Table 1.

Etiologies of HH and bilateral cortical blindness (bilateral CB) reported in the literature.

		HH	Bilateral CB
PCA stroke	N = 904 (Zhang et al., 2006a)	69.6%	–
	N = 25 (Aldrich et al., 1987)	–	32%
	N = 332 (Brandt et al., 2000)1	43–74%	5–8%
TBI	N = 904 (Zhang et al., 2006a)	13.6%	–
	N = 880 (Bruce et al., 2006)	11.7%	–
Tumors	N = 904 (Zhang et al., 2006a)	11.3%	–
Brain surgery	N = 904 (Zhang et al., 2006a)	2.4%	–
Cardiac surgery	N = 25 (Aldrich et al., 1987)	–	20%
Demyelination	N = 904 (Zhang et al., 2006a)	1.4%	–
Cerebral angiography	N = 25 (Aldrich et al., 1987)	–	12%

N, number of patients included in the studies; VFDs are given in percentages in each study; –, not reported in the study.