Visual stimulation rehabilitation for cortical blindness after vertebral artery interventional surgery: A case report and literature review

Abstract

Introduction and importance: Cortical blindness (CB) after vertebral artery interventional surgery is not a frequently reported complication. In this study, the efficacy of visual stimulation rehabilitation consisting of visual recovery training and repetitive transcranial magnetic stimulation (rTMS) for cortical blindness was investigated by clinical evaluation, ophthalmologic examination, and electroencephalography (EEG).

Case presentation: This study reports on a 55-year-old male who showed partial bilateral posterior cerebral artery cortical branch occlusion after timely embolectomy due to thrombus dislodgement during right vertebral artery opening, stenting resulting in basilar artery tip occlusion. The lesions were mainly located in the right cerebellar hemisphere and bilateral occipital lobes, and the patient suffered from bilateral loss of vision, with only light perception preserved. The patient began to receive visual recovery training and 15 sessions of right occipital high-frequency transcranial magnetic stimulation 5 days after the onset.

Clinical discussion: After treatment, the patient's capacity to identify things improved, allowing him to watch television, as did the precision and fluency of random hand movements, walking, and self-care.

Conclusion: Visual stimulation rehabilitation composed of visual recovery training and rTMS is a promising therapy option for cortical blindness, and our case report provides clinical experience with vision recovery for patients with cortical blindness.

Keywords: Case report; Cortical blindness; EEG; Transcranial magnetic stimulation; Vision recovery; Visual evoked potential.

Fig. 1

The first cervical vascular CTA result. The picture shows severe stenosis of the left carotid bulb and the V1 segment of the bilateral vertebral arteries.

Fig. 2

Head MRI results on the day and one month after surgery. (A) and (B) Head MRI fluid attenuated inversion recovery (FLAIR) sequence and diffusion weighted imaging (DWI) sequence showed that the patient had acute cerebral infarctions in the bilateral occipital lobes and right cerebral hemisphere on the day after surgery. (C) and (D) Head MRI FLAIR and DWI sequence showed old infarctions in the bilateral occipital lobes and right cerebral hemisphere one month after surgery.

Fig. 3

The results of the postoperative Humphrey perimetry and visual evoked potential examination on the day after surgery. The results of the Humphrey perimetry are shown on the left picture, showing complete bilateral visual field loss. The results of the visual evoked potential are shown in the right picture, showing severe bilateral visual pathway impairment.

Fig. 4

The results of the visual evoked potential examination one day after the completion of treatment. The results show poor repeatability of the waveform in both eyes, a mild to moderate delay in the P2 wave, and a moderate decrease in the P2 wave amplitude.

Fig. 5

The EEG paradigm. The “+” in the screen's center appears for 500 ms at a time. Each time, a white square appears at random around the “+” for 2000 ms. Only the white square in the upper left corner of the “+” is the target stimulus.

Fig. 6

Results of time-domain analysis of working memory EEG task states in the patient (bottom) and the age-sex-matched healthy control (top). The mean EEG waveforms for all channels for the patient (bottom) and healthy control (top), and the mean scalp 2D circular flat topographic maps for all channels are illustrated in the figure. The topographic maps were examined specifically in 100 ms steps in the interval between 0 and 2000 ms after stimulus onset.

Fig. 7

Results of time-frequency analysis of working memory EEG task states in the patient (bottom) and the age-sex-matched healthy control (top). The mean time-frequency diagram of O1 and O2 leads for the patient and healthy control is shown, with the time window selected from 0.5 s before to 2 s after the appearance of the white square. The blue color in the time-frequency diagram represents the energy drops, while the red color represents the energy rise. The healthy control demonstrated a larger increase in early beta power in the temporal regions compared to the patient (healthy control: time range = 0.723–1.09 s). The patient demonstrated an increase in early alpha power in the frontal regions compared to the healthy control (patient: time range = 0.179–0.436 s)