Subarachnoid hemorrhage clinical features
Sudden headache is the cardinal feature, but patients might not report the mode of onset, usually with vomiting, syncope (apoplexy), neck pain (meningismus), and photophobia. If there is LOC, patient may subsequently recover consciousness. Focal cranial nerve deficits may occur (e.g. third nerve palsy from aneurysmal compression, causing diplopia and/or ptosis), Low back pain may develope due to irritation of lumbar nerve roots by dependent blood.
Loss of consciousness (LOC) is a common presenting symptom of subarachnoid hemorrhage (SAH) that is presumed to result from transient intracranial circulatory arrest.
In patients with a normal level of consciousness without focal neurological deficits the presence of neck stiffness is helpful but not pathognomic for the diagnosis of SAH. Moreover, the absence of neck stiffness does not rule out SAH, especially when evaluated ≤6h after symptom onset 1).
Focal cranial nerve deficits may occur (e.g. third nerve palsy from aneurysmal compression, causing diplopia and/or ptosis).
Low back pain may develop due to irritation of lumbar nerve roots by dependent blood.