Ischaemic stroke

Thrombolysis

Clot-busting drugs, or thrombolyticsA medication that breaks up blood clots., are the definitive treatment for an ischaemic stroke Any sudden neurological problem caused by a bleed or a clot in a blood vessel. - a stroke that is caused by an interruption of bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. to the brain.[4] Thrombolytics are highly effective in restoring bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. flow to the brain and are widely used.[1,3]

The value of this treatment depends on the length of time that has passed since any symptoms first appeared. In the past, this window was thought to be a period of 3 hours since the onset of symptoms. However, more recent studies suggest that thrombolyticsA medication that breaks up blood clots. may be effective until 4.5 hours, or even as much as 6 hours, have passed from the start of symptoms.[4]

Because of this time window, imaging investigations are of the essence. It is paramount to demonstrate clearly the presence of ischaemiaInsufficient oxygenation to a part of the body due to poor blood supply. within the brain before thrombolysisBreaking up a blood clot by administering medications called thrombolytics. can be given.[4] Administering thrombolytic medication to someone who has had a haemorrhagic stroke Any sudden neurological problem caused by a bleed or a clot in a blood vessel. - in other words, one caused by a bleed in or around the brain - would worsen their condition drastically.

Unfortunately, despite the fact that thrombolytic therapy is incredibly effective for an ischaemic stroke, not everyone who has experienced such a stroke can receive it. This is partly due to the short therapeutic time window, and partly due to a lack of physicians who are experts in stroke management around the world. The short therapeutic time window makes early recognition of a stroke paramount, so that urgent medical care can be given.[2]

Steps to make thrombolytic therapy available to more people who need it include the implementation of telemedicineTelephone or internet use to obtain advice from experts at another site.. With this practice, images taken of a person's brain may be sent to a stroke specialist at another health centre, who can assess them and go on to advise on treatment. In this way, specialist knowledge can be made available even when a specialist is not present at the healthcare centre. Learn more about telemedicine in stroke.[5,6]

The main adverse effect of thrombolytic therapy is major bleeding, for example, intracerebral haemorrhage[Defined separately] - a bleed within the brain. People who are at greater risk of this include those who are older and/or who have high bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. pressure,[2,3] and people who have had a longer interval between the onset of their symptoms and taking thrombolytic therapy.[4]

References: 
  1. Lees KR. Stroke: success for extending acuteHas a sudden onset. treatment.  Lancet Neurol 2009; 8: 2-4.
  2. Donnan GA, Fisher M, Macleod M et al. Stroke. Lancet 2008; 371: 1612-23.
  3. Khaja AM and Grotta JC. Established treatments for acuteHas a sudden onset. ischaemic stroke. Lancet 2007; 369: 319-30.
  4. Schellinger PD, Fiebach JB, Hacke W et al. Imaging-based decision making in thrombolytic therapy for ischemic stroke: present status. Stroke 2003; 34: 575-83.
  5. Hess DC, Wang S, Gross H et al. Telestroke: extending stroke expertise into underserved areas.  Lancet Neurol 2006; 5: 275-78.
  6. Audebert H. Telestroke: effective networking. Lancet Neurol 2006; 5: 279-82.