Silent Brain Abnormalities in Thalassemia Intermedia: A Combined MRI/PET Study.

Patients with thalassemia intermedia (TI) have an increased risk of thrombosis compared with thalassemia major patients. Thromboembolic events are more frequently observed in older TI patients (>20 yrs) who are splenectomized and non-transfused. Brain involvement has not been widely studied; however, one study has documented silent strokes on brain MRI in 37% of patients, indicating that further investigation is warranted.

This was a cross-sectional study on 30 TI patients >18 years of age, splenectomized, not receiving regular transfusion therapy, and receiving no antiplatelet or anticoagulant medication. Patients were initially screened to establish absence of neurological signs or symptoms and other stroke-related disease (diabetes, hypertension, carotid stenosis, cardiac disease or prothrombotic mutations). All patients underwent both MRI and 18F-FDG PET scan on the same day. The criterion for abnormality on PET was the decrease in neuronal function (glucose utilization). MRIs were performed using T1- and T2- weighted spin-echo techniques. Abnormality was defined as an area of abnormally increased signal intensity on the T2-weighted pulse sequences.

The mean age was 31.9 yrs (range: 18–54 yrs) with a male to female ratio of 13:17. Among the group of 30 subjects, 18 (60%) had abnormal MRI findings, 19 (63.3%) had abnormal PET findings, and 26 (86.7%) had either an abnormal MRI or abnormal PET or both. Solitary findings were identified in 7 (26.9%) of patients while multiple lesions were observed in 19 (73.1%) of patients who had abnormality. Bilateral findings were documented in 14 (53.8%) of patients with abnormality. The most common regions of abnormality were the parietal (76.9%) and frontal (69.2%) lobes; followed by the temporal (53.8%) and occipital (15.4%) lobes.

MRI/PET evaluation has demonstrated that silent brain abnormality is a common finding in this population of adult, splenectomized, non-regularly-transfused TI patients.

Taher:Novartis: Honoraria, Research Funding.