Key topics for NEET PG 2019 – HYT 013: Subarachnoid hemorrhage

Risk Factors for Subarachnoid Hemorrhage are:

Hypertension

Smoking

Excessive alcohol consumption

Polycystic kidney disease

Family history of subarachnoid hemorrhage

Coarctation of the aorta

Marfan syndrome

Ehlers-Danlos syndrome type IV

Triple H Therapy

Vasospasm after surgery is a major cause of morbidity and mortality following Subarachnoid hemorrhage. Construction of the cerebral arterial vasculature occurs as free subarachnoid blood under high pressure comes to contact with the surface of vessels, particularly in the basal cisterns. The mainstay of medical treatment of cerebral vasospasm, in addition to calcium channel blockade with nimodipine, is “triple H therapy”. The combination of induced hypervolemia, hemodilution, and hypertension (Triple H Therapy) is based upon the assumption that, in the presence of cerebral vasospasm, cerebral blood flow pressure autoregulation is impaired and blood flow becomes pressure dependent. 

Subarachnoid Hemorrhage
Subarachnoid hemorrhage most commonly results from ruptured congenital berry aneurysms of the circle of Willis in the subarachnoid space. The most prominent symptom of subarachnoid hemorrhage is sudden, severe headache, usually occipital and often associated with signs of meningeal irritation (eg, stiff neck), Drowsiness, loss of consciousness, coma, and death may occur rapidly.

Subarachnoid hemorrhage may be diagnosed by CT scan or cerebrospinal fluid examination. CT angiography (CTA) or magnetic resonance angiography (MRA) may identify intracranial aneurysm and will exclude other causes of subarachnoid hemorrhage. Supportive treatment, including control of blood pressure and vasodilator therapy, are important during the acute phase of subarachnoid hemorrhage.