The window for brain stroke – extended up to 24 hours – find out who and which condition the new findings benefit
One hears the word ‘stroke’ and assumes that it’s a condition of the heart. This is an incomplete understanding of what happens at the physiological level. Rather than a malfunction of the heart, a stroke denotes poor blood circulation to the brain.
When the brain receives an inadequate supply of oxygen-rich blood, brain cells begin to die. Deprivation of oxygen to the brain is called Cerebral Hypoxia. It is a serious condition with effects such as disability or loss of bladder control that can be prolonged or even permanent. The more the delay in regaining blood supply, the more extensive the damage to brain cells.
This is why the ‘window for stroke’ – the lapse of time in which a stroke has to be treated is of overwhelming importance. Damage to brain cells can result in difficulty in understanding words, slurring of speech, moving a body part (usually one side), or vision problems. Clinics check for damage using advanced imaging.
Type of brain stroke dictates treatment window
Ischemic stroke: This is the phenomenon of a complete lack of blood flow to the brain. It could be because of a clot in the arteries supplying blood to the brain or narrowing of the arteries. Conditions such as obesity, diabetes, high blood cholesterol levels, and the use of tobacco can result in narrowed arteries, resulting in ischemic stroke.
Hemorrhagic stroke: Brain damage also occurs when uncontrolled bleeding causes pooling of blood within the skull. It can be caused by the rupture of a blood vessel, injury to the head, or a brain aneurysm. While it is a life-threatening condition that needs emergency care within the first few hours of detecting the symptoms, this is a far less common condition compared to ischemic stroke.
The window for brain stroke – prioritizing survival, minimizing damage, and long-term effects
From the perspective of survival, the window for stroke was believed to be six hours. This means the treatment has to begin within minutes of the occurrence of the stroke. But the chances of survival are apt to get dimmer with each passing hour.
Depending on the causes, the extent of cell damage, and symptoms exhibited in each case, chances of survival in the first 24 hours are now better. Based on clinical trials, the window for the treatment was extended from 6 to 24 hours from the occurrence of the stroke. Neurologists, however, caution that the extension of the window doesn’t apply to everyone.
New guidelines from the American Heart Association and American Stroke Association postulate that stroke patients now have higher chances of recovering from paralysis, loss of motor control, loss of sensory abilities and chronic pain resulting from a stroke. It states that this extension of the treatment window is mainly for patients with clots in their arteries.
In effect, this means a larger number of ischemic stroke patients stand to benefit from mechanical thrombectomy to dissolve the clots.
This is good news for the majority of stroke victims and a shot in the arm for medical practitioners striving to improve the health of the general populace.
Dr. Vikram Huded, Senior Consultant – Neurology, Mazumdar Shaw Medical Center, Bommasandra, Bangalore