PMC8422431_01
Neuroimaging findings of the patient. Head computed tomography performed on admission reveals a low-density area in the left frontal cortex (a). Axial image from diffusion-weighted magnetic resonance imaging (MRI) reveals no abnormalities that indicate acute cerebral ischemia (b). Fluid-attenuated inversion recovery (FLAIR) shows high-intensity lesions in the left frontal cortex and very thin subdural hematoma (arrows) (c). Gadolinium-enhanced MRI shows leptomeningeal enhancement along the superior frontal gyrus, which is involved in focal cortical hyperintensity in the left frontal lobe of FLAIR imaging (d-f). Note that dural thickening, pituitary swelling, and tonsil herniation are not observed (e and g). Magnetic resonance venography shows patency of the intracranial main venous system (h).
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F1
A head computed tomography scan performed after arrival at the hospital showed a low-density area in the left frontal lobe [Figure 1a]. Although no fresh infarction was detected [Figure 1b], subsequent head magnetic resonance imaging (MRI) revealed a left frontal lesion and a small subdural hematoma [Figure 1c], without diffuse dural thickening, cerebellar tonsillar herniation, or enlargement of the pituitary gland [Figure 1d-g]. MRI showed the contrast effect of the pia mater along the superior frontal sulcus [Figure 1d-g]. Magnetic resonance venography (MRV) showed that the main cerebral venous sinuses were patent [Figure 1h].
Intraoperative photographs of the patient. The fluid-attenuated inversion recovery high-intensity lesion is exposed through small craniotomy (a). Note that a tack-up suture is placed (arrows) since the dura mater separates away from the skull spontaneously (a and b), although the brain does not look sunken in the photographs because we lowered the patient's head position to increase the intracranial pressure. Magnified intraoperative photo shows that the cortical vein is discolored (black) (c), and indocyanine green video angiography shows the absence of flow that signifies thrombosis of the vein (d).
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F2
After craniotomy, we had to change his head position from 15 to 20 cm above the heart to 0 cm and perform a tack-up suture in a hurry because we noticed that the dura mater separated away from the skull spontaneously and steadily because of low intracranial pressure [Figure 2a and b]. A dural incision led to the recognition of regional cortical vein thrombosis [Figure 2c and d].