I read the article by Brzozowski et al. about the percentage of intracranial haemorrhage in type I dural arteriovenous fistula with great interest [1]. In the paper, the authors demonstrated that 50% of patients with dural arteriovenous fistula presented with intracranial haemorrhage. However, the results of the paper were not concordant with the already published data in some larger studies (n = 236-1075), which have demonstrated a risk of intracranial haemorrhage between 12% and 23.7% [2-5] (Table 1). In the paper published by Li et al., only two cases out of the reported 91 with Borden type I (Cognard type I and type IIa) dural arteriovenous fistulas presented with an intracranial haemorrhage, as compared to 28.6% in the authors’ paper. The sample size of the study and the inclusion of only those patients who were managed with embolisation probably contributed to this discrepancy.

Table 1

Review of literature on the presence of intracranial haemorrhage in patients with dural arteriovenous fistula

PaperNumber of patients% of patients presenting with haemorrhage% of patients presenting with haemorrhage in Cognard type 1 dural arteriovenous fistula
Li et al.23623.7% (n = 56)3.6% (n = 2)
Hiramatsu et al.107512.0% (n = 129)
Piippo et al.26113.0% (n = 34)
Singh et al.40218.0% (n = 72)


The author declares no conflict of interests.