PATIENT PRESENTATION
An 80‐year‐old woman was brought to our emergency department by ambulance service with head laceration after falling. She was found night wandering with unsteady gait after falling several times. There were no complaints of nausea or vomiting. Her medical history included only dementia. No focal neurological deficit was noted during physical examination. Computed tomography (CT) of the brain showed hyperdensity at the left frontal lobe (Figure 1).
FIGURE 1.
Axial computed tomography (CT) of brain showed hyperdensity at the left frontal lobe (arrow) and bilateral parietal scalp hematoma
DIAGNOSIS
Tadpole sign of acute bridging vein thrombosis
Sagittal and coronal views of brain CT revealed tadpole‐like hyperdense structure indicating acute thrombosed bridging vein (Figures 2 and 3). The oval body of tadpole represented thrombus within the vein, and the bent tadpole tail indicated the torn bridging vein, which was expanded by blood clot. Our patient received conservative treatment with symptoms gradually improving and was discharged.
FIGURE 2.
Sagittal computed tomography (CT) view revealed an engorged hyperdense thrombosed bridging vein traversing the subdural space. The bent tail indicated the torn bridging vein, which was expanded by blood clot (arrow)
FIGURE 3.
Coronal computed tomography (CT) view demonstrated the characteristic tadpole sign of acute bridging vein thrombosis. The oval‐shaped “body” of tadpole (arrow) represented thrombus within. Acute subdural hemorrhage also noted along right cerebral hemisphere (arrowhead)
Acute bridging vein thrombosis occurs in the setting of head injury with acceleration‐deceleration and rotational forces 1 or as a result of retrograde extension of cerebral venous thrombosis. Bridging veins traverse the subarachnoid and subdural spaces, with the subdural portion particularly vulnerable to disruption. Thrombosis develops within the disrupted bridging veins in a few hours, 1 presenting as the tadpole sign. This finding supports the traumatic cause of subdural hemorrhage. Notably, in the setting of non‐accidental injury among infants, 2 , 3 further investigation for abusive head trauma is warranted. It is important to recognize this tadpole sign given its diagnostic value.
Chang K‐H, Hwang Z‐A. Elderly woman with unsteady gait. JACEP Open. 2021;2:e12587. 10.1002/emp2.12587
REFERENCES
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