Implications of Circadian Rhythm in Stroke Occurrence: Certainties and Possibilities

Stroke occurrence is not randomly distributed over time but has circadian rhythmicity with the highest frequency of onset in the morning hours. This specific temporal pattern is valid for all subtypes of cerebral infarction and intracerebral hemorrhage. It also correlates with the circadian variation of some exogenous factors such as orthostatic changes, physical activity, sleep-awake cycle, as well as with endogenous factors including dipping patterns of blood pressure, or morning prothrombotic and hypofibrinolytic states with underlying cyclic changes in the autonomous system and humoral activity. Since the internal clock is responsible for these circadian biological changes, its disruption may increase the risk of stroke occurrence and influence neuronal susceptibility to injury and neurorehabilitation. This review aims to summarize the literature data on the circadian variation of cerebrovascular events according to physiological, cellular, and molecular circadian changes, to survey the available information on the chronotherapy and chronoprophylaxis of stroke and its risk factors, as well as to discuss the less reviewed impact of the circadian rhythm in stroke onset on patient outcome and functional status after stroke.

“Mirum est si intellectus noster omnem scientiam accipiens ex phantasmate”

Albert`s so called “anthropology” is putting the human being on the top of a hierarchy of living things in virtue of a unique feature – i.e. the possession of the intellect – that offers the possibility to transcend the changing realm of nature and to rise its possessor to the dignity of his creator. Although, throughout his corpus Albert often defends the independence of the human intellect from matter and consequently from the body and senses, his works of natural philosophy seem to give us a different perspective. In De animalibus, Albert is considering the brain as the divine member of the body responsible for the operations of sensation and, to a certain degree, of intellection. Such being the case, the entire humoral activity of the human body has a direct influence on the activity of the intellect, in spite of its divine nature. Accordingly, the main purpose of my study is to point out how the classical humoral theory is integrated by Albert the Great in his physiological consideration for an explanation of the intellect placed between the murky boundaries of natural philosophy and metaphysics.