Cold temperatures up stroke risk

Vipul Gupta

Advertisement

As the temperature dips down, especially in North India, there’s a sudden upsurge in ischemic (a condition where blood supply to brain is cut off due to clot formation) and hemorrhagic strokes (blood vessel bursts in the brain causing fatal bleeding). Women, elderly (especially above 65 years of age), and those with previous hypertension or hypercholesterolemia are more susceptible to cold-induced ischemic stroke. Cold weather can increase the risk of stroke by up to 30 per cent, warns a new study.

Sudden drop in temperature can result in sharp increase in the risk of potentially-deadly brain clots. Scientists have discovered that for every 2.9ºC (5.2F) decline in outside air temperature over a 24-hour period, the number of strokes in the general population goes up by 11 per cent. But among those already at high risk, due to raised blood pressure, smoking or being overweight, the increase is 30 per cent.

On an average approximately 1.5 million people in India suffer a stroke every year. And, around 500,000 people are living with stroke-related disability. Therefore, it becomes all the more important for us to understand what doubles up the risk of stroke during winter. Basically, as the temperature goes down, the blood becomes thicker and stickier and increases the potential to clot formation. A greater plasma fibrinogen level and factor VII clotting activity in the winter have been reported as possible mechanisms. The elevation and activation of these coagulation factors may lead to a pro-coagulant status in cool climates which may promote the formation of blood clots within the heart chambers and increase the risk of stroke in patients with irregular heart rhythm. Previous studies have indicated that colder temperatures can be linked to increased blood pressure, especially in elderly.

Though anyone is susceptible, people with existing cardiac problem, high blood pressure, smokers, obese and elderly need to be watchful as with the weather getting cold they are the ones more vulnerable to get a stroke. In fact, such patients have a higher risk of even dying from heart disease or stroke.

Symptoms

It is important to know initial symptoms, especially if we know someone who is at a greater stroke risk. We need to make people aware that a stroke is treatable if the patient is immediately hospitalised. Hence it is important that one should be able to recognise the initial symptoms. The easiest way to remember symptoms of stroke is by reminding oneself of acronym FAST:

Face drooping: A section of the face, usually only on one side, is drooping and difficult to move.

Arm weakness: The inability to raise one’s arm fully.

Speech difficulty: An inability or difficulty to understand or produce speech.

Call a doctor: If any of the above symptoms are showing, time is of the essence; call the emergency services or rush to a hospital.

Treatment

Treatment may depend on factors like the type of stroke, the part of brain that has been affected by stroke and most importantly how soon the patient was diagnosed and treated for stroke.

Clot-busting drugs usually have a small window (less than 4.5 hours) to reduce the damage. Mechanical thrombectomy is now strongly recommended for patients in whom large arteries within the brain are blocked. To open the blocked artery, doctors thread a catheter through the groin artery to the occlusion site in the brain. The stent opens and grabs the clot, allowing doctors to remove the stent with the trapped clot. The procedure should be done within six hours of acute stroke symptoms. In more than 80 per cent of patients, the blockage can be opened and flow in the artery be established with this treatment. Approximately 60 per cent of patients will have good recovery and be independent at three months.

Precautionary measures 

While it’s impossible to control the weather conditions, there are a couple of ways to reduce or combat stroke risk. These include: 

• Eat a balanced diet and adopt healthy lifestyle habits like quitting smoking. 
• It is recommended that people with blood pressure problem should see their doctor as soon as the weather starts changing because sometimes blood pressure control medication needs to be altered. 
• To keep blood pressure under control one should consume low salt diet during winters. 
• Enjoying hot soups, mulled wine or a drink in moderation is advisable. 
• It is essential that blood pressure patients get their regular checks to ensure everything is under control. 
• Take extra precautions to stay warm. Indulge in activities like exercising, aerobics or dancing, etc. for a simple reason that the heart has to work much harder in cold weather to keep the body warm. 
• Elderly can even take a hot water bottle to bed so as to keep themselves warm. 
• Cover head be it with a scarf or a muffler. Step out wrapped in warm layers. 

The writer is director, Neuro-intervention, Agrim Institute for Neuro Sciences, Artemis Hospital, Gurgaon