Subarachnoid hemorrhage is a life-threatening emergency that occurs when an aneurysm of the cerebral arteries ruptures. With a frequency of 10:100,000, it most commonly affects people between the ages of 40–60. When the aneurysm ruptures, arterial blood suddenly flows into the liquor-filled subarachnoid space between the brain and the base of the skull, causing an acute increase in intracranial pressure.
Risk factors for an aneurysm include high blood pressure, smoking and alcohol abuse. In rare cases, there is also a familial accumulation of aneurysms due to a genetic disposition.
The main symptom is a sudden, severe and extremely painful headache also known as thunderclap headache. The pain can be felt throughout the head and can radiate to the neck and back. In severe cases, unconsciousness or a seizure may occur only seconds later. In addition, there may be variable neurological symptoms such as speech disorders, paralysis, sensory disturbances and double vision.
First of all, emergency cranial imaging is performed using computed tomography (CT) including vascular imaging or, less frequently, magnetic resonance imaging (MRI). In patients with impaired consciousness and reduced wakefulness or intubated patients, an external ventricular drain is placed after confirmation of the diagnosis in order to drain cerebrospinal fluid (CSF) and reduce the increased intracranial pressure. Within 24 hours, we perform cerebral catheter angiography to precisely localize the site of bleeding. An interdisciplinary, specialized team of neurosurgeons and neuroradiologists then decides how to treat the aneurysm and prevent recurrent bleeding: by endovascular aneurysm closure (coiling) oder eine microsurgical operation (clipping).
In patients with typical symptoms but no evidence of blood on emergency CT or MRI, a lumbar puncture is performed for further diagnosis. This is typically done 18–24 hours after the onset of the headache. We check whether the CSF is bloody or xantochromic (pink, reddish brown or yellow) after centrifugation and whether siderophages can be detected. These are indications of hemorrhages in the brain. If the CSF is positive, a cerebral catheter angiography is performed.
After aneurysm removal, our patients are closely monitored in the intensive care unit or the neurosurgical-neurological intermediate care unit, as the large cerebral vessels with blood contact in the subarachnoid space regularly begin to constrict after 3–7 days. This so-called vascular spasm or vasospasm carries the risk of neurological deterioration due to cerebral infarctions. Cerebral infarctions occur in about 10–20% of all patients. Prophylactic medication with the calcium antagonist nimodipine as well as close clinical, instrumental and hemodynamic monitoring by specially trained staff are administered. Often there is also disturbed cerebrospinal fluid circulation and/or reabsorption. These patients require external ventricular drainage or lumbar CSF drainage.
Patients who develop signs of severe cerebral vasospasm or cerebral infarction are treated according to a stepwise regimen with induced hypertension, hypervolemia, and hemodilution (so-called triple-H therapy). If symptoms persist treatment includes intra-arterial administration of nimodipine or balloon angioplasty. The vasospasm resolves after about 2 weeks.
Up to 15% of all subarachnoid hemorrhages are fatal within the first few hours. If the patient survives the hemorrhage, more than half of those affected are still permanently disabled. For patients with only minor symptoms, the prognosis is good if they are taken immediately to a specialized treatment center.
At the Inselspital, patients with subarachnoid hemorrhage are cared for by an interdisciplinary, highly specialized team from the University Departments of Neurosurgery, Neuroradiology and Intensive Care Medicine. The optimal treatment of aneurysms as well as the therapy of vasospasms are among the major research areas at our hospital.
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