Isolated Lateral Sinus Thrombosis Presenting as Cerebellar Infarction in a Patient with Iron Deficiency Anemia
A 55-year-old man was admitted to the emergency department with a 15-day history of headache, nausea, and mild dizziness. The patient had no medication history and no underlying diseases including cancer, infection and hematologic disorder. In addition, he had not suffered from trauma. The patient was alert mentality and there were no abnormal neurologic findings for cranial nerves, muscle strength and deep tendon reflex. The cerebellar function test, however, showed a mild disturbance in tandem gait.\nVital signs at admission showed a body temperature 36.7℃, a blood pressure of 100/60 mm Hg, and a heart rate of 70 beats/minute. Laboratory findings were as follows : hemoglobin 7.2 g/dL, hematocrit 24.8%, white blood cell count 4600/µL, platelet count 130000/µL, erythrocyte sedimentation rate 12 mm/hr, and C-reactive protein 1.447 mg/L. Coagulation profiles demonstrated a prothrombin time of 82%, an international normalized ratio of 1.13, an activated partial thromboplastin time of 28.8 seconds, and a bleeding time of 3.00. The following laboratory examinations were done to evaluate his anemia : total iron-binding capacity 324 ug/dL, serum iron concentration 54 ug/dL, vitamin B12 294 pg/mL, and folate 11.4 ng/mL. Peripheral blood smear test showed normocytic normochromic anemia with anisopoikilocytosis. These findings were consistent with IDA. Magnetic resonance image (MRI) of the brain showed high signal intensity on the T2 weighted/FLAIR image and low signal intensity on the T1 weighted image of the right cerebellar hemisphere compressing the fourth ventricle (). There was multifocal petechial hemorrhage and irregular enhancement in the right cerebellar hemisphere on the gadolinium-enhanced T1 weighted image (). In addition, there was a high signal lesion on the junction of the right transverse sinus and proximal sigmoid sinus on the T2 weighted image and FLAIR image. To determine the malignant neoplasm, PET-CT scans and tumor markers were examined. PET-CT showed no hypermetabolic lesion in the cerebellar parenchyme. However, diffuse hypermetabolism was detected in bone marrow, which was probably a reactive change due to the patient's anemic condition. Tumor markers were normal : AFP 1.86 ng/mL, CEA 0.659 ng/mL, CA 19-9 1.32 U/mL, CA125 10.01 U/mL, and PSA 0.509 ng/mL. Cerebral angiography demonstrated a filling defect in the right side transverse sinus and proximal sigmoid sinus in the venous phase (). Some venous congestion along with collateral vessels was also developed in the right cerebellar region.\nThere were negative findings for antinuclear antibody, lupus anticoagulant, antiphospholipid antibody IgG/M, anticardiolipin antibody IgG/M, anti beta2 GPI antibody IgG/M, and PNH flowcytometry. In addition, no abnormality was found in the level of protein C and protein S : protein C antigen 55% and protein S antigen 52%. Thyroid function test was done as follows : T3 87.2 ng/dL, TSH 5.66 uIU/mL, and fT4 1.08 ng/dL.\nThe patient received mannitol to control the increased intracranial pressure, and ferrous sulfate 256 mg (80 mg as iron) was given daily for the IDA. For preventive purpose, aspirin and clopidogrel were also prescribed. Cerebellar edema was markedly improved on the follow-up CT scan (). Laboratory findings were also improved : hemoglobin 8.6 g/dL and hematocrit 29.0%. The patient was discharged with no neurologic deficits. After 1 month, the patient had no symptoms and anemia was completely recovered : hemoglobin 11.3 g/dL and hematocrit 35.8%.