Related Experiment Video
Updated: Jul 14, 2026
09:00
The Rabbit Blood-shunt Model for the Study of Acute and Late Sequelae of Subarachnoid Hemorrhage: Technical Aspects
Published on: October 2, 2014
14.2K
Idiopathic subarachnoid hemorrhage: Pattern and long-term outcome.
María Concepción García Ortiz1, Marcelino Sanchez Casado1, Francisco Javier Morán Gallego1
1Servicio de Medicina Intensiva, Hospital Universitario de Toledo, Toledo, España.
Medicina Clinica
|April 5, 2026
Summary
Idiopathic subarachnoid hemorrhage (SAHi) patients show good long-term outcomes and functional status. Perimesencephalic SAHi cases demonstrate even better results, with low mortality and morbidity.
Area of Science:
- Neurology
- Neurosurgery
- Critical Care Medicine
Background:
- Subarachnoid hemorrhage (SAH) is a critical neurological event.
- Identifying SAH without a clear vascular lesion (SAHi) is crucial for prognosis.
- Understanding the long-term evolution of SAHi is essential for patient management.
Purpose of the Study:
- To analyze the clinical presentation and long-term outcomes of idiopathic subarachnoid hemorrhage (SAHi).
- To characterize the evolution of SAHi patients, including morbidity, mortality, and functional status.
Main Methods:
- A descriptive follow-up study was conducted in an Intensive Care Unit (ICU).
- Patients with SAH and initially negative arteriography were included (2007-2022).
- Data collected included demographics, severity scales, ICU stay, radiological findings, and Glasgow Outcome Scale Extended (GOSE).
Main Results:
- 114 patients (16.1%) were diagnosed with SAHi after initial negative arteriography.
- SAHi patients had significantly lower rates of mechanical ventilation, tracheostomy, and ICU deaths compared to those with lesions.
- Long-term follow-up (70.5 months) showed 11.4% mortality, with no rebleeding or late brain injury. Survivors achieved a median GOSE of 7 (7-8).
- Perimesencephalic SAH, a subset of SAHi, had a 7.8% mortality and a median GOSE of 7 (6-8).
Conclusions:
- Idiopathic subarachnoid hemorrhage (SAHi) is associated with favorable long-term morbidity and mortality.
- Patients with perimesencephalic SAH experience particularly good functional outcomes.
Keywords:
Aneurysmal subarachnoid hemorrhageAngiogram-negative subarachnoid haemorrhageHemorragia subaracnoidea aneurismáticaHemorragia subaracnoidea angiográficamente negativaHemorragia subaracnoidea idiopáticaHemorragia subaracnoidea no aneurismáticaIdiopathic subarachnoid haemorrhageLong-term outcomeNon-aneurysmal subarachnoid hemorrhagePronóstico largo plazoMore Related Videos
Related Concept Videos
01:15Ischemic Stroke ll: Pathophysiology
An ischemic stroke occurs when a cerebral blood vessel becomes obstructed, most often by a thrombus or embolus, interrupting the delivery of oxygen and glucose to brain tissue. Because neurons rely on continuous aerobic metabolism, energy failure begins within minutes of reduced perfusion. The region receiving the least blood flow becomes the infarct core, an area of irreversible cellular death. Surrounding this core lies the penumbra, a zone of hypoperfused but still viable tissue that is...
01:17Hemorrhagic Stroke l: Introduction
A hemorrhagic stroke is an acute neurological event that occurs when a weakened cerebral blood vessel ruptures, allowing blood to accumulate within or around the brain. The sudden release of blood forms a focal hematoma that increases intracranial pressure, displaces neural tissue, and can obstruct cerebrospinal fluid pathways. These effects may be compounded by intraventricular extension of the hemorrhage, cerebral edema, or compression of adjacent structures, all of which contribute to...
01:29Hemorrhagic Stroke ll: Pathophysiology
A hemorrhagic stroke develops when a cerebral blood vessel ruptures, allowing blood to escape into the surrounding brain tissue, as in intracerebral hemorrhage (ICH), or into the subarachnoid space, as in subarachnoid hemorrhage (SAH). Because the skull is a rigid compartment, the sudden presence of extravascular blood rapidly increases intracranial pressure and compresses adjacent neural structures, leading to immediate tissue injury and impaired cerebral perfusion.Mass Effect and Primary...
01:22Cerebral Edema ll: Pathophysiology
Vasogenic edema is a major form of cerebral edema characterized by abnormal accumulation of fluid in the brain’s extracellular space due to disruption of the blood–brain barrier (BBB). The BBB is a specialized structure composed of endothelial cells connected by tight junctions, supported by astrocytic endfeet and a basement membrane. Under normal conditions, it tightly regulates the movement of ions, proteins, and solutes between the bloodstream and brain parenchyma. When this barrier loses...
01:25Secondary Spinal Cord Injury llI: Pathophysiology
Early Ischemia and Ionic ImbalanceWithin minutes of spinal cord injury, a secondary cascade begins, progressing over hours to weeks. Vascular damage reduces blood flow, causing ischemia and mitochondrial dysfunction. ATP depletion leads to ion pump failure, membrane depolarization, sodium influx, potassium efflux, and water accumulation, resulting in cellular swelling. Increased intracellular calcium further disrupts mitochondria and accelerates cellular injury.Excitotoxicity and Neuronal...