Researchers have indicated that Ischemic strokes have a tendency of occurring in the morning as against hemorrhagic strokes, which show a patternof occurrence during the early evening.
This fact was revealed when they studied 12,957 patients who had suffered a cerebral infarction, an intracerebral hemorrhage, or a subarachnoid hemorrhage. The presence of two peaks were prominent, the 6 a.m. to 8 a.m peak, and the 6 p.m. to 8 p.m. peak. There was an obvious plunge during sleep.
When researchers probed further, cerebral infarction showed a bimodal pattern with a higher peak in the morning, a slight fall at noon, a lower peak in the early evening, and a total fall at night. The researchers attributed this difference to the impact of cerebral infarctions in which stroke onset happened during sleep; 20% of the cases showed an occurrence during sleep- during the time of waking up from sleep, with only 10% of hemorrhagic strokes occurring in the midst of sleep.