Subarachnoid Haemorrhage
KNOW THE SIGNS, PREVENT DEATH AND DISABILITY
Subarachnoid haemorrhage (SAH) is a subtype of stroke. It is classified as an haemorrhagic stroke and occurs in about 5% of cases of stroke. The other significant haemorrhagic stroke subtype is the spontaneous intracerebral haemorrhage (ICH) which is found in approximately 15% of cases.
The annual incidence of SAH varies in many populations with smaller incidence in India and the recorded highest incidence in Finland (up to 20/100,000). We have previously reported that unavailability of CT scans may impact on the incidence figures in developing countries.
Patients with SAH present in three ways mainly. The first is with prodromal symptoms of an impending rupture. This has been called the sentinel or warning leak. Typically, over half of the patients with SAH have some preceeding headache or constitutional signs of ill-health. This is often ignored by both patients and more worrying, doctors. The second phase is the catastrophic SAH which cannot be ignored by the patient and associated with severe headache and varying levels of loss of consciousness. Finally, some patients present with delayed effects of vasospasm or rebleeding.
The key solution to the problem of SAH is in the early identification of the aneurysm before it ruptures and effective surgical or endovascular treatment. For too long, doctors have made mistakes in the assessment of patients presenting with unusual headaches- unusual for the patient. The classical history has been misdiagnosed as migraine in some cases with fatal consequences for the patient.
Subarachnoid haemorrhage is a devastating illness which affects mostly women around the age of 50 years. Over the decades the treatment of patients with SAH has improved with better diagnosis and definitive therapy. Long-term trends indicate that the mortality of SAH may be decreasing. Falling incidence rates have been postulated though others believe that better medical practice and standard of care is likely to be a major factor. The improvements in microsurgical, endovascular techniques and general medical management of the acutely ill patient, has to a large extent appeared to improve the outcome for our patients.
In reality, the morbidity and mortality has not really changed from the days of Wylie McKissock and others. Pakarinen and other found that on average 40-50% of patients die without getting to the hospital and of the survivors, a third will die, a third become disabled and a third achieve good outcome. Surgery and endovascular therapy have made a significant and visible impact in good grade patients but overall, the morbidity and mortality is related to the effects of the initial haemorrhage and brain damage, vasospasm and rebleeding. Subarachnoid haemorrhage is a devastating illness and the mortality has not changed dramatically over the years. |
