Shireen Khawar, Shahid Rafiq.
Circadian Fluctuation in timing of onset of acute Ischemic Stroke.
Biomedica Jan ;12(1):37-8.

Fifty patients of acute ischaemic stroke were analysed to find out the time of onset of stroke. The number of strokes per 4 hour period were the following; 12 midnight A.M. 4(8%);4 A.M 8 A.M. 15(30%);8 A.M 12 noon 12(24%); 12 Noon 4 P.M. 6(12%);4 P.M 8 P.M. 6(12%) and 8 P.M 12 midnight 7(14%). It was observed that most of the strokes occurred between 4 A.M. and noon (54%) and the most frequent time of stroke onset was 4 A.M 8 A.M. It was also noted that 44% of the strokes occurred within first hour of awakening. This study has indicated that there is a circadian variation in the time of onset of ischaemic stroke peaking in the early morning;and decreasing as day passes.

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