Fatal ischemic stroke following Tityus serrulatus scorpion sting in a patient with essential thrombocythemia

Context: Stroke following scorpion stings is rare. We report a fatal envenomation involving multiple, extensive brain infarcts in a patient with a previous diagnosis of essential thrombocythemia (ET) who was stung by Tityus serrulatus (T. serrulatus).

Case details: A 44-year-old woman with a diagnosis of low-risk ET (platelets <1,000,000/mm³, age <60 years and no history of thrombosis; positive JAK2V617F mutation) was admitted to a local ED 1?h after being stung by T. serrulatus on the left foot. She developed signs of severe envenomation, including several episodes of profuse vomiting, pallor and confusion soon after the sting, followed by shock (BP: 90/60 to 60/40?mmHg) and was treated with scorpion antivenom, vasopressors and mechanical ventilation. A brain computed tomography (CT) scan (54-h poststing) revealed diffuse bilateral cerebellar hypodensity, with partial involvement of both occipital lobes and thalamus, obstructive hydrocephaly with signs of cerebrospinal fluid extravasation, and ascending transtentorial herniation, suggestive of bilateral ischemia involving the posterior cerebral circulation. External ventricular drainage resulted in no improvement and brain death was confirmed on day 10.

Discussion: Several mechanisms have been proposed to explain stroke following scorpion stings, such as sympathetic stimulation, myocardial dysfunction, hypotension/shock, arrhythmias and coagulopathy. Ischemic stroke is one of the most serious complications of ET. The risk factors for thrombotic/ischemic events in patients with ET include age (≥60 years) and previous vascular events. Severe scorpion envenomation resulting in myocardial dysfunction and systemic inflammatory response syndrome may increase the overall risk of arterial thrombosis in this patient.