A previously healthy 25-year-old male presented to the Emergency Room with a history of subacute onset, progressive headache evolving over the last six days. He had recently received his first dose of the ChAdOx1 nCoV-19 (AstraZeneca) vaccine 15 days prior to presentation. One day prior he had been evaluated elsewhere with a CT brain which was normal and a hemogram which reported a platelet count of 60000/mm 3 . On the day of presentation, he had new onset weakness progressive over few hours of the left half of his body, evidenced by an inability to sit up from bed without support, and difficulty in gripping objects. Neurological examination confirmed hemiparesis with a hemi-sensory loss and dysmetria localized to the left with nystagmus (fast beating component to the left) on horizontal gaze to the left.
Diagnosis
Magnetic resonance (MR) imaging (Fig 1) of the brain showed a right high parietal hematoma measuring 4.7x2.3 cm with oedema, and signs of micro hemorrhage in the left parietal lobe and cerebellar hemisphere. CT angiography of the brain revealed thrombosis of the superior sagittal and right transverse sinus. Hemogram showed thrombocytopenia of 53000 /mm 3 [150,000 - 400,000]. D-Dimer was 6060.67 ng/mL (0.00 - 500.00). Routine coagulation tests and Bone marrow aspiration and biopsy was normal. The screening test for antibodies against platelet factor 4 (PF4)–heparin by chemiluminescenceimmunoassay (CLIA), was negative . Due to poor sensitivity for PF-4 antibodies by CLIA(2), blood samples were sent for PF-4 antibody by Enzyme Linked Immunosorbent Assay (ELISA, tests couriered offsite with a turnaround time of 4 weeks)(3). The sample degenerated in transit and was not reported. 6T (Table1) score -5/6.
Management
Due to the obvious bleed with thrombocytopenia, he received platelet transfusions on arrival. The unusual site of thrombosis coupled with a platelet count not usually associated with spontaneous intra cerebral bleeds strongly favored VITT. He was initiated on measures to reduce intracerebral edema and was admitted in the ICU. He was started on IV Dexamethasone and Intravenous Immunoglobulin (IVIG) at a dose of 1g/kg body weight on day 1 followed by a repeat dose on day 2 . In view of the bleed and thrombocytopenia initial anticoagulation was initiated with Apixaban at 2.5mg once daily. The patient deteriorated over the initial 24 hours with motor aphasia, and left facial palsy. Supported by a marginal increase in platelet levels, Apixaban was administered at 5mg twice daily thereafter from day 2. He remained on IV Dexamethasone and anticoagulation.
Follow up
Headaches resolved during the following days. An interval CT brain, done two days later, revealed no signs of hematoma expansion. He demonstrated near complete resolution of neurological deficits and was self-ambulatory at the time of discharge with repeat CT brain showing complete resolution of the thrombus. During his follow-up visit, all lab values were within normal ranges and his condition was normal.
Table 1: 6T score sheet for VITT
Category
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Thrombocytopenia
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>50% fall or nadir < 75000/mm3
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Test for PF4 antibody
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Positive by ELISA
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Timing
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Within 30 days of the first dose of vaccination
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Time/Age
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Less than 30 years
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Thrombosis
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Documented thrombus ( if suspecting CVT a venogram is needed)
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Trephine/Other causes for Thrombocytopenia
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Normal/ No alternate likley etiology
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Treatment/high likelihood of VITT
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Alteast 5 out of the 6 Ts
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