PMC10351957_01
Preoperative images. (A) Angiography showing stenosis (arrow in red) of the cervical portion of the right internal carotid artery from the superior margin of the C3 vertebral body to the midline of the C2 vertebral body. Stenosis is 80% according to the North American Symptomatic Carotid Endarterectomy Trial criteria. (B) Preoperative cerebral fluid-attenuated inversion recovery magnetic resonance imaging showing an old cerebral watershed infarction of the right frontal centrum semiovale. The red arrow indicates the point of stenosis.
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Cerebral angiography showed 80% right ICA stenosis from the superior margin of the C3 vertebral body to the midline of the C2 vertebral body (Fig. 1A). Cerebral magnetic resonance imaging (MRI) fluid-attenuated inversion recovery (FLAIR) imaging revealed an old cerebral watershed infarction of the right frontal centrum semiovale (Fig. 1B).
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-Isopropyl-p-[123I] iodoamphetamine single-photon emission computed tomography (123I-IMP SPECT). (A) Preoperative 123I-IMP SPECT showing widespread reduction in the cerebral blood flow (CBF) (blue) in the right hemisphere. (B) Emergency 123I-IMP SPECT performed on postoperative day 1 showing widespread CBF elevation (red) in the right hemisphere. (C) CT perfusion performed on postoperative day 3 showing no CBF laterality.
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Resting N-isopropyl-p-[123I] iodoamphetamine single-photon emission computed tomography (123I-IMP SPECT) showed a widespread reduction in cerebral blood flow (CBF) to the right hemisphere (Fig. 2A). Emergency 123I-IMP SPECT confirmed elevated CBF on the operative side, and the ratio of CBF in the unaffected to the affected side was more than two times greater than that before surgery (Fig. 2B). CHS, we initiated sedation under propofol with ventilator management as well as lacosamide (LCM; 100 mg/day), a novel antiseizure medication (ASM). CT perfusion performed on postoperative day 3 showed no CBF laterality (Fig. 2C), and sedation was terminated on postoperative day 4.
Long-term video electroencephalographic monitoring performed on postoperative day 4 showing generalized periodic discharges averaging 1.6 Hz (A) transferred to epileptiform discharges averaging >2.5 Hz (B) for at least 10 s. The patient exhibited prolonged impaired awareness and roving eye movements.
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The 6-h VEEG showed generalized periodic discharges averaging 1.6 Hz (Fig. 3A) transferred to epileptiform discharges averaging >2.5 Hz for at least 10 s (Fig. 3B), which met the criteria of ESz according to the American Clinical Neurophysiology Society's (ACNS) standardized critical-care electroencephalography (EEG) terminology (2021 version).
Interictal electroencephalographic monitoring on postoperative day 7 showing improvement in epileptic discharges.
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EEG on postoperative day 7 showed improvement in EEG findings (Fig. 4).
Postoperative cerebral fluid-attenuated inversion recovery magnetic resonance imaging on postoperative day 90 showing no new structural lesions.
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FLAIR MRI on postoperative day 90 showed no new structural lesions (Fig. 5).