Subarachnoid hemorrhage of unknown cause

Area of Science:

• Neurology
• Radiology
• Neurosurgery

Background:

• Spontaneous subarachnoid hemorrhage (SAH) diagnosis often relies on initial imaging.
• Determining the exact cause of SAH is crucial for appropriate patient management and prognosis.
• Previous studies reported a higher incidence of SAH with unknown etiology.

Purpose of the Study:

• To evaluate the effectiveness of repeated four-vessel studies in identifying the cause of spontaneous subarachnoid hemorrhage.
• To determine the incidence of SAH with unknown etiology after implementing computed tomography (CT) and rigorous angiography protocols.
• To assess the long-term prognosis of patients diagnosed with SAH.

Main Methods:

• Retrospective analysis of 814 spontaneous subarachnoid hemorrhage cases treated between April 1978 and December 1984.
• Initial diagnosis using computed tomography (CT) followed by four-vessel cerebral panangiography.
• Repeated four-vessel studies were performed on patients with initially undetermined SAH causes.
• Long-term follow-up monitoring for SAH recurrence and patient rehabilitation.

Main Results:

• Computed tomography (CT) and initial four-vessel studies identified the cause in most SAH cases.
• Repeated four-vessel studies identified ruptured aneurysms in 22.0% of initially undetermined cases.
• The final diagnosis of SAH with unknown etiology was low at 3.9% (32 cases) at discharge and 3.8% (31 cases) ultimately.
• No SAH recurrence was reported during a median follow-up of 27.1 months; most patients were rehabilitated.

Conclusions:

• A strict examination schedule, including repeated angiography, significantly lowers the incidence of diagnosing spontaneous subarachnoid hemorrhage of unknown cause.
• This diagnostic approach leads to a favorable prognosis for patients with SAH.
• Early and thorough etiological investigation is vital for effective SAH management.