Cerebral infarction does not occur typically at night.

In a hospital-based series of 66 consecutive patients with non-progressive cerebral infarction, the time of onset and the type of infarction on computed tomography were studied retrospectively. Forty-six (78%) patients suffered cerebral infarction between 6 am and 6 pm. Only five patients (8%) had their infarct between midnight and 6 am. Only three patients had a watershed-infarct, and these occurred during the daytime. Our results do not support the belief that atherothrombotic brain infarction is largely determined by haemodynamic factors.