Spontaneous subarachnoid hemorrhage

Approximately 85% of spontaneous SAHs are caused by ruptured aneurysm 10% are perimesencephalic and the remainder are caused by rare disorders (van Gijn and Rinkel 2001). The pattern of bleeding on CT is a clue to the underlying cause. Blood in the interhemispheric fissure suggests an anterior communicating artery aneurysm and in the sylvian fissure suggests internal carotid artery or middle cerebral artery aneurysm (Fig. 30.1). 

Intracranial aneurysms are not congenital but develop over the course of life. Approximately 10% of aneurysms are familial, and candidate genes identified thus far include those coding for the extracellular matrix. Saccular aneurysms tend to occur at branching points on the circle of Willis and proximal cerebral arteries approximately 40% on the anterior communicating artery complex, 30% on the posterior communicating artery or distal internal carotid artery, 20% on the middle cerebral artery and 10% in the posterior 

Aneurysms may present with various clinical features  

Grade Glasgow Coma Scale Motor or language deficit 

Headache may be the only symptom in SAH or there may be accompanying symptoms that may also be seen with other causes of sudden-onset headache and so are not diagnostic. Patients are often irritable and photophobic. Loss of consciousness occurs in around half the patients but may only be brief. Nausea and vomiting are less common. Partial or generalized seizures occasionally occur at the onset period since these do not occur in perime-sencephalic hemorrhage or in thunderclap headache, their presence is a strong indicator of aneurysmal rupture (Pinto et al. 1996). 

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It is interesting to note that following spontaneous subarachnoid hemorrhage (SAH), body temperature falls and then rises immediately after the SAH-induced transient global cerebral ischemia without cardiac arrest (57). This may be a natural cerebral protection mechanism activated by the body shortly after the insult. 

Dissection of the internal carotid and vertebral arteries is a common cause of stroke, particularly in young patients. Although many occur due to trauma, it is estimated that over half occur spontaneously. The mechanism of stroke following arterial dissection is either by artery-to-artery embolism, by thrombosis in situ, or by dissection-induced lumenal stenosis with secondary cerebral hypoperfusion and low-flow watershed infarction. Occasionally, dissection may lead to the formation of a pseudoaneurysm as a source of thrombus formation. Vertebrobasilar dissections that extend intracranially have a higher risk of rupture leading to subarachnoid hemorrhage (SAH). ° ... 

According to the authors, the cause of death was a spontaneous intracerebral hemorrhage and subarachnoid hemorrhage without vasculitis. 

Ginkgo Increases effects, spontaneous bleeding, subarachnoid hemorrhage... 

Phthalide 30 did not affect mean arterial blood pressure in normal anesthetized rats [313] or subarachnoid hemorrhaged rats [329, 330], In spontaneous hypertensive rats, however, 30 elicited a transient reduction in systolic blood pressure without affecting the activities of plasma and tissue angiotensin converting enzymes or urine output, which were diuresis indicators [354]. 

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