Why do Most of the Strokes Happen Early Morning 6 am to 12 pm?

A Stroke is caused by a lack of blood supply to the brain due to a blocked artery.

1 in 5 Stroke patients (i.e. 20%) wake up with a Stroke (most commonly weakness of 1 side of the body and speech defects or slurring). The reason for early morning Strokes are due to changes in circadian rhythm, thickness of the blood (homeostatic factors), irregular cardiac rhythm (atrial fibrillation), early morning blood pressure rise and other factors such as obstructive sleep apnoea.

The common risk factors for Stroke are high blood pressure, high cholesterol, diabetes, obesity and lack of physical exercise. A more recently understood risk factor is sleep apnea. Obstructive Sleep Apnea (OSA) is an independent risk factor. 

 Research has shown that OSA is an independent risk factor for Stroke. This means that people with OSA have an increased risk of experiencing a Stroke, even in the absence of other risk factors. However, not everyone with OSA will experience a Stroke.

While the reason for this increased risk is still being studied, experts have suggested several possible explanations for why people with OSA have a greater risk of Stroke.

Reduced blood flow to the brain: Repeated airway collapses during sleep create negative air pressure inside the chest, which can slow down blood flow to the brain.

Limited oxygen: OSA also causes a decrease in oxygen saturation, meaning that the blood does not carry enough oxygen to meet the body's needs. When this happens repeatedly, it can cause abnormal changes in the blood vessels within the brain.

Effects on other risk factors for Stroke: OSA raises the risk of other conditions, including heart disease, hypertension, diabetes, and abnormal heart rhythms. These and other health consequences of OSA can increase the risk of Stroke.

The risk of having a Stroke increases with the severity of OSA.

It’s very important to know the exact time of Stroke onset (the golden period) to start the clot-busting drugs or other acute treatments.

When the first clot-busting drug rtPA was approved in 1995, the time window was only 3 hrs. Over the next 30 years, significant advances have been made in acute stroke therapy and imaging.

With newer imaging techniques ( MRI, MR and CT perfusion), we can now extend the time window of reperfusion (commonly to 6 hrs, but in rare cases up to 24 hrs from Stroke onset). We now have many other ways and newer drugs (apart from intravenous tPA) to treat Stroke patients. One such is thrombectomy (removing the clot using a stent, a suction device or both)

In 1995 we only depended on time (3 hours from the onset of Stroke).

Now using sophisticated imaging we can make out which part of the brain is salvageable and decide when to use such procedures up to 24 hours

But remember that millions of brain cells die every minute that an artery remains blocked. So time is brain and please be alert and understand the signs of Stroke:

• Balance
• Eye vision loss
• Face weakness
• Arm weakness
• Speech difficulties

• Time is the brain. Reach the nearest stroke-ready hospital at the earliest.

Stroke patients for any form of revascularization must be accessed at a stroke-ready hospital that has a Stroke protocol that includes 24x7 imaging facilities, 24x7 advanced Catheterization lab & 24x7 Neurologist on call and ICU care.

As important as acute treatment is prevention and it can be done in simple ways:

• Keep blood pressure in check

• Avoid extra salt in your diet

• Exercise daily

• Maintain correct body weight

• Vitamin replacement particularly for vegetarians

• Control blood sugar & cholesterol

• Avoid tobacco in any form

• A yearly check with your doctor is advisable for everyone.