Table 1:

Arterial components and brain structures surrounding the distal ICA on the affected side versus the contralateral side

	Affected Side (n = 20)	Contralateral Side (n = 20)	P Value^{^a}
A1	Dysplasia = 15 (75.0%)	Dysplasia = 1 (5.0%)	.001
M1	Dysplasia = 2 (10.0%)	Dysplasia = 0 (0.0%)	.487^{^b}
OA	Ectopic = 5 (25.0%)	Ectopic = 1 (5.0%)	.219
AchoA	Dysplasia = 5 (25.0%)	Dysplasia = 0 (0.0%)	.047^{^b}
PcomA	Dysplasia = 14 (70.0%)	Dysplasia = 3 (15.0%)	.003
BA/PCA	Dysplasia = 14 (70.0%)	Dysplasia = 1 (5.0%)	<.001
Midbrain	Hypoplasia = 9 (45.0%)	Hypoplasia = 0 (0.0%)	.001^{^b}

Note:—A1 indicates a segment of the anterior cerebral artery; M1, a segment of the MCA. BA/PCA indicates either BA or PCA, or both.
↵a McNemar test.
↵b Fisher exact test.