Subarachnoid Haemorrhage – Current Thinking and Future Strategy
Subarachnoid Haemorrhage – Current Thinking and Future Strategy
European Neurological Review, 2009;4(2):38-41
Abstract
Subarachnoid haemorrhage (SAH) accounts for only 5% of all strokes, but is responsible for 25% of all fatalities related to stroke. The most important vascular risk factors for SAH are hypertension, smoking and high alcohol intake. One-quarter of patients with acute SAH are not diagnosed at their first medical encounter. To identify the aneurysm causing SAH and allow urgent treatment, angiography must be performed as soon as possible. The most important neurological complications of SAH are re-bleeding, intracerebral haematoma and intraventricular haemorrhage, vasospasm, delayed cerebral ischaemia, hydrocephalus and seizures. Patients with SAH should be referred urgently to a tertiary care centre with expertise in cerebral aneurysm treatment, including endovascular, neurosurgical and neurointensive care. Currently, we can recommend that in a patient with acute aneurysmal SAH in whom both coiling and clipping are feasible, coiling is the preferred choice, if it can be performed within 72 hours after SAH. Adequate fluid replacement and calcium channel blockers are used to prevent vasospasm. Future health gains in SAH will depend on co-ordinated efforts between basic research and clinical research.
Keywords
Subarachnoid haemorrhage (SAH), headache, cerebrospinal fluid (CSF), magnetic resonance angiography, re-bleeding, vasospasm, hydrocephalus, endovascular coiling
Disclosure: José M Ferro has received travel grants from Bayer (manufacturer of nimodipine) and a research grant from the manufacturer of nicardipine. Patricia Canhão has no conflicts of interest to declare.
Received: 6 January 2009 Accepted: 11 May 2009
Correspondence: José M Ferro, Department of Neurosciences, Hospital de Santa Maria, 1649-035 Lisboa, Portugal. E: jmferro@fm.ul.pt
Current Thinking
Epidemiology Subarachnoid haemorrhage (SAH) is a severe disease: although SAH accounts for only 5% of all strokes, it is responsible for 25% of all fatalities related to stroke. The incidence of SAH has not decreased inrecent years, remaining stable at around 10/100,000/year.1 SAH is more common in females than in males (3:2). Although SAH affectsyounger adults than those afflicted by cerebral infarction, the incidence of SAH increases with age.2 The most important vascular risk factors for SAH are:
- hypertension (relative risk [RR] in longitudinal studies 2.5, odds ratio [OR] in case–control studies 2.6);
- smoking (RR in longitudinal studies 2.2, OR in case–control studies 3.1); and
- high alcohol intake (RR in longitudinal studies 2.1, OR in case– control studies 1.5).3
Clinical Features
The classic clinical picture of SAH is that of a sudden-onset, very severe headache occurring during activity. Half of patients will have a disturbance of consciousness, ranging from a transient syncope to coma. Neck stiffness and other meningeal signs are the main findings on physical examination. Fundoscopy may reveal a retinal, subhyaloid or vitreous haemorrhage (Terson’s syndrome).4 Less commonly, SAH produces:
- motor defects;
- aphasia;
- seizures;
- ptosis;
- diplopia or a complete three-nerve palsy (posterior communicating artery aneurysm);
- visual troubles (carotid aneurysms);
- amnesia and psychiatric manifestations (anterior communicating artery aneurysm);5
- radicular pain mimicking sciatica;
- back pain; or
- a coup de poignard syndrome.6
SAH is preceded in about 10% (0–40%) of cases by a ‘sentinel headache’ or warning leak – an episode of headache similar to that of SAH, preceding it by days or weeks. This is in fact a minor undiagnosed SAH.7 Clinical Differential Diagnoses Headache is a very common complaint that is rarely caused by SAH. Even among acute-onset headache, SAH accounts for only 11% of cases.8 One-quarter of patients with acute SAH are not diagnosed on their first medical encounter,9 the most common misdiagnoses being migraine, tension headache and headache related to high blood pressure.
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Subarachnoid haemorrhage (SAH), headache, cerebrospinal fluid (CSF), magnetic resonance angiography, re-bleeding, vasospasm, hydrocephalus, endovascular coiling, acute Subarachnoid haemorrhage,
