Abstract
Therapy-responsive immune thrombocytopenia and anemia shortly after the second dose of an mRNA-based SARS-CoV-2 vaccine, which was complicated by symptomatic bleeding within a pre-existing brainstem cavernoma, has not been reported. The patient is a 68yo male who experienced gait disturbance and hypoesthesia of the left face and left upper extremity two days after the second dose of the mRNA-based SARS-CoV-2 vaccine BNT162b2 (Tozinameran). Clinical neurologic exam revealed hypoesthesia of the left face and the left upper extremity and ataxic gait. Blood tests revealed macrocytic anemia and marked thrombocytopenia, interpreted as vaccination induced immune thrombocytopenia (ITP). Cerebral MRI revealed subacute bleeding within a pre-existing solitary cavernoma located in the right cerebellar peduncle. With proceeding resorption of the bleeding, symptoms gradually regressed. This case shows that SARS-CoV-2 vaccinations may be followed by ITP and bleeding in pre-existing vascular malformations. In order to avoid cavernoma bleeding in patients with SARS-CoV-2 vaccination associated ITP and thrombocyte dysfunction, urgent treatment of ITP is warranted. In order to identify patients at risk for experiencing SARS-CoV-2 vaccination induced ITP, further studies are urgently warranted.