Cerebral fat embolism syndrome mimicking thrombotic thrombocytopenic purpura in a patient with hemoglobin SC disease

Abstract

A 54-year-old man with hemoglobin SC disease and a history of substance abuse presented to the Emergency Department from a nursing home with 2 days of progressive weakness, shortness of breath, and lower back pain. He developed a fever, hypoxia, and tachycardia on the day of admission. He did not have any recent changes in medications, and his family as well as the nursing home staff denied any access to illicit drugs.The patient's clinical presentation raises concern for a vaso-occlusive crisis, specifically acute chest syndrome (ACS.) ACS should be suspected when a patient with a sickle cell disorder (SCD) experiences fever, chest pain, and dyspnea, with laboratory testing demonstrating the presence of a leukocytosis and an associated decrease in hemoglobin and platelets [1]. Supportive care with hydration, oxygen, pain control, and broad-spectrum antibiotics should be initiated while awaiting hematologic, metabolic, infectious, and radiographic workups.On arrival to the hospital, his vital signs demonstrated a temperature of 39.48C, a heart rate of 140 beats per minute, and a blood pressure of 159/120 mmHg. He was hypoxic and required supplemental oxygen. Physical exam was remarkable for altered mental status (AMS) and a rapidly decreasing level of consciousness, dry mucous membranes, dilated, slightly irregular, and nonreactive pupils, and a torsional nystagmus. A later review of records from his ophthalmologist documented the presence of iris atrophy as a complication of his sickle cell disease. Upon evaluation, the patient was intubated for airway protection.ACS and the systemic inflammatory response syndrome (SIRS) remain atop the differential diagnosis. Other important considerations include severe sepsis secondary to pneumonia or meningitis, illicit drug use, metabolic disturbances, heart failure, hypertensive emergency, and embolic diseases. In general, neurologic complications are seen in 11% of patients presenting with ACS, with 31% of those patients also developing a relative thrombocytopenia [2]. While there are many etiologies that might contribute to this clinical picture, one finding that stands out is his torsional nystagmus, indicating a dysfunction in his cerebellum or brainstem. With such a finding, a metabolic or ischemic cause for his acute encephalopathy becomes more likely.Initial complete blood count showed a decrease in hemoglobin from a baseline of 13-14 to 12.4 g/dl, a decrease in platelets from a baseline of 222 to 92 k/mm 3 , and serum WBCs of 11.8 k/ml. Peripheral blood smears showed moderate amount of target cells and sickle cells, a markedly elevated number of nucleated red blood cells (65 nucleated RBCs/100 WBCs), and a slight number of schistocytes.There also was evidence of neutrophil precursors with 3% neutrophil bands, 2% metamyelocytes, and 1% myelocytes. A comprehensive metabolic panel showed an elevation of serum creatinine from a baseline of 1.2 to 1.6 mg/dl and a total bilirubin of 3.4 mg/dl. His troponin I level was 0.96 ng/ml. Further hematological work-up demonstrat...

An autopsy case of non‐traumatic fat embolism syndrome

“…We have described a rare case of non‐traumatic FES. Previously reported cases of non‐traumatic FES are summarized in Table . Although there have been several reports of non‐ traumatic FES associated with fatty liver, this is the first report of non‐traumatic FES associated with hepatocellular carcinoma.…”

“…FES usually occurs after fracture of long bones, and the symptoms appear 24–72 h after the initial trauma . On the other hand, non‐traumatic FES has also been reported in association with bone marrow necrosis in sickle cell disease, corticosteroid administration, fatty liver disease, bone marrow transplantation, pancreatitis, liposuction, and diabetes mellitus (DM) . Although FES is characterized by both pulmonary and systemic fat embolism, the biological mechanism of FES has not been clarified in detail …”

Neurologic recovery in systemic nontraumatic fat embolism syndrome in an elderly patient with hemoglobin SC disease: A case report

“…3,4 Reports of successful treatment of cerebral FES in SCD are even rarer. 3,5 This is an important clinical entity for healthcare personnel to recognize as (a) it can easily be misdiagnosed as other mimicking pathologies such as sepsis, vasculitis, hypoxic-ischemic encephalopathy, acute hemorrhagic leukoencephalitis, or thrombotic microangiopathies, 6,7 and (b) early intervention reduces morbidity and mortality.…”

Look into my eyes: An unusual first presentation of sickle cell disease

“…Among patients with sickle hemoglobinopathies, compound heterozygotes are the most common genotypes associated with fat emboli syndrome, possibly related to high blood viscosity. Although numerous case reports and case series of this syndrome in SC and sickle‐ β+ thalassemia exist, they are often associated with multi‐organ failure such as acute chest syndrome, renal dysfunction, or hepatic failure . Isolated cerebral symptoms are rare and require a high index of suspicion.…”