Swedish nationwide study of 377 patents with non-aneurysmal subarachnoid haemorrhage : a disease with distinct demographics and risk factors
(2025) In Journal of Neurology, Neurosurgery and Psychiatry- Abstract
Background Non-aneurysmal subarachnoid haemorrhage (NASAH) accounts for less than 20% of spontaneous subarachnoid haemorrhage (SAH). However, its epidemiological characteristics, risk factors and aetiology remain poorly defined. Methods All patients with spontaneous SAH admitted to a neurosurgical centre in Sweden over a 3.5-year period were prospectively enrolled in a database. Epidemiological data, risk factors, Fisher grade and follow-up radiological findings were analysed, comparing NASAH cases to aneurysmal SAH (aSAH). Results A total of 1532 patients with SAH were included, of whom 377 (24.6%) were diagnosed with NASAH. Five NASAH patients exhibited microaneurysms in the perforating arteries (MAPAs) of the vertebrobasilar... (More)
Background Non-aneurysmal subarachnoid haemorrhage (NASAH) accounts for less than 20% of spontaneous subarachnoid haemorrhage (SAH). However, its epidemiological characteristics, risk factors and aetiology remain poorly defined. Methods All patients with spontaneous SAH admitted to a neurosurgical centre in Sweden over a 3.5-year period were prospectively enrolled in a database. Epidemiological data, risk factors, Fisher grade and follow-up radiological findings were analysed, comparing NASAH cases to aneurysmal SAH (aSAH). Results A total of 1532 patients with SAH were included, of whom 377 (24.6%) were diagnosed with NASAH. Five NASAH patients exhibited microaneurysms in the perforating arteries (MAPAs) of the vertebrobasilar circulation, identified on follow-up cone-beam CT angiography. Gender distribution and Fisher grade presentation differed significantly between the NASAH and aSAH groups (p<0.001). Risk factors, such as smoking, hypertension and alcohol overuse, were significantly more common in aSAH than NASAH. Conversely, diabetes mellitus (DM) was more prevalent in NASAH than in aSAH (p<0.001). Conclusions This is the largest epidemiological study of NASAH to date. The observed incidence of NASAH was higher than in the previous reports, suggesting either underdiagnosis in earlier studies or a changing proportion of aSAH to NASAH cases. The distinct differences in population characteristics and risk factors suggest that NASAH and aSAH arise from fundamentally different pathophysiological mechanisms. DM emerged as a risk factor for NASAH, and MAPAs were identified as one of the underlying sources of haemorrhage in this subgroup.
(Less)
- author
- organization
- publishing date
- 2025
- type
- Contribution to journal
- publication status
- epub
- subject
- keywords
- ANEURYSM, CEREBROVASCULAR DISEASE, EPIDEMIOLOGY, STROKE, SUBARACHNOID HAEMORRHAGE
- in
- Journal of Neurology, Neurosurgery and Psychiatry
- publisher
- BMJ Publishing Group
- external identifiers
-
- pmid:41266126
- scopus:105022753456
- ISSN
- 0022-3050
- DOI
- 10.1136/jnnp-2025-336970
- language
- English
- LU publication?
- yes
- id
- 98592b8b-541f-4a00-9756-0d349a60735e
- date added to LUP
- 2026-02-09 11:57:54
- date last changed
- 2026-02-09 11:59:01
@article{98592b8b-541f-4a00-9756-0d349a60735e,
abstract = {{<p>Background Non-aneurysmal subarachnoid haemorrhage (NASAH) accounts for less than 20% of spontaneous subarachnoid haemorrhage (SAH). However, its epidemiological characteristics, risk factors and aetiology remain poorly defined. Methods All patients with spontaneous SAH admitted to a neurosurgical centre in Sweden over a 3.5-year period were prospectively enrolled in a database. Epidemiological data, risk factors, Fisher grade and follow-up radiological findings were analysed, comparing NASAH cases to aneurysmal SAH (aSAH). Results A total of 1532 patients with SAH were included, of whom 377 (24.6%) were diagnosed with NASAH. Five NASAH patients exhibited microaneurysms in the perforating arteries (MAPAs) of the vertebrobasilar circulation, identified on follow-up cone-beam CT angiography. Gender distribution and Fisher grade presentation differed significantly between the NASAH and aSAH groups (p<0.001). Risk factors, such as smoking, hypertension and alcohol overuse, were significantly more common in aSAH than NASAH. Conversely, diabetes mellitus (DM) was more prevalent in NASAH than in aSAH (p<0.001). Conclusions This is the largest epidemiological study of NASAH to date. The observed incidence of NASAH was higher than in the previous reports, suggesting either underdiagnosis in earlier studies or a changing proportion of aSAH to NASAH cases. The distinct differences in population characteristics and risk factors suggest that NASAH and aSAH arise from fundamentally different pathophysiological mechanisms. DM emerged as a risk factor for NASAH, and MAPAs were identified as one of the underlying sources of haemorrhage in this subgroup.</p>}},
author = {{Klurfan, Paula and Jakola, Asgeir and Baldvinsdóttir, Bryndís and Kronvall, Erik and Aineskog, Helena and Alpkvist, Peter and Eneling, Johanna and Friðriksson, Steen and Enblad, Per and Lindvall, Peter and Nilsson, Ola G. and Svensson, Mikael and Ronne Engström, Elisabeth and Hillman, Jan}},
issn = {{0022-3050}},
keywords = {{ANEURYSM; CEREBROVASCULAR DISEASE; EPIDEMIOLOGY; STROKE; SUBARACHNOID HAEMORRHAGE}},
language = {{eng}},
publisher = {{BMJ Publishing Group}},
series = {{Journal of Neurology, Neurosurgery and Psychiatry}},
title = {{Swedish nationwide study of 377 patents with non-aneurysmal subarachnoid haemorrhage : a disease with distinct demographics and risk factors}},
url = {{http://dx.doi.org/10.1136/jnnp-2025-336970}},
doi = {{10.1136/jnnp-2025-336970}},
year = {{2025}},
}