Correspondence concerning “Posterior reversible encephalopathy syndrome (PRES) associated with COVID-19”

Dear Editor,

We thank Siegler et al. for their work to help us understand the situation of posterior reversible encephalopathy syndrome (PRES) disease under the COVID-19 pandemic [1]. However, herein, we have a different point of view of case 1 in the case series. We believe that the patient had reversible cerebral vasoconstriction syndrome (RCVS) rather than PRES.

First of all, the patient was a 49-year-old female, which fit the characteristic that RCVS is more common among women than men, especially in middle age [2]. In addition, thunderclap headache is one of the clinical features of RCVS. Unfortunately, we did not find a history of thunderclap headache in the patient from the information presented in the paper. However, about 5% of RCVS may not show the obvious typical thunderclap headache [3], [4]. For this patient, it may not be necessary.

Secondly, as shown in Fig. 2, in particular, digital subtraction angiography clearly showed that posterior circulatory system of the case had diffuse “string of beads” changes, which is one of the distinct manifestations of RCVS [2], [3], [4]. More interestingly, this patient used the calcium antagonist nimodipine in the arteries. In terms of clinical outcome, it well alleviated symptoms for the patient, and to some extent supported the diagnosis of RCVS.

It is important to note that most of the RCVS disease course is limited to 3 months. It means that the vascular stenosis originally from vasoconstriction is reduced or even completely restored in the vascular examinations such as magnetic resonance angiography, computed tomography angiography, and digital subtraction angiography after 3 months [2], [3], [4]. Therefore, for this patient, we suggest that a complete follow-up vascular investigation three months after the onset of her vasoconstriction can be a necessary choice. In addition, transcranial Doppler is a non-invasive inspection tool that can dynamically check the flow rate of intracranial blood vessels and can be used to track cerebral vasoconstriction and monitor the progress of patients with RCVS [5]. These will benefit the diagnosis, treatment and prognosis of the patient.

Last but not least, there has always been a dispute between RCVS and PRES. They have similar risk factors, pathogenesis, clinical spectrums, and neuroimaging manifestations so that the two are often confused. Singhal et al. proposed the RCVS₂ score to help distinguish RCVS from non-RCVS. Score ≥5 is highly likely to be considered RCVS. Score between 3 and 4 has moderate specificity and low sensitivity, and score ≤2 for excluding RCVS [6]. The RCVS₂ score applied to this patient was 4 points, which tended to be RCVS. Besides, we believe that the possibility of RCVS combined with PRES in this patient cannot be completely ruled out if more information about the case is obtained. This is because previous studies have shown that from 9% to 38% of RCVS patients have been reported with PRES, and the angiographic changes of RCVS are also recorded in the most patients with PRES [4], [5], [7].

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.