Cerebral Fat Embolism in Hemoglobin SC Disease

Abstract

A 63-year-old Caribbean man was admitted to the hospital for low back and pelvic pain. His medical history included sickle cell hemoglobin (Hb) C disease with no vasoocclusive crisis within the last 20 years, and chronic obstructive pulmonary disease treated with inhaled corticosteroids for the last 4 years. A few hours after admission, respiratory distress with polypnea occurred, requiring an oxygen flow rate of 12 L per minute. At that time, a thrombocytopenia was detected in peripheral blood, with a platelet count of 112,000/mm 3 , as well as increased hemolysis (LDH 4990 IU/L; normal range 125-250). He was transferred to the Intensive Care Unit. The patient's neurological and respiratory status got worse in the Intensive Care Unit, with agitation, confusion, and hypercapnic acidosis leading to his intubation. Disseminated intravascular coagulation, thrombocytopenia, and leukopenia developed. Chest computed tomography scan showed lung bilateral alveolar condensation in the posterior basal segment and bilateral pleural effusions. A bone marrow smear was performed and showed bone marrow necrosis. The diagnosis of pulmonary infection without bacterial identification was made; the patient required antibiotic therapy combination and blood transfusion. The wake-up after initial sedation was delayed and no real consciousness after 4 days without sedation was detected, therefore leading to further investigations. ASSESSMENT An electroencephalogram, a lumbar puncture, and a cerebral magnetic resonance imaging (MRI) scan were performed: Funding: None.

How I investigate bone marrow necrosis

“…Other benign noninfectious causes include anorexia, medication and chemical effect, alcohol abuse, G‐CSF administration, non‐Hgb S hemoglobinopathies, acute graft vs host disease after allogenic bone marrow transplant, and hemophagocytosis . Bone marrow necrosis can sometimes be associated with fat embolization syndrome (FES), a life‐threatening disorder associated with neurologic dysfunction and multiorgan failure; FES is more commonly seen in patients with hemoglobinopathies …”

“…Clinical findings associated with bone marrow necrosis include bone pain and fever, cytopenias, elevated LDH and ferritin, and leukoerythroblastosis . Rarely, such as in fat embolization syndrome (FES), bone marrow necrosis can be associated with thrombotic microangiopathy, neurologic dysfunction, and multiorgan failure …”

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.…”

Neuroimaging in Sickle Cell Disease: A Review

“…94 Contrary to all other manifestations of SCD, the majority of FES occur in patients with milder forms of the disease, such as sickle cell trait and sickle cell β-thalassemia. 97 Moreover, patients with sickle cell trait are only half as likely as patients with SCD to make a full recovery. 94 The reason for this is unclear, but immune dysregulation in patients who have not undergone autosplenectomy (which is the most common in patients bearing the HbSS genotype) has been proposed.…”

“…Contrary to all other manifestations of SCD, the majority of FES occur in patients with milder forms of the disease, such as sickle cell trait and sickle cell β‐thalassemia 97 . Moreover, patients with sickle cell trait are only half as likely as patients with SCD to make a full recovery 94 .…”