“Atypical” Cause of Stroke that You Need to Know

Dr. LEUNG Kar Ming

Co-Director, Neurosurgery Centre

Honorary Consultant in Neurosurgery

Specialist in Neurosurgery

Apart from hypertension, diabetes and hyperlipidemia, there are some other factors that can lead to stroke, even in healthy individuals.

One of my patients Mr. NG is a typical example. Looking at his healthy body build and good stamina today, one cannot imagine that three months ago he almost ended up in hemiplegia.

He was playing football with his friends in a weekend, when he suddenly had blurred vision in his right eye. 5 minutes later, he started to have weakness in his left arm and leg, so much so that he can barely stand with support by his friends. He was immediately brought to hospital. After initial examination, an MRI study was performed which showed that there was dissection in his right carotid artery. As a result, the arterial lumen was markedly narrowed and blood supply to the brain was compromised. He was immediately treated with blood thinning medication. Unfortunately, there was not much improvement. So we decided to perform angioplasty and stenting for his carotid artery to open up the narrowed segment. The procedure was a success. Blood supply to his brain was resumed and his symptoms subsided immediately.

Carotid dissection refers to a tear in the inner wall of the carotid artery (an artery in neck that supplies blood to the brain). The torn segment will then occlude part of the arterial lumen and make it become narrow, thus compromising blood supply to the brain. Blood platelets will also clump and form small pieces of blood clot, which then occlude smaller arteries in the downstream. The end result will be an ischaemic stroke.

It can be trauma related or primary (i.e. without apparent cause). Trauma-related dissection can occur when the neck is forcefully and abruptly twisted and extended. This can happen in high speed road traffic accident, boxing or wrestling. There are also reports saying that people suffered from carotid dissection and stroke after inappropriate neck massage or manipulation. Incidence of carotid dissection is estimated to be 2 – 3 per 100,000. The mostly affected age group is between 40- 50 years old. In fact, it is now recognised as one of the major causes of stroke in relatively healthy individuals. People with certain connective tissue diseases such as Marfan syndrome and Ehlers Danlos syndrome are more prone to this condition.

Doctors will use anti-coagulants or anti-platelets drugs to prevent further occlusion of the affected blood vessel and maintain blood perfusion. This can allow the dissected segment to heal by itself, which occur in a few months’ time. However, if there is no significant improvement with medication or patient’s condition gets worse, stenting and angioplasty can be considered to open up the narrowed arterial segment.

In order to prevent this serious condition, one should avoid sudden and forceful neck twisting, such as improper manipulation. One should also have enough warm-up exercise to prepare the body before vigorous physical activities.