In the univariable analysis, greater age (OR 1.026, 95% CI 1.006–1.046, p = 0.011), the presence of hypertension (OR 0.477, 95% CI 0.275–0.825, p = 0.008), greater ICH volume (OR 1.040, 95% CI 1.029–1.051, p < 0.001), the presence of IVH (OR 1.731, 95% CI 1.006–2.980, p = 0.048) and the presence of the APOE ε4 allele (OR 1.923, 95% CI 1.037–3.565, p = 0.038) were associated with the presence of the island sign (Table 2). Here, APOE is linked to hypertensive disorder.