli to fat embolism syndrome]

The occurrence of a fat embolism syndrome (FES) can be explained by two hypothetic mechanisms. In the mechanical hypothesis, bone marrow enters into the cardiovascular system during an intramedullary peak pressure. This peak could occur during either long bone fracture and/or intramedullary nailing or cemented or noncemented arthroplasty. According to the biochemical hypothesis, the FES could occur in nontraumatic conditions such as lipid emulsion infusion or sickle cell disease. The C-reactive protein is a possible factor for destabilizing plasma fat (chylomicrons or Intralipid liposomes). Treatment with heparin has been reported to interfere with lipid metabolism through a "creaming" phenomenon. Plasma fatty acids increase lipid peroxidation, with potential severe oxidative stress of lung. Vascular lung injury is increased by granulocytes and the clotting cascade is activated by neutral fat. After a symptom-free period, the full clinical picture is characterized by pulmonary insufficiency with hypoxaemia, neurological impairment, pyrexia and petechial haemorrhages. The accurate incidence cannot be assessed as many subclinical forms remain unrecognized. Transoesophageal echocardiography with color-flow Doppler allows considerable insight into the sequence of embolic events and patent foramen ovale (PFO). A PFO induces an increase in right-to-left shunt in case of an elevated intrapulmonary pressure. PFO might elicit systemic manifestations of the FES, particularly with neurological impairment. Carotid ultrasonography helps to visualize embolism. Magnetic resonance imaging of cerebral fat emboli is a better diagnostic tool for detecting brain embolism than computerized tomography. Quantification of cells containing fat droplets in bronchoalveolar lavage material could also be helpful. Pulmonary microvascular cytology analysis of capillary blood samples obtained through a pulmonary artery catheter in combination with blood gas changes are of value for earlier stage FES. Prophylactic and therapeutic measures are aimed to counteract the various mechanisms leading to FES. The decrease in time delay of fracture management is probably the most effective prophylactic means. A reaming procedure can be noxious, particularly in a patient with a severe thoracic trauma. The insertion without reaming of a small diameter nail, plating or external fixation have several advantages. Albumin infusion is recommended for restoration of blood volume and binding of fatty acids. Among pharmacologic measures, only corticosteroids have a proven benefit, not only for prophylaxis but also for therapy. Aprotinin and heparin are beneficial in counteracting blood cell aggregation. A prophylactic use of vena cava filters has been advocated. Prevention or early treatment of hypovolaemia and hypoxaemia are essential.

Cerebral fat embolism studied by magnetic resonance imaging, transcranial Doppler sonography, and single photon emission computed tomography: case report

Cerebral fat embolism syndrome is an uncommon complication of trauma. We present a patient who developed cerebral fat embolism syndrome secondary to long-bone fractures. Although computed tomography of the brain failed to show any intracranial lesion, magnetic resonance imaging (MRI) detected scattered, high-signal-intensity lesions on T2-weighted images. 99mTc-d, 1-hexamethyl-propylene amine oxine single photon emission computed tomography (99mTc-HMPAO SPECT) and transcranial Doppler sonography (TCD) demonstrated low cerebral blood flow in the acute stage. MRI, 99mTc-HMPAO SPECT, and TCD correlated well with the clinical course of cerebral fat embolism syndrome.

Hemiplegia caused by inadvertent intra-carotid infusion of total parenteral nutrition

A 24 year-old woman developed acute hemiplegia and a seizure following accidental catheterization of the right common carotid artery and total parenteral nutrition infusion. Magnetic resonance imaging of the brain showed lesions in the frontal lobe and putamen consistent with an ischemic stroke. Angiography through the central venous catheter confirmed its intra-arterial location. The patient's weakness improved after hyperbaric oxygen treatment. We concluded that stroke or seizures during total parenteral nutrition administration through a central venous catheter should alert one to the possibility of inadvertent intra-arterial infusion, especially in patients who have had central lines inserted several times previously.

Cytologic diagnosis of fat emboli in peripheral blood during sickle cell infarctive crisis

A diagnosis of fat emboli can be suspected in a patient presenting with the typical symptoms of the fat embolism syndrome, but is rarely proved pathologically, except at autopsy. We described a 25-yr-old man with sickle cell anemia who developed an infarctive crisis complicated by unexplained fever, neurologic change, and respiratory abnormalities. Blood drawn from the femoral vein and examined cytopathologically yielded necrotic bone marrow elements admixed with fat. The cytologic finding of fat emboli from necrotic bone marrow provided the diagnosis and helped guide subsequent medical intervention. This sample test is recommended for patients at risk for fat emboli to aid in the clinical diagnosis.

Assessment of cerebral fat embolism by magnetic resonance imaging in the acute stage

The authors assessed the characteristic appearance of magnetic resonance imaging (MRI) of cerebral fat embolism in three patients. The MRI features in the acute stage were characterized by widespread, spotty lesions in the white matter, which appeared hyperintense on T2-weighted images and iso- or hypointense on T1-weighted images. The relation between clinical features and MRI findings are discussed.

Magnetic resonance imaging of cerebral fat embolism: a case report

Fat embolism syndrome (FES) is one of the most important causes of morbidity and mortality following multiple fractures. Neurological involvement (cerebral fat embolism) has been reported frequently. A case of cerebral fat embolism is reported. While CT scan revealed no abnormalities, MRI, performed in this patient 8 days after trauma, showed relative low-intensity areas on T1-weighted images and high intensity areas on T2-weighted images involving cerebral white matter, corpus callosum and basal ganglia. MRI follow-up (1 and 3 months post-trauma) showed nearly complete resolution of the abnormal signal. MRI seems to be a useful diagnostic tool for detecting and quantifying lesions in fat embolism syndrome.

Nontraumatic fat embolism syndrome in sickle cell anemia

A 14-year-old girl with sickle cell disease and nephrotic syndrome developed bone pain, followed by pulmonary edema, seizures, coma, and bilateral flaccid paralysis. Fat embolism syndrome was diagnosed by cranial magnetic resonance imaging and an exchange transfusion was performed. Within 3 months, all symptoms had resolved. It is concluded that fat embolism syndrome must be considered as a possible cause of acute neurologic deterioration in patients with sickle cell anemia.

[Tetraplegia in fat embolism]

This is a report of two cases of tetraplegia complicating fat embolism after fracture of long bones. In the first case, a 26 year-old male sustained fractures of femur and tibia. One day after admission, the patient became comatose (Glasgow coma score = 6) with dyspnaea and petechiae present on the anterior chest wall. In second case, a 22 year-old man with a fracture of tibia and humerus, suffered two days after admission from similar signs of fat embolism (dyspnaea, Glasgow score coma = 6, petechiae). A tetraplegia occurred after 7 days in the first patient and 6 days in the second. No lesions were visible on brain CT scan. Magnetic resonance imaging showed relative high-intensity areas on T2 weighted views. The outcome at three weeks was favourable, without neurologic sequelae.

Cerebral fat embolism studied with MRI and SPECT

In a patient with fat embolism to the brain CT showed no abnormality. MRI performed after recovery from coma, when the patient had aphasia and quadriparesis, demonstrated multiple high signal abnormalities in the white matter on both T1- and T2-weighted images. HMPAO-SPECT showed left-sided hypoperfusion which resolved in parallel with clinical improvement 1 month later.