Evidence map›Paper›PMID 40837325›Full record

ArticleSurgical neurology international2025

Subarachnoid hemorrhage secondary to Chiari 1 malformation in a patient presenting with recurrent severe headache: A case report, imaging, and anatomic considerations.

Alireza Habibi, Michael Anthony Rizzuto, Michael K Tso

Abstract readCase Reports
In one paragraph

Article in Surgical neurology international, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors.

Alireza HabibiFaculty of Medicine, University of British Columbia, Vancouver, Canada.
Michael Anthony RizzutoDepartment of Surgery, Division of Neurosurgery, University of British Columbia, Vancouver, Canada.
Michael K TsoDepartment of Surgery, Division of Neurosurgery, University of British Columbia, Vancouver, Canada.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Chiari 1 malformation (CM1) is a structural anomaly characterized by cerebellar tonsillar herniation through the foramen magnum. While typically associated with syringomyelia or hydrocephalus, its potential relationship with subarachnoid hemorrhage (SAH) remains poorly reported in the literature. Case Description: We present the case of a 77-year-old woman who experienced recurrent episodes of thunderclap headache, which eventually progressed to altered consciousness following admission. Neuroimaging revealed a SAH involving the fourth ventricle and basal cisterns, alongside cerebellar tonsillar herniation and obstructive hydrocephalus, with no arterial source identified on serial angiography. Magnetic resonance imaging confirmed CM1, with tonsillar descent to the C1 level. The patient underwent suboccipital decompression for refractory intracranial hypertension that prevented weaning from the external ventricular drain. Intraoperative exploration revealed an abnormal posterior spinal vein traversing the arachnoid membrane, which was suspected to be the source of the hemorrhage and was successfully coagulated. Conclusion: To the best of our knowledge, this is the first documented case of CM1 presenting with recurrent SAH in the absence of aneurysmal or arteriovenous pathology. Our findings suggest a possible venous etiology related to anomalous posterior spinal venous drainage, which may have contributed to the hemorrhage and obstructive hydrocephalus. The patient's clinical improvement following Chiari decompression supports the role of surgical intervention in relieving cerebrospinal fluid outflow obstruction and elevated intracranial pressure in such cases. This case highlights the importance of considering venous anomalies in the differential diagnosis of non-aneurysmal SAH and underscores the need for heightened awareness of vascular variations in CM1 patients presenting with acute neurological symptoms.

Indexed as

Chiari 1 malformationChiari decompressionHydrocephalusPosterior cranial fossaSubarachnoid hemorrhageThunderclap headache

Identifiers

PMID40837325
PMCPMC12361651

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-SA
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.