Subarachnoid haemorrhage of unknown aetiology

Abstract

The authors review the literature on subarachnoid haemorrhage of unknown aetiology (SAHUE) and analyze a personal series of 212 patients diagnosed as SAHUE. These patients represent 30% of all cases of primary SAH admitted over a 14.5 year period. The age, sex, antecedents and initial clinical presentation of patients with SAHUE were indistinguishable from those of patients with subarachnoid haemorrhage due to ruptured aneurysm (SAHRA). However, the present series of SAHUE compare favourably with both a personal and a previously reported series of SAHRA insofar as clinical grade on admission (94% of patients in grades I-II of Botterell), presence of blood on CT (51%), vasospasm (5%), ischaemic deficits (3.3%), persistent hydrocephalus (3.5%), rebleeding (6%) and fatal result (3.9%) are concerned. The amount of blood on CT scan in our patients with SAHUE was associated with a significantly higher incidence of brain ischaemia and hydrocephalus but did not correlate with the Botterell grade on admission or final outcome, which were good in the majority of cases regardless of the presence or not of visible cisternal haemorrhage. The results of the present series confirm that the final prognosis of patients with primary SAH showing normal four-vessel cerebral angiography is essentially favourable.

Idiopathic subarachnoid hemorrhage: a multicentre series of 220 patients

“…Less than half of our anISAH cases had a second angiogram performed, far from the 100% recommendation made by many authors 5,18,20,23,24,38 . Anyway, our series confirm the results of other reports 7,12,16,20,25,33,45 in that, once the acute phase has been overcome, the anISAH patients' clinical evolution is significantly better than ANSAH patients, with no rebleedings from discharge until final outcome at six months.…”

Long term outcome after subarachnoid haemorrhage of unknown aetiology

“…Some researchers do not accept this and speculate that spontaneous thrombosis, vasospasm, destruction of the aneurysm by haemorrhage, narrowing of the aneurysmal neck, alterations in blood flow, inadequate angiographic technique or observer error may be responsible 2. Outcome of angiogram negative SAH is good in 90% of cases 4 7 8 12 13. However, many groups report non-specific symptoms such as headache, neuropsychological deficits or depressive symptoms in up to 62% of patients 14–16.…”

“…However, many groups report non-specific symptoms such as headache, neuropsychological deficits or depressive symptoms in up to 62% of patients 14–16. The rebleeding rate is approximately 5% (0–10%)7 8 15–18 and the risk of death in non-aneurysmal bleeding has been estimated to be 0–15%2 4 7 8 12 13 15 17 18 Greebe and Rinkel15 concluded that patients with an angiographic negative perimesencephalic pattern of SAH have a normal life expectancy but Hawkins et al 17 found the cumulative proportional survival after 22 years to be 69% compared with an expected survival of 89% in patients with SAH of unknown aetiology.…”

Clinical relevance of negative initial angiogram in spontaneous subarachnoid hemorrhage

“…3 Based on this early characterization, numerous authors have sought to clarify risk factors, etiology, symptoms, clinical presentation, diagnosis, treatment, complications, and outcomes in patients with these SAH subtypes. 1,[4][5][6][7][8][9] Diverse events may lead to non-aneurysmal SAH, and often the mechanism of bleeding remains unknown in these patients.…”